<<if: ZXIDBOOK>>
<<else: >>97 ZXID FAQ
======
> N.B. Some of these FAQs are repeated in the topic specific documentation,
> e.g. zxid-java.pd.
1.1 Other documents
-------------------
<<doc-inc.pd>>
<<htmlpreamble: <title>ZXID FAQ</title><link type="text/css" rel=stylesheet href="zx.css"><body><h1>ZXID FAQ</h1> >>
<<fi: >>
<<ignore: $Id: zxid-faq.pd,v 1.6 2010-01-08 02:10:09 sampo Exp $ >>
97.1 Compilation Problems
-------------------------
(*** also in INSTALL.zxid)
* Makefile tries to compile a bunch of check programs early in the
compilation to detect common problems with missing headers (include
files) and missing libraries.
* If the checks fail, you need to adjust the -I and -L flags in Makefile
variables CDIR and LIBS (around line 123)
* Alternately you can create localconf.mk file that will be
included by the main Makefile and put your modifications there.
* ZXID dependency libraries are libcurl, openssl (libssl, libcrypto), and zlib
* Although compiling the dependency libraries from source is adviced,
usually you can use the versions that are supplied with your distribution.
However in this case you MUST install also the headers. Usually these
are called "development" packages.
* zxid assumes openssl, libcurl, Java, and Apache to be installed
in the locations where source distributions of those packages
install them in their default configuration (e.g. /usr/local/ssl,
/usr/local/httpd, etc.)
* Many distributions (e.g. Ubuntu, Redhat, SUSE, ...) choose to install
those libraries in different places, thus requiring distribution
specific edits to localconf.mk
* If you have difficulty in finding the headers and libraries (or whether
a package is installed at all), try the following commands
find / -name 'stdio.h'
find / -name 'libc.*'
find / -name 'zlib.h'
find / -name 'libz.*'
find / -name 'opensslv.h'
find / -name 'libssl.*'
find / -name 'libcrypto.*'
find / -name 'curlver.h'
find / -name 'libcurl.*'
find / -name 'ap_release.h'
find / -name 'apr_version.h'
find / -name 'libapr-1.*'
find / -name 'servlet-api.jar'
If you find more than one of any of the above, you need to be extra
careful about which one you use.
97.1.1 OpenSSL not found: you need to create localconf.mk
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ZXID does NOT have a configure script. It ships with a notion
of "standard" locations for the three dependency libraries,
but if these libraries are not where it expects to find them,
then typically you see (n.b. lines were folded for presentation):
make
If you get compilation errors, try: make help
gcc -g -fpic -fmessage-length=0 -Wno-unused-label -Wno-unknown-pragmas
-fno-strict-aliasing -D_REENTRANT -DDEBUG -DUSE_CURL -DUSE_OPENSSL
-DLINUX -I/tmp/zxid-0.20 -I/usr/local/ssl/include -I/usr/local/include
-c -o zxid.o zxid.c
zxid.c:34:23: curl/curl.h: No such file or directory
In file included from zxid.c:38:
zx.h:26:25: openssl/rsa.h: No such file or directory
...
What happened is that OpenSSL for some reason is not in the location
where standard OpenSSL distribution would install it (as indicated by
-I/usr/local/ssl/include flag that ships with ZXID Makefile). You need
to determine where OpenSSL is installed in your case. You can use
find / -name rsa.h -ls
to locate candidates.
For example, if it turns out that OpenSSL is installed in /opt/ssl, then
you need to create a localconf.mk file that indicates this location:
echo OPENSSL_ROOT=/opt/ssl >>localconf.mk
There are several other make variables you may need to tweak. In the
above example, we also notice that libcurl was not found where
expected. This would be fixed like this
echo CURL_ROOT=/opt/curl >>localconf.mk
Net result? ZXID does not try to guess where the libraries are. It
makes you do the foot work of locating the correct libraries (some
people have more than one instance installed) and prepare the
localconf.mk. This may seem like a lot of work, but in my experience,
fixing GNU autohell configure scripts that guess wrong is thousand
times more frustrating. The system is dumb by design so you, as a human,
do not have to try to second guess it - you are in control.
97.1.2 Missing gperf
~~~~~~~~~~~~~~~~~~~~
gcc -g -fpic -fmessage-length=0 -Wno-unused-label -Wno-unknown-pragmas -fno-strict-aliasing -D_REENTRANT -DDEBUG -DUSE_CURL -DUSE_OPENSSL -DLINUX -I/c/cvs/zxid_cvs -I/usr/local/ssl/include -I/usr//include -c -o c/zx-a-aux.o c/zx-a-aux.c
c/zx-a-aux.c: In function "zx_NEW_a_Action":
c/zx-a-aux.c:80: error: "zx_a_Action_ELEM" undeclared (first use in this function)
This happens because c/zx-const.h was misgenerated (it should not happen at
all if you do not supply ENA_GEN=1) and does not include the necessary defines.
c/zx-const.h should have more than 1900 lines and look something like
/* generated file, do not edit! zx_ _ATTR */
#ifndef _zx__ATTR
#define _zx__ATTR
#define zx_use_ATTR 0
#define zx_used_ATTR 1
#define zx_sequence_ATTR 2
...
#define zx_wantDSEPR_ATTR 347
#define zx_ZX_TOK_NOT_FOUND_ATTR 348
#define zx__ATTR_MAX 349
#endif
/* generated file, do not edit! zx_ _ELEM */
#ifndef _zx__ELEM
#define _zx__ELEM
#define zx_ds_Y_ELEM 0
#define zx_gl_Y_ELEM 1
#define zx_gl_esrd_ELEM 2
...
#define zx_wst_OnBehalfOf_ELEM 1629
#define zx_ZX_TOK_NOT_FOUND_ELEM 1630
#define zx__ELEM_MAX 1631
#endif
97.1.3 make samlmod gives "incompatible types in assignment"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Should not happen with version 0.21 or later. See zxidnoswig.h
for explanation of the problem.
97.1.4 Perl compiled with different compiler than zxid
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** this section also appears in zxid-perl.pd)
Perl modules generally want to be compiled with the same C compiler
and options as were used to compile perl itself (see perl -V). If this
happens to be different than the compiler you have defined in CC
variable (gcc by default, near top of Makefile or in localconf.mk), you may
get an error like:
cd Net; perl Makefile.PL && make
Warning: -L.. changed to -L/home/sampo/zxid/Net/..
Writing Makefile for Net::SAML
make[1]: Entering directory `/home/sampo/zxid/Net'
cc -c -I.. -I/apps/openssl/std/include -I/apps/include -D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBUGGING -fno-strict-aliasing -pipe -Wdeclaration-after-statement -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -march=i586 -mtune=i686 -fmessage-length=0 -Wall -D_FORTIFY_SOURCE=2 -g -Wall -pipe -DVERSION=\"\" -DXS_VERSION=\"\" -fPIC "-I/usr/lib/perl5/5.8.8/i586-linux-thread-multi/CORE" SAML_wrap.c
/bin/sh: cc: command not found
make[1]: *** [SAML_wrap.o] Error 127
make[1]: Leaving directory `/zxid/Net'
make: *** [samlmod] Error 2
*Solutions*
1. Compile zxid with compiler that was used for perl, e.g.
make CC=the-compiler-that-perl-wants
2. Recompile perl using the compiler that you want to use for zxid
3. Tinker with PATH environment variable so that both C compilers
are found. However, using two different compilers is not really supported.
In general these types of problems happen when you use perl installed
by your distribution, but have later compiled a gcc of your own. It may
even be that you never installed the distribution cc - in that case
consider installing it and then trying approaches 1 or 3.
A similar situation can arise with incompatibility of the compiler and
options used for dependency libraries, such as OpenSSL or libcurl, and
those used for compiling zxid itself.
97.1.5 All files under zx missing
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** this section also appears in zxid-java.pd and zxid-perl.pd)
You need to symlink zx to zxid source directory, thus
ln -s . zx
If you do not have it, then you will get a lot of file inclusion errors for
headers that are supposed to be in path starting by zx/
The symlink is there to keep all handwritten source files on top
level of directory for ease of development, yet allow inclusions to go
through ~zx~ subdirectory. When zxid is installed, it goes to
/usr/include/zx. Hence the symlink keeps the includes the same whether
developing or using installed version.
97.1.6 Compiler Warnings
~~~~~~~~~~~~~~~~~~~~~~~~
(*** this section also appears in zxid-java.pd and zxid-perl.pd)
If you compile zxid with compiler warnings turned on (CFLAGS += -Wall),
you will see quite a number of warnings, most of which are
unwarranted. Since the warnings are unwarranted, I ship zxid Makefile
with warnings turned off. If this bothers you, feel free to investigate
the warnings and report to me any issues you uncover.
Following warnings in partuclar are unwarranted:
1. Any unusued variable warnings, especially in generated code. Most
common of these is ~se~ variable (see enc-templ.c).
2. "Suggest parenthesis around assignment when used as truth value." I
rely on C language operator precedence. Also, in most cases the
assignment is the only expression in the truth test - there simply
is no opportunity for ambiguity -- and no justified case for gcc to
warn about this.
3. "Suggest parenthesis around && when used in ||". I rely on C
language operator precedence, hence the suggestion is redundant.
Some warnings you may want to worry about
A. "int format, long int arg". On 32 bit platforms int and long
are both 32 bits so this warning is not an issue. On 64 bit platforms,
however, there may be cause for worry.
97.1.7 SWIG and Java Problems
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** this section also appears in zxid-java.pd)
javac -J-Xmx128m -g zxid.java zxidjava/*.java
zxidjava/zxidjni.java:159: cannot find symbol
symbol : class SWIGTYPE_p_p_void
location: class zxidjava.zxidjni
public static zx_str zx_rsa_pub_enc(zx_ctx c, zx_str plain, SWIGTYPE_p_p_void rsa_pkey, int pad) {
^
zxidjava/zxidjni.java:164: cannot find symbol
symbol : class SWIGTYPE_p_p_void
location: class zxidjava.zxidjni
public static zx_str zx_rsa_pub_dec(zx_ctx c, zx_str ciphered, SWIGTYPE_p_p_void rsa_pkey, int pad) {
^
zxidjava/zxidjni.java:169: cannot find symbol
symbol : class SWIGTYPE_p_p_void
location: class zxidjava.zxidjni
public static zx_str zx_rsa_priv_dec(zx_ctx c, zx_str ciphered, SWIGTYPE_p_p_void rsa_pkey, int pad) {
^
zxidjava/zxidjni.java:174: cannot find symbol
symbol : class SWIGTYPE_p_p_void
location: class zxidjava.zxidjni
public static zx_str zx_rsa_priv_enc(zx_ctx c, zx_str plain, SWIGTYPE_p_p_void rsa_pkey, int pad) {
^
This was due to missing SWIG generated classes. Probably interrupted file transfer.
javac -J-Xmx128m -g zxid.java zxidjava/*.java
zxid.java:24: cannot find symbol
symbol : method new_conf(java.lang.String)
location: class zxidjava.zxidjni
cf = zxidjni.new_conf("/var/zxid/");
^
zxid.java:27: cannot find symbol
symbol : method url_set(zxidjava.zxid_conf,java.lang.String)
location: class zxidjava.zxidjni
zxidjni.url_set(cf, url);
^
zxid.java:28: cannot find symbol
jar cf zxidjava.jar *.class
jar cf /tmp/zxidjava.jar zxidjava/*.class
javac -J-Xmx128m -g zxid.java
zxid.java:187: cannot access zxid_conf
bad class file: /Library/Java/Extensions/zxidjava.jar(zxid_conf.class)
class file contains wrong class: zxidjava.zxid_conf
Please remove or make sure it appears in the correct subdirectory of the classpath.
public static int mgmt_screen(zxid_conf cf, zxid_cgi cgi, zxid_ses ses, char op)
^
1 error
Underscore in linking error
./zxid-java.sh
Start...
Exception in thread "main" java.lang.NoSuchMethodError: zxidjava.zxidjni.new_conf(Ljava/lang/String;)Lzxidjava/zxid_conf;
at zxid.main(zxid.java:24)
This was due to finding some old copies from system paths.
java -classpath .:zxidjava -Djava.library.path=zxidjava zxid
Start...
Exception in thread "main" java.lang.UnsatisfiedLinkError: _zxid_new_conf
at zxidjava.zxidjniJNI._zxid_new_conf(Native Method)
at zxidjava.zxidjni.new_conf(zxidjni.java:586)
at zxid.main(zxid.java:24)
97.1.8 SWIG and Perl Problems
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** this section also appears in zxid-perl.pd)
ZXID is tested and known to work with SWIG version 1.3.40. It is known not
to work with SWIG-2.0.4. The telltale sign is
perl -MNet::SAML -e 'print Net::SAML::call($cf,$ses,$svctype,$url,0,0,$soap)'
TypeError in method 'zxid_call', argument 5 of type 'char const *'
SWIG version should not be a concern for those using .tgz distributions of
ZXID as the tar gzip archives already contain the files generated by SWIG.
Also installs from cpan should not be affected.
97.2 Platform Specifics
-----------------------
If your Unix platform is not mentioned, you should try saying just
make
which will compile with Linux options. These options actually
are pretty close to pure POSIX compile so you should get very close
to working configuration.
97.2.1 Linux
~~~~~~~~~~~~
Native development platform. Just say
make
Seems there are some "improvements" that distributions have made. ZXID
adopts the policy of expecting dependency modules where the module
author meant it to be installed by default - for example OpenSSL by
default installs in /usr/local/ssl (naming is historic, but has stuck).
Many distros tinker with these paths. This means you need to create
a localconf.mk.
Redhat used to have an issue with Net::SAML (make samlmod). This has
since been fixed, please see zxidnoswig.h for explanation.
No doubt, distros will eventually pick up ZXID and provide it as a package.
Once that happens they will solve any path issues accoring to their
disto policy and that is fine, just do not ask me to comply with any
such policy.
97.2.2 FreeBSD
~~~~~~~~~~~~~~
No target available on Makefile, but a port is available from
http://www.freshports.org/security/zxid/
97.2.3 Solaris (Sparc)
~~~~~~~~~~~~~~~~~~~~~~
make TARGET=sol8
make TARGET=xsol8 # Cross compile for Solaris (e.g. on Linux host)
97.2.4 MacOS X (PowerPC?)
~~~~~~~~~~~~~~~~~~~~~~~~~
make TARGET=macosx
97.2.5 Windows Using MinGW
~~~~~~~~~~~~~~~~~~~~~~~~~~
make zxid.dll TARGET=xmingw # Cross compile on Linux host (best supported)
make zxid.dll TARGET=mingw # Native compile for mingw target in Cygwin environment
Either way, the net result is native Windows DLL that does not have
Cygwin library dependencies or GPL encumberation.
See Makefile for further mingw notes.
97.2.6 Windows Using Cygwin
~~~~~~~~~~~~~~~~~~~~~~~~~~~
make TARGET=cygwin
Very experimental (as of Oct 2007) native build for Cygwin.
Cygwin appears to not have neither flock(2) nor lockf(2). This is
strange because at least one of these is implemented on MinGW.
Current workaround is to define flock() to be empty macro. This
of course means there is no file locking. There are 3 known races
where things can go wrong
1. Audit logs can get garbled. This does not stop ZXID from working,
but may make log analysis more complicated.
2. Auto-CoT metadata writes can get garbled. This is very unprobable,
but if it happens, the ZXID deployment will not work towards
affected IdP. Nothing to worry about really.
3. Locking is used to protect against updates of zxid.conf while
zxid is running. Again any corruption is very unlikely. Nothing
to worry about.
The results of Cygwin compile may be GPL encumbered due to libraries.
97.2.7 Windows Using MSVC
~~~~~~~~~~~~~~~~~~~~~~~~~
Never been done (as of Oct 2007), but probably this is not very
difficult given that MinGW port already has addressed many Windows
platform issues. Please send any success reports, and receipes, my way.
As of June 2010 the MSVC support has improved. The sed dependency
was removed and any C language constructs that MSVC has indigestion with
have been removed. We are still aiming at Makefile based
build using Microsoft's cl compiler. You should try
make TARGET=win32cl
If you manage to build it using some IDE project, please contribute
the project file. For ongoing maintenance, it would be good if the
project was a text file to which new source code files and be added
easily *without using the IDE*, i.e. using simple text editor.
97.3 Configuration Questions
----------------------------
(*** Some of these may be repeated in zxid-conf.pd)
1. Q: In mod_auth_saml, what is the relation between ZXIDConf and httpd.conf?
A: httpd.conf can contain ZXIDConf directives. Those directives are
processed as if they came from /var/zxid/zxid.conf file (which is
processed first, before and ZXIDConf directives), except that if you
specify ZXIDConf "PATH=/your/path", this triggers reporcessing of
the zxid.conf (from the new path).
2. Q: In mod_auth_saml, what is the relation between the +port+ in ZXIDConf
and the +port+ in the httpd.conf?
A: The ports must agree. ZXID configuration must match the way the
Apache layer is configured.
3. Q: Multiple roles of same entity, acting as SP, WSC, and WSP for
different services
Asa:
> Part of what you are saying is that the service
> registration is WSC. This is rather confusing since the case is a WSP
> acting as a WSC of the Discovery Service. For the ClientLib thus far,
> I have chosen to think of service registration as a WSP to WSP. What is
> the downside to this approach?
Conor:
> Service registrations can't be done WSP to WSP with any Liberty protocol
> (in fact, we don't define any such method of invocation as the invoking
> party is always a WSC for the intent of that message - there's no
> problem with a WSP in turn being a WSC of another service instance, just
Right. You can don WSC role whenever convenient. There is nothing confusing
about WSP of one service being WSC of another service. Perhaps the
confusion would be avoided if everybody fully qualified their descriptions
until common convention about less than fully qualified roles emerges.
Entity E1, an ID-DAP WSP (primary role), will act as Discovery WSC
(secondary role) to perform metadata registration. This same entity E1
will also have SP interface (another secondary role) which allows
the user to trigger discovery association, again E1 acting in secondary
role of Discovery WSC.
No confusion as far as I can see.
4. Q: What the "Entity ID" and the "Service Type" should be?
While entityID and Service Type selection are flexible and there is sophisticated
philosophy behind them, the short answers are:
a. entityID should be the URL from which your metadata can be fetched. The
URL should match the entityID field inside the metadata document. In
zxid deployments the entityID usually ends in "?o=B" and be beginning
part depends on the URL configuration parameter.
b. Service Type should be the namespace URI of the (first) top level child
of SOAP envelope Body element.
97.3.1 No certificates appear in metadata
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Q: +I've been trying to set up ZXID's mod_auth_saml on an OS X server. The
EntityDescriptor XML doesn't seem to contain the public x.509 cert.+
A: The metadata (the URL ending in o=B) will not have certificates if
none actually were available. Thus visualizing the metadata in
a brower is a good way to check whether it is finding the certs. So
it is a feature ;-)
Q: +Does mod_auth_saml use the cert from /var/zxid/pem/ssl-nopw-cert.pem?+
A: The certs for metadata live in files
/var/zxid/pem/sign-nopw-cert.pem
/var/zxid/pem/enc-nopw-cert.pem
In more recent versions (current is 0.38, which version were you using?)
ZXID will automatically generate self signed certs if the certs are
not installed yet. However it may fail to write them to the filesystem
due to permissions problem. You should check that the user as which
Apache runs can indeed read from and write to /var/zxid/pem directory.
If you want to use officially issued certificates, you will of course
need to place them in the two files mentioned. Please note that the
files should be concatenation of certificate and the private key. Due
to this and the practise of not using password on the private keys
you should pay attention to protecting these files with filesystem
permissions - the caveat is that if you protect too well then
even the apache process can't read them. Recommended permissions are
chown APACHEUSER /var/zxid/pem
chmod -R 02750 /var/zxid/pem
where APACHEUSER is distribution dependent user account used to
run the apache process. You can do `ps axu | grep httpd' to see
what user apache runs as.
97.3.2 Skipping IdP Selection: Hardwiring the IdP
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> I was hoping that you could answer a question for me about mod_auth_saml.
> I have it installed on CentOS5 with Apache and every request to our
> protected URL does bring up the IDP selection screen. Since we only want
> customers to use the sole IDP we have configured, we'd like to
> automatically redirect to the IDP instead of having the users's click a
> login button.
>
> Is there a setting for zxid.conf or Apache that I need to set so it will
> always redirect to the sole IDP if a session needs to be created without
> presenting that IDP selection screen?
This in fact is possible. It is a bit convoluted (and not documented)
in that it effectively works by simulating submission of the
IdP selection screen, with the form fields and all. This is done
by setting DEFAULTQS configuration option. For example, following
ZXIDConf "DEFAULTQS=l0https://idp.tas3.eu/zxididp%25%33%66o%25%33%3dB=1%26fc=1%26fn=prstnt"
would simulate clicking login button for idp.tas3.eu. Note the URL
escaping that needs to be applied: %25%33%66 is decoded by the
configuration layer to mean "%3f", which is how at query string
layer the question mark needs to be escaped. The %26 means
ampersand that separates the arguments at querystring layer. It
is encoded only once. Hope this is not too confusing.
> > The big question is which IdP? If for your
> > user base there is only one, then user can be redirected to that one
> > without any further ado and if they are already logged in at the IdP,
> > they will be redirected back without user having to interact (otherwise
> > user needs to log into the IdP and then he is redirected back).
> In this case, it'll be an internal IdP, totally private.
Ok, that makes it easy. With mod_auth_saml you may want to set the
configuration option DEFAULTQS=l2EEE=1 where EEE is the EntityID URL
of the IdP. Without mod_auth_saml, upon user clicking "Login using SAML",
you would formulate to zxid_simple() call a query string containing
"l2EEE=1". Then redirect to the return value.
97.3.3 Web Service Provider Metadata
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The metadata is needed in the web service call mainly to know the
certificates. The endpoints in the metadata are ignored for purposes
of the web service call as the endpoint is supplied by the EPR.
Since SAML defines a metadata format with certificates (and SAML
relevant endpoints), the convention is that web service call consults
the SAML metadata for the certificates.
It is very common for same service to be accessible as a web GUI (SAML
SP) and web service (ID-WSF WSP), therefore it is considered
convenient for the SAML metadata to be used.
If the service does not want to be SAML SP and only wants to be ID-WSF
WSP, then it still needs to supply the SAML SP metadata just for the
purpose of the certificates (the SAML SP end point URLs will not be
used).
> My service only wants to be a ID-WSF WSP. For example, Custodix want
> to be able to call a SOA Gateway web service, and the SOA Gateawy
> knows nothing about SAML, etc.
> I need to ensure that ZXID will process necessary soap headers and
> accept or reject as appriorate.
You still need to generate metadata. Since your service does not have
SAML SP facet, you can't (directly) use o=B method (but see my example
zxidwspdemo.java how it still supports o=B). However you can just hand
edit a metadata file (perhaps using something from o=B as a template).
If you place the hand edited metadata in the right file on WSC side,
using
.zxcot -a <meta.xml
then no dynamic metadata fetch will be attempted and you
do not need to support o=B.
See also zxid-idp.pd for registration of EPR and bootstrap.
97.3.4 Two site in same domain: sessions interfere
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If two sites share a domain, they also share cookies. To avoid the
cookies intefering with each other, use the SES_COOKIE_NAME
configuration option to set the cookies different (the default is
ZXIDSES). You may also have similar issue WRT PTM_COOKIE_NAME.
One particular instance of this issue manifests when IdP and SP
run on same host. On SP log right after SSO you may see
zx E get_ses: File(/var/zxid/ses/MMSESNULVSoj4lBYsqYhxCvXodNLM/.ses) not found errno=2 err(No such file or directory). flags=0x0 0, euid=443 egid=443 cwd(/var/zxid/webroot/zxid.org)
zx d No session(MMSESNULVSoj4lBYsqYhxCvXodNLM) active op(P)
This is because the IdP already set the session cookie (IdP sessions
usually start with "MMSES") and the SP is errornously picking it up
and then not finding the corresponding session in its session store.
97.3.5 Using HTTP or SOCKS proxy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ZXID uses libcurl as its underlying HTTP client. Although ZXID does
not offer any proxy related options, it respects the environment
variables ~https_proxy~, ~all_proxy~, and ~no_proxy~, because libcurl sees
them and uses them. Thus you can
all_proxy=corpproxy:1080 zxcot -g https://some.external.com/url
all_proxy=corpproxy:1080 zxcall ...
or you can set the variables more permently
export all_proxy=corpproxy:1080
export no_proxy=localhost
zxcot -g https://external.url/
See libcurl documentation at curl.haxx.se for more information.
97.4 API Questions
------------------
1. *Q*: What do I need to pass in as +enve+ argument to zxidjni.wsc_prepare_call()?
*A*: zxidjni.wsc_prepare_call() has some auto detection. If you pass entire
SOAP <e:Envelope>, then it will just add some headers. If you pass <e:Body>
it will add <e:Envelope> and headers. If you pass anything else, it
assumes that is meant to be content of the body and will add
<e:Envelope><e:Headers>...</><e:Body>your stuff</></>
2. *Q*: What exactly is a "sha1 name"?
*A*: Since ZXID (originally) uses filesystem as backend, a method
for generating filesystem-safe strings, to be used as filenames,
was needed. Further, there was occasionally requirement that each
different file have different name. Solution to these problems
is to hash the whatever part that is unique and use safe base64 [RFC3548]
encoding of the hash as the filename.
They are not very human friendly, but they are filesystem safe
and unique as required. They are also constant width, which tends
to make directory listing prettier, and also handles anomalously
long Entity IDs gracefully.
sha1 hashing is much less error prone than trying to escape or squash
the various Entity IDs, Name IDs, and who-know-what to be filesystem
safe. Add to the squasing bugs, the convolutions of ensuring uniqueness
and dealing with too long input and you should see why sha1 names are
the most secure, easiest to implement, approach.
See also sha1_safe_base64() in zxutil.c
97.4 Common Mistakes
--------------------
1. When I try accessing https://sp1.zxidsp.org:8443/zxidtest.sh nothing happens!
Assuming you have the web server correctly running, the most common
gotcha is that zxidhlo has dynamic linking problem.
See <<see: ZXID-Installing-CannedTutorialRunningZXIDasCGIundermini_httpd-AccessingZXID>>
subsection "Dynamic Linking Problems", for explanation and resolution.
2. Single Logout does not end the IdP session (i.e. IdP does
not force you to supply password when you do SSO next time).
Usual cause is that the management form (the one with the SLO buttons)
does not have correct or any session ID. Do a view source on the
the page and look for field called "s". The session ID is
supposed to be extracted from the Single Sign-On result. For
zxid_simple() you need to parse the returned LDIF and
take the sesid. Pass that to zxid_fed_mgmt() as second argument.
3. Login buttons do nothing.
A possible cause is that the entity ID is not passed from
the IdP selection form. If the form is using POST method,
you must make sure you actually read the HTTP body and
pass its contents to the zxid_simple() as the ~qs~ argument.
4. The SP Login, a.k.a. IdP selection, page shows, but SSO does not work
a. Your configuration does not match actual URL used to
access the zxid system. For the zxidhlo family of
examples you MUST edit the configuration string
to match your situation. Watch out for domain name
and port number.
b. Connectivity issue prevents IdP from fetching metadata.
Make sure your domain name is resolvable at IdP (e.g.
add it to /etc/hosts). See also next point.
c. IdP is not configured to get your metadata automatically.
You have to configure your metadata to the IdP manually.
How to do this depends on IdP product. Do not ask us.
d. You supplied IdP URL that, in fact, is not the well known
location for fetching IdP metadata. Or the IdP does
not have well known location enabled. In the latter
case you will need to install the IdP metadata
manually (*** procedure to be documented). See [SAML2meta]
section 4.1 "Publication and Resolution via Well-Known Location",
p.29, for normative description of this method.
e. Connectivity issue at web browser level. Make sure your
web browser can resolve both SP and IdP domain names.
Edit /etc/hosts as needed on the machine where the browser runs.
f. Personal firewall blocks access. Check firewall set up on
* browser machine
* SP machine
* IdP machine
5. The SP Login, a.k.a. IdP selection, page does not show at all
a. Connectivity issue at web browser level. Make sure your
web browser can resolve both SP and IdP domain names.
Edit /etc/hosts as needed.
b. Personal firewall blocks access. Check firewall set up on
* browser machine
* SP machine
c. You deployed the zxid in some other URL than you thought.
Double check your webserver or servlet container
configuration and be sure you understand where
zxid is supposed to appear. Be sure you are editing
the right configuration - some people run multiple
web servers in their machine and get confused about
which one actually is active on which port and where
the configuration files are located.
d. ZXID lacks execute permissions, dynamic link libraries
are missing (use "ldd zxid" to check), or CGI permission
setup prevents it from running. See previous bullet.
6. Mystery configuration problems. Double check /var/zxid/zxid.conf
or consider removing it if you do not understand what it does.
Double check the conf string if using zxid_simple() interface.
7. Writes a user...
> Once it has been compiled, I copied the files zxidhlo.php and zxid.php
> to /var/www/zxid (my webroot). I accessed zxidhlo.php?o=E with my browser
> and I saw a page asking for IDP metadata. But when I looked at
> the /var/log/apache2/error.log, I found these:
>
> tb77f96c0 zxidmeta.c:352 zxid_get_ent_by_sha1_name zxid d Trying
> sha1_name(cot) open (vopen_fd_from_path): No such file or directory
Did you create the /var/zxid hierarchy (make dir) and make sure your
web user (nobody?) has write permission to the ~log~ directory? Or did
you configure it to use some other directory than /var/zxid?
8. What is this /var/zxidcot directory?
It is supposed to be /var/zxid/cot
When configuring PATH, did you forget trailing slash? E.g.
"PATH=/var/zxid&URL=..." # WRONG!
"PATH=/var/zxid/&URL=..." # Right
9. If configuration appears to be prematurely truncated, then
see if you need to adjust ZXID_MAX_CONF (default 4KB) in
zxidconf.h and recompile.
10. *Q1:* I get rejection due to NotOnOrAfter or NotBefore. I think I have
synchronized the clocks on IdP and SP. Log messages are
t zxidsso.c:466 zxid_validate_cond zx d ssof: NotOnOrAfter ok. Time to expiry 21900 secs
t zxidsso.c:476 zxid_validate_cond zx E ssof: NotBefore rejected with slop of 7300. Time to validity 21600 secs
*A1:* This seems awful lot like a timezone issue. Slop is ZXID config
parameter that defines the tolerance. I recently reduced it from 1 day
to 3 hours because I got feeback that it was security issue to have
such overbroad tolerance (which it is, but 1 day slop allows people
with bad time zone configs to still have initial success - may be
I go back to one day).
On both IdP and SP, run
TZ=GMT date
and see if that is about 6 hour difference. I stronly suspect other
machine being correctly on GMT (which does not even have concept
of summer time that causes so much productivity losss :-) and other
is on something like US Central time (your guess if summer time error applies).
You can synchronize using
TZ=GMT ntpdate pool.ntp.org
(there may be server closer to you than Finland)
*Q2:* I double checked the clocks, the SP and IdP are very close to our NTP
server, within 100ms or so. Why would it say there's a slop of 7300
seconds?
*A2:* Slop is just tolerance. The real problem is "Time to validity 21600 secs".
If you can't get the clocks to synchronize, you can increase
the config option BEFORE_SLOP=22000 in /var/zxid/zxid.conf. This
of course has some security implications.
*Q3:* My time zone is set to CDT on both machines. Is it possible that
Shibboleth is using GMT and zxid is using my local time? (Or the
other way around) 21600 seconds seems too obvious to
be a real clock skew. If both systems have the same locale settings, then
something in software must be choosing the wrong time zone.
I set TIMEOUT_FATAL=0 and it does work. I get my nid and my login session
is working! So, major hurtle accomplished, but I think I'd like to get to
the bottom of this and find out what the real problem is.
*A3:* 21600 seems very obvious timezone issue.
On Unix the timezone behavior of a process is determined by setting
of TZ environment variable. To my best knowledge I always use gmtime(3)
which to my best understanding ignores the TZ environment variable.
However, it is possible that I errornously or the Shib IdP use
localtime(3), which will take TZ in account. Therefore I recommend
launching all processes with environment TZ=GMT (see the date
example above).
97.4.2 Doubts
~~~~~~~~~~~~~
How to decode auto_flags
0x1d54 1 = debug; d = FORMT + FORMF + MGMTC; 5 = METAC + LOGINC; 4 = SOAPC
97.5 Consent
------------
A frequent concern among the business people and lawyer types is
whether the architecture provides for consent by the user. Usually
this is related to (avoidance of) liability. If the system can be
said to have gathered the consent of the user, we are safe.
Unfortunately the standards do not mandate an uniform user interface,
thus there is no single specific way how the consent is gathered or
determined: it depends from business situation and application to
another. Fortunately the Liberty and SAML 2.0 architectures provide
plenty of ways and hooks to gather and convey the consent. Consider the
following:
1. When arriving to SP, user chooses IdP for SSO. This act
of course manifests user's intent to perform SSO.
2. IdP can ask the user whether he wants to perform SSO to
the SP (IdP can make this question even if user is already
logged in to the IdP, though most demos omit the question
in the already logged in case).
At this point the IdP may also ask whether the user
wants to create a federation so that the SP can track
the user. Creating federation is consenting to be
tracked by the SP.
If the federation already exists, the IdP can still
offer a choice: should the federation be used
this time, i.e. does the user consent to be tracked
this time specifically.
If user does not consent to federation and use of
federation this time, but still consents to SSO,
the SSO will be made using a temporary name ID.
3. If user gives any Personally Identifying Information
to the SP (beyond the federated pseudonym), then
the SP may be able to "connect the dots" and
correlate user's actions on the SP with his actions
in some other systems (technically this is called
collusion).
In a very technical sense users should be aware
of this risk or the implication and therefore by
providing such information they are effectively
consenting to be correlated across systems.
However, lawyers would probably say that if
the SP intends to correlate, it should state
so to the user at the time the information is
asked so that the user can make an informed decision.
If, after being informed, the user still supplies
the information, then user is clearly
consenting to the information being used for
the stated purpose, i.e. correlation.
4. When user starts to use an ID web service, the user is
consenting to this service being visible to at least
some parties (why use the service if you did not
intend this).
To make this consent explicit, the user interface
of the ID Web Service can ask.
Also, the Discovery Service can ask consent using
the Liberty Interaction Service. It is quite
appropriate for the DS to ask this consent
because it allows the ACL to be set correctly
right from the beginning, when the service is
registered.
5. When the user later accesses an SP that needs to
contact an ID Web Service, it could be
construed that the user, by using the SP
at all, is effectively consenting that the SP
may access the ID Web Services of the user.
If this is not enough, the Discovery Service
can use the Interaction Service on per service
invocation basis to ask if the user consents
to the specific request.
Finally, the actual ID Web Service can also
invoke the Interaction Service to ask the
user to consent to the specific request,
or otherwise enforce its policies.
6. When using People Service, the inviter (Alice)
consents to the access by the invitee (Bob)
by requesting an invitation string from the
system.
Once the invitation has been sent (and
accepted by invitee) there is no easy way
to collect consent from inviter on per
request basis. For example Alice may not
be online at the time when Bob accesses
her resource.
Alice can later revoke Bob's invitation,
but in the window between Alice sending
the invite and revoking it, Bob can access
Alice's resource without Alice actively
consenting to every access.
Of course the resource can implement ACL
policies, like only allowing Bob to access
the resource a limited number of times,
such as once.
7. When the invitee (Bob) uses inviter's (Alice's)
ID Web Services (resources), Bob has
consented to some form of tracking by
Alice's resources by accepting the
invite. Further consent may be obtained
by Bob's own IdP, see bullet 2.
97.6 Deployment Planning
------------------------
Here is a rudimentary decision tree for deployment planning
1. List your applications
a. Any provided by external partner?
b. Non web apps
2. Document your existing identity stores and approaches to
a. User provisioning (when someone is employed)
b. Application provisioning (when someone starts using app)
c. Authorization: how do you know who is supposed to be
doing what?
d. Deprovisioning: what happens when someone is fired?
e. Login? Per app? Harmonized user names? Enterprise SSO?
3. Document your goal: federated SAML SSO über alles :-)
a. Do you want to run IdP?
b. Could you out-source IdP?
c. Will your partners / customers be running their own IdPs?
d. Will you participate (or run) single CoT or do you
need to consider cross CoT inter-operation (e.g. IdP proxying)
To be continued...
97.7 Use of Signing and Crypto, Security Concerns
-------------------------------------------------
97.7.1 How is mod_auth_saml better than HTTP Basic Auth that it claims to emulate? HTTP Basic Auth does not address transport encryption. Is mod_auth_saml HTTP Basic Auth emulation vulnearable due to this?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> I have looked at HTTP basic auth and it does not provide any
> transport level security, is it secure to use HTTP basic auth with
> certificates? is it common to do it that way?
HTTP-Basic is a method for authenticating a user using username and
password. This is orthogonal to whether the connection is encrypted.
Most common current practise is to combine HTTP-Basic-Auth with TLS (SSL)
encryption. This is considered safe, to the extent that passwords
can ever be safe. mod_auth_saml keeps the TLS encryption part intact,
but improves on the password insecurity part by either allowing
nonpassword authentication, such as Yubikey token, or at least allowing
one password disclosed to only one party (the IdP), rather than multiple
passwords at multiple parties (the weakness of the latter approach
is that the users tend to use the same passwords at the multiple
parties, allowing each party to impersonate the user at the other
party - and then there is the guessable password vulnearability).
97.7.2 Receipe for debugging signature validation problems
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This mail thread fragment discusses how to debug signature problems
between ZXID deployments. If the signer is not ZXID, then you
need to figure out how to get it to print the canonicalized
form. Often this turns out to be surprisingly difficult because
the signing end uses some library which does not document
how this vital debugging information can be obtained.
<<logoutput:
> > Message digest does not match because canonicalizations
> > are different. You can dig the canonicalized forms of body from /var/zxid/log/xml.dbg
> > There should be one entry from time when signature is created and another from time
> > the signature validation was attempted. The two are different.
> >
> > BTW, I usually run
> >
> > tailf /var/zxid/log/xml.dbg | ./xml-pretty.pl
> >
> The failure appears in log as:
>
> <!-- XMLBEG 1548:46 zxsig.c:308 zxsig_validate zx d call: VFY FAIL CANON BLOB len=337 -->
> <a:MessageID xmlns:a="http://www.w3.org/2005/08/addressing"
> xmlns:e="http://schemas.xmlsoap.org/soap/envelope/"
> xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"
> wsu:Id="MID" e:actor="http://schemas.xmlsoap.org/soap/actor/next"
> e:mustUnderstand="1">urn:MlQY4jARBIitwHPf6vIIyk_LZ</a:MessageID>
> <!-- XMLEND 1548:46 -->
>
> now what?
Yes, this is the failure, but somewhere earlier in the log (perhaps in different server - the
WSC server), there should be block labelled similar to
<!-- XMLBEG 13098:108 zxsig.c:124 zxsig_sign zx d call: SIG CANON len=337 -->
...
<!-- XMLEND 13098:108 -->
You can find it quickly by searching backwards for something like the message ID or timestamp
string.
That block indicates how the signer canonicalized the blob. I claim the two will turn
out to be different. Once the difference is known, I can investigate whether it is
my bug or due to somehow malformed or incomplete input.
>>
97.7.3 Signature validation problems in body
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In typical web service call, using zxid_call() API, the programmer supplies
a fragment of payload XML. This can be a source of canonicalization problems.
ZXID will attempt to canonicalize it on basis of well formed XML and if it is not
well formed, it will almost certainly give unpredictable results.
Another common problem is omitting namespace declarations: ZXID considers
all XML to have namespace, and if it does not find a namespace, then it will
fabricate one. By supplying a namespace declaration, you control the situation
instead of relying on unpredictable fabricated one.
97.7.4 VFY FAIL CANON SIGINFO
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The logs say VFY FAIL CANON SIGINFO
Basically a signature has message digests at two layers: 1. over
payload data (e.g. #BDY), 2. over the <SignedInfo> element. The latter
is what gets private key encrypted when signature is made. The
encrypted value appears in <SignatureValue>.
The validation decrypts <SignatureValue> with public key from cert. If
the public key does not match the private key, you will get, if you
are lucky, a padding error, which you were getting earlier. But if you
are not lucky, you will just get garbage decrypt.
The garbage decrypt is then compared against message digest computed
over <SignedInfo>.
This is reported as VFY FAIL CANON SIGINFO, which may be misleading if
the real reson was garbage decrypt. However, it would be the right
error message in case the <SignatureValue> decrypt was valid, but the
<SignedInfo> had actually been tampered with.
I would concentrate the investigation on the theory of garbage decrypt
due to wrong certificate.
The certificate for signature validation is chosen on basis of
<Sender> header's ~providerID~ XML attribute.
97.7.5 Perils of Turning Off AuthnReq Signing
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Q: In response to signature problems relating to missing root
authority certificate and AuthnRequest, other vendor is proposing
that they do not require signed requests for web applications. Is it
possible to turn off the need for certificates?
A: Yes. In SP's zxid.conf, set AUTHN_REQ_SIGN=0
However, this opens the IdP to a variant of unsolicited
request attack as they would not know if the request is coming from
a legitimate source. It saves the request signature verification cost,
but allows Denial of Service by incurring SAML assertion generation and
signing cost. You could argue that these cancel each other out. In any
case the user would be entering the password to legitimate place: the IdP,
so this is not really a phising attack.
If IdP is buggy and blindly trusts the AssertionConsumerServiceURL
field in the authentication request, not verifying the request
signature could lead to inappropriate party being able to obtain the
SSO assertion. Unless the assertion is encrypted (the default in
ZXID), this could lead to that party gaining knowledge of the
attributes passed in that assertion. It is not uncommon for IdPs to be
buggy in this way (as of 2012). Such bug constitutes a violation of
SAML2 specs, but may not be caught in software testing as everything
seems to work. Only negative testing would catch it. (Needless to say,
zxididp paid attention to this detail.)
97.8 Audit Trail
----------------
1. How can I see what attributes the single sign on assertion contains?
From IdP side (assuming zxididp, for other IdPs consult respective documentation):
a. Locate the SSOA7N line from IdP activity log, e.g.
grep SSOA7N /var/zxid/log/act
which might return (single line, linewrap is only for this document)
PP - 20100112-144157.750 20100112-144157.750 127.0.0.1:- \
9u_7LsQjkz0VaXKucmx1_sYjQnM - AWTILy8_0yre96om7n4H-4fMW ENC \
zxidp U K SSOA7N - -
b. The 8th field is the assertion ID, here AWTILy8_0yre96om7n4H-4fMW. With
A7N ID you can grep the issued assertions, e.g.
grep -l AWTILy8_0yre96om7n4H-4fMW /var/zxid/idplog/issue/*/a7n/*
which might return something like
/var/zxid/idplog/issue/9u_7LsQjkz0VaXKucmx1_sYjQnM/a7n/MxevnQGqKFwyBTPUZ-hI7m1PR-Q
This file contains the assertion in plain text. You can inspect it to
see what NameID is sent and what attributes are sent. One convenient command is
grep -l AWTILy8_0yre96om7n4H-4fMW /var/zxid/idplog/issue/*/a7n/* \
| xargs cat | ./xml-pretty.pl
From SP side the steps would be
i. Locate FEDSSO line
grep SSOA7N /var/zxid/log/act
which might return (single line, linewrap is only for this document)
PP - 20100112-144639.184 20100112-144157.501 -:- \
xsKJr3DL7sUPDdbdqgC2H_eP-UM - AWTILy8_0yre96om7n4H-4fMW \
FIrFwFdR4wO2UFLQZl8c3LlUW zx O K FEDSSO MSES6GOG4ta-nQdYlRVJriv24dj8 -
ii. The 8th field is the assertion ID. To locate the assertion in the rely
audit trail of the SP you can grep as follows:
grep -l AWTILy8_0yre96om7n4H-4fMW /var/zxid/log/rely/*/a7n/* \
| xargs cat | ./xml-pretty.pl
97.9 Vendor products
--------------------
97.9.1 Symlabs Federated Identity Suite (SFIS)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Interoperates. SP and IdP.
Metadata import to IdP?
What I usually do is
cd /opt/SYMfiam/3.0.x/conf/symdemo-idpa
echo 'sp: zxid-sp1$https://sp1.zxidsp.org:8443/zxid?o=B$$' >>cot.ldif
Double check with text editor that the file is sensible.
Note that the single quotes are essential as the dollars
are to be interpretted literally, as separators.
cd pem
wget https://sp1.zxidsp.org:8443/zxid?o=B >zxid-sp1.xml
Here the intent is to fetch the metadata from the SP and
store it in a file whose name (without .xml extension)
matches the first component of the sp: line. I am not
100% on the wget syntax. You can also use browser
to fetch the metadata and simply Save as under the
correct name.
cd /opt/SYMfiam/3.0.x/conf/symdemo-idpa/start.sh restart
This should restart the IdP server process and cause a
refresh of the metadata it may have cached. You may
want to
tail -f /opt/SYMfiam/3.0.x/conf/symdemo-idpa/log/debug.log
to see if its getting indigestion.
N.B. FIAM seems to have NameID encryption on by default, Turn
this off by editing slimidp.ldif:
encnids: 0
If this is not done, the SSO will fail (with what appears like signature
error).
97.9.2 Shibboleth and OpenSAML
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shibboleth 2.1.5 IdP interoperates since 0.65. Earlier versions
interoperated in some configurations.
Many Shibboleth SPs interoperate (exact version numbers lost).
97.9.3 Lasso and Authentic
~~~~~~~~~~~~~~~~~~~~~~~~~~
Used to work, may be still does. Not tested in recent memory.
97.9.4 OpenSSO
~~~~~~~~~~~~~~
Used to work, may be still does. Not tested in recent memory.
97.9.5 simpleSAMLphp
~~~~~~~~~~~~~~~~~~~~
Interoperates, but as of Sept 2010, simpleSAMLphp IdP has problems with
EncryptedAssertions. Nothing ZXID can do (but you can turn off the
encryption if you are willing to assume the consequences).
simpleSAMLphp SP works.
97.9.6 Ping
~~~~~~~~~~~
Not tested in recent memory.
97.9.7 SiteMinder
~~~~~~~~~~~~~~~~~
CRLF emitting. Works since 0.65.
97.9.8 Bouncing Castle vs. OpenSSL Padding Problem
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
There is a XML ENC padding problem between OpenSSL and Bouncing Castle
Java Crypto Library. See OpenSSL bug number 1067:
http://rt.openssl.org/Ticket/Display.html?user=guest&;pass=guest&id=1067
<<logoutput:
From: sampo@symlabs.com
To: rt@openssl.org, xml-encryption@w3.org
Cc: eric@projectliberty.org, sampo@symlabs.com
Subject: OpenSSL symmetric crypto padding check incompatible with XMLENC
Date: Thu, 12 May 2005 20:22:50 +0000
Please find below a patch, with spec reference, against OpenSSL 0.9.7g.
It could be argued that XMLENC spec is wrong in insisting on unpredictable
values for the padding because this allows padding to be used as a
covert channel. However, to deploy interoperable implementations it seems
patching OpenSSL is the right thing to do. It has been observed that
other crypto libraries, such as bouncing castle (a pure Java
implementation) do not set all padding bytes to OpenSSL's satisfaction.
--Sampo
--- evp_enc.c~ 2005-01-28 14:03:53.000000000 +0000
+++ evp_enc.c 2005-05-12 03:26:44.000000000 +0000
@@ -509,6 +509,21 @@
EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
return(0);
}
+#ifdef PADDING_CHECK
+ /* Following loop checks that all padding has known value,
+ * presumably to prevent covert channel or some form of
+ * chosen text attack. However this check is in violation
+ * of [XMLENC] specification section 5.2 subsection
+ * "Padding", which states that only last octet of the
+ * block matters and values of other octets are not
+ * predictable. Thus to implement XMLENC decryption with
+ * openssl it is necessary to disable this code.
+ * -- 11.5.2005, Sampo Kellomaki (sampo@symlabs.com)
+ *
+ * [XMLENC] D. Eastlake, ed., XML Encryption Syntax and
+ * Processing, W3C Recommendation 10. Dec. 2002,
+ * http://www.w3.org/TR/2002/REC-xmlenc-core-20021210 */
+
for (i=0; i<n; i++)
{
if (ctx->final[--b] != n)
@@ -517,6 +532,7 @@
return(0);
}
}
+#endif
n=ctx->cipher->block_size-n;
for (i=0; i<n; i++)
out[i]=ctx->final[i];
-----------
OpenSSL is complying with various other standards with its current
behaviour. For example PKCS#7.
If the EVP functions are being called directly (instead of inside
OpenSSL in its PKCS#7 code for example) you can disable the padding
altogether EVP_CIPHER_CTX_set_padding() and perfom padding and pad
checking at an application level.
Steve.
>>
Since ZXID version 0.65 (Oct 2010), this has been addressed via
the EVP_CIPHER_CTX_set_padding() route.
97.9.7 Active Directory Federation Services (ADFS)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ZXID 1.02 SP has been confirmed to work with ADFS IdP (STS,
unknown verion in April 2012).
Sometimes ADFS IdP does not emit assertion at all. There seems to be
some configuration change in ADFS viz its default install that is
needed to get it to emit SAML2. Symptom may be the following ZXID
debug log (see Apache error.log, catalina.out, or
/var/tmp/zxid.stderr, depending on your installation) entries:
p2192 zxlog.c:682 zxlog_blob zx d dec_redir_post nosig: LOGBLOB15(<samlp:Response) len=3994 path(/var/zxid/log/rely/hJ7us-0hhS2XLwl3VTPZoStmgRY/wir/n4CfarJbNloArnYTCI1BfOmIHg4)
p2192 zxidlib.c:540 zxid_saml_ok zx E SAML Fail what(SAMLresp) SC1(urn:oasis:names:tc:SAML:2.0:status:Responder)
although this could be caused by other errors that send status. Basically
you can check the file indicated by the path on the LOGBLOB15 line and
verify that it does not have Assertion. The Status element may also
have human readable error string, though in the specific case of ADFS refusing
to send assertion, no human readable error was supplied. At any
rate, the status code
urn:oasis:names:tc:SAML:2.0:status:Responder
signifies that the error happened due to the IdP (which is responding
to the AuthnRequest, hence "Responder") and that the request sent by
SP was considered OK.
Sometimes ADFS IdP emits an assertion without NameID (or EncryptedID)
element, which makes it difficult for other SAML2 compliant SPs to
work. Symptom may be the following ZXID debug log (see Apache
error.log, catalina.out, or /var/tmp/zxid.stderr, depending on your
installation) entries:
p18379 zxidlib.c:662 zxid_chk_sig zx d No signature in Response
p18379 zxidlib.c:595 zxid_decrypt_nameid zx E ssof: Neither NameID nor EncryptedID available 0
p18379 zxidsso.c:617 zxid_sp_sso_finalize zx E ssof: SSO failed: assertion does not have Subject->NameID. 0x0
Reportedly the fix at ADFS IdP side is
> "Create a claim rule to set the PartnerImmutableID as the the unique identifier.
> This should then send it as the SAML NameID in assertion."
97.10 Known Bugs
----------------
Following are known limitations. We document them here
because we do not plan to fix them in foreseeable future.
1. Namespace qualified XML attributes have underscore instead of colon
97.11 Mysterious Error Messages
-------------------------------
"Random number generator not seeded!!!"
This warning indicates that randomize() was not able to read
/dev/random or /dev/urandom, possibly because your system does not
have them or they are differently named. You can still use SSL, but
the encryption will not be as strong. Investigate setting up
EGD (entropy gathering daemon) or PRNG (Pseudo Random Number
Generator). Both are available on the net.
"msg 123: 1 - error:140770F8:SSL routines:SSL23_GET_SERVER_HELLO:unknown proto"
SSLeay error string. First number (123) is PID, second number (1) indicates
the position of the error message in SSLeay error stack. You often see
a pile of these messages as errors cascade.
"msg 123: 1 - error:02001002::lib(2) :func(1) :reason(2)"
The same as above, but you didn't call load_error_strings() so SSLeay
couldn't verbosely explain the error. You can still find out what it
means with this command:
/usr/local/ssl/bin/ssleay errstr 02001002
97.11.1 snprintf() multibyte character related errors in log
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is due to locale setting. Try
export LANG=C
This will disable any UTF-8 processing in sprintf().
BTW, Win32 native _snprintf() on does not nul terminate if buffer is
full. Gotcha! All zxid code has additional manual nul termination,
just in case.
97.11.2 My own messages are redirected back to me
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In several SAML profiles a HTTP redirect is performed to
send the user to other party, usually with a request or
response in the query string.
A mysterious error is when you see yourself receiving
as input the stuff that was supposed to be sent to the
other end. The way this happens is, if for some reason the
other party's URL can not be determined, then the
Location header will only consist of the query string
that you are trying to send. Without domain name part
of the URL, the browser will redirect back to the
web site where the redirection came from. This is
called "local redirect" and is usually the cause
of you receiving your own output as input.
To fix this, make sure you have the other site's metadata
and make sure it parses and loads correctly. If that
does not resolve the problem, see if the metadata
has any binding for the operation you are trying.
No binding will result in no URL.
97.12 Certificates and Private Keys
-----------------------------------
97.12.1 Password is being asked for private key
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is normal behaviour if your private key is encrypted. Either
you have to supply the password or you have to use unencrypted
private key.
One way to remove password is
openssl rsa -in key.pem -out keyout-nopw.pem
For this to work, key.pem must have only the private key. On the other
hand, for ZXID to work, the file must have both certificate and
private key. You will need to use your favorite text editor to
accomplish this.
Scan OpenSSL.org for the FAQ for full explanation on how to
remove password from the private key.
97.12.2 Quick command for looking at certificate
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** also appears in zxid-cot.pd)
Sometimes you get warning messages (in browser) or signature
validation errors (in IdP end) because the Subject field of the
certificate does not match your actual domain name. You can
check this with
openssl x509 -text </var/zxid/pem/ssl-nopw-cert.pem | grep Subject:
If the domain name is different, then you need to obtain a certificate
with correct domain name, see next question.
97.12.3 Self signed certificate
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** also appears in zxid-cot.pd)
ZXID ships with zxid.pem which gets by default copied to /var/zxid/pem
under various different names. This is fine for testing, but disastrous
for production or security sentitive use as the private key corresponding
to zxid.pem certificate is of public knowledge (it is distributed with
every copy of ZXID) - it offers no security and no non-repudiation
what-so-ever.
For production or security sensitive install you need to either
1. Obtain certificates from an official certification authority,
usually a commercial one. ZXID uses same certificate format as
Apache (i.e. the pem format), so aquiring certificates is easi. Or,
2. Generate your own certificate. The simplest case is a self signed
certificate:
openssl req -new -x509 -nodes -keyout pkey.pem -out cert.pem
cat cert.pem pkey.pem >/var/zxid/pem/ssl-nopw-cert.pem
The cat step is there because you need to supply both certificate
and the private key in same file for ZXID to understand it.
> Warning: Although ZXID wants to see the private key in the same
> file as the certificate, you MUST NOT give this concatenated
> file to any outsider. Others have legitimate need to know your
> certificate, but they MUST NOT know your private key. If they
> ask, you should take special care to delete the private key from
> the file prior to giving it to them. Often those who need to
> get your certificate, actually need your metadata: just tell them
> to fetch it from the Well Known Location URL (i.e. the Entity ID
> of your SP). ZXID will never leak the private key to the metadata.
97.12.4 Installing CA Certificates
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Some versions of libcurl apparently do not respect setting
CURLOPT_SSL_VERIFYHOST to 0 and thus require a CA certificate to be
trusted. This may result SSL connection error messages like
CURLcode(35) CURLerr(SSL connect error)
See: http://gagravarr.org/writing/openssl-certs/others.shtml#ca-openssl
To fix this
1. Determine what is your OpenSSL library's directory ("OPENSSLDIR")
strace -e file openssl version 2>&1 | grep openssl.cnf
may result
open("/apps/openssl/0.9.8g/ssl/openssl.cnf", O_RDONLY|O_LARGEFILE) = 3
Here the /apps/openssl/0.9.8g/ssl/ is the ~OPENSSLDIR~.
2. Download from the certificate authority their certificate
in PEM format ("Apache" format) and save it in OPENSSLDIR/cert.pem
3. Check
openssl verify -CApath OPENSSLDIR/certs/ OPENSSLDIR/cert.pem
which should in successful case print
/apps/openssl/0.9.8g/ssl/certs/the_ca.pem: OK
If the hash is not right, it will print something like
/apps/openssl/0.9.8g/ssl/certs/the_ca.pem: /C=US/O=TheCA/OU=TheCA
error 18 at 0 depth lookup:self signed certificate
OK
4. Alternative approach using certs/ directory with hashes. Save the
certificate under OPENSSLDIR/certs with any name (say, the_ca.pem)
5. Create a hash
cd OPENSSLDIR
ln -s the_ca.pem `openssl x509 -hash -noout -in the_ca.pem`.0
6. Check: see step 3, substituting cert.pem with the_ca.pem.
97.13 Author's Pet Peeves
-------------------------
1. What is Schema Grammar (.sg) and why are you using it?
* Schema Grammar is a compact formal description of XML documents. It is
mostly bidirectionally convertible to XML Schema (XSD) and captures
the useful essence of most XML schemata.
* Schema Grammars are intuitive and compact, often allowing the
essence to be understood at glance, and even most complex cases
being only about 50% of the volume of the corresponding XSD.
* We use Schema Grammar descriptions because they are more human readable
than XSD and still equally amenable to automated code generation.
* Schema Grammar descriptions are usually converted using xsd2sg.pl, which is
part of the PlainDoc distribution.
* See http://mercnet.pt/plaindoc
* N.B. You do not need xsd2sg.pl or PlainDoc if you just want to compile and use ZXID.
2. What is PlainDoc (.pd)?
* PlainDoc is a document preparation system that uses intuitive plain text files
with minimal markup to generate PDF and HTML outputs.
* We use PlainDoc because it makes it easy to maintain documentation.
* See http://mercnet.pt/plaindoc
* N.B. You do not need PlainDoc if you just want to compile and use ZXID.
3. How come zxid is so heavy to compile?
* SAML 2.0 and related specs have a lot of functionality and detail, even
if you really only need 1% of it. We do not wish to arbitrate which
functionality is best or most needed, so we simply provide it all.
* A lot of the code is generated, thus the input for C compiler is well
in excess of half a million lines of code (of which only about 6k
were written by a human).
* Some of the generated files are gigantic, e.g. Net/SAML/zxid_wrap.c
is over 380k lines. Compiler has to process all of this as a single
compilation unit.
* gcc and gnu ld were, perhaps, not designed to process this large inputs
efficiently. Often the implementation strategy of keeping
everything in memory will cause a smaller machines to swap.
* My 1GHz CPU, 256 MB RAM machine definitely swaps and thus
takes about 45 minutes to compile all this stuff.
* I recommend at least 1GB RAM and 3GHz CPU for development
machine. On such machine, you should be able to build in about 10 min.
4. Why do you not use ./configure and GNU autoconf?
* ~autoconf~ is not for everyone. World does not stop without
~autoconf~. Or indeed need ~autoconf~. It is Yet Another Dependency
I Do Not Need (YADIDNN).
* I find the GNU ~autoconf~ stuff much more difficult to understand than
my own ~Makefile~. Why should I debug ~autoconf~ when I could
spend the time debugging my ~Makefile~ or the actual code?
* I find resolving problems much easier at source code and ~Makefile~ level
than trying to debug a million line script generated by some system
I do not understand (perhaps some hardcore ~autoconf~ advocate could
try to convince me and educate me, but I doubt).
* My policy is to only support systems I have first hand experience with,
or I have trustworthy friends to rely on. It does not help me
to have a system that tries to guess +gazillion irrelevant variables+
to an unpredictable state. It's much easier to stick to standards like
POSIX and make sure you have predictable results from predictable inputs.
* If the deterministic and predictable results are wrong, they can
at least be debugged and fixed with a finite amount of work.
* Supporting all relevant systems manually is not that much of work. The
inhabitants of the irrelevant systems can support themselves, probably
learning a great deal on the side.
97.13.1 What does ZXID aim at - an answer
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A recent (Sept 2006) conversation that touched on the aims of ZXID project:
> Q: So just generally, what are your goals for it, are you interested in making
> it work well with what other people are producing (e.g. SAML -> WSF
> cross-over), etc? I'm certainly assuming the answer's yes to that.
I aim at full stack client side implementation. ID-FF, SAML 2.0, WSF
(both versions). The generation technique I use will yield the
encoders and decoders for both WSP and WSC, but the hand written
higher level logic will at first be only written for SP and WSC.
Some WSP support has now been written as well (complete WSP support
was completed as of July 2007).
It is Apache licensed project, of course, so if someone contributes
the IdP and WSP capabilities, I'll merge them into the
distribution. (IdP and Discovery exist in the distribution as of
Janyary 2010.)
I am interested to have it working with other people's code at 3 levels:
1. Over-the-wire interoperability
2. I have split the functionality of the SP from the WSC such that
zxid SP could probably be used with someone else's WSC and someone
else's SP would reasonably easily be able to use zxid WSC.
3. Interfaces to non IdM parts of the complete system, typically
used to implement the application layer, shall be
plentiful: C/C++ API, Net::SAML/mod_perl, php - whatever you
can SWIGify.
One thing I am NOT interested in is "layered" stack. I strongly
believe it's better each vertically integrated slice is implemented by
one mind. Thus, except for lowest HTTP, TLS, and TCP/IP layers, my SP,
or WSC, or WSP, handles the whole depth of the stack - SOAP,
signature, and app interface layers (of course the actual app should
be its own layer and probably user written). That is by design.
I have found in practise that if you attempt a layered stack, you have
impedance mismatches between the modules at different layers because
they were designed and written by different minds. By having vertical
integration I avoid impedance mismatches. This is the reason why
monolithic TCP/IP implementations tend to be better than explicitly
layered, such as the streams approach.
Now, if someone else wanted to take my generated encoders and
decoders and use them as a "layer" in their layered stack, I guess
I would not have any issue. If you do that, please let me know
because I would have to commit to API stability at that layer.
I am willing to do that once there are real projects that depend
on it, but until then I still may redesign those APIs, after
all, I am at revision 0.4 :-)
In the end, it seems that ZXID is actually somewhat layered approach -
what I mean by "vertical integration" is that all the layers are
designed and controlled by the same mind.
> Q: I gather that it's SAML 2.0 at the moment, which I can't offer any test
> capability for, but if you get to SAML 1.1, I'm happy to set up some kind of
> IdP test capability for that.
In SSO world SAML 1.1 and ID-FF 1.2 capabilities are definitely on the
road map. In ID-WSF world, I'll probably start with 2.0 DS-WSC (don't
we all) followed by ID-DAP WSC and then tackle 1.1 after
that.<<footnote: As of version 0.18, July 2007, both WSC and WSP roles
of ID-DAP as well as ID-HR-XML have been implemented. Discovery client
was implemented as well. This means the generic WSC and WSP support is
there.>>
97.13.2 Annoyances and improvement ideas
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(*** http://systoilet.wordpress.com/2010/09/29/i-hate-saml/)
There is a lot of commonality that is not leveraged, especially in the
way service end points are chosen given the metadata. The descriptors
are nearly identical so casting them to one should work.
Many of the SAML2 responses are nearly identical. Rather than
construct them fully formally, we could have just one "SAML any
response" function. Perhaps this could be supported by some schema
grammar level aliasing feature: if an element derives from base type
without adding anything at all of its own, we might as well only
generate code for the base type.
Namespace aliasing scheme would allow us to consider two versions of
schema the same. It seems to be fairly common that the schema
changes are so minor that there is no justification for two
different decoding engines.
97.13.3 Non-obvious SAML
~~~~~~~~~~~~~~~~~~~~~~~~
1. Destination XML attribute is needed in redirect and POST bindings.
2. Assertion//SubjectConfirmationData/@InResponseTo XML attribute
is needed in SSO assertions, unless the SSO was unsolicited.
SAML is not very explicit about this, [SAML2core], ll.729-732
describes it as optional, but [SAML2prof], ll.580-582 and
ll.559-560 seem to imply this requirement.
3. Some deployments use POST binding for many more things than
officially sanctioned by SAML [SAML2conf], Table 1 "Possible
Implementations", p.6. None of the offical profiles, see
[SAML2conf], Table 2 "Feature Matrix", p.9, require support
for POST for sending or receiving Single Logout or Manage NameID
requests. Nor is sending AuthnRequest using POST officially
sanctioned. Using artifact profile for anything else than
fetching the SSO assertion is not official. Never-the-less,
some of these bindings are perfectly implementable and some
deployments actually use them. ZXID may support some of them,
especially the POST bindings, if it is easy to do so, but
we make no commitment beyound official SAML conformance.
4. In SAML SOAP bindings it is bit unclear if the caller needs
to be authenticated. Currently ZXID solves this by signing
the SOAP requests (see SSO_SOAP_SIGN configuration options).
Other approaches are using HTTP Basic authentication,
using Client-TLS, or simply not authenticating the peer.
5. Interpretation of metadata KeyDescriptor/EncryptionMethod
Algos on [SAML2conf], section 4.2 "XML Encryption Algorithms",
ll.252-253.
The interpretation in [SAML2meta], section 2.4.1.1 "Element
<KeyDescriptor>", ll.621-624, p.16, and the example
on l.1117.
Since the <EncryptionMethod> can appear several times, it
would seem reasonable to specify it once for assymmetric crypto
and once for symmetric crypto. If specified, then for each
of the cases, only one of the allowed algos may be used.
If not specified, then any algo authorized in [SAML2conf]
is allowed. If specified, but the algo is not authorized
by [SAML2conf], then implementation is nonconformant.
6. The selection of protocol binding for return path of
SSO is non-trivial. The Authentication Request may
specify any number of parameters like ProtocolBinding
or Index. Generally it should not be specified at
all, leaving the decision to the IdP, or it should
be specified using the Index method.
7. When passing around Name IDs or storing them in database,
remember to store all components, including NameQualifier
and SPNameQualifier.
8. Single Logout: IdP should not call originator of SLO when
it is logging out everybody.
9. SAML Redirect binding signs the base64 and URL encoded
payload. This is problematic as there is no canonical
way to URL encode, i.e. some implementations encode
more than others. When signature needs to be verified,
CGI or other layer of processing may already have
removed the URL encoding, thus breaking the signature.
Correct implementation requires capturing the URL encoded
version of ~SAMLRequest~ or ~SAMLResponse~ field
as it came from wire and using that for signature
verification. This is what ZXID does, but historically
some implementations have tried to URL reencode for
signature verification, resulting "it depends" type
bugs where sometimes it works when sender's URL
encoding happens to match the URL encoding the receiver
applies. Of course all of this could have been avoided
had the design been to sign the base64 encoded form
prior to URL encoding. And URL encoding would not
have been needed at all if safebase64 ([RFC3548], sec 4)
encoding had been used in the first place.
10. SAML SimpleSignPOST binding may superficially seem
similar to Redirect binding in the signature area. Well,
it is not. SimpleSign signs the payload data prior to
base64 (and URL) encoding. This avoids the bug that
easily creeps into Redirect signature verification,
see above. Downside is that the payload can't really be
binary, unless you base64 encode twice.
11. EncryptedAssertion and EncryptedID: how is the EncryptedKey
found?
a. The EncryptedData/KeyInfo/RetrievalMethod references the Id attribute of
the EncryptedKey element, which is sister of the EncryptedData.
Shibboleth 2010 can be kludged to work with this method if
EncryptedKey element has Recipient XML attribute equal to the
EntityID of the SP. This is nowhere well documented, but appears
to work.
b. EncryptedKey is child of EncryptedData/KeyInfo, i.e.
EncryptedData/KeyInfo/EncryptedKey. Shibboleth SP appears to use
this latter method as of 2010. Scott ackowledged method (a) as
also valid and will fix Shibboleth SP.
See saml-core-2.0-os.pdf, sec 2.2.4 Element <EncryptedID>, p.14, l.495
specifies that EncryptedData and EncryptedKey are sister elements.
See also ll.515-521 for schema fragment.
Sec 2.3.4 Element <EncryptedAssertion> on p.17 contains similar language.
as does 2.7.3.2 Element <EncryptedAttribute> on p.31.
<<ignore:
Oliver: 2010-09-06 08:06:29 DEBUG OpenSAML.MessageDecoder.SAML2 [30]: extracting issuer from SAML 2.0 protocol message
2010-09-06 08:06:29 DEBUG OpenSAML.MessageDecoder.SAML2 [30]: message from (https://zxidp.org/idp)
2010-09-06 08:06:29 DEBUG OpenSAML.MessageDecoder.SAML2 [30]: searching metadata for message issuer...
2010-09-06 08:06:29 DEBUG OpenSAML.SecurityPolicyRule.MessageFlow [30]: evaluating message flow policy (replay checking on, expiration 60)
2010-09-06 08:06:29 DEBUG XMLTooling.StorageService [30]: inserted record (R6AEwkbaM6nahxpvSNOyr0dTe) in context (MessageFlow)
2010-09-06 08:06:29 DEBUG Shibboleth.SSO.SAML2 [30]: processing message against SAML 2.0 SSO profile
2010-09-06 08:06:29 ERROR Shibboleth.SSO.SAML2 [30]: Unable to locate an encrypted key.
Sampo: Ok, looking for encrypted key.
? This is is what I sent on the wire.
Oliver: ok let me make a diff and see if that is what i received
Sampo: If we analyze this you can see that EncryptedKey is sister element of EncryptedData element.
Oliver: ok it is exactly identical to what i have in the log
Sampo: The KeyInfo of the EncryptedData references #EK39 and the EncryptedKey has Id attribute EK39
? That is the mechanism by which it is supposed to find the encrypted key.
? Now the next step is that EncryptedKey itself has KeyInfo that contains X509 certificate.
? That certificate is supposed to be your SP's encryption certificate, taken from your metadata.
? Do you follow me?
Oliver: yes
Sampo: Now, at cursory inspection the cert in the message matches the cert in your metadata.
? Can you spot any error here?
Oliver: let me do a diff to double check ... one sec
Sampo: Your metadata says you are using same certificate for encryption and signing.
? Next verification would be to see if your metadata matches the certificate actually used by SP at this step.
? I think the log messages that Scott provides are too terse to analyze this problem. Giving one blanket "Unable to locate an encrypted key" error message for all potential points of failure outlined thus far is not sufficient.
? I have to go eat now. I hope these ideas help. I'll be back in an hour.
? You do have credentials on zxidp.org so you can reproduce all this at will, right?
Oliver: i am checking ... but so far everything looks identical to what is in the log
? i have an account there yes
Sampo: Good. Talk to you in an hour.
Oliver: enjoy your lunch
Sampo: I'm back
Oliver: hey
? double checked the certs in fhe configuration and compared them to what you were sending and they are identical
Sampo: Next theory why it is not working?
Oliver: as you might have noticed ... i am not an saml expert ... so I don't really have a theory why it is not working
? the strange thing is that it seems to work fine with protectnetwork and the kantara idp
Sampo: Huh, I actually thought you were SAML knowledgeable or at least wanted to learn and become SAML expert?
Oliver: i am doing the system administration for kantara ... and very much interested in saml and learning more about it
? but still far from being an expert
Sampo: Can you capture the wire message from protect network?
? For example turn off JavaScript and perform the login. When it stops on the POST page, save that page so you can see what the IdP is sending to the SP.
Oliver: sure let me login via protect network and capture it ... once sec
? i can see the wire message in the logs
? just once sec
* Oliver posted file protect-network.debug to members of this chat
? here is what i got from them
Sampo: THe assertion is not encrypted at all!
? That leaves them open to attacks by infected web browsers.
? The so called active intemediary man in the middle attack.
? Can you make similar verification to see if Kantara IdP encrypts the assertion?
Oliver: oh you wanted the encrypted version?
Sampo: If encrypted version was passed on the wire, I want to see it.
? If https is used, the most reliable place to capture is stopthe POST flow just before the form with the assertion is posted to the SP. Give me the content of the SAMLResponse form field.
Oliver: ok let me try the turn off javascript thing then
* Oliver posted file encrypted.txt to members of this chat
? this is the enctypted version from protect network
Sampo: Analyzing...
? Ok, I see the difference: I use EncryptedData/KeyInfo/RetrievalMethod to designate the EncryptedKey where as protectednet uses EncryptedData/KeyInfo/EncryptedKey
? Schemawise both appear valid and I support both in my SP.
Oliver: ok
Sampo: Which code does protect-network use?
Oliver: so you think it is a bug in shibboleth?
Sampo: protected-network uses shibboleth?
Oliver: no that is our sp
? i don't know what they use
Sampo: Yes, I think it is bug in shibboleth SP. It should accept either way of doing it.
Oliver: ok so maybe we should forward that info to scott
Sampo: What software do you use for Kantara IdP?
Oliver: simplesamlphp
Sampo: Can you capture their output and see how they designate the EncryptedKey?
Oliver: sure you want the decrypted version only right?
Sampo: Meanwhile, I will add to my IdP an option to generate it the EncryptedData/KeyInfo/EncryptedKey way.
? Since the problem is with encryption, I want the encrypted version.
* Oliver posted file encrypted.txt to members of this chat
? oops sorry wrong file
? one sec
* Oliver posted file encrypted-simplesamlphp.txt to members of this chat
Sampo: Fundamentally this is a bug in xml-enc and saml specs in not specifying only one way of doing it.
Oliver: the second one is the correct file (the one that says simplesamlphp) the first one was the one from protecnetwork
Sampo: Yes, I am looking at it...
? The encrytped-simplesamlphp.txt does not contain encrypted assertion (or ancrypted anything).
? If this really is what you captured from the POST SAMLResponse field, then your IdP is vulnearable to the MITM attack.
? You are using the POST binding in all cases, right?
Oliver: yes
? one sec looking at the xml
Sampo: That is important because encrypting the assertion is not needed in artifact binding.
Oliver: yes i see the encrypted is missing
? i need to update the software on the ipd anyway. so i will try to get this to work right during that maintenance
? thanks for pointing that out
Sampo: See saml-bindings-2.0-os.pdf, sec 3.5.5.2 Security Considerations, p.24, ll.847-851
? After publication it was understood that the SHOULD NOT could be eliminated if EncryptedAssertion is used.
Oliver: noted
Sampo: See saml-core-2.0-os.pdf, sec 2.2.4 Element <EncryptedID>, p.14, l.495 specifies that EncryptedData and EncryptedKey are sister elements. Thus this really appears to be a bug in shibboleth SP.
? See also ll.515-521 for schema fragment.
Oliver: ok
Sampo: Sec 2.3.4 Element <EncryptedAssertion> on p.17 contains similar language.
Oliver: so what do we do? include scott in the loop?
Sampo: Please raise this issue with Scott.
Oliver: ok
? will do
Sampo: Meanwhile I will implement an option to be spec noncompliant so that it still works with his buggy code.
Oliver: ok sent him an email
? lets see what he says
Sampo: It is quite sad that sec 6 SAML and XML Encryption Syntax and Processing, p.73, does not provide any clarification on this matter either. The core spec does not provide a single example of EncryptedID or EncryptedAssertion. Seems OASIS SSTC was pretty sloppy when defining this part of the spec.
Oliver: yes that should be defined in detail
Sampo: Umm, it seems you did not Cc me in the mail. Please let me know what he replies.
Oliver: oops sorry
? yes will forward the answer as soon as i get it
Sampo: Little progress now:
? opensaml::FatalProfileException at (http://kantarainitiative.org/Shibboleth.sso/SAML2/POST)
Unable to locate satisfiable bearer SubjectConfirmation in assertion.
? I guess that means it is at least able to decrypt. Can you paste there the corresponding log lines?
Oliver: oncesec
* Oliver posted file shibd.log to members of this chat
Sampo: 2010-09-06 12:13:16 ERROR OpenSAML.SecurityPolicyRule.BearerConfirmation [30]: bearer confirmation failed with recipient mismatch
? I have a hunch on this. I'll check the specs.
Oliver: ok
Sampo: Is there any way I could just use http request to a CGI to obtain a tail of your log?
Oliver: we don't have anything setup right now
Sampo: There may be a good policy reason why not to set up such log access, but if there is no rule against it, it would be pretty trivial php or perl CGI script to write.
? Think about that while I think about BearerConfirmation :-)
Oliver: yes would not be too hard to write a little php for that but I would have to check with joni if she is ok with it
? i think there have a national holiday there today though
? they
Sampo: Hope that means Scott has time to read mails :-)
Oliver: true
Sampo: One step further.
? shibsp::ConfigurationException at (http://kantarainitiative.org/Shibboleth.sso/SAML2/cookie:982a07ae)
Shibboleth handler invoked at an unconfigured location.
Oliver: just sent you the responce from scott
? do you want the logs from the errorß
? ?
Sampo: At least the tail of the log from DEBUG Shibboleth.SSO.SAML2 [30]: extracting issuer from SAML 2.0 assertion onwards
? Hopefully that is so little you can just paste it here.
Oliver: one sec
Sampo: I'll check Scott's response...
Oliver: 2010-09-06 12:52:36 DEBUG Shibboleth.SSO.SAML2 [46]: extracting issuer from SAML 2.0 assertion
2010-09-06 12:52:36 DEBUG OpenSAML.SecurityPolicyRule.MessageFlow [46]: evaluating message flow policy (replay checking on, expiration 60)
2010-09-06 12:52:36 DEBUG XMLTooling.StorageService [46]: inserted record (Ajq-JsiQEM4thfqIZ4T911pUp) in context (MessageFlow)
2010-09-06 12:52:36 DEBUG OpenSAML.SecurityPolicyRule.XMLSigning [46]: validating signature profile
2010-09-06 12:52:36 DEBUG XMLTooling.TrustEngine.ExplicitKey [46]: attempting to validate signature with the peer's credentials
2010-09-06 12:52:36 DEBUG XMLTooling.TrustEngine.ExplicitKey [46]: signature validated with credential
2010-09-06 12:52:36 DEBUG OpenSAML.SecurityPolicyRule.XMLSigning [46]: signature verified against message issuer
2010-09-06 12:52:36 DEBUG OpenSAML.SecurityPolicyRule.BearerConfirmation [46]: assertion satisfied bearer confirmation requirements
2010-09-06 12:52:36 DEBUG Shibboleth.SSO.SAML2 [46]: decrypted NameID: <sa:NameID xmlns:sa="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient" NameQualifier="https://zxidp.org/idp" SPNameQualifier="https://kantarainitiative.org/shibboleth-sp">TdDu9HPCRGB3cdEaRgVtdgmkD</sa:NameID>
2010-09-06 12:52:36 DEBUG Shibboleth.SSO.SAML2 [46]: SSO profile processing completed successfully
2010-09-06 12:52:36 DEBUG Shibboleth.SSO.SAML2 [46]: extracting pushed attributes...
2010-09-06 12:52:36 DEBUG Shibboleth.AttributeExtractor.XML [46]: skipping unmapped NameID with format (urn:oasis:names:tc:SAML:2.0:nameid-format:transient)
2010-09-06 12:52:36 INFO Shibboleth.AttributeExtractor.XML [46]: skipping unmapped SAML 2.0 Attribute with Name: urn:liberty:disco:2006-08:DiscoveryEPR, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
2010-09-06 12:52:36 INFO Shibboleth.AttributeExtractor.XML [46]: skipping unmapped SAML 2.0 Attribute with Name: idpinfo, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
2010-09-06 12:52:36 INFO Shibboleth.AttributeExtractor.XML [46]: skipping unmapped SAML 2.0 Attribute with Name: cn, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
2010-09-06 12:52:36 INFO Shibboleth.AttributeExtractor.XML [46]: skipping unmapped SAML 2.0 Attribute with Name: zxididp, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
2010-09-06 12:52:36 DEBUG Shibboleth.SSO.SAML2 [46]: resolving attributes...
2010-09-06 12:52:36 DEBUG Shibboleth.AttributeResolver.Query [46]: found AttributeStatement in input to new session, skipping query
2010-09-06 12:52:36 DEBUG Shibboleth.SessionCache [46]: creating new session
2010-09-06 12:52:36 DEBUG Shibboleth.SessionCache [46]: storing new session...
2010-09-06 12:52:36 DEBUG XMLTooling.StorageService [46]: inserted record (session) in context (_a1e19c299c142bf732871dbff386f7d9)
2010-09-06 12:52:36 DEBUG XMLTooling.StorageService [46]: inserted record (TdDu9HPCRGB3cdEaRgVtdgmkD) in context (NameID)
2010-09-06 12:52:36 DEBUG XMLTooling.StorageService [46]: inserted record (Ajq-JsiQEM4thfqIZ4T911pUp) in context (_a1e19c299c142bf732871dbff386f7d9)
2010-09-06 12:52:36 INFO Shibboleth.SessionCache [46]: new session created: ID (_a1e19c299c142bf732871dbff386f7d9) IdP (https://zxidp.org/idp) Protocol(urn:oasis:names:tc:SAML:2.0:protocol) Address (93.108.147.200)
2010-09-06 12:52:36 DEBUG Shibboleth.SSO.SAML2 [46]: ACS returning via redirect to: cookie%3A982a07ae
Sampo: It appears SP side session was created all right.
? I think we are now at the point where SAML is no longer involved.
Oliver: yes I still need to map some attributes but looks allright
Sampo: Where did that cookie%3A982a07ae come from?
? It appears that the equals sign got URI escaped and perhaps that is throwing it off?
Oliver: is there maybe a ? missing?
Sampo: That could be, as well.
? Lets entertain the theory that cookie%3A982a07ae came from the RelayState field and investigate how it was passed in AuthnRequest and Response.
Oliver: but then the same thing should happen with the protect network
Sampo: If you look at the original HTTP redirect that is made to convey AuthnRequest, you can see QueryString argument RelayState=cookie%3A8cd0ff4c
? So clearly your SP (or WAYF service?) already passes it in that format. As far as I have understood the protocol, I am not supposed to decode it (nor reencode).
? If I intercept a POST, I can see the field <input name="RelayState" value="cookie%3A982a07ae" type="hidden">
? Perhaps the field should have been <input name="RelayState" value="cookie=982a07ae" type="hidden">
? I.e. the RelayState gets encoded twice because the browser, when posting the form will encode again.
Oliver: i think it needs to be a :
? this is what i am getting from protect network
? <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<body onload="document.forms[0].submit()">
<noscript>
<p>
<strong>Note:</strong> Since your browser does not support JavaScript,
you must press the Continue button once to proceed.
</p>
</noscript>
<form action="http://kantarainitiative.org/Shibboleth.sso/SAML2/POST" method="post">
<div>
<input type="hidden" name="RelayState" value="cookie:109e37f6"/>
? ...
Sampo: Hex 3a is a colon? Not equals?
Oliver: i think so yes
? looked it up
Sampo: I'll try this and see if it fixes...
Oliver: ok
Sampo: It went through!
? But I landed back on the Current Members page where I had started by clicking the Log In.
? The Log In still appears.
Oliver: yes probably some attribute mapping missing hold on
Sampo: How do I know that I am logged in?
? Shouldn't Single Logout button of some sort appear (and Log In disappear)?
Oliver: yes your username appears
? hold one one second
? need to logout and login to try it
Sampo: But how can I logout? I do not see any logout button?
Oliver: no i do have to logout to try it here
Sampo: So zap cookies is the only way?
Oliver: 2010-09-06 13:34:04 DEBUG Shibboleth.AttributeDecoder.NameID [28]: decoding NameIDAttribute (persistent-id) from SAML 2 NameID with Format (urn:oasis:names:tc:SAML:2.0:nameid-format:persistent)
2010-09-06 13:34:04 INFO Shibboleth.AttributeExtractor.XML [28]: skipping unmapped SAML 2.0 Attribute with Name: urn:liberty:disco:2006-08:DiscoveryEPR, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
2010-09-06 13:34:04 INFO Shibboleth.AttributeExtractor.XML [28]: skipping unmapped SAML 2.0 Attribute with Name: idpinfo, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
2010-09-06 13:34:04 INFO Shibboleth.AttributeExtractor.XML [28]: skipping unmapped SAML 2.0 Attribute with Name: zxididp, Format:urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
Sampo: FYI, the page I am using for these tests: http://kantarainitiative.org/confluence/display/GI/Current+Members
? Those attributes can be safely ignored for time being.
Oliver: where do you pass the username?
? what attribute?
? and format?
Sampo: No attribute. I pass pseudonymous NameID.
? That appears in Subject element of the SAML assertion.
? In your log 2010-09-06 13:34:04 DEBUG Shibboleth.AttributeDecoder.NameID [28]: decoding NameIDAttribute (persistent-id) from SAML 2 NameID with Format (urn:oasis:names:tc:SAML:2.0:nameid-format:persistent)
? would appear to correspond to that.
Oliver: ok so let me try to map NameID to our username
Sampo: But perhaps we need to take a step back at this point: assume a random user of zxidp.org wants to access kantara. How would kantara know that user (identified by persistent pseudonym) is in fact a user that is allowed to access Kantara?
? I vaguely recollect that last time I asked this question, the answer was that Kantara does not care.
Oliver: all end up in the standard user group first
? where you see the same as if you were not logged in
? and then you contact staff and ask to be assigned to another group
Sampo: But you should see at least the logout button or some indication that you are logged in.
Oliver: yes you see your username where it says login etc
? can edit your profile
? etc.
Sampo: "username"? Is that something Kantara assigns internally?
Oliver: it is something like omaerz@protectnetwork.com
Sampo: Are you expecting the IdP to pass you that?
Oliver: yes
Sampo: That looks like globally unique id, a correlation handle.
Oliver: that is why i was looking at the attributes
Sampo: That is privacy hostile.
Oliver: that is the way the shibboleth plugin for confluence works
Sampo: Liberty Alliance spent 8 years engineering relationshipwise pseudonymous privacy friendly protocols and now you want global correlation handle.
Oliver: we can map that username, name and email address if we get it from an idp
? i don't
? the people who implement the plugin do
? i was only asked to set that system up in that way
Sampo: Basically my IdP will give you persistent pseudonym. That allows you to keep your local database that knows some things about me.
? Towards some other SP the IdP will give a different pseudonym so that the other site can not correlate information with Kantara.
? This is very important for privacy.
? In the end it reduces to what is the minimum amount of information that Kantara needs to know about me.
Oliver: ok
Sampo: Perhaps some email is needed, but I would hope to use different email at each SP.
Oliver: email is optional and you can fill it in manually in confluence
Sampo: How tightly are the mailinglists integrated to the web site?
Oliver: same with name
? no mailman integration
Sampo: Ok, so I can SSO with IdP and then selectively supply the pieces of information and the versions of those pieces just for Kantara.
Oliver: do you know of a saml module for mailman?
Sampo: In that case, wouldn't it work well to just use the persistent pseudonym as username?
Oliver: the only thing i need to get this to work is a username
? yes let me try
? what does that pseudonym look like?
Sampo: Base64 encoded 128bit random number.
Oliver: i have to make sure they are unique ... so some other idp does not give us the same username
? i.e. you second ipd
? idp
Sampo: <sa:NameID xmlns:sa="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:persistent" NameQualifier="https://zxidp.org/idp" SPNameQualifier="https://kantarainitiative.org/shibboleth-sp">FRsLTG-ZdKuVJ-Pes_MiQ44cz</sa:NameID>
? In this XML snippet you see NameQualifier.
? That is essentially the namespace inside which the 128bit thing (FRsLTG-ZdKuVJ-Pes_MiQ44cz) is unique.
? So to form your username, you could concatenate the two. You could even use @ character as a separator, but that still would not make it workable email.
? BTW, the SPNameQualifier for you is always same. But for IdP serving multiple SPs that also forms important part of the namespace.
? Another approach you could take is simply do a sha1 hash over the canonical serialization of the whole NameID element.
? and use that as username.
? When SAML was designed, the choice was to identify IdP by a URL rather than just domain name. This makes it difficult to construct any meaningful email address that would include IdP identification.
? You can talk to Scott about that. May be he remembers why this design was adopted.
Oliver: hmm this is really ugly: https://zxidp.org/idp!https://kantarainitiative.org/shibboleth-sp!frsltg-zdkuvj-pes_miq44cz
? also this will break confluence
Sampo: That would be a bug in Confluence, IMNSHO.
Oliver: like when click on a user to see his profile
? is it really such a big deal if you passed some unique identifier that looks more like an email address?
? i mean you could stick the id in there
Sampo: How about this: FRsLTG-ZdKuVJ-Pes_MiQ44cz@yBeCTPt0NQ2vMuI-srKw5h4N2i8
Oliver: something like sp!frsltg-zdkuvj-pes_miq44cz@zxidp.org
? or that
Sampo: where the FR stuff is the persistent pseudonym and the yBe stuff is safe_base64 encoded sha1 hash of https://zxidp.org/idp
Oliver: sure
Sampo: Personally I would find FRsLTG-ZdKuVJ-Pes_MiQ44cz@zxidp.org ok as long as you do not make any assumption that you can actually send mail there :-0
Oliver: no
? it is not used as an email address
? the email address CAN be passed as an attribute but that is optional
? if it is passed then only to pre-populate the email field in confluence the very first time somebody logs in
Sampo: If you adopt that convention it would be really cool if you also documented it so that could become a widely adopted solution and convention to this problem in the confluence and even wider world.
? What attribute others are passing to you to pick the user name?
Oliver: you mean the FRsLTG-ZdKuVJ-Pes_MiQ44cz type usernames?
Sampo: Does anyone else try to pass you persistent pseudonym?
Oliver: protectnetwork is passing <protectnetwork username>@protectnetwork.com
? kantara idp is passing the username without the @... at the then
? end
Sampo: I guess what I am saying that if there is some industry convention (that I do not know about), I could pass the pseudonym the same way.
? So for kantaraidp you need to add the @idp.ki
? ?
Oliver: i guess i could add it
Sampo: What is the name of the attribute protectnetwork uses to pass this?
Oliver: hold on let me look it up
? http://www.protectnetwork.org/support/policies/attribute-release-policy
? we do not user firstname lastname though
? as the confluence plugin expects the whole name in one field
? so urn:oid:1.3.6.1.4.1.5923.1.1.1.6 is what we use for the username
? they do not pass the email
? to us
Sampo: That is, urn:mace:dir:attribute-def:eduPersonPrincipalName .
Oliver: but they do not pass it to us
? for whatever reason
? they pass it to others
Sampo: In urn:oid:1.3.6.1.4.1.5923.1.1.1.6 they the pass the email like thing.
Oliver: yes
Sampo: So they do not pass email attribute, but pass in eduPersonPrincipalName something that most of the time is the email.
Oliver: they do not pass either one
? neither the real email nor the first + lastname in one field
Sampo: Ok, decision now: do I reconfig my IdP to pass in urn:oid:1.3.6.1.4.1.5923.1.1.1.6 something like FRsLTG-ZdKuVJ-Pes_MiQ44cz@zxidp.org
Oliver: sure that looks good
Sampo: or do you just add the @zxidp.org to the persistent pseudonym I pass to you (i.e. no change for me)?
? I take it that you pick the first option. Very well. It will take me perhaps 20min or so.
Oliver: ok that would really be the best solution
? i am looking at a way how i could put the name together on my side
Sampo: I suspect there are other sysadmins who would appreciate this as well.
Oliver: but it would probably take longer that 20 mins
? this is the config for shib + confluence
? https://studio.plugins.atlassian.com/wiki/display/SHBL/How+to+Shibbolize+Confluence
? ok gotta run to the store will be back in 30 mins
Sampo: Ok, I'll do the same. Back in 30 min.
? Back.
Oliver: oral exam
? oops wrong window
Sampo Kellomäki: I am now sending urn:oid:1.3.6.1.4.1.5923.1.1.1.6 but I still am not considered logged in.
Oliver: let me look at the log one sec
? was the format
? you are sending it as urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified
? added it to the attribute map and now it works
Sampo Kellomäki: Should I tweak my code to send something other than unspec?
Oliver: no it is fine i added it to the attribute map
Sampo Kellomäki: I see protectednetwork sent urn:oasis:names:tc:SAML:2.0:attrname-format:uri
? Perhaps I do the same.
Oliver: ok
Sampo Kellomäki: Ok, now I see my login succeed.
? I'll implement the Recipient work around Scott suggests.
Oliver: just forwarded you another mail from scott that i have received
Sampo Kellomäki: In the Recipient case it is not clear what should go to that field.
Oliver: i don't know either
? :(
Sampo Kellomäki: I'll put the EntotyID URL and we will see.
? Works with the Recipient workaround.
? On the Kantara site, where can I edit my test user's profile?
? I notice you lowercase the persistent pseudonym when you form the username. You realize that my uniqueness guarantee assumes full 64 character characterset. By lowercasing you loose nearly one bit of search space :-)
? Out of 128.
? I guess you are still ok, statistically speaking.
Oliver: that is an intersting point
? i wonder if confluence does that or the shib plugin
? you can edit your userprofile when you click on your name
? and then there should be a dropdown menu with the item profile
? once on your profile you need to click on the edit link
Sampo Kellomäki: No doubt this needs JavaScript...
? The user name appears in the "Full Name" field. Is there no provision for human readable nick name?
Oliver: you can just overwrite that
? click on the edit link
? it is put in there if no name is passed from the idp
? confluence probably needs something in there
Sampo Kellomäki: The internal federated username is just initial value for Full Name - I see.
Oliver: yup
Sampo Kellomäki: Ok, appears to work.
? I'll make a new release of zxid and upgrade idp.tas3.eu to the latest and greatest. Then we can consider this issue closed for time being.
Oliver: cool
>>
97.13.4 Non-obvious ID-WSF
~~~~~~~~~~~~~~~~~~~~~~~~~~
1. Should you include Sender SOAP header? Conor says usually
not. But how do you then know SOAP request issuer? Perhaps
from some field of the signature?
2. In case bearer token is <EncryptedAssertion>, how is
env->Header->Security->SecurityTokenReference->KeyIdentifier
populated (normally it would be populated from Assertion->ID)?
97.13.5 Non-obvious XML Exclusive Canonicalization (XML-EXC-C14N)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
XML Exclusive Canonicalization bugs cause vast majority of signature
failures (once trivial configuration issues like using wrong
certificates are taken care of). Here are some gotchas:
1. XML namespace prefixes must be tracked correctly and they
can alter at every layer, even reusing already used
prefixes.
2. InclusiveNamespaces/@PrefixList namespaces must always be
rendered. However, if the list inclides a prefix that in
fact has not been declared in parent node of the canonicalization,
then this prefix is supposed to be ignored (says Scott Cantor, 20101005).
I have not found any specification references saying this to be
the case. In fact [XML-EXC-C14N] section 3, bullet 2, and section
3.1, bullet 3.2.1, seem to imply otherwise. However if the prefix
has not been declared, it is not easy to see how the spec could
be satisfied (unless a bug leaks the declaration from inside
the canonicalized element, such as ~ds~ from embedded signature).
3. Pay attention to line end canonicalization ([XML-C14N], section 1.1
"Terminology", 3rd bullet): CRLF to LF. Many implementations
only ever produce NL, or avoid producing any superfluous whitespace at
all (best strategy to avoid interop problems), and therefore work fine
until the day when CRLF emitting implementation appears.
4. Namespace declarations are ordered by namespace prefix, while
namespaced attributes are ordered by namespace URI. Gotcha!
<<ignore:
Seems this thread is vendors (even if some are open
source) galore, so here goes my blurb...
I'm sorry ZXID.org documentation is seen
as "disgusting". At least it was found.
The criticism is bit unconstructive as it does not give
me any idea about what the gaps were or why it was not
palatable.
At any rate, I recommend starting from top level
of the documentation (left hand column of zxid.org web site)
before drilling to the low level reference sections that
were linked in the article.
If you find a gap, just mail zxid.user@lists.unh.edu
or me: sampo@zxidp.org
Regarding the claimed segfault: I would love to receive
a bug report on this (and any claims should cite version
number). As of zxid-0.76 I challenge the critiquer
to reproduce the problem. Only that way things get
fixed.
Re SAML not open: I find SAML itself is fully open, albeit
complex and with too much alternative/optional behaviour
opening scope for bugs.
The real evil comes from XML (agree with critiquer),
especially its namespace mechanism and the underspecified
canonicalization mechanism. It does not help that the
committee overseeing XML-DSIG and canonicalization
are not open to clarifications. You can report to them
any number of bugs in their specs and they will find
a reason to not publish errata.
The interested reader should check my <a href="http://zxid.org/html/zxid-faq.html#-ZXIDFAQ-AuthorsPetPeeves-NonobviousXMLExclusiveCanonicalizationXMLEXCC14N">FAQ</a>.
Cheers,
--Sampo
>>
97.13.6 I do not want to know service type, but I want to call the service
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Q:: Can I create a new ~struct zx_a_EndpointReference_s~ (~zxid_epr~ since 0.69)
from scratch where i can set the url that can be get from\\
zxidjni.get_epr_address(cf, epr)?
A:: EPRs are complex objects. Even if you created a blank EPR with just
URL in it, it would not be all that useful without the <Metadata> and
especially <SecurityContext> with token within.
Gulyx:: Ok i see, however as we discussed the statement:
zxid_epr epr = zxidjni.get_epr(cf, zxses, "x-recurs", null, null, null, 1);
may be moven from the axis2 zxid module to the application level
in this way the developer can choose.
What i am saying is that a developer of a web service client
can explicitely define a url, or may use your disco in order to look
for the most appropriate one
Sampo:: Explicitly defining URL is inadequate unless you also define
the security token to access the service. Generally creating security
token without consulting discovery (or ID Mapper service in more
general context) is not feasible. Therefore having a simple
constructor for EPR accomplishes very little.
Gulyx:: What i am saying is that is due to the developer of a web service client choose
Sampo:: If you know the URL (and the service has been registered to
discovery), then you can get the EPR with
zxidjni.get_epr(cf, ses, svc_type, URL, null, null, 1).
Gulyx:: an explicit url or look for one from a disco
thus this part of the zxidapi should be used (in case) at the application layer
Sampo:: Rather than look for URL from disco, why not just get the EPR
from disco, i.e. call get_epr()?
Gulyx:: and not in the zxid security module
Sampo:: What would you do with the EPR created by the constructor?
Gulyx:: well it is ok to use zxidjni.get_epr(cf, ses, svc_type, URL,
null, null, 1). However is not always given that "svc_type"
is known/available what happen if it is not provided? that it may be
possible i understand that is important from a discovery point of view
but the coould be the case in which the developer of a web service
client do not want to use it or does not know it he would only contat
that URL
Sampo:: If you do not know service type, how do you know what kind of
SOAP body you are supposed to send to the service? Developer of the
web service ultimately is the authority that decides what the service
type URI. If he does not know it, he can just invent it.
Gulyx:: for example because i am executing a RPC and i got all the information from the wsdl
in this case i simply need a URL
isn't it ?
Sampo:: As a general rule, if web service developer has poor
imagination in inventing a service type URI, I recommend using the
namespace URI of the top level element in the SOAP body.
Gulyx:: sampo i am not saying that what you are proposing is wrong
i am just sayin that in some cases people do not use the service type.
Sampo:: To speak RPC, you do need to know how to format the SOAP body
according to the RPC marshalling conventions. Clearly you need to
know what the body looks like, therefore you should know its
namespace.
Gulyx:: and the zxid module in axis shuould support both
Sampo:: If people do not use service type, then they can not get registered in discovery.
Gulyx:: so the case in which the developer (at the application level)
specified the service type and the case when he does not
Sampo:: If they are not registered in discovery, how do you propose to
generate the token for accessing the web service?
Gulyx:: Recap
* service MUST have a service type
* service MUST register to a disco with a service type
* clients SHOULD know the service type and MAY use it in order to look for a service
* client MAY contact directly a service without knowing a service type
Sampo:: I claim that client can not contact the service without
knowing what the SOAP body looks like.
Gulyx:: Of course, but they can also do it from the wsdl as i said above
Sampo:: Yes, knowing WSDL constitutes knowing what the SOAP body is.
If you know WSDL, you know what the namespace URI of the top level
element of the SOAP body is. Now if you follow the convention that
the namespace is the service-type, then you are done.
Gulyx:: So a client may not know the service type
Sampo:: If the service developer chose a service type different from
the namespace, then you have to find out from the documentation the
service developer provided.
Gulyx:: I am only proposing to include into the zxid axis2 module both
the possibility possibilities with and without service type
Sampo:: If you want to support the without service type case, then you
should program in the axis2 module automatic derivation of the service
type using the rule that the namespace of the top level element is the
service type.
Gulyx:: Well if is it possible to forge from the service url an
"appropriate" epr that i can pass to the zxidjni.wsc_prepare_call I
would prefere what do you think?
Sampo:: If you "forge" wrong, then things will not work.
Gulyx:: if the automatic derivation is wrong , then things will not work too :-D
Sampo:: Having a default rule like using top level namespace as service
type will work if that indeed was the convention everybody uses. But
there is no universal agreement that this is always the convention.
Gulyx:: exactely
Sampo:: In practise in Liberty it has been the convention, but there is no guarantee.
Gulyx:: so having something like zxidjni.get_defaultEpr(URL)
Sampo:: Why are you so hell bent in not wanting to know the service type?
Gulyx:: would be useful
Sampo:: What service type do you not know?
Gulyx:: i want service type and i am almost supporting it into the
module i am just saying that people that i hope would use the module
may not use service type
Sampo:: If the people want to play in TAS3, they need to know the
service type. Knowing it is a requirement to join TAS3.
Gulyx:: so i would that the module supports both the cases. I was
referring people out of TAS3. I mean if we realese the zxid module for
apache, I assume that axis2 users may prefer zxid module instead of
rampart so i would include this feature into the module too.
Sampo:: Ok, if you do not want to make TAS3 web service calls and do
not want to use identities or security tokens, then plain EPR with
just URL would be good enough.
Gulyx:: right
97.14 Best Practises
--------------------
1. Each entity chooses its own Entity ID. When you are setting
up a SP, you choose your Entity ID and the IdP(s) MUST be
able to adapt to your choice. Similarily, an IdP decides
its own Entity ID and all SPs MUST be able to adapt to it.
2. Entity IDs MUST be unique within a Circle of Trust (CoT). Given
that CoT relationships may change from time to time, its best
to choose Entity ID so that it is globally unique. If Entity ID
contains a domain name as a component, then the +globally unique+
property tends to be enforced by the domain name allocation
system.
3. Entity ID SHOULD be the Well Known Location (WKL), i.e. the
URL from which the metadata can be fetched.
4. Providing metadata by URL, ideally by the Entity ID, SHOULD
always be enabled. This greatly facilitates configuration.
5. <KeyDescriptor> elements should have ~use~ XML attribute
6. After you get an installation to work, be sure to review whether
the default configuration is appropriate for production use
a. Decide whether you want to run open federation, see MD_FETCH
config option (default: 1=open federation)
b. Prune your Circle of Trust. Use zxcot(8) tool to list who you
trust and delete the misfits.
c. Check validity time tolerances you accept: BEFORE_SLOP
and AFTER_SLOP. The defaults are rather generous for
production use.
d. Review that you did not turn off any signature
validation just to get it to work (SIG_FATAL=0, NOSIG_FATAL=0
and similar config options). All signature
validations are there for reason and you should not
go to production if any of them fail.
e. Check permissions on /var/zxid/pem and think whether
your private keys, including web server SSL one,
are protected. Could they have been compromised
during trial period?
f. Check that your public image is conveyed right in your metadata,
e.g. NICE_NAME, ORG_NAME, ORG_URL, and FEDUSERNAME_SUFFIX (if
used, generally only on IdP). However, be forewarned
that changing these on last minute changes your metadata and you may
need to engage in an additional round of metadata exchanges
when you go to production.
g. Make sure you have a solution in place to keep your audit trail
in case you ever have to go to court. See zxid-log.pd for
details. You may also want to think about encrypting or deleting some
items after a while to reduce your liability for breaches.
97.15 Cardspace / Infocard / DigitalMe Tutorial
-----------------------------------------------
N.B. zxid.org does not yet support Infocard, but since we
are starting the investigation, we thought to share
some of it in next sections...
97.15.1 Installing DigitalMe and Firefox plugin
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DigitalMe by Bandit project is an open source Infocard
implementation, providing functionality roughly similar to
CardSpace. You can download it from
http://www.bandit-project.org/index.php/Digital_Me
rpm2cpio digitalme-0.4.1238-2.1.i586.rpm | cpio -di
97.15.2 Setting up IdP account
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For one InfoCard aware IdP, please see: http://www.cdatazone.org/index.php?/archives/27-Managed-Infocard-Demo.html
1. Register at the IdP site (e.g. https://www.ctindustries.net/icard/index.php)
2. Download the card ("Retrieve Managed Card" link (savea as "cdatamanaged.crd" by default).
3. Install the card to DigitalMe
97.15.3 Yubikey Support
~~~~~~~~~~~~~~~~~~~~~~~
ZXID supports the yubikey USB One Time Password (OTP) tokens from yubico.com.
The token should be personalized such that the prefix of the ticket is the
UID and the remainder is the ticket proper. The AES128 shared secret in hex is
populated in UID/.yk directory. See also zxid-log.pd for description.
You would typically plan the user names, taking in account the yubikey modhex
restrictions, and then use ykpersonalize to create thephysical tokens. At the
same time you would generate and record the AES128 shared secrets to the .yk
files (and inside the yubikey USB tokens themselves, of course).
The contents of the .yk file is 32 hexadecimal digits (ascii 0-9a-f)
representing 128 bits of key information.
The value is not hashed, salted, or nonced, so it needs to be carefully
protected by the filesystem permissions.
97.16.9 Legal
~~~~~~~~~~~~~
Microsoft promises to not sue you: http://www.microsoft.com/interop/osp/default.mspx
97.17 Attributes
----------------
Q:: I want to read the attributes that come in the assertion. How do I do that?
A:: You get attributes back as an LDIF entry as return value of zxid_simple()
The attributes are also available by reparsing the assertion, which gets
stored in /var/zxid/rely hierarchy.
/var/zxid/ses/SuzZQS5Ub/.ses file contains the path to the assertion file.
Q:: In the zxid directory you store some users. What does the extension .mni stand for?
Why is the info stored? I assume it is some sort of local cache. I would like
to store the attributes there too. How do I do that?
A:: The .mni file is used to support Manage NameID requests. In normal operation of ZXID
it really is not needed, but to support some of the SAML conformance test requests
it is needed.
Rather than store attributes in that directory, I'd suggest reparsing
the assertion when you need them. But if you must, you could create a
file of your own in that directory. We of course need a naming
convention that prevents naming conflicts with future versions of
ZXID: Your file extension should start by ".x-", for example:
"attributes.x-attr"
Q:: The ldif returned by zxid_simple() is perfect for my needs, but
nothing is being stored in log/rely directory. Could be some
configuration issue? Also, can I have zxid automatically store the
ldif file returned zxid_simple()?
A:: The log/rely should be populated by default, but if the directory
structure itself is missing, may be it does not work. Try make dirs.
Or check that web server user's permissions allow writing there.
A:: Re ldif cached: the logic is supposed to be that the zxid_simple() will
be called to protect every page, therefore its return value is available
on every page.
If you do not call it every time, but instead bootstrap some sort of
app specific session, then you would store the LDIF (or the attributes
parsed out of it) to that app specific session.
97.17 SOAP Binding
------------------
97.17.1 Axis2 wants wsa:Action header
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The recommended course of action is to change Axis2 config such that it does not
require wsa:Action header. All the necessary information for dispatch of
the SOAP message is already available on the top child element of SOAP Body element.
HTTP Action header and the wsa:Action SOAP header are historical design errors
as they effectively duplicate information from the top child of the Body. Exactly
how this duplication is to be done is poorly specified and great source of
interoperability problems.
Please point me to a specification document (with line number or section reference)
where wsa:Action is specified as mandatory. Remember that Axis2 is just an implementation
and just because Axis2 happens to want it, does not make it required by any standard.
If you can show it to be mandatory, then point me to document that specifies what
the proper value would be.
Historically many web service specs have been silent on the value of wsa:Action as
they were designed not to use wsa:Action. When people the try to use wsa:Action,
they end up inventing the value themselves and, voila, you have an interoperability
mess.
If you really want to have a wsa:Action header, you can generate one yourself:
zxid_call(...,"<e:Envelope><e:Header><a:Action>...</a:Action></e:Header>
<e:Body>...</e:Body></e:Envelope>", ...)
In other words, the zxid_call() family of functions will accept full SOAP envelope if
you give it one. It will then add the TAS3 specific headers to it, but it will preserve
the headers you supplied as long as there is no conflict.
98 Support
==========
98.1 Mailing list and forums
----------------------------
* Official ZXID mailing list is zxid.user@lists.unh.edu
* The archives can be seen at http://listproc.unh.edu/archives/zxid.user
98.2 Bugs
---------
Mail the author or mailing list until we get bug tracking set up. Or volunteer.
98.3 Developer access
---------------------
We use +git+ for source code. Anonymous access is available
git clone git://zxid.org/zxid # Main ZXID source
git clone git://zxid.org/pd # Plaindoc (pd2tex) and xsd2sg.pl tools
Commit access needs to be manually configured and is not
anonymous. If you contribute significantly, please write the author. Others
can send patches (good way to show you are worthy of git commit access)
to me. I've heard some mixed experiences about open source
sites like sourceforge. If you run such site and want to
host ZXID Project, please contact me.
If you just always want the latest source: get the tar ball from
the downloads section of the web site (zxid.org).
98.9 Commercial Support
-----------------------
Following companies provide consultancy and support contracts for
ZXID:
* symlabs.com
* Mercnet, Lda.
* Levelview, Lda.
<<ignore:
Tutorial: http://simplesamlphp.org/docs/1.6/simplesamlphp-sp
https://openidp.feide.no/simplesaml/module.php/core/loginuserpass.php?AuthState=_d165e5c0c137e655159f87fae7ea8223462b087b45
Kantara Initiative project web site (confluence) accepts TAS3 IdP authentication.
This means that you can use your Yubikey or other credentials you may have
at idp.tas3.eu to login. Here's how it works:
1. Start from http://kantarainitiative.org/confluence/dashboard.action
2. Click "Log In" link in the top right of that page.
3. On the "Select Your Home Organization" screen choose "TAS3 IdP" from
the popup and click Select.
4. You will now land on TAS3 IdP authentication screen. Use your Yubikey or
username and password to login.
5. You will see a post screen taking you back to KI web site. You are now
logged in. Your pseudonymous username will appear in top right
of that page. It something like this
fc5y3apqom8upyicon7g6qztx@idp.tas3.eu
6. Click on the username and choose "Profile" to edit the screen name
to be nicer to users (in the internal database the pseudonym
continues to be used so you do not need to worry about the
screen name being acceptable, e.g. duplicate).
7. Once you have your federation enabled Kantara account, you can use
it to join Kantara Work Groups. Their policy is that you do not have
to be Kantara member to login to the site and see the public part
of their work. However, to contribute to their work you need to
be a member (mainly for IPR reasons - to ensure free to implement and use).
This is done by "elevating" the status of your federated login. It is
done by Kantara, not by idp.tas3.eu
Cheers,
--Sampo
Shawn O'Connor <soconnor@falconknight.com> said:
> Any ideas? Thanks!
What was being attempted?
What was the ZXID version and what was the counter part
software and version?
If this was SSO attempt, then I would
be inclined to belive the error message, more below.
> -Shawn
>
> Begin forwarded message:
>
> > From: Denis Shaposhnikov <dsh@falconknight.com>
> > Date: May 25, 2012 11:05:52 AM PDT
> > To: Shawn O'Connor <soconnor@falconknight.com>
> > Subject: Re: Fwd: Test
> >
> > On 25/05/12 20:01, Shawn O'Connor wrote:
> >
> >> Did it work?
> >
> > I see next error messages:
> >
> > p79064 zxidmeta.c:127 zxid_mk_ent zx E ssof: Metadata did not have any certificates! Incomplete metadata? 0
> >
Have you checked
A. Is there metadata for the IdP in the /var/zxid/cot directory? (Directory
may vary due to your configuration.)
- If not: perhaps some firewalling or name resolution problem is
preventing the metadata from being fetched - or perhaps the IdP
in remote end does not support metadata fetch using Well Known
Location method?
- If you suspect any of the above, please attempt manual metadata
exchange (try running zxcot -h for brief summary)
B. If the metadata is there, does it actually have certs? If not, ask
remote IdP to produce metadata that has certs. It may well be
configuration error in their end.
C. If the metadata fetching is working OK, but the permissions in
/var/zxid/cot are not allowing the SP to write the metadata (or more
rarely read metadata that was already written), you could get error
messages of this nature.
> > p79064 zxsig.c:317 zxsig_validate zx E ssof: No certificate supplied. Only hashes (and hence canonicalization) verified. 0
> > p79064 zxidsso.c:400 zxid_sigres_map zx E ssof: Bad cert. 5
> > p79064 zxidsso.c:677 zxid_sp_sso_finalize zx E ssof: Fail SSO due to failed signature sigres=5
Presumably the message was signed, but if there is no certificate
to validate signature against, it will fail. There are ways to configure
ZXID to ignore this problem, but they should not be used in a production
deployment.
> > p79064 zxidsso.c:732 zxid_sp_sso_finalize zx E ssof: SSO fail (P)
> > p79064 zxidspx.c:110 zxid_sp_dispatch zx d ret=0 ses=0x7fffffffe200
> > p79064 zxidspx.c:117 zxid_sp_dispatch zx d *** FAIL, should send back to IdP select 0
> >
> > I don't know what does it mean. Should I ask on the zxid's forum?
I think it means what it says, but before you ask ZXID forum, you should
make more complete investigation on the IdP metadata.
Cheers,
--Sampo
>>
<<ignore:
Karthik Sudarshan <ksudarshan@xtivia.com> said:
> Hi all,
> I have downloaded the latest version of zxid (1.16) and compiled
Rest of the list: sorry folks, I did not announce it, but there is a
new release available :-)
There will be another before christmas.
> against Apache 2.2 on Ubuntu to get the mod_auth_saml.so. I have
> registered an IDP in my COT using the zxcot utility. I can see that in my
> dropdown list on the IDP selection page as well.
>
> I want to be able to bypass the IDP selection page and directly go to the
> IDP login page. For that I used the DEFAULTQS configuration option and it
> does not seem to work.
>
> My option in the apache conf file for the <Location> is as below:
>
> DEFAULTQS=10https://<hostname>/<path>/metadata.xml
The correct syntax is the query string syntax as if a form
had been submitted. Try the following
DEFAULTQS=l0https://<host>/<path>/idp.xml=1%26fp=1
Please note
1. The l0... stuff must end with "=1"
2. If there are any other fields you would like to pass, you need
to include them in the query string, but you need to URI escape
characters, such as ampersand ("&") with %26 (percent 26).
3. One other field in particular that you may want to pass is
fr (aka RelayState) which will control the redirection
after SSO if you have configured REDIR_TO_CONTENT=1
Cheers,
--Sampo
> I tried to give this in the zxid.conf file as well, and that didn't work
> either.
>
> Can someone please suggest how to set this configuration correctly?
>
> Regards,
> Karthik
>>