Dear all,
Is it possible to use a different discovery service depending on the SP
that sent a SAML AuthnRequest to SATOSA, or do I have to do that in the
discovery service's frontend somehow?
Best wishes,
Matthew
--
"The lyf so short, the craft so longe to lerne."
I want to again say "thanks" to Ioannis, Rainer, Scott, and everyone
else for their help and instruction during the various IdentityPython
and SATOSA meetings at TIIME this week. Chris Phillips and I were able
to get a SATOSA 3.4.8 deployment working in Chris's idp-installer test
bed. To that end I want to share my notes from the process, at the end
of which an interested party could perform a basic, end-to-end test of
the current SATOSA release using SAMLtest (https://samltest.id/)
1. I installed Ubuntu Server 18.04.1; run the following commands as root
to install the prerequisites:
```sh
apt update
apt dist-upgrade -y
apt install -y git python3-dev build-essential python3-pip libffi-dev
libssl-dev xmlsec1 libyaml-dev libxml2-utils
pip3 install --upgrade virtualenv
virtualenv -p python3 /opt/satosa
/opt/satosa/bin/pip install --upgrade pip setuptools
/opt/satosa/bin/pip install SATOSA
```
This is essentially the Docker image build process, only it uses the
current SATOSA release (etc.) on PyPI.
2. Copy
https://github.com/IdentityPython/SATOSA/tree/v3.4.8/docker/attributemap
s to /opt/satosa/attributemaps.
I'm not sure this is strictly necessary as the built-in pysaml2
attribute maps should be used by default, but it's what the Docker image
build process does.
3. Copy https://github.com/IdentityPython/SATOSA/tree/v3.4.8/example to
/opt/satosa/etc.
4. SATOSA doesn't have a default configuration, so you must provide it
yourself.
```sh
cp /opt/satosa/etc/proxy_conf.yaml.example \
/opt/satosa/etc/proxy_conf.yaml
cp /opt/satosa/etc/internal_attributes.yaml.example \
/opt/satosa/etc/internal_attributes.yaml
cp /opt/satosa/etc/plugins/frontends/saml2_frontend.yaml.example \
/opt/satosa/etc/plugins/frontends/saml2_frontend.yaml
cp /opt/satosa/etc/plugins/backends/saml2_backend.yaml.example \
/opt/satosa/etc/plugins/backends/saml2_backend.yaml
cp /opt/satosa/etc/plugins/microservices/static_attributes.yaml.example
\
/opt/satosa/etc/plugins/microservices/static_attributes.yaml
```
5. You may change the proxy URL (the value of BASE in
/opt/satosa/etc/proxy_conf.yaml), but it _must_ be a method plus
hostname without any trailing slash or path components, e.g.,
`https://proxy.example.com`, not `https://proxy.example.com/` nor
`https://proxy.example.com/satosa`. SATOSA must be hosted at the root
of your web site.
6. Comment out the `idp_blacklist_file` and `disco_srv` settings in
/opt/satosa/etc/plugins/backends/saml2_backend.yaml.
7. Generate IdP, SP, metadata signing, and web site keying material:
```sh
for i in frontend backend metadata https; do
openssl req -batch -x509 -nodes -days 3650 -newkey rsa:2048 \
-keyout /opt/satosa/etc/$i.key -out /opt/satosa/etc/$i.crt \
-subj /CN=proxy.example.com
done
```
8. Download the SAMLtest metadata.
```sh
curl https://samltest.id/saml/sp > /opt/satosa/etc/sp.xml
curl https://samltest.id/saml/idp > /opt/satosa/etc/idp.xml
```
9. Generate the proxy metadata. (How you do this changes in future
releases of SATOSA.)
```sh
. /opt/satosa/bin/activate
cd /opt/satosa/etc
satosa-saml-metadata proxy_conf.yaml metadata.key metadata.crt
--split-frontend --split-backend --dir /opt/satosa/etc
xmllint --format /opt/satosa/etc/Saml2IDP_0.xml >
/opt/satosa/etc/proxy-idp.xml
xmllint --format /opt/satosa/etc/Saml2_0.xml >
/opt/satosa/etc/proxy-sp.xml
```
10. Edit the proxy metadata files to remove the `<ns1:Signature>`
element, else SAMLtest will be unable to load them due to an invalid
signature.
11. Upload the proxy metadata to SAMLtest
(https://samltest.id/upload.php)
12. SAMLtest doesn't release the eduPerson Targeted ID attribute, so
you'll need to change the last three lines of
/opt/satosa/etc/internal_attributes.yaml to the following (and before
anyone says anything, NEVER USE AN EMAIL ADDRESS AS AN IDENTIFIER---this
is just a quick hack to get SATOSA working):
```
hash: [mail]
user_id_from_attrs: [mail]
user_id_to_attr: mail
```
13. Start SATOSA:
```sh
. /opt/satosa/bin/activate
cd /opt/satosa/etc
gunicorn -b0.0.0.0:443 --keyfile https.key --certfile https.crt
satosa.wsgi:app
```
14. At this point you should be able to perform an IdP test
(https://samltest.id/start-idp-test/) by specifying the entity ID of the
proxy's front end, e.g., https://example.com/Saml2IDP/proxy.xml. The
SAMLtest SP will request authentication by your proxy IdP, causing your
proxy SP to request authentication by the SAMLtest IdP. If everything
works right, you will end up back at the SAMLtest SP:
SAMLtest SP ---AuthnRequest---> SATOSA front end (IdP)/back end (SP)
---AuthnRequest---> SAMLtest IdP
SAMLtest SP <---AuthnResponse--- SATOSA front end (IdP)/back end (SP)
<---AuthnResponse--- SAMLtest IdP
I hope this helps other adopters. If you have any questions, please
reply on list so everyone can benefit from the discussion.
Best wishes,
Matthew
--
"The lyf so short, the craft so longe to lerne."
Not knowing whether my satosa instance is fully working yet (see my
other thread) I'm now continuing to try to get the application
(eduMEET) to work with satosa's oidc frontend, as per the app's
published config example:
https://github.com/havfo/multiparty-meeting/blob/master/server/config/confi…
So I've made up a client_id and client_secret on the RP side and
provided the client with an issuerURL (base URL of satosa), let it
request all the scopes in the world and set its own redirect_uri.
With those all set I do see requests to satosa's .well-known endpoints
from the application in satosa logs, e.g.
Found registered endpoint: module name:'oidc', endpoint: .well-known/openid-configuration
(And of course accessing the endpoint myself I can see that it works
and produces JSON with its config.)
Now on the OP side (satosa oidc frontend) I haven't done any setup
for the client yet, so I guess the error in the log is to be expected:
Error in authn req: Unknown client_id
Now what would be the next steps to register that client?
The request from the client (according to satosa's logs) has these
query parameters (where cid and csec are the correct client_id and
client_secret, respectively):
client_id=cid&scope=openid+email+profile&response_type=code&redirect_uri=https%3A%2F%2Fexample.org%2Fauth%2Fcallback&state=e30%3D&client_secret=csec
My plugins/frontends/openid_connect_frontend.yaml looks like the
published example, essentially:
module: satosa.frontends.openid_connect.OpenIDConnectFrontend
name: oidc
config:
signing_key_path: /etc/satosa/oidc-provider.key
#db_uri: mongodb://db.example.com # optional: only support MongoDB, will default to in-memory storage if not specified
client_db_path: /etc/satosa/oidc-clients.json
provider:
client_registration_supported: True
response_types_supported: ['code', 'token', 'id_token']
subject_types_supported: ['public', 'pairwise']
scopes_supported: ['openid', 'email', 'profile']
Only that I tried to enable pretty much everything (all repose and
subject types, all scopes, client registration) since I had no idea
what the RP side wants, yet. (Seems I can remove all response types
except 'code', as per the log shown above.)
I don't have MongoDB set up yet since the comment above suggests an
in-memory store would be used, which is fine for my current testing.
And looking at _create_provider() at frontends/openid_connect.py the
code would use the file referenced by client_db_path if db_uri isn't
set even before falling back to storing it in a variable.
The file referenced in client_db_path exists, is writable by the user
satosa runs as, and currently contains only '{}' (without the quotes).
So IMO that should be sufficient.
Any hints on how to register the application?
The documenation is a bit sparse here
https://github.com/IdentityPython/SATOSA/blob/master/doc/README.md#frontend…
only mentioning that *without* dynamic client registration (which I
have enabled for now, but maybe the RP doesn't support it) I'd have to
manually create the data structures in MongoDB (or the file in
client_db_path) for my client, as per the oidc spec for Client
Registration Responses.
Could someone share a json sample to put into the file referenced by
client_db_path (if that's how it's supposed to work)?
Cheers,
-peter
TL;DR: How can I get SaToSa to select one attribute's value from a
list of attribute names, not all of which may be present?
Ivan's recommendation from PR 222 doesn't work for me:
https://github.com/IdentityPython/SATOSA/pull/222#issuecomment-533238061
Context: I'm trying to use SaToSa as a SAML SP registered in a
saml2int identity federation (SAML2 backend module plugin) protecting
a bunch of OIDC RPs (openid connect frontend module plugin).
In the field not all SAML IDPs support all of the common identifier
attributes: Some may only support e.g. eduPersonPrincipalName while
others will also (or in an hypothetical future maybe: only) support
the "new" SAML standard identifier attributes Subject-ID and/or
Pairwise-ID. (And while I could hard-code 'eppn' as the lowest common
denominator for everyone that would nullify any benefits the new
standard identifier attributes might offer.)
FWIW, the Shibboleth SP calls its own support for this the REMOTE_USER
precedence list: The first attribute from a list of given attribute
names that has a value is chosen as the value for REMOTE_USER.
Implementing Ivan's recommendation from PR 222 (link above) doesn't
work for me, though. This fails:
attributes:
id:
openid: [sub]
saml: [subject-id, pairwise-id, eppn]
eppn:
openid: [eppn]
saml: [eduPersonPrincipalName]
user_id_from_attrs: [id]
The relevant log lines being:
skipped backend attribute ['subject-id', 'pairwise-id', 'eppn']: no value found
backend attribute ['eduPersonPrincipalName'] mapped to eppn (['foo(a)example.org'])
...
KeyError: 'id'
[ERROR] [satosa.proxy_server.__call__] Unknown error
I.e., eppn is available/mapped but generating the userid from the 'id'
attribute fails, seemingly because there is no 'id' attribute because
according to SaToSa the list ['eppn', 'subject-id', 'pairwise-id'] has
"no value found".
The available behaviour is unhelpful in two regards, AFAICT:
https://github.com/IdentityPython/SATOSA/pull/222#issuecomment-533240357
* It implements "all those attributes need to have a value (what
currently happens)" (Ivan's words from PR 222) when I've only ever
needed "at least one of these attributes needs to have a value" in
over a decade of running federations and federated services.
* The attributes I care about and would list as possible attribute
names are also *not* mutually exclusive, i.e., there may be none
(failure), some or all of them available from an IDP. In any case
I'd want the user id to only ever have the value of **one** such
attribute at maximum, even if multiple attributes may have values.
TBH, I can't see how the documented behaviour:
https://github.com/IdentityPython/SATOSA/tree/master/doc#user_id_from_attrs
> The attribute values of the attributes specified in this list will
> be concatenated and used as the subject identifier.
could ever be useful to anyone? What good would be the concatenation
of multiple attributes' values (e.g. ['subject-id', 'pairwise-id',
'eppn']) provided several of them were available?
"foobar@example.orgFOO987654321@example.orgFOO@example.org"
Whereas from my experience it's often necessary to support multiple
"acceptable alternatives" (different attributes for essentially the
same purpose/data) and therefore desireble to have the software pick
*one* attribute's value(s) from an ordered-by-preference list.
E.g. given ['subject-id', 'pairwise-id', 'eppn'] that would try
subject-id, then pairwise-id, then eppn and the first one that has a
value would be the one attribute whose values we'd return.
(I'd fail if none of the above were present/had a value.)
Is there a way to get that behaviour? I'm probably biased but to me that
would make a much saner default behaviour than what's available now.
Best regards,
-peter
