diff options
author | Erwin Nindl <nine@wirdorange.org> | 2007-07-13 16:05:16 +0000 |
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committer | Erwin Nindl <nine@wirdorange.org> | 2007-07-13 16:05:16 +0000 |
commit | 17b77485fa4ea8ecbf472e2d1daa15007ff93705 (patch) | |
tree | 1b1c72d09b898f8d5dcdd68dcbd86d030e66ded5 /srtp/crypto/cipher/aes_icm.c | |
parent | bugfix window size (diff) |
* removed srtp directory
* install libsrtp under /usr/local/lib
* cleaned up Makefile
Diffstat (limited to 'srtp/crypto/cipher/aes_icm.c')
-rw-r--r-- | srtp/crypto/cipher/aes_icm.c | 511 |
1 files changed, 0 insertions, 511 deletions
diff --git a/srtp/crypto/cipher/aes_icm.c b/srtp/crypto/cipher/aes_icm.c deleted file mode 100644 index b466ca9..0000000 --- a/srtp/crypto/cipher/aes_icm.c +++ /dev/null @@ -1,511 +0,0 @@ -/* - * aes_icm.c - * - * AES Integer Counter Mode - * - * David A. McGrew - * Cisco Systems, Inc. - */ - -/* - * - * Copyright (c) 2001-2006, Cisco Systems, Inc. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following - * disclaimer in the documentation and/or other materials provided - * with the distribution. - * - * Neither the name of the Cisco Systems, Inc. nor the names of its - * contributors may be used to endorse or promote products derived - * from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, - * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES - * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR - * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, - * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED - * OF THE POSSIBILITY OF SUCH DAMAGE. - * - */ - - -#define ALIGN_32 0 - -#include "aes_icm.h" -#include "alloc.h" - - -debug_module_t mod_aes_icm = { - 0, /* debugging is off by default */ - "aes icm" /* printable module name */ -}; - -/* - * integer counter mode works as follows: - * - * 16 bits - * <-----> - * +------+------+------+------+------+------+------+------+ - * | nonce | pakcet index | ctr |---+ - * +------+------+------+------+------+------+------+------+ | - * | - * +------+------+------+------+------+------+------+------+ v - * | salt |000000|->(+) - * +------+------+------+------+------+------+------+------+ | - * | - * +---------+ - * | encrypt | - * +---------+ - * | - * +------+------+------+------+------+------+------+------+ | - * | keystream block |<--+ - * +------+------+------+------+------+------+------+------+ - * - * All fields are big-endian - * - * ctr is the block counter, which increments from zero for - * each packet (16 bits wide) - * - * packet index is distinct for each packet (48 bits wide) - * - * nonce can be distinct across many uses of the same key, or - * can be a fixed value per key, or can be per-packet randomness - * (64 bits) - * - */ - -err_status_t -aes_icm_alloc_ismacryp(cipher_t **c, int key_len, int forIsmacryp) { - extern cipher_type_t aes_icm; - uint8_t *pointer; - int tmp; - - debug_print(mod_aes_icm, - "allocating cipher with key length %d", key_len); - - /* - * Ismacryp, for example, uses 16 byte key + 8 byte - * salt so this function is called with key_len = 24. - * The check for key_len = 30 does not apply. Our usage - * of aes functions with key_len = values other than 30 - * has not broken anything. Don't know what would be the - * effect of skipping this check for srtp in general. - */ - if (!forIsmacryp && key_len != 30) - return err_status_bad_param; - - /* allocate memory a cipher of type aes_icm */ - tmp = (sizeof(aes_icm_ctx_t) + sizeof(cipher_t)); - pointer = (uint8_t*)crypto_alloc(tmp); - if (pointer == NULL) - return err_status_alloc_fail; - - /* set pointers */ - *c = (cipher_t *)pointer; - (*c)->type = &aes_icm; - (*c)->state = pointer + sizeof(cipher_t); - - /* increment ref_count */ - aes_icm.ref_count++; - - /* set key size */ - (*c)->key_len = key_len; - - return err_status_ok; -} - -err_status_t aes_icm_alloc(cipher_t **c, int key_len, int forIsmacryp) { - return aes_icm_alloc_ismacryp(c, key_len, 0); -} - -err_status_t -aes_icm_dealloc(cipher_t *c) { - extern cipher_type_t aes_icm; - - /* zeroize entire state*/ - octet_string_set_to_zero((uint8_t *)c, - sizeof(aes_icm_ctx_t) + sizeof(cipher_t)); - - /* free memory */ - crypto_free(c); - - /* decrement ref_count */ - aes_icm.ref_count--; - - return err_status_ok; -} - - -/* - * aes_icm_context_init(...) initializes the aes_icm_context - * using the value in key[]. - * - * the key is the secret key - * - * the salt is unpredictable (but not necessarily secret) data which - * randomizes the starting point in the keystream - */ - -err_status_t -aes_icm_context_init(aes_icm_ctx_t *c, const uint8_t *key) { - v128_t tmp_key; - - /* set counter and initial values to 'offset' value */ - /* FIX!!! this assumes the salt is at key + 16, and thus that the */ - /* FIX!!! cipher key length is 16! Also note this copies past the - end of the 'key' array by 2 bytes! */ - v128_copy_octet_string(&c->counter, key + 16); - v128_copy_octet_string(&c->offset, key + 16); - - /* force last two octets of the offset to zero (for srtp compatibility) */ - c->offset.v8[14] = c->offset.v8[15] = 0; - c->counter.v8[14] = c->counter.v8[15] = 0; - - /* set tmp_key (for alignment) */ - v128_copy_octet_string(&tmp_key, key); - - debug_print(mod_aes_icm, - "key: %s", v128_hex_string(&tmp_key)); - debug_print(mod_aes_icm, - "offset: %s", v128_hex_string(&c->offset)); - - /* expand key */ - aes_expand_encryption_key(&tmp_key, c->expanded_key); - - /* indicate that the keystream_buffer is empty */ - c->bytes_in_buffer = 0; - - return err_status_ok; -} - -/* - * aes_icm_set_octet(c, i) sets the counter of the context which it is - * passed so that the next octet of keystream that will be generated - * is the ith octet - */ - -err_status_t -aes_icm_set_octet(aes_icm_ctx_t *c, - uint64_t octet_num) { - -#ifdef NO_64BIT_MATH - int tail_num = low32(octet_num) & 0x0f; - /* 64-bit right-shift 4 */ - uint64_t block_num = make64(high32(octet_num) >> 4, - ((high32(octet_num) & 0x0f)<<(32-4)) | - (low32(octet_num) >> 4)); -#else - int tail_num = octet_num % 16; - uint64_t block_num = octet_num / 16; -#endif - - - /* set counter value */ - /* FIX - There's no way this is correct */ - c->counter.v64[0] = c->offset.v64[0]; -#ifdef NO_64BIT_MATH - c->counter.v64[0] = make64(high32(c->offset.v64[0]) ^ high32(block_num), - low32(c->offset.v64[0]) ^ low32(block_num)); -#else - c->counter.v64[0] = c->offset.v64[0] ^ block_num; -#endif - - debug_print(mod_aes_icm, - "set_octet: %s", v128_hex_string(&c->counter)); - - /* fill keystream buffer, if needed */ - if (tail_num) { - v128_copy(&c->keystream_buffer, &c->counter); - aes_encrypt(&c->keystream_buffer, c->expanded_key); - c->bytes_in_buffer = sizeof(v128_t); - - debug_print(mod_aes_icm, "counter: %s", - v128_hex_string(&c->counter)); - debug_print(mod_aes_icm, "ciphertext: %s", - v128_hex_string(&c->keystream_buffer)); - - /* indicate number of bytes in keystream_buffer */ - c->bytes_in_buffer = sizeof(v128_t) - tail_num; - - } else { - - /* indicate that keystream_buffer is empty */ - c->bytes_in_buffer = 0; - } - - return err_status_ok; -} - -/* - * aes_icm_set_iv(c, iv) sets the counter value to the exor of iv with - * the offset - */ - -err_status_t -aes_icm_set_iv(aes_icm_ctx_t *c, void *iv) { - v128_t *nonce = (v128_t *) iv; - - debug_print(mod_aes_icm, - "setting iv: %s", v128_hex_string(nonce)); - - v128_xor(&c->counter, &c->offset, nonce); - - debug_print(mod_aes_icm, - "set_counter: %s", v128_hex_string(&c->counter)); - - /* indicate that the keystream_buffer is empty */ - c->bytes_in_buffer = 0; - - return err_status_ok; -} - - - -/* - * aes_icm_advance(...) refills the keystream_buffer and - * advances the block index of the sicm_context forward by one - * - * this is an internal, hopefully inlined function - */ - -inline void -aes_icm_advance_ismacryp(aes_icm_ctx_t *c, uint8_t forIsmacryp) { - /* fill buffer with new keystream */ - v128_copy(&c->keystream_buffer, &c->counter); - aes_encrypt(&c->keystream_buffer, c->expanded_key); - c->bytes_in_buffer = sizeof(v128_t); - - debug_print(mod_aes_icm, "counter: %s", - v128_hex_string(&c->counter)); - debug_print(mod_aes_icm, "ciphertext: %s", - v128_hex_string(&c->keystream_buffer)); - - /* clock counter forward */ - - if (forIsmacryp) { - uint32_t temp; - //alex's clock counter forward - temp = ntohl(c->counter.v32[3]); - c->counter.v32[3] = htonl(++temp); - } else { - if (!++(c->counter.v8[15])) - ++(c->counter.v8[14]); - } -} - -inline void aes_icm_advance(aes_icm_ctx_t *c) { - aes_icm_advance_ismacryp(c, 0); -} - - -/*e - * icm_encrypt deals with the following cases: - * - * bytes_to_encr < bytes_in_buffer - * - add keystream into data - * - * bytes_to_encr > bytes_in_buffer - * - add keystream into data until keystream_buffer is depleted - * - loop over blocks, filling keystream_buffer and then - * adding keystream into data - * - fill buffer then add in remaining (< 16) bytes of keystream - */ - -err_status_t -aes_icm_encrypt_ismacryp(aes_icm_ctx_t *c, - unsigned char *buf, unsigned int *enc_len, - int forIsmacryp) { - unsigned int bytes_to_encr = *enc_len; - unsigned int i; - uint32_t *b; - - /* check that there's enough segment left but not for ismacryp*/ - if (!forIsmacryp && (bytes_to_encr + htons(c->counter.v16[7])) > 0xffff) - return err_status_terminus; - - debug_print(mod_aes_icm, "block index: %d", - htons(c->counter.v16[7])); - if (bytes_to_encr <= (unsigned int)c->bytes_in_buffer) { - - /* deal with odd case of small bytes_to_encr */ - for (i = (sizeof(v128_t) - c->bytes_in_buffer); - i < (sizeof(v128_t) - c->bytes_in_buffer + bytes_to_encr); i++) - { - *buf++ ^= c->keystream_buffer.v8[i]; - } - - c->bytes_in_buffer -= bytes_to_encr; - - /* return now to avoid the main loop */ - return err_status_ok; - - } else { - - /* encrypt bytes until the remaining data is 16-byte aligned */ - for (i=(sizeof(v128_t) - c->bytes_in_buffer); i < sizeof(v128_t); i++) - *buf++ ^= c->keystream_buffer.v8[i]; - - bytes_to_encr -= c->bytes_in_buffer; - c->bytes_in_buffer = 0; - - } - - /* now loop over entire 16-byte blocks of keystream */ - for (i=0; i < (bytes_to_encr/sizeof(v128_t)); i++) { - - /* fill buffer with new keystream */ - aes_icm_advance_ismacryp(c, forIsmacryp); - - /* - * add keystream into the data buffer (this would be a lot faster - * if we could assume 32-bit alignment!) - */ - -#if ALIGN_32 - b = (uint32_t *)buf; - *b++ ^= c->keystream_buffer.v32[0]; - *b++ ^= c->keystream_buffer.v32[1]; - *b++ ^= c->keystream_buffer.v32[2]; - *b++ ^= c->keystream_buffer.v32[3]; - buf = (uint8_t *)b; -#else - if ((((unsigned long) buf) & 0x03) != 0) { - *buf++ ^= c->keystream_buffer.v8[0]; - *buf++ ^= c->keystream_buffer.v8[1]; - *buf++ ^= c->keystream_buffer.v8[2]; - *buf++ ^= c->keystream_buffer.v8[3]; - *buf++ ^= c->keystream_buffer.v8[4]; - *buf++ ^= c->keystream_buffer.v8[5]; - *buf++ ^= c->keystream_buffer.v8[6]; - *buf++ ^= c->keystream_buffer.v8[7]; - *buf++ ^= c->keystream_buffer.v8[8]; - *buf++ ^= c->keystream_buffer.v8[9]; - *buf++ ^= c->keystream_buffer.v8[10]; - *buf++ ^= c->keystream_buffer.v8[11]; - *buf++ ^= c->keystream_buffer.v8[12]; - *buf++ ^= c->keystream_buffer.v8[13]; - *buf++ ^= c->keystream_buffer.v8[14]; - *buf++ ^= c->keystream_buffer.v8[15]; - } else { - b = (uint32_t *)buf; - *b++ ^= c->keystream_buffer.v32[0]; - *b++ ^= c->keystream_buffer.v32[1]; - *b++ ^= c->keystream_buffer.v32[2]; - *b++ ^= c->keystream_buffer.v32[3]; - buf = (uint8_t *)b; - } -#endif /* #if ALIGN_32 */ - - } - - /* if there is a tail end of the data, process it */ - if ((bytes_to_encr & 0xf) != 0) { - - /* fill buffer with new keystream */ - aes_icm_advance_ismacryp(c, forIsmacryp); - - for (i=0; i < (bytes_to_encr & 0xf); i++) - *buf++ ^= c->keystream_buffer.v8[i]; - - /* reset the keystream buffer size to right value */ - c->bytes_in_buffer = sizeof(v128_t) - i; - } else { - - /* no tail, so just reset the keystream buffer size to zero */ - c->bytes_in_buffer = 0; - - } - - return err_status_ok; -} - -err_status_t -aes_icm_encrypt(aes_icm_ctx_t *c, unsigned char *buf, unsigned int *enc_len) { - return aes_icm_encrypt_ismacryp(c, buf, enc_len, 0); -} - -err_status_t -aes_icm_output(aes_icm_ctx_t *c, uint8_t *buffer, int num_octets_to_output) { - unsigned int len = num_octets_to_output; - - /* zeroize the buffer */ - octet_string_set_to_zero(buffer, num_octets_to_output); - - /* exor keystream into buffer */ - return aes_icm_encrypt(c, buffer, &len); -} - - -char -aes_icm_description[] = "aes integer counter mode"; - -uint8_t aes_icm_test_case_0_key[30] = { - 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, - 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c, - 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, - 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd -}; - -uint8_t aes_icm_test_case_0_nonce[16] = { - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 -}; - -uint8_t aes_icm_test_case_0_plaintext[32] = { - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, -}; - -uint8_t aes_icm_test_case_0_ciphertext[32] = { - 0xe0, 0x3e, 0xad, 0x09, 0x35, 0xc9, 0x5e, 0x80, - 0xe1, 0x66, 0xb1, 0x6d, 0xd9, 0x2b, 0x4e, 0xb4, - 0xd2, 0x35, 0x13, 0x16, 0x2b, 0x02, 0xd0, 0xf7, - 0x2a, 0x43, 0xa2, 0xfe, 0x4a, 0x5f, 0x97, 0xab -}; - -cipher_test_case_t aes_icm_test_case_0 = { - 30, /* octets in key */ - aes_icm_test_case_0_key, /* key */ - aes_icm_test_case_0_nonce, /* packet index */ - 32, /* octets in plaintext */ - aes_icm_test_case_0_plaintext, /* plaintext */ - 32, /* octets in ciphertext */ - aes_icm_test_case_0_ciphertext, /* ciphertext */ - NULL /* pointer to next testcase */ -}; - - -/* - * note: the encrypt function is identical to the decrypt function - */ - -cipher_type_t aes_icm = { - (cipher_alloc_func_t) aes_icm_alloc, - (cipher_dealloc_func_t) aes_icm_dealloc, - (cipher_init_func_t) aes_icm_context_init, - (cipher_encrypt_func_t) aes_icm_encrypt, - (cipher_decrypt_func_t) aes_icm_encrypt, - (cipher_set_iv_func_t) aes_icm_set_iv, - (char *) aes_icm_description, - (int) 0, /* instance count */ - (cipher_test_case_t *) &aes_icm_test_case_0, - (debug_module_t *) &mod_aes_icm -}; - |