| 1 | /*
|
|---|
| 2 | Unix SMB/CIFS implementation.
|
|---|
| 3 |
|
|---|
| 4 | Interface header: HMAC SHA-256 code
|
|---|
| 5 |
|
|---|
| 6 | Copyright (C) Andrew Tridgell 2008
|
|---|
| 7 |
|
|---|
| 8 | based in hmacsha1.c which is:
|
|---|
| 9 | Copyright (C) Stefan Metzmacher
|
|---|
| 10 |
|
|---|
| 11 | This program is free software; you can redistribute it and/or modify
|
|---|
| 12 | it under the terms of the GNU General Public License as published by
|
|---|
| 13 | the Free Software Foundation; either version 3 of the License, or
|
|---|
| 14 | (at your option) any later version.
|
|---|
| 15 |
|
|---|
| 16 | This program is distributed in the hope that it will be useful,
|
|---|
| 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|---|
| 19 | GNU General Public License for more details.
|
|---|
| 20 |
|
|---|
| 21 | You should have received a copy of the GNU General Public License
|
|---|
| 22 | along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|---|
| 23 | */
|
|---|
| 24 |
|
|---|
| 25 | /*
|
|---|
| 26 | taken direct from rfc2202 implementation and modified for suitable use
|
|---|
| 27 | */
|
|---|
| 28 |
|
|---|
| 29 | #include "replace.h"
|
|---|
| 30 | #include "../lib/crypto/crypto.h"
|
|---|
| 31 |
|
|---|
| 32 | /***********************************************************************
|
|---|
| 33 | the rfc 2104/2202 version of hmac_sha256 initialisation.
|
|---|
| 34 | ***********************************************************************/
|
|---|
| 35 | _PUBLIC_ void hmac_sha256_init(const uint8_t *key, size_t key_len, struct HMACSHA256Context *ctx)
|
|---|
| 36 | {
|
|---|
| 37 | int i;
|
|---|
| 38 | uint8_t tk[SHA256_DIGEST_LENGTH];
|
|---|
| 39 |
|
|---|
| 40 | /* if key is longer than 64 bytes reset it to key=HASH(key) */
|
|---|
| 41 | if (key_len > 64)
|
|---|
| 42 | {
|
|---|
| 43 | SHA256_CTX tctx;
|
|---|
| 44 |
|
|---|
| 45 | SHA256_Init(&tctx);
|
|---|
| 46 | SHA256_Update(&tctx, key, key_len);
|
|---|
| 47 | SHA256_Final(tk, &tctx);
|
|---|
| 48 |
|
|---|
| 49 | key = tk;
|
|---|
| 50 | key_len = SHA256_DIGEST_LENGTH;
|
|---|
| 51 | }
|
|---|
| 52 |
|
|---|
| 53 | /* start out by storing key in pads */
|
|---|
| 54 | ZERO_STRUCT(ctx->k_ipad);
|
|---|
| 55 | ZERO_STRUCT(ctx->k_opad);
|
|---|
| 56 | memcpy( ctx->k_ipad, key, key_len);
|
|---|
| 57 | memcpy( ctx->k_opad, key, key_len);
|
|---|
| 58 |
|
|---|
| 59 | /* XOR key with ipad and opad values */
|
|---|
| 60 | for (i=0; i<64; i++)
|
|---|
| 61 | {
|
|---|
| 62 | ctx->k_ipad[i] ^= 0x36;
|
|---|
| 63 | ctx->k_opad[i] ^= 0x5c;
|
|---|
| 64 | }
|
|---|
| 65 |
|
|---|
| 66 | SHA256_Init(&ctx->ctx);
|
|---|
| 67 | SHA256_Update(&ctx->ctx, ctx->k_ipad, 64);
|
|---|
| 68 | }
|
|---|
| 69 |
|
|---|
| 70 | /***********************************************************************
|
|---|
| 71 | update hmac_sha256 "inner" buffer
|
|---|
| 72 | ***********************************************************************/
|
|---|
| 73 | _PUBLIC_ void hmac_sha256_update(const uint8_t *data, size_t data_len, struct HMACSHA256Context *ctx)
|
|---|
| 74 | {
|
|---|
| 75 | SHA256_Update(&ctx->ctx, data, data_len); /* then text of datagram */
|
|---|
| 76 | }
|
|---|
| 77 |
|
|---|
| 78 | /***********************************************************************
|
|---|
| 79 | finish off hmac_sha256 "inner" buffer and generate outer one.
|
|---|
| 80 | ***********************************************************************/
|
|---|
| 81 | _PUBLIC_ void hmac_sha256_final(uint8_t digest[SHA256_DIGEST_LENGTH], struct HMACSHA256Context *ctx)
|
|---|
| 82 | {
|
|---|
| 83 | SHA256_CTX ctx_o;
|
|---|
| 84 |
|
|---|
| 85 | SHA256_Final(digest, &ctx->ctx);
|
|---|
| 86 |
|
|---|
| 87 | SHA256_Init(&ctx_o);
|
|---|
| 88 | SHA256_Update(&ctx_o, ctx->k_opad, 64);
|
|---|
| 89 | SHA256_Update(&ctx_o, digest, SHA256_DIGEST_LENGTH);
|
|---|
| 90 | SHA256_Final(digest, &ctx_o);
|
|---|
| 91 | }
|
|---|
