[Ffmpeg-cvslog] r7460 - trunk/libavutil/aes.c
Reimar Döffinger
Reimar.Doeffinger
Sun Jan 14 10:50:17 CET 2007
Hello,
On Sun, Jan 14, 2007 at 10:06:14AM +0100, michael wrote:
> Author: michael
> Date: Sun Jan 14 10:06:13 2007
> New Revision: 7460
>
> Added:
> trunk/libavutil/aes.c
>
> Log:
> aes support (unfinished)
Sorry, I didn't know you were working on this.
I was working on an 128-bit-only version, the speed is almost usable.
What do you suggest how to proceed?
Greetings,
Reimar D?ffinger
-------------- next part --------------
Index: libavutil/aes128.c
===================================================================
--- libavutil/aes128.c (revision 0)
+++ libavutil/aes128.c (revision 0)
@@ -0,0 +1,150 @@
+/*
+ * 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"
+
+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 ADDROUND(a, rk) \
+ ((uint32_t *)(a))[0] ^= ((uint32_t *)(rk))[0];\
+ ((uint32_t *)(a))[1] ^= ((uint32_t *)(rk))[1];\
+ ((uint32_t *)(a))[2] ^= ((uint32_t *)(rk))[2];\
+ ((uint32_t *)(a))[3] ^= ((uint32_t *)(rk))[3];
+#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 = 9;
+ uint8_t tmp[16];
+ memcpy(tmp, block, 16);
+ ADDROUND(tmp, c->key[10]);
+ SUBSTSHIFTROWS(block, tmp);
+ do {
+ ADDROUND(block, c->key[r]);
+ INVMIX(tmp, block);
+ SUBSTSHIFTROWS(block, tmp);
+ } while (--r);
+ ADDROUND(block, c->key[0]);
+}
+
+void aes128_decrypt(AES128Context *c, uint8_t *mem, int blockcnt, uint8_t *IV) {
+ uint8_t tmp[16];
+ long i;
+ while (blockcnt-- > 0) {
+ memcpy(tmp, mem, 16);
+ aes128_decrypt_block(c, mem);
+ i = 15; do { mem[i] ^= IV[i]; } while (--i >= 0);
+ memcpy(IV, tmp, 16);
+ mem += 16;
+ }
+}
Index: libavutil/aes128.h
===================================================================
--- libavutil/aes128.h (revision 0)
+++ libavutil/aes128.h (revision 0)
@@ -0,0 +1,13 @@
+#ifndef AES128_H
+#define AES128_H
+
+typedef struct {
+ uint32_t multbl[4][256];
+ uint8_t subst[256];
+ uint8_t key[11][16];
+} AES128Context;
+AES128Context *aes128_init(void);
+void aes128_set_key(AES128Context *c, const uint8_t *key);
+void aes128_decrypt(AES128Context *c, uint8_t *mem, int blockcnt, uint8_t *IV);
+
+#endif
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