diff options
Diffstat (limited to 'src/gsm/kdf/sha1.c')
| -rw-r--r-- | src/gsm/kdf/sha1.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/gsm/kdf/sha1.c b/src/gsm/kdf/sha1.c new file mode 100644 index 00000000..0d39f77b --- /dev/null +++ b/src/gsm/kdf/sha1.c @@ -0,0 +1,162 @@ +/* + * SHA1 hash implementation and interface functions + * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Alternatively, this software may be distributed under the terms of BSD + * license. + * + * See README and COPYING for more details. + */ + + +#include "common.h" +#include "sha1.h" +#include "crypto.h" + + +/** + * hmac_sha1_vector - HMAC-SHA1 over data vector (RFC 2104) + * @key: Key for HMAC operations + * @key_len: Length of the key in bytes + * @num_elem: Number of elements in the data vector + * @addr: Pointers to the data areas + * @len: Lengths of the data blocks + * @mac: Buffer for the hash (20 bytes) + * Returns: 0 on success, -1 on failure + */ +int hmac_sha1_vector(const u8 *key, size_t key_len, size_t num_elem, + const u8 *addr[], const size_t *len, u8 *mac) +{ + unsigned char k_pad[64]; /* padding - key XORd with ipad/opad */ + unsigned char tk[20]; + const u8 *_addr[6]; + size_t _len[6], i; + + if (num_elem > 5) { + /* + * Fixed limit on the number of fragments to avoid having to + * allocate memory (which could fail). + */ + return -1; + } + + /* if key is longer than 64 bytes reset it to key = SHA1(key) */ + if (key_len > 64) { + if (sha1_vector(1, &key, &key_len, tk)) + return -1; + key = tk; + key_len = 20; + } + + /* the HMAC_SHA1 transform looks like: + * + * SHA1(K XOR opad, SHA1(K XOR ipad, text)) + * + * where K is an n byte key + * ipad is the byte 0x36 repeated 64 times + * opad is the byte 0x5c repeated 64 times + * and text is the data being protected */ + + /* start out by storing key in ipad */ + os_memset(k_pad, 0, sizeof(k_pad)); + os_memcpy(k_pad, key, key_len); + /* XOR key with ipad values */ + for (i = 0; i < 64; i++) + k_pad[i] ^= 0x36; + + /* perform inner SHA1 */ + _addr[0] = k_pad; + _len[0] = 64; + for (i = 0; i < num_elem; i++) { + _addr[i + 1] = addr[i]; + _len[i + 1] = len[i]; + } + if (sha1_vector(1 + num_elem, _addr, _len, mac)) + return -1; + + os_memset(k_pad, 0, sizeof(k_pad)); + os_memcpy(k_pad, key, key_len); + /* XOR key with opad values */ + for (i = 0; i < 64; i++) + k_pad[i] ^= 0x5c; + + /* perform outer SHA1 */ + _addr[0] = k_pad; + _len[0] = 64; + _addr[1] = mac; + _len[1] = SHA1_MAC_LEN; + return sha1_vector(2, _addr, _len, mac); +} + + +/** + * hmac_sha1 - HMAC-SHA1 over data buffer (RFC 2104) + * @key: Key for HMAC operations + * @key_len: Length of the key in bytes + * @data: Pointers to the data area + * @data_len: Length of the data area + * @mac: Buffer for the hash (20 bytes) + * Returns: 0 on success, -1 of failure + */ +int hmac_sha1(const u8 *key, size_t key_len, const u8 *data, size_t data_len, + u8 *mac) +{ + return hmac_sha1_vector(key, key_len, 1, &data, &data_len, mac); +} + + +/** + * sha1_prf - SHA1-based Pseudo-Random Function (PRF) (IEEE 802.11i, 8.5.1.1) + * @key: Key for PRF + * @key_len: Length of the key in bytes + * @label: A unique label for each purpose of the PRF + * @data: Extra data to bind into the key + * @data_len: Length of the data + * @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 (e.g., PMK in IEEE 802.11i). + */ +int sha1_prf(const u8 *key, size_t key_len, const char *label, + const u8 *data, size_t data_len, u8 *buf, size_t buf_len) +{ + u8 counter = 0; + size_t pos, plen; + u8 hash[SHA1_MAC_LEN]; + size_t label_len = os_strlen(label) + 1; + const unsigned char *addr[3]; + size_t len[3]; + + addr[0] = (u8 *) label; + len[0] = label_len; + addr[1] = data; + len[1] = data_len; + addr[2] = &counter; + len[2] = 1; + + pos = 0; + while (pos < buf_len) { + plen = buf_len - pos; + if (plen >= SHA1_MAC_LEN) { + if (hmac_sha1_vector(key, key_len, 3, addr, len, + &buf[pos])) + return -1; + pos += SHA1_MAC_LEN; + } else { + if (hmac_sha1_vector(key, key_len, 3, addr, len, + hash)) + return -1; + os_memcpy(&buf[pos], hash, plen); + break; + } + counter++; + } + + return 0; +} |