Vendor annotations on P11 mechanisms

The hashAlg and the mgf values specified by CK_RSA_PKCS_OAEP_PARAMS must have the same SHA hash size. If they do not have the same hash size, then the encryption or decryption fails with a return value of CKR_MECHANISM_PARAM_INVALID. The supported pairs of values are as follows:

For a hash length h and RSA modulus length k in bytes, the longest message that can be encrypted is k-2h-2 bytes long.

The hashAlg and the mgf values specified by CK_RSA_PKCS_PSS_PARAMS must have the same SHA hash size. If they do not have the same hash size, then the signing or verifying fails with a return value of CKR_MECHANISM_PARAM_INVALID.

The sLen value is expected to be the length of the message hash in bytes. If this is not the case, then the signing or verify again fails with a return value of CKR_MECHANISM_PARAM_INVALID.

The supported sets of values for hashAlg, mgf and sLen are as follows:

To use a mechanism with SHA hash size n bits, the public modulus of the RSA key must be at least 2n+2 bits long.