/*
  * Copyright (C) 2007 Michael Niedermayer <michaelni@gmx.at>

  * Copyright (C) 2009 Konstantin Shishkov

  * based on public domain SHA-1 code by Steve Reid <steve@edmweb.com>

  * and on BSD-licensed SHA-2 code by Aaron D. Gifford

  *
  * 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
  */

 #include <string.h>

 
 #include "attributes.h"

 #include "avutil.h"

 #include "bswap.h"

 #include "sha.h"

 #include "intreadwrite.h"

 #include "mem.h"

 /** hash context */

 typedef struct AVSHA {

     uint8_t  digest_len;  ///< digest length in 32-bit words

     uint64_t count;       ///< number of bytes in buffer

     uint8_t  buffer[64];  ///< 512-bit buffer of input values used in hash updating

     uint32_t state[8];    ///< current hash value

     /** function used to update hash for 512-bit input block */
     void     (*transform)(uint32_t *state, const uint8_t buffer[64]);

 } AVSHA;

 const int av_sha_size = sizeof(AVSHA);

 
 struct AVSHA *av_sha_alloc(void)
 {
     return av_mallocz(sizeof(struct AVSHA));
 }

 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
 
 /* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */

 #define blk0(i) (block[i] = AV_RB32(buffer + 4 * (i)))

 #define blk(i)  (block[i] = rol(block[i-3] ^ block[i-8] ^ block[i-14] ^ block[i-16], 1))

 #define R0(v,w,x,y,z,i) z += ((w&(x^y))^y)     + blk0(i) + 0x5A827999 + rol(v, 5); w = rol(w, 30);
 #define R1(v,w,x,y,z,i) z += ((w&(x^y))^y)     + blk (i) + 0x5A827999 + rol(v, 5); w = rol(w, 30);
 #define R2(v,w,x,y,z,i) z += ( w^x     ^y)     + blk (i) + 0x6ED9EBA1 + rol(v, 5); w = rol(w, 30);
 #define R3(v,w,x,y,z,i) z += (((w|x)&y)|(w&x)) + blk (i) + 0x8F1BBCDC + rol(v, 5); w = rol(w, 30);
 #define R4(v,w,x,y,z,i) z += ( w^x     ^y)     + blk (i) + 0xCA62C1D6 + rol(v, 5); w = rol(w, 30);

 
 /* Hash a single 512-bit block. This is the core of the algorithm. */
 

 static void sha1_transform(uint32_t state[5], const uint8_t buffer[64])

 {

     uint32_t block[80];

     unsigned int i, a, b, c, d, e;

     a = state[0];
     b = state[1];
     c = state[2];
     d = state[3];
     e = state[4];

 #if CONFIG_SMALL

     for (i = 0; i < 80; i++) {

         int t;

         if (i < 16)

             t = AV_RB32(buffer + 4 * i);

         else
             t = rol(block[i-3] ^ block[i-8] ^ block[i-14] ^ block[i-16], 1);
         block[i] = t;
         t += e + rol(a, 5);
         if (i < 40) {
             if (i < 20)
                 t += ((b&(c^d))^d)     + 0x5A827999;
             else
                 t += ( b^c     ^d)     + 0x6ED9EBA1;
         } else {
             if (i < 60)
                 t += (((b|c)&d)|(b&c)) + 0x8F1BBCDC;
             else
                 t += ( b^c     ^d)     + 0xCA62C1D6;

         }

         e = d;
         d = c;
         c = rol(b, 30);
         b = a;
         a = t;

     }
 #else

 
 #define R1_0 \
     R0(a, b, c, d, e, 0 + i); \
     R0(e, a, b, c, d, 1 + i); \
     R0(d, e, a, b, c, 2 + i); \
     R0(c, d, e, a, b, 3 + i); \
     R0(b, c, d, e, a, 4 + i); \
     i += 5
 
     i = 0;
     R1_0; R1_0; R1_0;

     R0(a, b, c, d, e, 15);
     R1(e, a, b, c, d, 16);
     R1(d, e, a, b, c, 17);
     R1(c, d, e, a, b, 18);
     R1(b, c, d, e, a, 19);

 
 #define R1_20 \
     R2(a, b, c, d, e, 0 + i); \
     R2(e, a, b, c, d, 1 + i); \
     R2(d, e, a, b, c, 2 + i); \
     R2(c, d, e, a, b, 3 + i); \
     R2(b, c, d, e, a, 4 + i); \
     i += 5
 
     i = 20;
     R1_20; R1_20; R1_20; R1_20;
 
 #define R1_40 \
     R3(a, b, c, d, e, 0 + i); \
     R3(e, a, b, c, d, 1 + i); \
     R3(d, e, a, b, c, 2 + i); \
     R3(c, d, e, a, b, 3 + i); \
     R3(b, c, d, e, a, 4 + i); \
     i += 5
 
     R1_40; R1_40; R1_40; R1_40;
 
 #define R1_60 \
     R4(a, b, c, d, e, 0 + i); \
     R4(e, a, b, c, d, 1 + i); \
     R4(d, e, a, b, c, 2 + i); \
     R4(c, d, e, a, b, 3 + i); \
     R4(b, c, d, e, a, 4 + i); \
     i += 5
 
     R1_60; R1_60; R1_60; R1_60;

 #endif

     state[0] += a;
     state[1] += b;
     state[2] += c;
     state[3] += d;
     state[4] += e;
 }
 

 static const uint32_t K256[64] = {
     0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
     0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
     0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
     0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
     0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
     0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
     0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
     0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
     0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
     0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
     0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
     0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
     0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
     0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
     0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
     0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 };
 
 
 #define Ch(x,y,z)   (((x) & ((y) ^ (z))) ^ (z))

 #define Maj(z,y,x)  ((((x) | (y)) & (z)) | ((x) & (y)))

 
 #define Sigma0_256(x)   (rol((x), 30) ^ rol((x), 19) ^ rol((x), 10))
 #define Sigma1_256(x)   (rol((x), 26) ^ rol((x), 21) ^ rol((x),  7))
 #define sigma0_256(x)   (rol((x), 25) ^ rol((x), 14) ^ ((x) >> 3))
 #define sigma1_256(x)   (rol((x), 15) ^ rol((x), 13) ^ ((x) >> 10))
 
 #undef blk
 #define blk(i)  (block[i] = block[i - 16] + sigma0_256(block[i - 15]) + \
                             sigma1_256(block[i - 2]) + block[i - 7])
 
 #define ROUND256(a,b,c,d,e,f,g,h)   \
     T1 += (h) + Sigma1_256(e) + Ch((e), (f), (g)) + K256[i]; \
     (d) += T1; \
     (h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
     i++
 
 #define ROUND256_0_TO_15(a,b,c,d,e,f,g,h)   \
     T1 = blk0(i); \
     ROUND256(a,b,c,d,e,f,g,h)
 
 #define ROUND256_16_TO_63(a,b,c,d,e,f,g,h)   \
     T1 = blk(i); \
     ROUND256(a,b,c,d,e,f,g,h)
 
 static void sha256_transform(uint32_t *state, const uint8_t buffer[64])
 {
     unsigned int i, a, b, c, d, e, f, g, h;
     uint32_t block[64];

     uint32_t T1;

 
     a = state[0];
     b = state[1];
     c = state[2];
     d = state[3];
     e = state[4];
     f = state[5];
     g = state[6];
     h = state[7];
 #if CONFIG_SMALL
     for (i = 0; i < 64; i++) {

         uint32_t T2;

         if (i < 16)
             T1 = blk0(i);
         else
             T1 = blk(i);
         T1 += h + Sigma1_256(e) + Ch(e, f, g) + K256[i];
         T2 = Sigma0_256(a) + Maj(a, b, c);
         h = g;
         g = f;
         f = e;
         e = d + T1;
         d = c;
         c = b;
         b = a;
         a = T1 + T2;
     }
 #else
 

     i = 0;
 #define R256_0 \
     ROUND256_0_TO_15(a, b, c, d, e, f, g, h); \
     ROUND256_0_TO_15(h, a, b, c, d, e, f, g); \
     ROUND256_0_TO_15(g, h, a, b, c, d, e, f); \
     ROUND256_0_TO_15(f, g, h, a, b, c, d, e); \
     ROUND256_0_TO_15(e, f, g, h, a, b, c, d); \
     ROUND256_0_TO_15(d, e, f, g, h, a, b, c); \
     ROUND256_0_TO_15(c, d, e, f, g, h, a, b); \
     ROUND256_0_TO_15(b, c, d, e, f, g, h, a)
 
     R256_0; R256_0;
 
 #define R256_16 \
     ROUND256_16_TO_63(a, b, c, d, e, f, g, h); \
     ROUND256_16_TO_63(h, a, b, c, d, e, f, g); \
     ROUND256_16_TO_63(g, h, a, b, c, d, e, f); \
     ROUND256_16_TO_63(f, g, h, a, b, c, d, e); \
     ROUND256_16_TO_63(e, f, g, h, a, b, c, d); \
     ROUND256_16_TO_63(d, e, f, g, h, a, b, c); \
     ROUND256_16_TO_63(c, d, e, f, g, h, a, b); \
     ROUND256_16_TO_63(b, c, d, e, f, g, h, a)
 
     R256_16; R256_16; R256_16;
     R256_16; R256_16; R256_16;

 #endif
     state[0] += a;
     state[1] += b;
     state[2] += c;
     state[3] += d;
     state[4] += e;
     state[5] += f;
     state[6] += g;
     state[7] += h;
 }
 
 

 av_cold int av_sha_init(AVSHA *ctx, int bits)

 {

     ctx->digest_len = bits >> 5;
     switch (bits) {
     case 160: // SHA-1

         ctx->state[0] = 0x67452301;
         ctx->state[1] = 0xEFCDAB89;
         ctx->state[2] = 0x98BADCFE;
         ctx->state[3] = 0x10325476;
         ctx->state[4] = 0xC3D2E1F0;
         ctx->transform = sha1_transform;

         break;
     case 224: // SHA-224
         ctx->state[0] = 0xC1059ED8;
         ctx->state[1] = 0x367CD507;
         ctx->state[2] = 0x3070DD17;
         ctx->state[3] = 0xF70E5939;
         ctx->state[4] = 0xFFC00B31;
         ctx->state[5] = 0x68581511;
         ctx->state[6] = 0x64F98FA7;
         ctx->state[7] = 0xBEFA4FA4;
         ctx->transform = sha256_transform;
         break;
     case 256: // SHA-256
         ctx->state[0] = 0x6A09E667;
         ctx->state[1] = 0xBB67AE85;
         ctx->state[2] = 0x3C6EF372;
         ctx->state[3] = 0xA54FF53A;
         ctx->state[4] = 0x510E527F;
         ctx->state[5] = 0x9B05688C;
         ctx->state[6] = 0x1F83D9AB;
         ctx->state[7] = 0x5BE0CD19;
         ctx->transform = sha256_transform;
         break;
     default:
         return -1;
     }
     ctx->count = 0;

     return 0;

 }
 

 void av_sha_update(AVSHA* ctx, const uint8_t* data, unsigned int len)

 {

     unsigned int i, j;
 

     j = ctx->count & 63;
     ctx->count += len;

 #if CONFIG_SMALL

     for (i = 0; i < len; i++) {
         ctx->buffer[j++] = data[i];
         if (64 == j) {

             ctx->transform(ctx->state, ctx->buffer);

             j = 0;
         }
     }
 #else

     if ((j + len) > 63) {

         memcpy(&ctx->buffer[j], data, (i = 64 - j));

         ctx->transform(ctx->state, ctx->buffer);

         for (; i + 63 < len; i += 64)

             ctx->transform(ctx->state, &data[i]);

         j = 0;
     } else
         i = 0;

     memcpy(&ctx->buffer[j], &data[i], len - i);

 #endif

 }
 

 void av_sha_final(AVSHA* ctx, uint8_t *digest)

 {

     int i;

     uint64_t finalcount = av_be2ne64(ctx->count << 3);

     av_sha_update(ctx, "\200", 1);

     while ((ctx->count & 63) != 56)

         av_sha_update(ctx, "", 1);
     av_sha_update(ctx, (uint8_t *)&finalcount, 8); /* Should cause a transform() */

     for (i = 0; i < ctx->digest_len; i++)

         AV_WB32(digest + i*4, ctx->state[i]);

 }
 
 #ifdef TEST
 #include <stdio.h>
 

 int main(void)
 {

     int i, j, k;

     AVSHA ctx;

     unsigned char digest[32];

     static const int lengths[3] = { 160, 224, 256 };

     for (j = 0; j < 3; j++) {
         printf("Testing SHA-%d\n", lengths[j]);

         for (k = 0; k < 3; k++) {
             av_sha_init(&ctx, lengths[j]);
             if (k == 0)
                 av_sha_update(&ctx, "abc", 3);
             else if (k == 1)
                 av_sha_update(&ctx, "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 56);
             else
                 for (i = 0; i < 1000*1000; i++)
                     av_sha_update(&ctx, "a", 1);
             av_sha_final(&ctx, digest);
             for (i = 0; i < lengths[j] >> 3; i++)
                 printf("%02X", digest[i]);
             putchar('\n');
         }
         switch (j) {
         case 0:
             //test vectors (from FIPS PUB 180-1)
             printf("A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D\n"
                    "84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1\n"
                    "34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F\n");
             break;
         case 1:
             //test vectors (from FIPS PUB 180-2 Appendix A)
             printf("23097d22 3405d822 8642a477 bda255b3 2aadbce4 bda0b3f7 e36c9da7\n"
                    "75388b16 512776cc 5dba5da1 fd890150 b0c6455c b4f58b19 52522525\n"
                    "20794655 980c91d8 bbb4c1ea 97618a4b f03f4258 1948b2ee 4ee7ad67\n");
             break;
         case 2:
             //test vectors (from FIPS PUB 180-2)
             printf("ba7816bf 8f01cfea 414140de 5dae2223 b00361a3 96177a9c b410ff61 f20015ad\n"
                    "248d6a61 d20638b8 e5c02693 0c3e6039 a33ce459 64ff2167 f6ecedd4 19db06c1\n"
                    "cdc76e5c 9914fb92 81a1c7e2 84d73e67 f1809a48 a497200e 046d39cc c7112cd0\n");
             break;
         }

     }

 
     return 0;
 }
 #endif