view src/core/ngx_md5.c @ 7726:559d19037984

Limit req: unlocking of nodes on complex value errors. Previously, if there were multiple limits configured, errors in ngx_http_complex_value() during processing of a non-first limit resulted in reference count leak in shared memory nodes of already processed limits. Fix is to explicity unlock relevant nodes, much like we do when rejecting requests.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 08 Oct 2020 17:44:34 +0300
parents 9eefb38f0005
children
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/*
 * An internal implementation, based on Alexander Peslyak's
 * public domain implementation:
 * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_md5.h>


static const u_char *ngx_md5_body(ngx_md5_t *ctx, const u_char *data,
    size_t size);


void
ngx_md5_init(ngx_md5_t *ctx)
{
    ctx->a = 0x67452301;
    ctx->b = 0xefcdab89;
    ctx->c = 0x98badcfe;
    ctx->d = 0x10325476;

    ctx->bytes = 0;
}


void
ngx_md5_update(ngx_md5_t *ctx, const void *data, size_t size)
{
    size_t  used, free;

    used = (size_t) (ctx->bytes & 0x3f);
    ctx->bytes += size;

    if (used) {
        free = 64 - used;

        if (size < free) {
            ngx_memcpy(&ctx->buffer[used], data, size);
            return;
        }

        ngx_memcpy(&ctx->buffer[used], data, free);
        data = (u_char *) data + free;
        size -= free;
        (void) ngx_md5_body(ctx, ctx->buffer, 64);
    }

    if (size >= 64) {
        data = ngx_md5_body(ctx, data, size & ~(size_t) 0x3f);
        size &= 0x3f;
    }

    ngx_memcpy(ctx->buffer, data, size);
}


void
ngx_md5_final(u_char result[16], ngx_md5_t *ctx)
{
    size_t  used, free;

    used = (size_t) (ctx->bytes & 0x3f);

    ctx->buffer[used++] = 0x80;

    free = 64 - used;

    if (free < 8) {
        ngx_memzero(&ctx->buffer[used], free);
        (void) ngx_md5_body(ctx, ctx->buffer, 64);
        used = 0;
        free = 64;
    }

    ngx_memzero(&ctx->buffer[used], free - 8);

    ctx->bytes <<= 3;
    ctx->buffer[56] = (u_char) ctx->bytes;
    ctx->buffer[57] = (u_char) (ctx->bytes >> 8);
    ctx->buffer[58] = (u_char) (ctx->bytes >> 16);
    ctx->buffer[59] = (u_char) (ctx->bytes >> 24);
    ctx->buffer[60] = (u_char) (ctx->bytes >> 32);
    ctx->buffer[61] = (u_char) (ctx->bytes >> 40);
    ctx->buffer[62] = (u_char) (ctx->bytes >> 48);
    ctx->buffer[63] = (u_char) (ctx->bytes >> 56);

    (void) ngx_md5_body(ctx, ctx->buffer, 64);

    result[0] = (u_char) ctx->a;
    result[1] = (u_char) (ctx->a >> 8);
    result[2] = (u_char) (ctx->a >> 16);
    result[3] = (u_char) (ctx->a >> 24);
    result[4] = (u_char) ctx->b;
    result[5] = (u_char) (ctx->b >> 8);
    result[6] = (u_char) (ctx->b >> 16);
    result[7] = (u_char) (ctx->b >> 24);
    result[8] = (u_char) ctx->c;
    result[9] = (u_char) (ctx->c >> 8);
    result[10] = (u_char) (ctx->c >> 16);
    result[11] = (u_char) (ctx->c >> 24);
    result[12] = (u_char) ctx->d;
    result[13] = (u_char) (ctx->d >> 8);
    result[14] = (u_char) (ctx->d >> 16);
    result[15] = (u_char) (ctx->d >> 24);

    ngx_memzero(ctx, sizeof(*ctx));
}


/*
 * The basic MD5 functions.
 *
 * F and G are optimized compared to their RFC 1321 definitions for
 * architectures that lack an AND-NOT instruction, just like in
 * Colin Plumb's implementation.
 */

#define F(x, y, z)  ((z) ^ ((x) & ((y) ^ (z))))
#define G(x, y, z)  ((y) ^ ((z) & ((x) ^ (y))))
#define H(x, y, z)  ((x) ^ (y) ^ (z))
#define I(x, y, z)  ((y) ^ ((x) | ~(z)))

/*
 * The MD5 transformation for all four rounds.
 */

#define STEP(f, a, b, c, d, x, t, s)                                          \
    (a) += f((b), (c), (d)) + (x) + (t);                                      \
    (a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s))));                \
    (a) += (b)

/*
 * SET() reads 4 input bytes in little-endian byte order and stores them
 * in a properly aligned word in host byte order.
 *
 * The check for little-endian architectures that tolerate unaligned
 * memory accesses is just an optimization.  Nothing will break if it
 * does not work.
 */

#if (NGX_HAVE_LITTLE_ENDIAN && NGX_HAVE_NONALIGNED)

#define SET(n)      (*(uint32_t *) &p[n * 4])
#define GET(n)      (*(uint32_t *) &p[n * 4])

#else

#define SET(n)                                                                \
    (block[n] =                                                               \
    (uint32_t) p[n * 4] |                                                     \
    ((uint32_t) p[n * 4 + 1] << 8) |                                          \
    ((uint32_t) p[n * 4 + 2] << 16) |                                         \
    ((uint32_t) p[n * 4 + 3] << 24))

#define GET(n)      block[n]

#endif


/*
 * This processes one or more 64-byte data blocks, but does not update
 * the bit counters.  There are no alignment requirements.
 */

static const u_char *
ngx_md5_body(ngx_md5_t *ctx, const u_char *data, size_t size)
{
    uint32_t       a, b, c, d;
    uint32_t       saved_a, saved_b, saved_c, saved_d;
    const u_char  *p;
#if !(NGX_HAVE_LITTLE_ENDIAN && NGX_HAVE_NONALIGNED)
    uint32_t       block[16];
#endif

    p = data;

    a = ctx->a;
    b = ctx->b;
    c = ctx->c;
    d = ctx->d;

    do {
        saved_a = a;
        saved_b = b;
        saved_c = c;
        saved_d = d;

        /* Round 1 */

        STEP(F, a, b, c, d, SET(0),  0xd76aa478, 7);
        STEP(F, d, a, b, c, SET(1),  0xe8c7b756, 12);
        STEP(F, c, d, a, b, SET(2),  0x242070db, 17);
        STEP(F, b, c, d, a, SET(3),  0xc1bdceee, 22);
        STEP(F, a, b, c, d, SET(4),  0xf57c0faf, 7);
        STEP(F, d, a, b, c, SET(5),  0x4787c62a, 12);
        STEP(F, c, d, a, b, SET(6),  0xa8304613, 17);
        STEP(F, b, c, d, a, SET(7),  0xfd469501, 22);
        STEP(F, a, b, c, d, SET(8),  0x698098d8, 7);
        STEP(F, d, a, b, c, SET(9),  0x8b44f7af, 12);
        STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17);
        STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22);
        STEP(F, a, b, c, d, SET(12), 0x6b901122, 7);
        STEP(F, d, a, b, c, SET(13), 0xfd987193, 12);
        STEP(F, c, d, a, b, SET(14), 0xa679438e, 17);
        STEP(F, b, c, d, a, SET(15), 0x49b40821, 22);

        /* Round 2 */

        STEP(G, a, b, c, d, GET(1),  0xf61e2562, 5);
        STEP(G, d, a, b, c, GET(6),  0xc040b340, 9);
        STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14);
        STEP(G, b, c, d, a, GET(0),  0xe9b6c7aa, 20);
        STEP(G, a, b, c, d, GET(5),  0xd62f105d, 5);
        STEP(G, d, a, b, c, GET(10), 0x02441453, 9);
        STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14);
        STEP(G, b, c, d, a, GET(4),  0xe7d3fbc8, 20);
        STEP(G, a, b, c, d, GET(9),  0x21e1cde6, 5);
        STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9);
        STEP(G, c, d, a, b, GET(3),  0xf4d50d87, 14);
        STEP(G, b, c, d, a, GET(8),  0x455a14ed, 20);
        STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5);
        STEP(G, d, a, b, c, GET(2),  0xfcefa3f8, 9);
        STEP(G, c, d, a, b, GET(7),  0x676f02d9, 14);
        STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20);

        /* Round 3 */

        STEP(H, a, b, c, d, GET(5),  0xfffa3942, 4);
        STEP(H, d, a, b, c, GET(8),  0x8771f681, 11);
        STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16);
        STEP(H, b, c, d, a, GET(14), 0xfde5380c, 23);
        STEP(H, a, b, c, d, GET(1),  0xa4beea44, 4);
        STEP(H, d, a, b, c, GET(4),  0x4bdecfa9, 11);
        STEP(H, c, d, a, b, GET(7),  0xf6bb4b60, 16);
        STEP(H, b, c, d, a, GET(10), 0xbebfbc70, 23);
        STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4);
        STEP(H, d, a, b, c, GET(0),  0xeaa127fa, 11);
        STEP(H, c, d, a, b, GET(3),  0xd4ef3085, 16);
        STEP(H, b, c, d, a, GET(6),  0x04881d05, 23);
        STEP(H, a, b, c, d, GET(9),  0xd9d4d039, 4);
        STEP(H, d, a, b, c, GET(12), 0xe6db99e5, 11);
        STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16);
        STEP(H, b, c, d, a, GET(2),  0xc4ac5665, 23);

        /* Round 4 */

        STEP(I, a, b, c, d, GET(0),  0xf4292244, 6);
        STEP(I, d, a, b, c, GET(7),  0x432aff97, 10);
        STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15);
        STEP(I, b, c, d, a, GET(5),  0xfc93a039, 21);
        STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6);
        STEP(I, d, a, b, c, GET(3),  0x8f0ccc92, 10);
        STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15);
        STEP(I, b, c, d, a, GET(1),  0x85845dd1, 21);
        STEP(I, a, b, c, d, GET(8),  0x6fa87e4f, 6);
        STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10);
        STEP(I, c, d, a, b, GET(6),  0xa3014314, 15);
        STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21);
        STEP(I, a, b, c, d, GET(4),  0xf7537e82, 6);
        STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10);
        STEP(I, c, d, a, b, GET(2),  0x2ad7d2bb, 15);
        STEP(I, b, c, d, a, GET(9),  0xeb86d391, 21);

        a += saved_a;
        b += saved_b;
        c += saved_c;
        d += saved_d;

        p += 64;

    } while (size -= 64);

    ctx->a = a;
    ctx->b = b;
    ctx->c = c;
    ctx->d = d;

    return p;
}