SAML Security: Digital Signatures, Encryption, and X.509 Certificate Verification
Security Assertion Markup Language (SAML) employs robust security mechanisms to ensure secure identity federation. This post examines SAML’s cryptographic foundations, focusing on XML Digital Signatures, XML Encryption, X.509 certificate verification, and defenses against replay attacks. 1. XML Digital Signatures in SAML SAML messages utilize XML Digital Signature (XML DSig) to guarantee message integrity and authenticity through asymmetric cryptography. Implementation Details: Signature Generation: Apply canonicalization (typically Exclusive XML Canonicalization) to normalize the XML structure Generate a message digest using SHA-256 or stronger algorithms Encrypt the digest with the sender’s private key Embed the signature in a <ds:Signature> element containing: SignedInfo (canonicalization method, signature algorithm, references) SignatureValue KeyInfo (optional X.509 certificate) Verification Process: ...