BLOWFISH(3) BSD Programmer's Manual BLOWFISH(3)NAME
blf_key, blf_enc, blf_dec - Blowfish encryption
SYNOPSIS
#include <blf.h>
void
blf_key(blf_ctx *state, const u_int8_t *key, u_int16_t keylen);
void
blf_enc(blf_ctx *state, u_int32_t *data, u_int16_t datalen);
void
blf_dec(blf_ctx *state, u_int32_t *data, u_int16_t datalen);
void
blf_ecb_encrypt(blf_ctx *state, u_int8_t *data, u_int32_t datalen);
void
blf_ecb_decrypt(blf_ctx *state, u_int8_t *data, u_int32_t datalen);
void
blf_cbc_encrypt(blf_ctx *state, u_int8_t *iv, u_int8_t *data,
u_int32_t datalen);
void
blf_cbc_decrypt(blf_ctx *state, u_int8_t *iv, u_int8_t *data,
u_int32_t datalen);
DESCRIPTION
Blowfish is a fast unpatented block cipher designed by Bruce Schneier. It
basically consists of a 16-round Feistel network. The block size is 64
bits and the maximum key size is 448 bits.
The blf_key() function initializes the 4 8-bit S-boxes and the 18 Subkeys
with the hexadecimal digits of Pi. The key is used for further randomiza-
tion. The first argument to blf_enc() is the initialized state derived
from blf_key(). The stream of 32-bit words is encrypted in Electronic
Codebook Mode (ECB) and datalen must be even. blf_dec() is used for de-
crypting Blowfish encrypted blocks.
The functions blf_ecb_encrypt() and blf_ecb_decrypt() are used for en-
crypting and decrypting octet streams in ECB mode. The functions
blf_cbc_encrypt() and blf_cbc_decrypt() are used for encrypting and de-
crypting octet streams in Cipherblock Chaining Mode (CBC).
The functions Blowfish_initstate(), Blowfish_expand0state(),
Blowfish_expandstate(), Blowfish_encipher() and Blowfish_decipher() are
used for customization of the Blowfish cipher, e.g., for the blowfish
password hashing function.
SEE ALSOpasswd(1), crypt(3), passwd(5)AUTHORS
Niels Provos <provos@physnet.uni-hamburg.de>
MirOS BSD #10-current February 13, 1997 1