sha1_t_prf() function

sha1_t_prf - EAP-FAST Pseudo-Random Function (T-PRF) @key: Key for PRF @key_len: Length of the key in bytes @label: A unique label for each purpose of the PRF @seed: Seed value to bind into the key @seed_len: Length of the seed @buf: Buffer for the generated pseudo-random key @buf_len: Number of bytes of key to generate Returns: 0 on success, -1 of failure This function is used to derive new, cryptographically separate keys from a given key for EAP-FAST. T-PRF is defined in RFC 4851, Section 5.5.