Chapter 2 Algorithm Info Types 159
AI_PKCS_OAEPRecode
Failure to properly initialize these parameters may cause errors when they are
implemented in future versions of Crypto-C. In this case, the default parameters for
pSourceParams
should be set by the caller as follows:
Format of info supplied to B_GetAlgorithmInfo:
NULL_PTR.
Crypto-C procedures to use with algorithm object:
B_EncodeInit, B_EncodeUpdate, B_EncodeFinal, B_DecodeInit, B_DecodeUpdate, and
B_DecodeFinal.
The final call to
B_EncodeUpdate does not contain message data. Rather, the trailing
call to
B_EncodeUpdate is included to pass in a number of random seed bytes for the
OAEP encoding process. It is recommended that the caller use
AI_X962Random_V0 or
AI_SHA1Random to generate hLen bytes initialized with 160 bits of entropy. The default
digest algorithm for PKCS #1 v2.0 OAEP is SHA1. SHA1 produces a digest of 20
bytes, so
hLen for SHA1 is 20 bytes.
B_Decode_Update does not contain an extra call for seed bytes.
Algorithm methods to include in application's algorithm chooser:
AM_SHA is required for the default
pSource
digest function and also for the default MGF
underlying digest method.
hashFuncParams.len = 0;
hashFuncParams.data = NULL_PTR
maskGenFuncParams.len = 0;
maskGenFuncParams.data = NULL_PTR
maskGenFuncUnderlyingAlgParams.len = 0;
maskGenFuncUnderlyingAlgParams.data = NULL_PTR
pSourceParams.len = 0;
pSourceParams.data = NULL_PTR;
