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Diffstat (limited to 'third_party/bearssl/src/multihash.c')
| -rw-r--r-- | third_party/bearssl/src/multihash.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/third_party/bearssl/src/multihash.c b/third_party/bearssl/src/multihash.c new file mode 100644 index 0000000..b6df2e0 --- /dev/null +++ b/third_party/bearssl/src/multihash.c @@ -0,0 +1,166 @@ +/* + * Copyright (c) 2016 Thomas Pornin <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "inner.h" + +/* + * An aggregate context that is large enough for all supported hash + * functions. + */ +typedef union { + const br_hash_class *vtable; + br_md5_context md5; + br_sha1_context sha1; + br_sha224_context sha224; + br_sha256_context sha256; + br_sha384_context sha384; + br_sha512_context sha512; +} gen_hash_context; + +/* + * Get the offset to the state for a specific hash function within the + * context structure. This shall be called only for the supported hash + * functions, + */ +static size_t +get_state_offset(int id) +{ + if (id >= 5) { + /* + * SHA-384 has id 5, and SHA-512 has id 6. Both use + * eight 64-bit words for their state. + */ + return offsetof(br_multihash_context, val_64) + + ((size_t)(id - 5) * (8 * sizeof(uint64_t))); + } else { + /* + * MD5 has id 1, SHA-1 has id 2, SHA-224 has id 3 and + * SHA-256 has id 4. They use 32-bit words for their + * states (4 words for MD5, 5 for SHA-1, 8 for SHA-224 + * and 8 for SHA-256). + */ + unsigned x; + + x = id - 1; + x = ((x + (x & (x >> 1))) << 2) + (x >> 1); + return offsetof(br_multihash_context, val_32) + + x * sizeof(uint32_t); + } +} + +/* see bearssl_hash.h */ +void +br_multihash_zero(br_multihash_context *ctx) +{ + /* + * This is not standard, but yields very short and efficient code, + * and it works "everywhere". + */ + memset(ctx, 0, sizeof *ctx); +} + +/* see bearssl_hash.h */ +void +br_multihash_init(br_multihash_context *ctx) +{ + int i; + + ctx->count = 0; + for (i = 1; i <= 6; i ++) { + const br_hash_class *hc; + + hc = ctx->impl[i - 1]; + if (hc != NULL) { + gen_hash_context g; + + hc->init(&g.vtable); + hc->state(&g.vtable, + (unsigned char *)ctx + get_state_offset(i)); + } + } +} + +/* see bearssl_hash.h */ +void +br_multihash_update(br_multihash_context *ctx, const void *data, size_t len) +{ + const unsigned char *buf; + size_t ptr; + + buf = data; + ptr = (size_t)ctx->count & 127; + while (len > 0) { + size_t clen; + + clen = 128 - ptr; + if (clen > len) { + clen = len; + } + memcpy(ctx->buf + ptr, buf, clen); + ptr += clen; + buf += clen; + len -= clen; + ctx->count += (uint64_t)clen; + if (ptr == 128) { + int i; + + for (i = 1; i <= 6; i ++) { + const br_hash_class *hc; + + hc = ctx->impl[i - 1]; + if (hc != NULL) { + gen_hash_context g; + unsigned char *state; + + state = (unsigned char *)ctx + + get_state_offset(i); + hc->set_state(&g.vtable, + state, ctx->count - 128); + hc->update(&g.vtable, ctx->buf, 128); + hc->state(&g.vtable, state); + } + } + ptr = 0; + } + } +} + +/* see bearssl_hash.h */ +size_t +br_multihash_out(const br_multihash_context *ctx, int id, void *dst) +{ + const br_hash_class *hc; + gen_hash_context g; + const unsigned char *state; + + hc = ctx->impl[id - 1]; + if (hc == NULL) { + return 0; + } + state = (const unsigned char *)ctx + get_state_offset(id); + hc->set_state(&g.vtable, state, ctx->count & ~(uint64_t)127); + hc->update(&g.vtable, ctx->buf, ctx->count & (uint64_t)127); + hc->out(&g.vtable, dst); + return (hc->desc >> BR_HASHDESC_OUT_OFF) & BR_HASHDESC_OUT_MASK; +} |