Hashing Session Keys

When an application uses the CryptHashSessionKey function to hash a session key, only the base key material must be hashed. For a 40-bit key, this will be 5 bytes of data.

The key should be hashed in big-endian byte order. For example, if the Microsoft Base Cryptographic Provider is used to create and hash a session key with a value of 4a 3a ee 77 37, the bytes need to be reversed before the hashing operation is performed. In this example, the following hash values are produced:

For an MD5 hash

0b 15 55 0a a0 03 f9 3f 75 82 f7 e7 91 32 bc 8c

For an SHA hash

3c 37 72 93 53 ff 2a 4f ef 12 54 18 5b 3a c4 63 03 fd 07 5d