Mercurial > hg > nginx
view src/core/ngx_sha1.c @ 7401:a7ff19afbb14
Negative size buffers detection.
In the past, there were several security issues which resulted in
worker process memory disclosure due to buffers with negative size.
It looks reasonable to check for such buffers in various places,
much like we already check for zero size buffers.
While here, removed "#if 1 / #endif" around zero size buffer checks.
It looks highly unlikely that we'll disable these checks anytime soon.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 26 Nov 2018 18:29:56 +0300 |
parents | 9eefb38f0005 |
children |
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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; }