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Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/crypto/sha1extra.c')
| -rw-r--r-- | contrib/syslinux-4.02/gpxe/src/crypto/sha1extra.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/crypto/sha1extra.c b/contrib/syslinux-4.02/gpxe/src/crypto/sha1extra.c new file mode 100644 index 0000000..c144a0f --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/crypto/sha1extra.c @@ -0,0 +1,165 @@ +/* + * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <gpxe/crypto.h> +#include <gpxe/sha1.h> +#include <gpxe/hmac.h> +#include <stdint.h> +#include <byteswap.h> + +/** + * SHA1 pseudorandom function for creating derived keys + * + * @v key Master key with which this call is associated + * @v key_len Length of key + * @v label NUL-terminated ASCII string describing purpose of PRF data + * @v data Further data that should be included in the PRF + * @v data_len Length of further PRF data + * @v prf_len Bytes of PRF to generate + * @ret prf Pseudorandom function bytes + * + * This is the PRF variant used by 802.11, defined in IEEE 802.11-2007 + * 8.5.5.1. EAP-FAST uses a different SHA1-based PRF, and TLS uses an + * MD5-based PRF. + */ +void prf_sha1 ( const void *key, size_t key_len, const char *label, + const void *data, size_t data_len, void *prf, size_t prf_len ) +{ + u32 blk; + u8 keym[key_len]; /* modifiable copy of key */ + u8 in[strlen ( label ) + 1 + data_len + 1]; /* message to HMAC */ + u8 *in_blknr; /* pointer to last byte of in, block number */ + u8 out[SHA1_SIZE]; /* HMAC-SHA1 result */ + u8 sha1_ctx[SHA1_CTX_SIZE]; /* SHA1 context */ + const size_t label_len = strlen ( label ); + + /* The HMAC-SHA-1 is calculated using the given key on the + message text `label', followed by a NUL, followed by one + byte indicating the block number (0 for first). */ + + memcpy ( keym, key, key_len ); + + memcpy ( in, label, strlen ( label ) + 1 ); + memcpy ( in + label_len + 1, data, data_len ); + in_blknr = in + label_len + 1 + data_len; + + for ( blk = 0 ;; blk++ ) { + *in_blknr = blk; + + hmac_init ( &sha1_algorithm, sha1_ctx, keym, &key_len ); + hmac_update ( &sha1_algorithm, sha1_ctx, in, sizeof ( in ) ); + hmac_final ( &sha1_algorithm, sha1_ctx, keym, &key_len, out ); + + if ( prf_len <= SHA1_SIZE ) { + memcpy ( prf, out, prf_len ); + break; + } + + memcpy ( prf, out, SHA1_SIZE ); + prf_len -= SHA1_SIZE; + prf += SHA1_SIZE; + } +} + +/** + * PBKDF2 key derivation function inner block operation + * + * @v passphrase Passphrase from which to derive key + * @v pass_len Length of passphrase + * @v salt Salt to include in key + * @v salt_len Length of salt + * @v iterations Number of iterations of SHA1 to perform + * @v blocknr Index of this block, starting at 1 + * @ret block SHA1_SIZE bytes of PBKDF2 data + * + * The operation of this function is described in RFC 2898. + */ +static void pbkdf2_sha1_f ( const void *passphrase, size_t pass_len, + const void *salt, size_t salt_len, + int iterations, u32 blocknr, u8 *block ) +{ + u8 pass[pass_len]; /* modifiable passphrase */ + u8 in[salt_len + 4]; /* input buffer to first round */ + u8 last[SHA1_SIZE]; /* output of round N, input of N+1 */ + u8 sha1_ctx[SHA1_CTX_SIZE]; + u8 *next_in = in; /* changed to `last' after first round */ + int next_size = sizeof ( in ); + int i, j; + + blocknr = htonl ( blocknr ); + + memcpy ( pass, passphrase, pass_len ); + memcpy ( in, salt, salt_len ); + memcpy ( in + salt_len, &blocknr, 4 ); + memset ( block, 0, SHA1_SIZE ); + + for ( i = 0; i < iterations; i++ ) { + hmac_init ( &sha1_algorithm, sha1_ctx, pass, &pass_len ); + hmac_update ( &sha1_algorithm, sha1_ctx, next_in, next_size ); + hmac_final ( &sha1_algorithm, sha1_ctx, pass, &pass_len, last ); + + for ( j = 0; j < SHA1_SIZE; j++ ) { + block[j] ^= last[j]; + } + + next_in = last; + next_size = SHA1_SIZE; + } +} + +/** + * PBKDF2 key derivation function using SHA1 + * + * @v passphrase Passphrase from which to derive key + * @v pass_len Length of passphrase + * @v salt Salt to include in key + * @v salt_len Length of salt + * @v iterations Number of iterations of SHA1 to perform + * @v key_len Length of key to generate + * @ret key Generated key bytes + * + * This is used most notably in 802.11 WPA passphrase hashing, in + * which case the salt is the SSID, 4096 iterations are used, and a + * 32-byte key is generated that serves as the Pairwise Master Key for + * EAPOL authentication. + * + * The operation of this function is further described in RFC 2898. + */ +void pbkdf2_sha1 ( const void *passphrase, size_t pass_len, + const void *salt, size_t salt_len, + int iterations, void *key, size_t key_len ) +{ + u32 blocks = ( key_len + SHA1_SIZE - 1 ) / SHA1_SIZE; + u32 blk; + u8 buf[SHA1_SIZE]; + + for ( blk = 1; blk <= blocks; blk++ ) { + pbkdf2_sha1_f ( passphrase, pass_len, salt, salt_len, + iterations, blk, buf ); + if ( key_len <= SHA1_SIZE ) { + memcpy ( key, buf, key_len ); + break; + } + + memcpy ( key, buf, SHA1_SIZE ); + key_len -= SHA1_SIZE; + key += SHA1_SIZE; + } +} |