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The transcoders also support an option to rely on SAML metadata extension tags to provide SP-specific naming rules. This is an alternative to the use of the relyingParties approach of naming specific SPs in a rule to limit its use. This feature can be combined with “default” naming via a rule such that the metadata is checked for a per-SP name in preference to the default in a rule, with the default applying in the absence of a tag value applying.
Note that this approach only works for encoding into SAML, and does not support the decoding side because the “source name” of a SAML Attribute would then not be known to the system independently of a specific SP (the encoding direction works because the source name there is the internal attribute ID, which is required to be specified in the rule).
To use this feature, the rule must contain the saml2.nameFromMetadata property set to true. The rule may or may not also contain the default saml2.name (and saml2.nameFormat) properties as a fallback.
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