From a264a081b20746a29231a013e7e9465d08aac0f1 Mon Sep 17 00:00:00 2001 From: Reimar Döffinger Date: Thu, 8 Feb 2007 21:09:11 +0000 Subject: special-case AES-128 decrypter is no longer necessary, the more general AES-implementation works at least as well in all case I tested. Originally committed as revision 7884 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavutil/aes128.c | 180 ----------------------------------------------------- libavutil/aes128.h | 20 ------ 2 files changed, 200 deletions(-) delete mode 100644 libavutil/aes128.c delete mode 100644 libavutil/aes128.h (limited to 'libavutil') diff --git a/libavutil/aes128.c b/libavutil/aes128.c deleted file mode 100644 index 321554e13d..0000000000 --- a/libavutil/aes128.c +++ /dev/null @@ -1,180 +0,0 @@ -/* - * AES 128 bit decryption - * Copyright (c) 2007 Reimar Doeffinger. - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * - * Based on public domain AES reference code by Paulo Barreto, Vincent Rijmen - */ - -#include "common.h" -#include "aes128.h" - -#ifdef CONFIG_GCRYPT -AES128Context *aes128_init(void) { - AES128Context *res = av_malloc(sizeof(*res)); - gcry_cipher_open(&res->ch, GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CBC, 0); - return res; -} -void aes128_set_key(AES128Context *c, const uint8_t *key) { - gcry_cipher_ctl(c->ch, GCRYCTL_SET_KEY, key, 16); -} -void aes128_cbc_decrypt(AES128Context *c, uint8_t *mem, int blockcnt, uint8_t *IV) { - blockcnt <<= 4; - gcry_cipher_ctl(c->ch, GCRYCTL_SET_IV, IV, 16); - memcpy(IV, &mem[blockcnt - 16], 16); - gcry_cipher_decrypt(c->ch, mem, blockcnt, mem, blockcnt); -} -#else -static const uint8_t rcon[10] = { - 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 -}; -static const uint8_t logtbl[256] = { - 0, 0, 25, 1, 50, 2, 26, 198, 75, 199, 27, 104, 51, 238, 223, 3, - 100, 4, 224, 14, 52, 141, 129, 239, 76, 113, 8, 200, 248, 105, 28, 193, - 125, 194, 29, 181, 249, 185, 39, 106, 77, 228, 166, 114, 154, 201, 9, 120, - 101, 47, 138, 5, 33, 15, 225, 36, 18, 240, 130, 69, 53, 147, 218, 142, - 150, 143, 219, 189, 54, 208, 206, 148, 19, 92, 210, 241, 64, 70, 131, 56, - 102, 221, 253, 48, 191, 6, 139, 98, 179, 37, 226, 152, 34, 136, 145, 16, - 126, 110, 72, 195, 163, 182, 30, 66, 58, 107, 40, 84, 250, 133, 61, 186, - 43, 121, 10, 21, 155, 159, 94, 202, 78, 212, 172, 229, 243, 115, 167, 87, - 175, 88, 168, 80, 244, 234, 214, 116, 79, 174, 233, 213, 231, 230, 173, 232, - 44, 215, 117, 122, 235, 22, 11, 245, 89, 203, 95, 176, 156, 169, 81, 160, - 127, 12, 246, 111, 23, 196, 73, 236, 216, 67, 31, 45, 164, 118, 123, 183, - 204, 187, 62, 90, 251, 96, 177, 134, 59, 82, 161, 108, 170, 85, 41, 157, - 151, 178, 135, 144, 97, 190, 220, 252, 188, 149, 207, 205, 55, 63, 91, 209, - 83, 57, 132, 60, 65, 162, 109, 71, 20, 42, 158, 93, 86, 242, 211, 171, - 68, 17, 146, 217, 35, 32, 46, 137, 180, 124, 184, 38, 119, 153, 227, 165, - 103, 74, 237, 222, 197, 49, 254, 24, 13, 99, 140, 128, 192, 247, 112, 7 -}; -static const uint8_t invsubst[256] = { - 82, 9, 106, 213, 48, 54, 165, 56, 191, 64, 163, 158, 129, 243, 215, 251, - 124, 227, 57, 130, 155, 47, 255, 135, 52, 142, 67, 68, 196, 222, 233, 203, - 84, 123, 148, 50, 166, 194, 35, 61, 238, 76, 149, 11, 66, 250, 195, 78, - 8, 46, 161, 102, 40, 217, 36, 178, 118, 91, 162, 73, 109, 139, 209, 37, - 114, 248, 246, 100, 134, 104, 152, 22, 212, 164, 92, 204, 93, 101, 182, 146, - 108, 112, 72, 80, 253, 237, 185, 218, 94, 21, 70, 87, 167, 141, 157, 132, - 144, 216, 171, 0, 140, 188, 211, 10, 247, 228, 88, 5, 184, 179, 69, 6, - 208, 44, 30, 143, 202, 63, 15, 2, 193, 175, 189, 3, 1, 19, 138, 107, - 58, 145, 17, 65, 79, 103, 220, 234, 151, 242, 207, 206, 240, 180, 230, 115, - 150, 172, 116, 34, 231, 173, 53, 133, 226, 249, 55, 232, 28, 117, 223, 110, - 71, 241, 26, 113, 29, 41, 197, 137, 111, 183, 98, 14, 170, 24, 190, 27, - 252, 86, 62, 75, 198, 210, 121, 32, 154, 219, 192, 254, 120, 205, 90, 244, - 31, 221, 168, 51, 136, 7, 199, 49, 177, 18, 16, 89, 39, 128, 236, 95, - 96, 81, 127, 169, 25, 181, 74, 13, 45, 229, 122, 159, 147, 201, 156, 239, - 160, 224, 59, 77, 174, 42, 245, 176, 200, 235, 187, 60, 131, 83, 153, 97, - 23, 43, 4, 126, 186, 119, 214, 38, 225, 105, 20, 99, 85, 33, 12, 125 -}; -#define XORBLOCK(a, rk) \ - ((uint64_t *)(a))[0] ^= ((uint64_t *)(rk))[0];\ - ((uint64_t *)(a))[1] ^= ((uint64_t *)(rk))[1]; -#define COPYBLOCK(b, a) \ - ((uint64_t *)(b))[0] = ((uint64_t *)(a))[0];\ - ((uint64_t *)(b))[1] = ((uint64_t *)(a))[1]; -#define SUBSTSHIFTROWS(b, a) \ - b[0] = invsubst[a[0]]; b[1] = invsubst[a[13]]; b[2] = invsubst[a[10]];\ - b[3] = invsubst[a[7]]; b[4] = invsubst[a[4]]; b[5] = invsubst[a[1]];\ - b[6] = invsubst[a[14]]; b[7] = invsubst[a[11]]; b[8] = invsubst[a[8]];\ - b[9] = invsubst[a[5]]; b[10] = invsubst[a[2]]; b[11] = invsubst[a[15]];\ - b[12] = invsubst[a[12]]; b[13] = invsubst[a[9]]; b[14] = invsubst[a[6]];\ - b[15] = invsubst[a[3]]; -#define INVMIX(b, a) \ - ((uint32_t *)(b))[0] = c->multbl[0][a[0]] ^ c->multbl[1][a[1]] ^ c->multbl[2][a[2]] ^ c->multbl[3][a[3]];\ - ((uint32_t *)(b))[1] = c->multbl[0][a[4]] ^ c->multbl[1][a[5]] ^ c->multbl[2][a[6]] ^ c->multbl[3][a[7]];\ - ((uint32_t *)(b))[2] = c->multbl[0][a[8]] ^ c->multbl[1][a[9]] ^ c->multbl[2][a[10]] ^ c->multbl[3][a[11]];\ - ((uint32_t *)(b))[3] = c->multbl[0][a[12]] ^ c->multbl[1][a[13]] ^ c->multbl[2][a[14]] ^ c->multbl[3][a[15]]; - -#define MUL(a, b) ((a && b) ? invlogtbl[(logtbl[a] + logtbl[b])%255] : 0) -AES128Context *aes128_init(void) { - AES128Context *c = av_mallocz(sizeof(*c)); - uint8_t *invlogtbl = av_malloc(256); - uint8_t *tbl0, *tbl1, *tbl2, *tbl3; - int i; - for (i = 0; i < 256; i++) { - c->subst[invsubst[i]] = i; - invlogtbl[logtbl[i]] = i; - } - invlogtbl[255] = 1; - tbl0 = (uint8_t *)c->multbl[0]; - tbl1 = (uint8_t *)c->multbl[1]; - tbl2 = (uint8_t *)c->multbl[2];; - tbl3 = (uint8_t *)c->multbl[3]; - for (i = 0; i < 256; i++) { - tbl0[4*i+0] = MUL(0xe, i); tbl0[4*i+1] = MUL(0x9, i); - tbl0[4*i+2] = MUL(0xd, i); tbl0[4*i+3] = MUL(0xb, i); - tbl1[4*i+0] = MUL(0xb, i); tbl1[4*i+1] = MUL(0xe, i); - tbl1[4*i+2] = MUL(0x9, i); tbl1[4*i+3] = MUL(0xd, i); - tbl2[4*i+0] = MUL(0xd, i); tbl2[4*i+1] = MUL(0xb, i); - tbl2[4*i+2] = MUL(0xe, i); tbl2[4*i+3] = MUL(0x9, i); - tbl3[4*i+0] = MUL(0x9, i); tbl3[4*i+1] = MUL(0xd, i); - tbl3[4*i+2] = MUL(0xb, i); tbl3[4*i+3] = MUL(0xe, i); - } - av_free(invlogtbl); - return c; -} - -void aes128_set_key(AES128Context *c, const uint8_t *key) { - uint8_t tmp[4][4]; - long r, i, j; - memcpy(tmp, key, 16); - memcpy(c->key[0], tmp, 16); - for (r = 1; r < 11; r++) { - for (i = 0; i < 4; i++) tmp[0][i] ^= c->subst[tmp[3][(i+1)&3]]; - tmp[0][0] ^= rcon[r - 1]; - for (i = 0; i < 4; i++) for(j = 1; j < 4; j++) tmp[j][i] ^= tmp[j-1][i]; - memcpy(c->key[r], tmp, 16); - } -} - -static void aes128_decrypt_block(AES128Context *c, uint8_t *block) { - long r = 8; - uint8_t tmp[16]; - XORBLOCK(block, c->key[10]); - SUBSTSHIFTROWS(tmp, block); - XORBLOCK(tmp, c->key[9]); - INVMIX(tmp, tmp); - SUBSTSHIFTROWS(block, tmp); - do { - XORBLOCK(block, c->key[r]); - INVMIX(tmp, block); - SUBSTSHIFTROWS(block, tmp); - } while (--r); - XORBLOCK(block, c->key[0]); -} - -void aes128_cbc_decrypt(AES128Context *c, uint8_t *mem, int blockcnt, uint8_t *IV) { - uint8_t tmp[16]; - if (blockcnt & 1) { - COPYBLOCK(tmp, mem); - aes128_decrypt_block(c, mem); - XORBLOCK(mem, IV); - COPYBLOCK(IV, tmp); - mem += 16; - } - blockcnt >>= 1; - while (blockcnt-- > 0) { - COPYBLOCK(tmp, mem); - aes128_decrypt_block(c, mem); - XORBLOCK(mem, IV); - mem += 16; - COPYBLOCK(IV, mem); - aes128_decrypt_block(c, mem); - XORBLOCK(mem, tmp); - mem += 16; - } -} -#endif diff --git a/libavutil/aes128.h b/libavutil/aes128.h deleted file mode 100644 index 8e5793cfa4..0000000000 --- a/libavutil/aes128.h +++ /dev/null @@ -1,20 +0,0 @@ -#ifndef AES128_H -#define AES128_H - -#ifdef CONFIG_GCRYPT -#include -typedef struct { - gcry_cipher_hd_t ch; -} AES128Context; -#else -typedef struct { - uint32_t multbl[4][256]; - uint8_t subst[256]; - uint8_t key[11][16]; -} AES128Context; -#endif -AES128Context *aes128_init(void); -void aes128_set_key(AES128Context *c, const uint8_t *key); -void aes128_cbc_decrypt(AES128Context *c, uint8_t *mem, int blockcnt, uint8_t *IV); - -#endif -- cgit v1.2.3