Chapter 2 Algorithm Info Types 135
AI_MD5WithRSAEncryptionBER
Algorithm methods to include in application’s algorithm chooser:
AM_MD2, and AM_RSA_CRT_ENCRYPT, AM_RSA_CRT_ENCRYPT_BLIND, or AM_RSA_ENCRYPT,
for signature creation; and
AM_RSA_DECRYPT for signature verification.
AM_RSA_CRT_ENCRYPT_BLIND performs blinding to protect against timing attacks,
whereas
AM_RSA_CRT_ENCRYPT does not.
Key info types for keyObjec t in B_SignInit:
KI_RSA_CRT, KI_PKCS_RSAPrivate, KI_PKCS_RSAPrivateBER, KI_RSAPrivate or
KI_RSAPrivateBSAFE1. Unless you use KI_RSA_CRT for your KI, you must include
AM_RSA_ENCRYPT in your application’s algorithm chooser.
Key info types for keyObjec t in B_VerifyInit:
KI_RSAPublic, KI_RSAPublicBER, or KI_RSAPublicBSAFE1.
Compatible representation:
AI_MD5WithRSAEncryption.
Output considerations:
The
signature
result of B_SignFinal will be the same size as the RSA key’s modulus.
Notes:
Although the RSA signature operation is called “encryption” and the verification
operation is called “decryption,” the signer uses the digest and the private key and
follows the steps needed to decrypt, while the verifier uses the transmitted digest and
the public key and follows the steps needed to encrypt.
