/*

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

 * Copyright (C) 2009 Konstantin Shishkov

 * Copyright (C) 2013 James Almer

 * based 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 "config.h"

#include "attributes.h"

#include "bswap.h"

#include "error.h"

#include "sha512.h"

#include "intreadwrite.h"

#include "mem.h"

/** hash context */

typedef struct AVSHA512 {

    uint8_t  digest_len;  ///< digest length in 64-bit words

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

    uint8_t  buffer[128]; ///< 1024-bit buffer of input values used in hash updating

    uint64_t state[8];    ///< current hash value

} AVSHA512;

const int av_sha512_size = sizeof(AVSHA512);

struct AVSHA512 *av_sha512_alloc(void)

{

    return av_mallocz(sizeof(struct AVSHA512));

}

static const uint64_t K512[80] = {

    UINT64_C(0x428a2f98d728ae22),  UINT64_C(0x7137449123ef65cd),

    UINT64_C(0xb5c0fbcfec4d3b2f),  UINT64_C(0xe9b5dba58189dbbc),

    UINT64_C(0x3956c25bf348b538),  UINT64_C(0x59f111f1b605d019),

    UINT64_C(0x923f82a4af194f9b),  UINT64_C(0xab1c5ed5da6d8118),

    UINT64_C(0xd807aa98a3030242),  UINT64_C(0x12835b0145706fbe),

    UINT64_C(0x243185be4ee4b28c),  UINT64_C(0x550c7dc3d5ffb4e2),

    UINT64_C(0x72be5d74f27b896f),  UINT64_C(0x80deb1fe3b1696b1),

    UINT64_C(0x9bdc06a725c71235),  UINT64_C(0xc19bf174cf692694),

    UINT64_C(0xe49b69c19ef14ad2),  UINT64_C(0xefbe4786384f25e3),

    UINT64_C(0x0fc19dc68b8cd5b5),  UINT64_C(0x240ca1cc77ac9c65),

    UINT64_C(0x2de92c6f592b0275),  UINT64_C(0x4a7484aa6ea6e483),

    UINT64_C(0x5cb0a9dcbd41fbd4),  UINT64_C(0x76f988da831153b5),

    UINT64_C(0x983e5152ee66dfab),  UINT64_C(0xa831c66d2db43210),

    UINT64_C(0xb00327c898fb213f),  UINT64_C(0xbf597fc7beef0ee4),

    UINT64_C(0xc6e00bf33da88fc2),  UINT64_C(0xd5a79147930aa725),

    UINT64_C(0x06ca6351e003826f),  UINT64_C(0x142929670a0e6e70),

    UINT64_C(0x27b70a8546d22ffc),  UINT64_C(0x2e1b21385c26c926),

    UINT64_C(0x4d2c6dfc5ac42aed),  UINT64_C(0x53380d139d95b3df),

    UINT64_C(0x650a73548baf63de),  UINT64_C(0x766a0abb3c77b2a8),

    UINT64_C(0x81c2c92e47edaee6),  UINT64_C(0x92722c851482353b),

    UINT64_C(0xa2bfe8a14cf10364),  UINT64_C(0xa81a664bbc423001),

    UINT64_C(0xc24b8b70d0f89791),  UINT64_C(0xc76c51a30654be30),

    UINT64_C(0xd192e819d6ef5218),  UINT64_C(0xd69906245565a910),

    UINT64_C(0xf40e35855771202a),  UINT64_C(0x106aa07032bbd1b8),

    UINT64_C(0x19a4c116b8d2d0c8),  UINT64_C(0x1e376c085141ab53),

    UINT64_C(0x2748774cdf8eeb99),  UINT64_C(0x34b0bcb5e19b48a8),

    UINT64_C(0x391c0cb3c5c95a63),  UINT64_C(0x4ed8aa4ae3418acb),

    UINT64_C(0x5b9cca4f7763e373),  UINT64_C(0x682e6ff3d6b2b8a3),

    UINT64_C(0x748f82ee5defb2fc),  UINT64_C(0x78a5636f43172f60),

    UINT64_C(0x84c87814a1f0ab72),  UINT64_C(0x8cc702081a6439ec),

    UINT64_C(0x90befffa23631e28),  UINT64_C(0xa4506cebde82bde9),

    UINT64_C(0xbef9a3f7b2c67915),  UINT64_C(0xc67178f2e372532b),

    UINT64_C(0xca273eceea26619c),  UINT64_C(0xd186b8c721c0c207),

    UINT64_C(0xeada7dd6cde0eb1e),  UINT64_C(0xf57d4f7fee6ed178),

    UINT64_C(0x06f067aa72176fba),  UINT64_C(0x0a637dc5a2c898a6),

    UINT64_C(0x113f9804bef90dae),  UINT64_C(0x1b710b35131c471b),

    UINT64_C(0x28db77f523047d84),  UINT64_C(0x32caab7b40c72493),

    UINT64_C(0x3c9ebe0a15c9bebc),  UINT64_C(0x431d67c49c100d4c),

    UINT64_C(0x4cc5d4becb3e42b6),  UINT64_C(0x597f299cfc657e2a),

    UINT64_C(0x5fcb6fab3ad6faec),  UINT64_C(0x6c44198c4a475817),

};

#define ror(value, bits) (((value) >> (bits)) | ((value) << (64 - (bits))))

#define Ch(x,y,z)   (((x) & ((y) ^ (z))) ^ (z))

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

#define Sigma0_512(x)   (ror((x), 28) ^ ror((x), 34) ^ ror((x), 39))

#define Sigma1_512(x)   (ror((x), 14) ^ ror((x), 18) ^ ror((x), 41))

#define sigma0_512(x)   (ror((x),  1) ^ ror((x),  8) ^ ((x) >> 7))

#define sigma1_512(x)   (ror((x), 19) ^ ror((x), 61) ^ ((x) >> 6))

#define blk0(i) (block[i] = AV_RB64(buffer + 8 * (i)))

#define blk(i)  (block[i] = block[i - 16] + sigma0_512(block[i - 15]) + \

                            sigma1_512(block[i - 2]) + block[i - 7])

#define ROUND512(a,b,c,d,e,f,g,h)   \

    T1 += (h) + Sigma1_512(e) + Ch((e), (f), (g)) + K512[i]; \

    (d) += T1; \

    (h) = T1 + Sigma0_512(a) + Maj((a), (b), (c)); \

    i++

#define ROUND512_0_TO_15(a,b,c,d,e,f,g,h)   \

    T1 = blk0(i); \

    ROUND512(a,b,c,d,e,f,g,h)

#define ROUND512_16_TO_80(a,b,c,d,e,f,g,h)   \

    T1 = blk(i); \

    ROUND512(a,b,c,d,e,f,g,h)

static void sha512_transform(uint64_t *state, const uint8_t buffer[128])

{

    uint64_t a, b, c, d, e, f, g, h;

    uint64_t block[80];

    uint64_t T1;

    int i;

    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 < 80; i++) {

        uint64_t T2;

        if (i < 16)

            T1 = blk0(i);

        else

            T1 = blk(i);

        T1 += h + Sigma1_512(e) + Ch(e, f, g) + K512[i];

        T2 = Sigma0_512(a) + Maj(a, b, c);

        h = g;

        g = f;

        f = e;

        e = d + T1;

        d = c;

        c = b;

        b = a;

        a = T1 + T2;

    }

#else

#define R512_0 \

    ROUND512_0_TO_15(a, b, c, d, e, f, g, h); \

    ROUND512_0_TO_15(h, a, b, c, d, e, f, g); \

    ROUND512_0_TO_15(g, h, a, b, c, d, e, f); \

    ROUND512_0_TO_15(f, g, h, a, b, c, d, e); \

    ROUND512_0_TO_15(e, f, g, h, a, b, c, d); \

    ROUND512_0_TO_15(d, e, f, g, h, a, b, c); \

    ROUND512_0_TO_15(c, d, e, f, g, h, a, b); \

    ROUND512_0_TO_15(b, c, d, e, f, g, h, a)

    i = 0;

    R512_0; R512_0;

#define R512_16 \

    ROUND512_16_TO_80(a, b, c, d, e, f, g, h); \

    ROUND512_16_TO_80(h, a, b, c, d, e, f, g); \

    ROUND512_16_TO_80(g, h, a, b, c, d, e, f); \

    ROUND512_16_TO_80(f, g, h, a, b, c, d, e); \

    ROUND512_16_TO_80(e, f, g, h, a, b, c, d); \

    ROUND512_16_TO_80(d, e, f, g, h, a, b, c); \

    ROUND512_16_TO_80(c, d, e, f, g, h, a, b); \

    ROUND512_16_TO_80(b, c, d, e, f, g, h, a)

    R512_16; R512_16; R512_16; R512_16;

    R512_16; R512_16; R512_16; R512_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_sha512_init(AVSHA512 *ctx, int bits)

{

    ctx->digest_len = bits >> 6;

    switch (bits) {

    case 224: // SHA-512/224

        ctx->state[0] = UINT64_C(0x8C3D37C819544DA2);

        ctx->state[1] = UINT64_C(0x73E1996689DCD4D6);

        ctx->state[2] = UINT64_C(0x1DFAB7AE32FF9C82);

        ctx->state[3] = UINT64_C(0x679DD514582F9FCF);

        ctx->state[4] = UINT64_C(0x0F6D2B697BD44DA8);

        ctx->state[5] = UINT64_C(0x77E36F7304C48942);

        ctx->state[6] = UINT64_C(0x3F9D85A86A1D36C8);

        ctx->state[7] = UINT64_C(0x1112E6AD91D692A1);

        break;

    case 256: // SHA-512/256

        ctx->state[0] = UINT64_C(0x22312194FC2BF72C);

        ctx->state[1] = UINT64_C(0x9F555FA3C84C64C2);

        ctx->state[2] = UINT64_C(0x2393B86B6F53B151);

        ctx->state[3] = UINT64_C(0x963877195940EABD);

        ctx->state[4] = UINT64_C(0x96283EE2A88EFFE3);

        ctx->state[5] = UINT64_C(0xBE5E1E2553863992);

        ctx->state[6] = UINT64_C(0x2B0199FC2C85B8AA);

        ctx->state[7] = UINT64_C(0x0EB72DDC81C52CA2);

        break;

    case 384: // SHA-384

        ctx->state[0] = UINT64_C(0xCBBB9D5DC1059ED8);

        ctx->state[1] = UINT64_C(0x629A292A367CD507);

        ctx->state[2] = UINT64_C(0x9159015A3070DD17);

        ctx->state[3] = UINT64_C(0x152FECD8F70E5939);

        ctx->state[4] = UINT64_C(0x67332667FFC00B31);

        ctx->state[5] = UINT64_C(0x8EB44A8768581511);

        ctx->state[6] = UINT64_C(0xDB0C2E0D64F98FA7);

        ctx->state[7] = UINT64_C(0x47B5481DBEFA4FA4);

        break;

    case 512: // SHA-512

        ctx->state[0] = UINT64_C(0x6A09E667F3BCC908);

        ctx->state[1] = UINT64_C(0xBB67AE8584CAA73B);

        ctx->state[2] = UINT64_C(0x3C6EF372FE94F82B);

        ctx->state[3] = UINT64_C(0xA54FF53A5F1D36F1);

        ctx->state[4] = UINT64_C(0x510E527FADE682D1);

        ctx->state[5] = UINT64_C(0x9B05688C2B3E6C1F);

        ctx->state[6] = UINT64_C(0x1F83D9ABFB41BD6B);

        ctx->state[7] = UINT64_C(0x5BE0CD19137E2179);

        break;

    default:

        return AVERROR(EINVAL);

    }

    ctx->count = 0;

    return 0;

}

void av_sha512_update(AVSHA512* ctx, const uint8_t* data, size_t len)

{

    unsigned int j;

    size_t i;

    j = ctx->count & 127;

    ctx->count += len;

#if CONFIG_SMALL

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

        ctx->buffer[j++] = data[i];

        if (128 == j) {

            sha512_transform(ctx->state, ctx->buffer);

            j = 0;

        }

    }

#else

    if (len >= 128 - j) {

        const uint8_t *end;

        memcpy(&ctx->buffer[j], data, (i = 128 - j));

        sha512_transform(ctx->state, ctx->buffer);

        data += i;

        len  -= i;

        end   = data + (len & ~127);

        len   = len % 128;

        for (; data < end; data += 128)

            sha512_transform(ctx->state, data);

        j = 0;

    }

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

#endif

}

void av_sha512_final(AVSHA512* ctx, uint8_t *digest)

{

    uint64_t i = 0;

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

    av_sha512_update(ctx, "\200", 1);

    while ((ctx->count & 127) != 112)

        av_sha512_update(ctx, "", 1);

    av_sha512_update(ctx, (uint8_t *)&i, 8);

    av_sha512_update(ctx, (uint8_t *)&finalcount, 8); /* Should cause a transform() */

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

        AV_WB64(digest + i*8, ctx->state[i]);

    if (ctx->digest_len & 1) /* SHA512/224 is 28 bytes, and is not divisible by 8. */

        AV_WB32(digest + i*8, ctx->state[i] >> 32);

}