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avutil/aes: use pthread_once to fill the static tables

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Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer
2025-04-06 20:57:58 -03:00
parent 890b8da1ce
commit aeed747f41
1 changed files with 30 additions and 23 deletions
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53
libavutil/aes.c
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@ -29,6 +29,7 @@
#include "intreadwrite.h"
#include "macros.h"
#include "mem.h"
#include "thread.h"
const int av_aes_size= sizeof(AVAES);
@ -197,6 +198,34 @@ static void init_multbl2(uint32_t tbl[][256], const int c[4],
}
}
static AVOnce aes_static_init = AV_ONCE_INIT;
static void aes_init_static(void)
{
uint8_t log8[256];
uint8_t alog8[512];
int i, j = 1;
for (i = 0; i < 255; i++) {
alog8[i] = alog8[i + 255] = j;
log8[j] = i;
j ^= j + j;
if (j > 255)
j ^= 0x11B;
}
for (i = 0; i < 256; i++) {
j = i ? alog8[255 - log8[i]] : 0;
j ^= (j << 1) ^ (j << 2) ^ (j << 3) ^ (j << 4);
j = (j ^ (j >> 8) ^ 99) & 255;
inv_sbox[j] = i;
sbox[i] = j;
}
init_multbl2(dec_multbl, (const int[4]) { 0xe, 0x9, 0xd, 0xb },
log8, alog8, inv_sbox);
init_multbl2(enc_multbl, (const int[4]) { 0x2, 0x1, 0x1, 0x3 },
log8, alog8, sbox);
}
// this is based on the reference AES code by Paulo Barreto and Vincent Rijmen
int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt)
{
@ -204,34 +233,12 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt)
uint8_t tk[8][4];
int KC = key_bits >> 5;
int rounds = KC + 6;
uint8_t log8[256];
uint8_t alog8[512];
a->crypt = decrypt ? aes_decrypt : aes_encrypt;
if (ARCH_X86)
ff_init_aes_x86(a, decrypt);
if (!enc_multbl[FF_ARRAY_ELEMS(enc_multbl) - 1][FF_ARRAY_ELEMS(enc_multbl[0]) - 1]) {
j = 1;
for (i = 0; i < 255; i++) {
alog8[i] = alog8[i + 255] = j;
log8[j] = i;
j ^= j + j;
if (j > 255)
j ^= 0x11B;
}
for (i = 0; i < 256; i++) {
j = i ? alog8[255 - log8[i]] : 0;
j ^= (j << 1) ^ (j << 2) ^ (j << 3) ^ (j << 4);
j = (j ^ (j >> 8) ^ 99) & 255;
inv_sbox[j] = i;
sbox[i] = j;
}
init_multbl2(dec_multbl, (const int[4]) { 0xe, 0x9, 0xd, 0xb },
log8, alog8, inv_sbox);
init_multbl2(enc_multbl, (const int[4]) { 0x2, 0x1, 0x1, 0x3 },
log8, alog8, sbox);
}
ff_thread_once(&aes_static_init, aes_init_static);
if (key_bits != 128 && key_bits != 192 && key_bits != 256)
return AVERROR(EINVAL);