AI_RC4WithMAC_BER
194 RSA BSAFE Crypto-C Library Reference Manual
AI_RC4WithMAC_BER
Purpose:
This AI is similar to AI_RC4WithMAC except that it uses the ASN.1 BER format. This AI
allows you to parse and create ASN.1 algorithm identifiers such as those used in
PKCS #7 and other protocols. You call
B_SetAlgorithmInfo to initialize an algorithm
object from the encoded algorithm identifier which includes ASN.1 encoding of the
B_RC4_WITH_MAC_PARAMS structure defined in the description of AI_RC4WithMAC. You
call
B_GetAlgorithmInfo with this AI to create an encoded algorithm identifier from
an algorithm object that was created using
AI_RC4WithMAC or AI_RC4WithMAC_BER.
T
he OID for this algorithm, excluding the tag and length bytes, in decimal is “42, 134,
72, 134, 247, 13, 3, 5
”.
Type of information this allows you to use:
the encoding of an algorithm identifier that specifies the RC4 With MAC encryption
algorithm.
Format of info supplied to B_SetAlgorithmInfo:
pointer to an ITEM structure that gives the address and length of the BER-encoded
algorithm identifier. The encoding is converted to DER before it is copied to the
algorithm object.
B_SetAlgorithmInfo returns BE_WRONG_ALGORITHM_INFO if the
algorithm identifier specifies an algorithm other than RC4.
Format of info returned by B_GetAlgorithmInfo:
pointer to an ITEM structure that gives the address and length of the DER-encoded
algorithm identifier.
Crypto-C procedures to use with algorithm object:
B_EncryptInit, B_EncryptUpdate, B_EncryptFinal, B_DecryptInit,
B_DecryptUpdate, and B_DecryptFinal. B_DecryptFinal returns BE_INPUT_DATA if the
MAC does not match. You may pass (
B_ALGORITHM_OBJ)NULL_PTR for all
randomAlgorithm
arguments.
Due to the nature of the RC4 algorithm, security is compromised if multiple data
blocks are encrypted with the same RC4 key. Therefore,
B_EncryptUpdate cannot be
