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view src/core/ngx_sha1.c @ 8085:043006e5a0b1

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SSL: optimized rotation of session ticket keys. Instead of syncing keys with shared memory on each ticket operation, the code now does this only when the worker is going to change expiration of the current key, or going to switch to a new key: that is, usually at most once per second. To do so without races, the code maintains 3 keys: current, previous, and next. If a worker will switch to the next key earlier, other workers will still be able to decrypt new tickets, since they will be encrypted with the next key.
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 12 Oct 2022 20:14:55 +0300
parents 9eefb38f0005
children
line wrap: on
line source


/*
 * Copyright (C) Maxim Dounin
 * Copyright (C) Nginx, Inc.
 *
 * An internal SHA1 implementation.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_sha1.h>


static const u_char *ngx_sha1_body(ngx_sha1_t *ctx, const u_char *data,
    size_t size);


void
ngx_sha1_init(ngx_sha1_t *ctx)
{
    ctx->a = 0x67452301;
    ctx->b = 0xefcdab89;
    ctx->c = 0x98badcfe;
    ctx->d = 0x10325476;
    ctx->e = 0xc3d2e1f0;

    ctx->bytes = 0;
}


void
ngx_sha1_update(ngx_sha1_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_sha1_body(ctx, ctx->buffer, 64);
    }

    if (size >= 64) {
        data = ngx_sha1_body(ctx, data, size & ~(size_t) 0x3f);
        size &= 0x3f;
    }

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


void
ngx_sha1_final(u_char result[20], ngx_sha1_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_sha1_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 >> 56);
    ctx->buffer[57] = (u_char) (ctx->bytes >> 48);
    ctx->buffer[58] = (u_char) (ctx->bytes >> 40);
    ctx->buffer[59] = (u_char) (ctx->bytes >> 32);
    ctx->buffer[60] = (u_char) (ctx->bytes >> 24);
    ctx->buffer[61] = (u_char) (ctx->bytes >> 16);
    ctx->buffer[62] = (u_char) (ctx->bytes >> 8);
    ctx->buffer[63] = (u_char) ctx->bytes;

    (void) ngx_sha1_body(ctx, ctx->buffer, 64);

    result[0] = (u_char) (ctx->a >> 24);
    result[1] = (u_char) (ctx->a >> 16);
    result[2] = (u_char) (ctx->a >> 8);
    result[3] = (u_char) ctx->a;
    result[4] = (u_char) (ctx->b >> 24);
    result[5] = (u_char) (ctx->b >> 16);
    result[6] = (u_char) (ctx->b >> 8);
    result[7] = (u_char) ctx->b;
    result[8] = (u_char) (ctx->c >> 24);
    result[9] = (u_char) (ctx->c >> 16);
    result[10] = (u_char) (ctx->c >> 8);
    result[11] = (u_char) ctx->c;
    result[12] = (u_char) (ctx->d >> 24);
    result[13] = (u_char) (ctx->d >> 16);
    result[14] = (u_char) (ctx->d >> 8);
    result[15] = (u_char) ctx->d;
    result[16] = (u_char) (ctx->e >> 24);
    result[17] = (u_char) (ctx->e >> 16);
    result[18] = (u_char) (ctx->e >> 8);
    result[19] = (u_char) ctx->e;

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


/*
 * Helper functions.
 */

#define ROTATE(bits, word)  (((word) << (bits)) | ((word) >> (32 - (bits))))

#define F1(b, c, d)  (((b) & (c)) | ((~(b)) & (d)))
#define F2(b, c, d)  ((b) ^ (c) ^ (d))
#define F3(b, c, d)  (((b) & (c)) | ((b) & (d)) | ((c) & (d)))

#define STEP(f, a, b, c, d, e, w, t)                                          \
    temp = ROTATE(5, (a)) + f((b), (c), (d)) + (e) + (w) + (t);               \
    (e) = (d);                                                                \
    (d) = (c);                                                                \
    (c) = ROTATE(30, (b));                                                    \
    (b) = (a);                                                                \
    (a) = temp;


/*
 * GET() reads 4 input bytes in big-endian byte order and returns
 * them as uint32_t.
 */

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


/*
 * 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_sha1_body(ngx_sha1_t *ctx, const u_char *data, size_t size)
{
    uint32_t       a, b, c, d, e, temp;
    uint32_t       saved_a, saved_b, saved_c, saved_d, saved_e;
    uint32_t       words[80];
    ngx_uint_t     i;
    const u_char  *p;

    p = data;

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

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

        /* Load data block into the words array */

        for (i = 0; i < 16; i++) {
            words[i] = GET(i);
        }

        for (i = 16; i < 80; i++) {
            words[i] = ROTATE(1, words[i - 3] ^ words[i - 8] ^ words[i - 14]
                                 ^ words[i - 16]);
        }

        /* Transformations */

        STEP(F1, a, b, c, d, e, words[0],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[1],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[2],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[3],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[4],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[5],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[6],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[7],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[8],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[9],  0x5a827999);
        STEP(F1, a, b, c, d, e, words[10], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[11], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[12], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[13], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[14], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[15], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[16], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[17], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[18], 0x5a827999);
        STEP(F1, a, b, c, d, e, words[19], 0x5a827999);

        STEP(F2, a, b, c, d, e, words[20], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[21], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[22], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[23], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[24], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[25], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[26], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[27], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[28], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[29], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[30], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[31], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[32], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[33], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[34], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[35], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[36], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[37], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[38], 0x6ed9eba1);
        STEP(F2, a, b, c, d, e, words[39], 0x6ed9eba1);

        STEP(F3, a, b, c, d, e, words[40], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[41], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[42], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[43], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[44], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[45], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[46], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[47], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[48], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[49], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[50], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[51], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[52], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[53], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[54], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[55], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[56], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[57], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[58], 0x8f1bbcdc);
        STEP(F3, a, b, c, d, e, words[59], 0x8f1bbcdc);

        STEP(F2, a, b, c, d, e, words[60], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[61], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[62], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[63], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[64], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[65], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[66], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[67], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[68], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[69], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[70], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[71], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[72], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[73], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[74], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[75], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[76], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[77], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[78], 0xca62c1d6);
        STEP(F2, a, b, c, d, e, words[79], 0xca62c1d6);

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

        p += 64;

    } while (size -= 64);

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

    return p;
}