It turns out that browsers silently convert backslash characters into
forward slashes, while apr_uri_parse() does not.
This mismatch allows an attacker to bypass the redirect URL validation
by using an URL like:
https://sp.example.org/mellon/logout?ReturnTo=https:%5c%5cmalicious.example.org/
mod_auth_mellon will assume that it is a relative URL and allow the
request to pass through, while the browsers will use it as an absolute
url and redirect to https://malicious.example.org/ .
This patch fixes this issue by rejecting all redirect URLs with
backslashes.
Using Apache environment variables in MellonCond expressions didn't
work for various reasons:
* The substitution was never executed if no backrefs were present.
* Only the OS environment was queried without checking the Apache
internal variable stores.
* The output string after substitution was set to an empty string.
Fixing these issues makes %{ENV:...} work properly.
Knowing if a SAML operation failed and the reason why is essential to
diagnose problems. The SAML Status Response is always included in all
SAML responses. In addition to the major reason why a transaction
failed it may also include extra expository information giving
additional details. Unfortunately we never logged any of the status
response information when a failure occurred. This patch adds code to
log the status response information.
In addition the patch adds diagnostic logging of received POST data.
Signed-off-by: John Dennis <jdennis@redhat.com>
If diagnostics is enabled we want error messages written to the
diagnostics log as well as the Apache error_log. AM_LOG_RERROR
replaces the use of ap_log_rerror, it invokes ap_log_rerror as
previously but then also logs the same message to the diagnostics
log. If diagnostics is not enabled it reverts to ap_log_rerror.
Signed-off-by: John Dennis <jdennis@redhat.com>
Field experience with Mellon has demonstrated there are many
opportunities for deployment problems. Although there are tools such
as browser plugins which can capture SAML messages it's onerous for
site personnel to install and capture the relevant information. The
problem with this approach is further compounded by the fact the
external SAML messages are not correlated to Mellon's
requests/responses. Mellon currently can dump the Lasso session and
SAML Response messages and place them in Apache environment variables,
however these do not appear in the log file. To get them into the log
you have to add custom logging to the Apache config. Another issue is
the dumps are not human readable, they are base64 encoded, anyone
looking at the logs after setting up the custom logging will have to
find the base64 text and then manually copy the text into an external
base64 decoder. At that point you'll discover the XML is not pretty
printed making human interpretation difficult.
The Mellon debug messages written to the Apache error are often
insufficient to diagnose problems. And since the Mellon log messages
are written to the Apache error log they are interspersed with a lot
of non-Mellon message.
Compounding the problem of writing Mellon debug messages to the Apache
error log is the fact Apache log messages have a fixed maximum length
(currently 8192) which is insufficient to completely write out such
things as SAML Assertions, metadata, etc. Apache logging also escapes
all control characters with the consequence line breaks are not
preserved and what was a nicely formatted human readable piece of text
becomes a single line with escape characters and may be truncated.
It would be really nice if we could capture diagnostic information
with these properties:
* All relevant data is collected in exactly one file.
* Only information relevant to Mellon appears in the file.
* All information is human readable (pretty printed, decrypted) with
no need to rely on other tools.
* The diagnostic information is grouped by requests.
* The requests can be cross correlated with other Apache logs because
they utilize the same unique request identifier.
This patch adds diagnostic logging to a independent Mellon diagnostics
log file. Every piece of relevant information is captured, including:
* Request information which includes:
- Request method
- Request URL (raw and processed)
- Scheme
- Port
- Request query parameters
- Server name
- Unique request ID
- process ID, thread ID
- Request headers
* Mellon per directory configuration
A complete dump of the entire am_dir_cfg_rec structure keyed using
both the Mellon directive it is associated with and it's internal
name. This is emitted once on first use for a given URL.
The per directory dump includes the pathname of each file read as
well as the file contents. This includes:
- IdP metadata
- SP metadata
- SP cert
- SP key
- IdP public key file
- IdP CA file
* All session management operations
- cookie
- session lookup
- session creation
- session deletion
- cache management
- cache entry information
* All SAML messages
Each SAML message is decrypted, decoded and XML pretty printed in
human readable form.
* Request pipeline operations
What operations Mellon performs, what decisions it makes and what
data is being used to make those decisions.
* Response
- response status
- response headers
- Apache user name
- auth_type
- all Apache environment variables
Diagnostics can be enabled/disabled both at compile time and run
time. Compile time inclusion of diagnostics is managed with the
ENABLE_DIAGNOSTICS preprocssor symbol. The configure script now accepts
the
--enable-diagnostics and --disable-diagnostics
option. Building with diagnostics is disabled by default, you must
specify --enable-diagnostics to enable the run time option of generating
diagnostics.
The following server config directives have been added (e.g. may be
specified in the main server config area or within a <VirtualHost>
directive). If Mellon was not built with diagnostics enabled then
these config directives are no-ops and their use will generated a
warning in the log file indicating they have been ignored and to be
effective you must builld Mellon with diagnostics enabled.
MellonDiagnosticsFile:
The name of the diagnostics file or pipe,
(default is logs/mellon_diagnostics)
MellonDiagnosticsEnable:
Currently either On or Off but it is designed so it can take other
flags in the future to control what type of information is
reported.
Signed-off-by: John Dennis <jdennis@redhat.com>
File information was handled inconsistently. Some configuration
directives which specified a file path replaced the file path with the
contents of the file. This made it impossible to report where the data
was read from. Other file configuration simply recorded the path. The
directives which immediately read the file contents would generate a
configuration error if the file wasn't readable, but those directives
which simply recorded the file path didn't check on the validity of
the path and relied on Lasso to report an error, however these errors
come significantly after configuration parsing because they are
evaluated in a lazy fashion on first use. The Lasso error reporting
can sometimes be cryptic making it difficult to realize the problem is
due to a improperly specified path in a configuration directive.
We want to be able to log the file pathnames where various files are
read from for diagnostic logging purposes.
This patch introduces a new struct am_file_data_t that encapsulates
all information concerning a file including it's pathname, it's stat
information, optionally it's content, when it was read, etc. as well
as maintaing error codes and an error description.
All file specifications and operations now use this mechanism for
consistency.
Signed-off-by: John Dennis <jdennis@redhat.com>
This patch fixes a segmentation fault when segmentation is enabled if
MellonPostDirectory is not set. This segmentation fault occurs when
trying to open the POSt directory.
The fix changes the behavior to log an error instead in this case.
Use APLOG_USE_MODULE if available.
This will also add the module name to its error log messages,
e.g. "[auth_mellon:error]" instead of just "[:error]".
No change for Apache 2.2.
Limit the domains that we will redirect to after login / logout to a
set of trusted domains. By default we only allow redirects to the
current domain.
This change breaks backwards compatibility with any site that relies on
redirects to separate domains.
Fixes #35
The OASIS specification "SAML V2.0 Enhanced Client or Proxy Profile
Version 2.0" added ECP service options into the HTTP PAOS header. We
previously were not looking for these optional flags. The function
am_validate_paos_header() was rewritten to correctly parse the service
value and the optional URN flags and return a bitmask of the ECP
service flags.
The following flags were added:
* ECP_SERVICE_OPTION_CHANNEL_BINDING
* ECP_SERVICE_OPTION_HOLDER_OF_KEY
* ECP_SERVICE_OPTION_WANT_AUTHN_SIGNED
* ECP_SERVICE_OPTION_DELEGATION
The flags are stored in the am_req_cfg_rec.ecp_service_options member.
Currently only the want_authn_signed option is acted upon, it sets the
lasso signature hint when generating a AuthnRequest.
Lasso as of 2.5.0 is missing 3 of the URN flag identifier constants, a
patch was submitted to upstream Lasso to include them and was
accepted. As a fallback they are conditionally added to lasso_compat.h
in case the version of lasso this is compiled against does not yet
have the new constants.
The function am_is_paos_request() was modified to return an error.
New error codes were added to auth_mellon.h.
New utility code to tokenize a string was added. This is used to
parse the PAOS header, primarily to handle quoted strings.
A new utility routine, *am_ecp_service_options_str() was added so log
messages could include the ECP service option flags in their output.
Signed-off-by: John Dennis <jdennis@redhat.com>
Replace the call to lasso_provider_get_metadata_one() with
lasso_provider_get_metadata_one_for_role() so that we can exlicitly
pass the LASSO_PROVIDER_ROLE_SP role. The former call obtains the
role from the provider object and then calls
lasso_provider_get_metadata_one_for_role() using that role. However
the role will not have been set in the provider until the first request is
processed. This means the first time we call this routine it won't
work correctly because the role will not have been set yet, by
explicitly passing the role we avoid this problem.
Signed-off-by: John Dennis <jdennis@redhat.com>
The modifications in this commit address the changes necessary to
support the SP component of SAML ECP. The Lasso library needs
additional modifications before SAML ECP will be fully functional,
those fixes have been submitted to upstream Lasso, mod_auth_mellon
will continue to operate correctly without the Lasso upgrade, it just
won't properly support ECP without the Lasso fixes.
Below are the major logical changes in the commit and the rationale
behind them.
* Allow compilation against older versions of Lasso by conditionally
compiling.
Add the following CPP symbols set by configure:
* HAVE_ECP
* HAVE_LASSO_UTILS_H
* Add lasso_compat.h
If we can't include lasso utils.h than pull in our own
local definitions so we can use some of the valuable
utilities.
* Add ECP specific documentation file
Documentation specific to ECP is now contained in ECP.rst
(using reStructuredText formatting). Information on general ECP
concepts, mod_auth_mellon user information, and internal
mod_auth_mellon coding issues are covered.
* Add am_get_boolean_query_parameter() utility
* Add am_validate_paos_header() utility
This utility routine validates the PAOS HTTP header. It is used
in conjunction with am_header_has_media_type() to determine if a
client is ECP capable.
* Add am_is_paos_request() utility
This utility checks to see if the request is PAOS based on the
required HTTP header content.
* Add utility function am_header_has_media_type() to check if an HTTP
Accept header includes a specific media type. This is necessary
because the SP detects an ECP client by the presence of a
application/vnd.paos+xml media type in the Accept
header. Unfortunately neither Apache nor mod_auth_mellon already had
a function to check Accept media types so this was custom written
and added to mod_auth_mellon.
* Add utility function am_get_assertion_consumer_service_by_binding()
because Lasso does not expose that in it's public API. It's
necessary to get the URL of the PAOS AssertionConsumerService.
* Add MellonECPSendIDPList config option
This option controls whether to include a list of IDP's when
sending an ECP PAOS <AuthnRequest> message to an ECP client.
* We need to do some bookkeeping during the processing of a
request. Some Apache modules call this "adding a
note". mod_auth_mellon was already doing this but because it only
needed to track one value (the cookie value) took a shortcut and
stuffed the cookie value into the per module request slot rather
than defining a struct that could hold a variety of per-request
values. To accommodate multiple per request bookkeeping values we
define a new struct, am_req_cfg_rec, that holds the previously used
cookie value and adds a new ECP specific value. This struct is now
the bookkeeping data item attached to each request. To support the
new am_req_cfg_rec struct the am_get_req_cfg macro was added (mirrors
the existing am_get_srv_cfg, am_get_mod_cfg and am_get_dir_cfg
macros). The am_create_request() Apache hook was added to
initialize the am_req_cfg_rec at the beginning of the request
pipeline.
* A new endpoint was added to handle PAOS responses from the ECP
client. The endpoint is called "paosResponse" and lives along side
of the existing endpoints (e.g. postResponse, artifactResponse,
metadata, auth, logout, etc.). The new endpoint is handled by
am_handle_paos_reply(). The metadata generation implemented in
am_generate_metadata() was augmented to add the paosResponse
endpoint and bind it to the SAML2 PAOS binding.
* am_handle_reply_common() was being called by am_handle_post_reply()
and am_handle_artifact_reply() because replies share a fair amount
of common logic. The new am_handle_paos_reply() also needs to
utilize the same common logic in am_handle_reply_common() but ECP
has slightly different behavior that has to be accounted for. With
ECP there is no SP generated cookie because the SP did not initiate
the process and has no state to track. Also the RelayState is
optional with ECP and is carried in the PAOS header as opposed to an
HTTP query/post parameter. The boolean flag is_paos was added as a
parameter to am_handle_reply_common() so as to be able to
distinguish between the PAOS and non-PAOS logic.
* Add PAOS AssertionConsumerService to automatically generated metadata.
Note, am_get_assertion_consumer_service_by_binding() should be able
to locate this endpoint.
* Refactor code to send <AuthnRequest>, now also supports PAOS
The creation and initialization of a LassoLogin object is different
for the ECP case. We want to share as much common code as possible,
the following refactoring was done to achieve that goal.
The function am_send_authn_request() was removed and it's logic
moved to am_init_authn_request_common(),
am_send_login_authn_request() and
am_set_authn_request_content(). This allows the logic used to create
and initialize a LassoLogin object to be shared between the PAOS and
non-PAOS cases. am_send_paos_authn_request() also calls
am_init_authn_request_common() and
am_set_authn_request_content(). The function
am_set_authn_request_content() replaces the logic at the end of
am_send_authn_request(), it is responsible for setting the HTTP
headers and body content based on the LassoLogin.
Signed-off-by: John Dennis <jdennis@redhat.com>
must-revalidate without max-age or Expire allows browser to
heuristically choose an arbitrary expiration time (especially if
the Last-Modified header is returned in the response). But after a
logout all cached content should be invalidated whatever its expiration
time; to prevent returning stale data to logged-out user we set
max-age=0.
We used to call RAND_pseudo_bytes, which will generate cryptographically
strong random bytes in most cases. Under memory pressure or other error
conditions, it can return weak random bytes.
It is unlikely that there is a way for an attacker to set up a condition
where the user is sucessfully logged in but receives a weak session
identifier, but to be safe, we switch to RAND_bytes.
Using the previously introduced storage facility convert storage of env
key/value pairs from being constrained to fixed sized strings to being
constrained only by the overall entry cache size.
Signed-off-by: Simo Sorce <simo@redhat.com>
git-svn-id: https://modmellon.googlecode.com/svn/trunk@235 a716ebb1-153a-0410-b759-cfb97c6a1b53
This patch changes the headers sent to prevent errornous caching of the
responses sent to only use a single header:
Cache-Control: private, must-revalidate
This single header should ensure that the data isn't shared between
multiple users, and that the browser checks that the content is still
valid for each request (enabling logout to work as expected).
This drops the Exires-header, which should be unnecessary since all
modern browsers support the Cache-Control-header.
Thanks to Arthur Müller for providing this patch.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@223 a716ebb1-153a-0410-b759-cfb97c6a1b53
Apache has fixed a bug/misfeature where
ap_unescape_url_keep2f() decoded %2f-escapes. This leaves us with no
functions that can be used to urldecode strings, so we have to roll
our own.
If we drop support for Apache 2.2, we can use
ap_unescape_urlencoded().
See: http://svn.apache.org/viewvc?view=revision&revision=578332
git-svn-id: https://modmellon.googlecode.com/svn/trunk@206 a716ebb1-153a-0410-b759-cfb97c6a1b53
We were mixing microseconds and seconds, causing us to always delete
all the repost data. This patch fixes the comparison, and also
optimizes it a bit.
Thanks to Matthew Slowe for diagnosing this bug!
git-svn-id: https://modmellon.googlecode.com/svn/trunk@201 a716ebb1-153a-0410-b759-cfb97c6a1b53
Since this function is used for both generating session IDs and for
generating POST data identifiers for POST replay, it should have a
generic name.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@181 a716ebb1-153a-0410-b759-cfb97c6a1b53
Now that the POST replay functionality has been disabled by default,
we can force the administrator to create this directory manually. This
saves us from worrying about temp file/directory vulnerabilities.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@178 a716ebb1-153a-0410-b759-cfb97c6a1b53
For historic reasons, we added several headers to both "headers_out"
and "err_headers_out". This has the unfortunate side effect of sending
the headers twice. This change modifies the code to only add those
headers to "err_headers_out", which is sent both for successful
requests and for errors.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@145 a716ebb1-153a-0410-b759-cfb97c6a1b53
functionalities. Supports regexp, negations, and attribute name remapping
though MellonSetEnv
git-svn-id: https://modmellon.googlecode.com/svn/trunk@114 a716ebb1-153a-0410-b759-cfb97c6a1b53
ap_construct_url() use the ServerName directive to reconstruct an
absolute URL. It allows to force the use of an https:// URL (when you
are behind an SSL proxy it is needed) by configuring your VirtualHost
like that:
ServerName https://example.com
git-svn-id: https://modmellon.googlecode.com/svn/trunk@110 a716ebb1-153a-0410-b759-cfb97c6a1b53
storage for attributes, as OID-named attributes sent by the Shibboleth
IdP consomes quite some space.
There is also a required Destination attribute in AuthnRequest elements.
It is done by trunk version of lasso, but not by any currently released
version, hence we do if it is not done.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@85 a716ebb1-153a-0410-b759-cfb97c6a1b53
containing an empty filed such as
<input type="hidden" name="foo" value=""/>
It was reposted as
<input type="hidden" name="foo" value="
"/>
git-svn-id: https://modmellon.googlecode.com/svn/trunk@71 a716ebb1-153a-0410-b759-cfb97c6a1b53
This chages am_getfile to use apr_file_read_full instead of
apr_file_read to avoid a potential problem if a signal is received
while reading the file data. A signal could cause the apr_file_read to
return less than the requested number of bytes.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@56 a716ebb1-153a-0410-b759-cfb97c6a1b53
Recent versions of Lasso supports loading the SP metadata,
certificate and private key from memory. This patch changes mod_mellon
to use this function if it is available. This makes it possible to store
the SP private key readable only from root.
Thanks to Emmanuel Dreyfus for this patch.
git-svn-id: https://modmellon.googlecode.com/svn/trunk@35 a716ebb1-153a-0410-b759-cfb97c6a1b53
Olav Morken
Markus Hosch
John Dennis
Thijs Kinkhorst
Rainer Jung
Olav Morken
vrasneur
Benjamin Dauvergne
Jarek Polok
olavmrk
manu@netbsd.org
benjamin.dauvergne