Mercurial > hg > nginx
view src/core/ngx_sha1.c @ 9300:5be23505292b
SSI: fixed incorrect or duplicate stub output.
Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set
if there are data in the first buffer sent in the subrequest. As a
result, following the change mentioned this flag cannot be used to
prevent duplicate ngx_http_ssi_stub_output() calls, since it is not
set if there was already some output, but the first buffer was empty.
Still, when there are multiple subrequests, even an empty subrequest
response might be delayed by the postpone filter, leading to a second
call of ngx_http_ssi_stub_output() during finalization from
ngx_http_writer() the subreqest buffers are released by the postpone
filter. Since r->request_output is not set after the first call, this
resulted in duplicate stub output.
Additionally, checking only the first buffer might be wrong in some
unusual cases. For example, the first buffer might be empty if
$r->flush() is called before printing any data in the embedded Perl
module.
Depending on the postpone_output value and corresponding sizes, this
issue can result in either duplicate or unexpected stub output, or
"zero size buf in writer" alerts.
Following 8124:f5515e727656 (1.23.4), it became slightly easier to
reproduce the issue, as empty static files and empty cache items now
result in a response with an empty buffer. Before the change, an empty
proxied response can be used to reproduce the issue.
Fix is check all buffers and set r->request_output if any non-empty
buffers are sent. This ensures that all unusual cases of non-empty
responses are covered, and also that r->request_output will be set
after the first stub output, preventing duplicate output.
Reported by Jan Gassen.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 04 Jul 2024 17:41:28 +0300 |
parents | 9eefb38f0005 |
children | 0086f8da5d8d |
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/* * 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; }