md5.c

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/*-------------------------------------------------------------------------
 *
 *  md5.c
 *    Implements the MD5 Message-Digest Algorithm
 *
 * Fallback implementation of MD5, as specified in RFC 1321.  This
 * implementation is a simple one, in that it needs every input byte
 * to be buffered before doing any calculations.
 *
 *  Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 *  Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *    src/common/md5.c
 *
 *-------------------------------------------------------------------------
 */
 
/*    $KAME: md5.c,v 1.3 2000/02/22 14:01:17 itojun Exp $     */
 
/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
 
#ifndef FRONTEND
#include "postgres.h"
#else
#include "postgres_fe.h"
#endif
 
#include "md5_int.h"
 
#define SHIFT(X, s) (((X) << (s)) | ((X) >> (32 - (s))))
 
#define F(X, Y, Z) (((X) & (Y)) | ((~X) & (Z)))
#define G(X, Y, Z) (((X) & (Z)) | ((Y) & (~Z)))
#define H(X, Y, Z) ((X) ^ (Y) ^ (Z))
#define I(X, Y, Z) ((Y) ^ ((X) | (~Z)))
 
#define ROUND1(a, b, c, d, k, s, i) \
do { \
    (a) = (a) + F((b), (c), (d)) + X[(k)] + T[(i)]; \
    (a) = SHIFT((a), (s)); \
    (a) = (b) + (a); \
} while (0)
 
#define ROUND2(a, b, c, d, k, s, i) \
do { \
    (a) = (a) + G((b), (c), (d)) + X[(k)] + T[(i)]; \
    (a) = SHIFT((a), (s)); \
    (a) = (b) + (a); \
} while (0)
 
#define ROUND3(a, b, c, d, k, s, i) \
do { \
    (a) = (a) + H((b), (c), (d)) + X[(k)] + T[(i)]; \
    (a) = SHIFT((a), (s)); \
    (a) = (b) + (a); \
} while (0)
 
#define ROUND4(a, b, c, d, k, s, i) \
do { \
    (a) = (a) + I((b), (c), (d)) + X[(k)] + T[(i)]; \
    (a) = SHIFT((a), (s)); \
    (a) = (b) + (a); \
} while (0)
 
#define Sa   7
#define Sb  12
#define Sc  17
#define Sd  22
 
#define Se   5
#define Sf   9
#define Sg  14
#define Sh  20
 
#define Si   4
#define Sj  11
#define Sk  16
#define Sl  23
 
#define Sm   6
#define Sn  10
#define So  15
#define Sp  21
 
#define MD5_A0  0x67452301
#define MD5_B0  0xefcdab89
#define MD5_C0  0x98badcfe
#define MD5_D0  0x10325476
 
/* Integer part of 4294967296 times abs(sin(i)), where i is in radians. */
static const uint32 T[65] = {
    0,
    0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
    0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
    0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
    0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
 
    0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
    0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
    0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
    0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
 
    0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
    0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
    0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
    0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
 
    0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
    0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
    0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
    0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
};
 
static const uint8 md5_paddat[MD5_BUFLEN] = {
    0x80, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
};
 
static void
md5_calc(const uint8 *b64, pg_md5_ctx *ctx)
{
    uint32      A = ctx->md5_sta;
    uint32      B = ctx->md5_stb;
    uint32      C = ctx->md5_stc;
    uint32      D = ctx->md5_std;
 
#ifndef WORDS_BIGENDIAN
    const uint32 *X = (const uint32 *) b64;
#else
    /* 4 byte words */
    /* what a brute force but fast! */
    uint32      X[16];
    uint8      *y = (uint8 *) X;
 
    y[0] = b64[3];
    y[1] = b64[2];
    y[2] = b64[1];
    y[3] = b64[0];
    y[4] = b64[7];
    y[5] = b64[6];
    y[6] = b64[5];
    y[7] = b64[4];
    y[8] = b64[11];
    y[9] = b64[10];
    y[10] = b64[9];
    y[11] = b64[8];
    y[12] = b64[15];
    y[13] = b64[14];
    y[14] = b64[13];
    y[15] = b64[12];
    y[16] = b64[19];
    y[17] = b64[18];
    y[18] = b64[17];
    y[19] = b64[16];
    y[20] = b64[23];
    y[21] = b64[22];
    y[22] = b64[21];
    y[23] = b64[20];
    y[24] = b64[27];
    y[25] = b64[26];
    y[26] = b64[25];
    y[27] = b64[24];
    y[28] = b64[31];
    y[29] = b64[30];
    y[30] = b64[29];
    y[31] = b64[28];
    y[32] = b64[35];
    y[33] = b64[34];
    y[34] = b64[33];
    y[35] = b64[32];
    y[36] = b64[39];
    y[37] = b64[38];
    y[38] = b64[37];
    y[39] = b64[36];
    y[40] = b64[43];
    y[41] = b64[42];
    y[42] = b64[41];
    y[43] = b64[40];
    y[44] = b64[47];
    y[45] = b64[46];
    y[46] = b64[45];
    y[47] = b64[44];
    y[48] = b64[51];
    y[49] = b64[50];
    y[50] = b64[49];
    y[51] = b64[48];
    y[52] = b64[55];
    y[53] = b64[54];
    y[54] = b64[53];
    y[55] = b64[52];
    y[56] = b64[59];
    y[57] = b64[58];
    y[58] = b64[57];
    y[59] = b64[56];
    y[60] = b64[63];
    y[61] = b64[62];
    y[62] = b64[61];
    y[63] = b64[60];
#endif
 
    ROUND1(A, B, C, D, 0, Sa, 1);
    ROUND1(D, A, B, C, 1, Sb, 2);
    ROUND1(C, D, A, B, 2, Sc, 3);
    ROUND1(B, C, D, A, 3, Sd, 4);
    ROUND1(A, B, C, D, 4, Sa, 5);
    ROUND1(D, A, B, C, 5, Sb, 6);
    ROUND1(C, D, A, B, 6, Sc, 7);
    ROUND1(B, C, D, A, 7, Sd, 8);
    ROUND1(A, B, C, D, 8, Sa, 9);
    ROUND1(D, A, B, C, 9, Sb, 10);
    ROUND1(C, D, A, B, 10, Sc, 11);
    ROUND1(B, C, D, A, 11, Sd, 12);
    ROUND1(A, B, C, D, 12, Sa, 13);
    ROUND1(D, A, B, C, 13, Sb, 14);
    ROUND1(C, D, A, B, 14, Sc, 15);
    ROUND1(B, C, D, A, 15, Sd, 16);
 
    ROUND2(A, B, C, D, 1, Se, 17);
    ROUND2(D, A, B, C, 6, Sf, 18);
    ROUND2(C, D, A, B, 11, Sg, 19);
    ROUND2(B, C, D, A, 0, Sh, 20);
    ROUND2(A, B, C, D, 5, Se, 21);
    ROUND2(D, A, B, C, 10, Sf, 22);
    ROUND2(C, D, A, B, 15, Sg, 23);
    ROUND2(B, C, D, A, 4, Sh, 24);
    ROUND2(A, B, C, D, 9, Se, 25);
    ROUND2(D, A, B, C, 14, Sf, 26);
    ROUND2(C, D, A, B, 3, Sg, 27);
    ROUND2(B, C, D, A, 8, Sh, 28);
    ROUND2(A, B, C, D, 13, Se, 29);
    ROUND2(D, A, B, C, 2, Sf, 30);
    ROUND2(C, D, A, B, 7, Sg, 31);
    ROUND2(B, C, D, A, 12, Sh, 32);
 
    ROUND3(A, B, C, D, 5, Si, 33);
    ROUND3(D, A, B, C, 8, Sj, 34);
    ROUND3(C, D, A, B, 11, Sk, 35);
    ROUND3(B, C, D, A, 14, Sl, 36);
    ROUND3(A, B, C, D, 1, Si, 37);
    ROUND3(D, A, B, C, 4, Sj, 38);
    ROUND3(C, D, A, B, 7, Sk, 39);
    ROUND3(B, C, D, A, 10, Sl, 40);
    ROUND3(A, B, C, D, 13, Si, 41);
    ROUND3(D, A, B, C, 0, Sj, 42);
    ROUND3(C, D, A, B, 3, Sk, 43);
    ROUND3(B, C, D, A, 6, Sl, 44);
    ROUND3(A, B, C, D, 9, Si, 45);
    ROUND3(D, A, B, C, 12, Sj, 46);
    ROUND3(C, D, A, B, 15, Sk, 47);
    ROUND3(B, C, D, A, 2, Sl, 48);
 
    ROUND4(A, B, C, D, 0, Sm, 49);
    ROUND4(D, A, B, C, 7, Sn, 50);
    ROUND4(C, D, A, B, 14, So, 51);
    ROUND4(B, C, D, A, 5, Sp, 52);
    ROUND4(A, B, C, D, 12, Sm, 53);
    ROUND4(D, A, B, C, 3, Sn, 54);
    ROUND4(C, D, A, B, 10, So, 55);
    ROUND4(B, C, D, A, 1, Sp, 56);
    ROUND4(A, B, C, D, 8, Sm, 57);
    ROUND4(D, A, B, C, 15, Sn, 58);
    ROUND4(C, D, A, B, 6, So, 59);
    ROUND4(B, C, D, A, 13, Sp, 60);
    ROUND4(A, B, C, D, 4, Sm, 61);
    ROUND4(D, A, B, C, 11, Sn, 62);
    ROUND4(C, D, A, B, 2, So, 63);
    ROUND4(B, C, D, A, 9, Sp, 64);
 
    ctx->md5_sta += A;
    ctx->md5_stb += B;
    ctx->md5_stc += C;
    ctx->md5_std += D;
}
 
static void
md5_pad(pg_md5_ctx *ctx)
{
    unsigned int gap;
 
    /* Don't count up padding. Keep md5_n. */
    gap = MD5_BUFLEN - ctx->md5_i;
    if (gap > 8)
    {
        memmove(ctx->md5_buf + ctx->md5_i, md5_paddat,
                gap - sizeof(ctx->md5_n));
    }
    else
    {
        /* including gap == 8 */
        memmove(ctx->md5_buf + ctx->md5_i, md5_paddat, gap);
        md5_calc(ctx->md5_buf, ctx);
        memmove(ctx->md5_buf, md5_paddat + gap,
                MD5_BUFLEN - sizeof(ctx->md5_n));
    }
 
    /* 8 byte word */
#ifndef WORDS_BIGENDIAN
    memmove(&ctx->md5_buf[56], &ctx->md5_n8[0], 8);
#else
    ctx->md5_buf[56] = ctx->md5_n8[7];
    ctx->md5_buf[57] = ctx->md5_n8[6];
    ctx->md5_buf[58] = ctx->md5_n8[5];
    ctx->md5_buf[59] = ctx->md5_n8[4];
    ctx->md5_buf[60] = ctx->md5_n8[3];
    ctx->md5_buf[61] = ctx->md5_n8[2];
    ctx->md5_buf[62] = ctx->md5_n8[1];
    ctx->md5_buf[63] = ctx->md5_n8[0];
#endif
 
    md5_calc(ctx->md5_buf, ctx);
}
 
static void
md5_result(uint8 *digest, pg_md5_ctx *ctx)
{
    /* 4 byte words */
#ifndef WORDS_BIGENDIAN
    memmove(digest, &ctx->md5_st8[0], 16);
#else
    digest[0] = ctx->md5_st8[3];
    digest[1] = ctx->md5_st8[2];
    digest[2] = ctx->md5_st8[1];
    digest[3] = ctx->md5_st8[0];
    digest[4] = ctx->md5_st8[7];
    digest[5] = ctx->md5_st8[6];
    digest[6] = ctx->md5_st8[5];
    digest[7] = ctx->md5_st8[4];
    digest[8] = ctx->md5_st8[11];
    digest[9] = ctx->md5_st8[10];
    digest[10] = ctx->md5_st8[9];
    digest[11] = ctx->md5_st8[8];
    digest[12] = ctx->md5_st8[15];
    digest[13] = ctx->md5_st8[14];
    digest[14] = ctx->md5_st8[13];
    digest[15] = ctx->md5_st8[12];
#endif
}
 
 
/* External routines for this MD5 implementation */
 
/*
 * pg_md5_init
 *
 * Initialize a MD5 context.
 */
void
pg_md5_init(pg_md5_ctx *ctx)
{
    ctx->md5_n = 0;
    ctx->md5_i = 0;
    ctx->md5_sta = MD5_A0;
    ctx->md5_stb = MD5_B0;
    ctx->md5_stc = MD5_C0;
    ctx->md5_std = MD5_D0;
    memset(ctx->md5_buf, 0, sizeof(ctx->md5_buf));
}
 
 
/*
 * pg_md5_update
 *
 * Update a MD5 context.
 */
void
pg_md5_update(pg_md5_ctx *ctx, const uint8 *data, size_t len)
{
    unsigned int gap,
                i;
 
    ctx->md5_n += len * 8;      /* byte to bit */
    gap = MD5_BUFLEN - ctx->md5_i;
 
    if (len >= gap)
    {
        memmove(ctx->md5_buf + ctx->md5_i, data, gap);
        md5_calc(ctx->md5_buf, ctx);
 
        for (i = gap; i + MD5_BUFLEN <= len; i += MD5_BUFLEN)
            md5_calc(data + i, ctx);
 
        ctx->md5_i = len - i;
        memmove(ctx->md5_buf, data + i, ctx->md5_i);
    }
    else
    {
        memmove(ctx->md5_buf + ctx->md5_i, data, len);
        ctx->md5_i += len;
    }
}
 
/*
 * pg_md5_final
 *
 * Finalize a MD5 context.
 */
void
pg_md5_final(pg_md5_ctx *ctx, uint8 *dest)
{
    md5_pad(ctx);
    md5_result(dest, ctx);
}