Version

5.7.6-stable

Description

RFC5280 defines an X.509 extension as

   Extension  ::=  SEQUENCE  {
        extnID      OBJECT IDENTIFIER,
        critical    BOOLEAN DEFAULT FALSE,
        extnValue   OCTET STRING
                    -- contains the DER encoding of an ASN.1 value
                    -- corresponding to the extension type identified
                    -- by extnID
        }

OpenSSL's function X509_EXTENSION_get_data returns the full extnValue OCTET STRING.
But WolfSSL's function wolfSSL_X509_EXTENSION_get_data doesn't seem to get the full OCTET STRING, but some data specific for each extension.

For example, for AuthorityKeyIdentifier, which is defined as

   AuthorityKeyIdentifier ::= SEQUENCE {
      keyIdentifier             [0] KeyIdentifier           OPTIONAL,
      authorityCertIssuer       [1] GeneralNames            OPTIONAL,
      authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL  }

it directly gives the keyIdentifier array (in my case {0x3d, 0x1, 0xd3, 0x87,...) instead of the SEQUENCE, which should start with {0x30, 0x16, 0x80, 0x14, 0x3d, 0x1, 0xd3, 0x87,...

wolfSSL_X509_EXTENSION_get_data is aliased to X509_EXTENSION_get_data, so I guess the intention is for them to have the same behavior. If they are not, is there a way to get the full extnValue OCTET STRING?