diff --git a/changelog.d/17098.feature b/changelog.d/17098.feature
new file mode 100644
index 0000000000..43e06481b2
--- /dev/null
+++ b/changelog.d/17098.feature
@@ -0,0 +1 @@
+Add the ability to allow numeric user IDs with a specific prefix when in the CAS flow. Contributed by Aurélien Grimpard.
diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md
index 2257318bcc..f4edbdcc3e 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -3558,6 +3558,15 @@ Has the following sub-options:
users. This allows the CAS SSO flow to be limited to sign in only, rather than
automatically registering users that have a valid SSO login but do not have
a pre-registered account. Defaults to true.
+* `allow_numeric_ids`: set to 'true' allow numeric user IDs (default false).
+ This allows CAS SSO flow to provide user IDs composed of numbers only.
+ These identifiers will be prefixed by the letter "u" by default.
+ The prefix can be configured using the "numeric_ids_prefix" option.
+ Be careful to choose the prefix correctly to avoid any possible conflicts
+ (e.g. user 1234 becomes u1234 when a user u1234 already exists).
+* `numeric_ids_prefix`: the prefix you wish to add in front of a numeric user ID
+ when the "allow_numeric_ids" option is set to "true".
+ By default, the prefix is the letter "u" and only alphanumeric characters are allowed.
*Added in Synapse 1.93.0.*
@@ -3572,6 +3581,8 @@ cas_config:
userGroup: "staff"
department: None
enable_registration: true
+ allow_numeric_ids: true
+ numeric_ids_prefix: "numericuser"
```
---
### `sso`
diff --git a/synapse/config/cas.py b/synapse/config/cas.py
index d23dcf96b2..fa59c350c1 100644
--- a/synapse/config/cas.py
+++ b/synapse/config/cas.py
@@ -66,6 +66,17 @@ class CasConfig(Config):
self.cas_enable_registration = cas_config.get("enable_registration", True)
+ self.cas_allow_numeric_ids = cas_config.get("allow_numeric_ids")
+ self.cas_numeric_ids_prefix = cas_config.get("numeric_ids_prefix")
+ if (
+ self.cas_numeric_ids_prefix is not None
+ and self.cas_numeric_ids_prefix.isalnum() is False
+ ):
+ raise ConfigError(
+ "Only alphanumeric characters are allowed for numeric IDs prefix",
+ ("cas_config", "numeric_ids_prefix"),
+ )
+
self.idp_name = cas_config.get("idp_name", "CAS")
self.idp_icon = cas_config.get("idp_icon")
self.idp_brand = cas_config.get("idp_brand")
@@ -77,6 +88,8 @@ class CasConfig(Config):
self.cas_displayname_attribute = None
self.cas_required_attributes = []
self.cas_enable_registration = False
+ self.cas_allow_numeric_ids = False
+ self.cas_numeric_ids_prefix = "u"
# CAS uses a legacy required attributes mapping, not the one provided by
diff --git a/synapse/handlers/cas.py b/synapse/handlers/cas.py
index 153123ee83..cc3d641b7d 100644
--- a/synapse/handlers/cas.py
+++ b/synapse/handlers/cas.py
@@ -78,6 +78,8 @@ class CasHandler:
self._cas_displayname_attribute = hs.config.cas.cas_displayname_attribute
self._cas_required_attributes = hs.config.cas.cas_required_attributes
self._cas_enable_registration = hs.config.cas.cas_enable_registration
+ self._cas_allow_numeric_ids = hs.config.cas.cas_allow_numeric_ids
+ self._cas_numeric_ids_prefix = hs.config.cas.cas_numeric_ids_prefix
self._http_client = hs.get_proxied_http_client()
@@ -188,6 +190,9 @@ class CasHandler:
for child in root[0]:
if child.tag.endswith("user"):
user = child.text
+ # if numeric user IDs are allowed and username is numeric then we add the prefix so Synapse can handle it
+ if self._cas_allow_numeric_ids and user is not None and user.isdigit():
+ user = f"{self._cas_numeric_ids_prefix}{user}"
if child.tag.endswith("attributes"):
for attribute in child:
# ElementTree library expands the namespace in
|
