diff options
Diffstat (limited to 'hmac.c')
| -rw-r--r-- | hmac.c | 198 |
1 files changed, 198 insertions, 0 deletions
@@ -0,0 +1,198 @@ +/* $OpenBSD: hmac.c,v 1.14 2020/02/26 13:40:09 jsg Exp $ */ +/* + * Copyright (c) 2014 Markus Friedl. All rights reserved. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "includes.h" + +#include <sys/types.h> + +#include <stdlib.h> +#include <string.h> + +#include "sshbuf.h" +#include "digest.h" +#include "hmac.h" + +struct ssh_hmac_ctx { + int alg; + struct ssh_digest_ctx *ictx; + struct ssh_digest_ctx *octx; + struct ssh_digest_ctx *digest; + u_char *buf; + size_t buf_len; +}; + +size_t +ssh_hmac_bytes(int alg) +{ + return ssh_digest_bytes(alg); +} + +struct ssh_hmac_ctx * +ssh_hmac_start(int alg) +{ + struct ssh_hmac_ctx *ret; + + if ((ret = calloc(1, sizeof(*ret))) == NULL) + return NULL; + ret->alg = alg; + if ((ret->ictx = ssh_digest_start(alg)) == NULL || + (ret->octx = ssh_digest_start(alg)) == NULL || + (ret->digest = ssh_digest_start(alg)) == NULL) + goto fail; + ret->buf_len = ssh_digest_blocksize(ret->ictx); + if ((ret->buf = calloc(1, ret->buf_len)) == NULL) + goto fail; + return ret; +fail: + ssh_hmac_free(ret); + return NULL; +} + +int +ssh_hmac_init(struct ssh_hmac_ctx *ctx, const void *key, size_t klen) +{ + size_t i; + + /* reset ictx and octx if no is key given */ + if (key != NULL) { + /* truncate long keys */ + if (klen <= ctx->buf_len) + memcpy(ctx->buf, key, klen); + else if (ssh_digest_memory(ctx->alg, key, klen, ctx->buf, + ctx->buf_len) < 0) + return -1; + for (i = 0; i < ctx->buf_len; i++) + ctx->buf[i] ^= 0x36; + if (ssh_digest_update(ctx->ictx, ctx->buf, ctx->buf_len) < 0) + return -1; + for (i = 0; i < ctx->buf_len; i++) + ctx->buf[i] ^= 0x36 ^ 0x5c; + if (ssh_digest_update(ctx->octx, ctx->buf, ctx->buf_len) < 0) + return -1; + explicit_bzero(ctx->buf, ctx->buf_len); + } + /* start with ictx */ + if (ssh_digest_copy_state(ctx->ictx, ctx->digest) < 0) + return -1; + return 0; +} + +int +ssh_hmac_update(struct ssh_hmac_ctx *ctx, const void *m, size_t mlen) +{ + return ssh_digest_update(ctx->digest, m, mlen); +} + +int +ssh_hmac_update_buffer(struct ssh_hmac_ctx *ctx, const struct sshbuf *b) +{ + return ssh_digest_update_buffer(ctx->digest, b); +} + +int +ssh_hmac_final(struct ssh_hmac_ctx *ctx, u_char *d, size_t dlen) +{ + size_t len; + + len = ssh_digest_bytes(ctx->alg); + if (dlen < len || + ssh_digest_final(ctx->digest, ctx->buf, len)) + return -1; + /* switch to octx */ + if (ssh_digest_copy_state(ctx->octx, ctx->digest) < 0 || + ssh_digest_update(ctx->digest, ctx->buf, len) < 0 || + ssh_digest_final(ctx->digest, d, dlen) < 0) + return -1; + return 0; +} + +void +ssh_hmac_free(struct ssh_hmac_ctx *ctx) +{ + if (ctx != NULL) { + ssh_digest_free(ctx->ictx); + ssh_digest_free(ctx->octx); + ssh_digest_free(ctx->digest); + if (ctx->buf) { + explicit_bzero(ctx->buf, ctx->buf_len); + free(ctx->buf); + } + freezero(ctx, sizeof(*ctx)); + } +} + +#ifdef TEST + +/* cc -DTEST hmac.c digest.c buffer.c cleanup.c fatal.c log.c xmalloc.c -lcrypto */ +static void +hmac_test(void *key, size_t klen, void *m, size_t mlen, u_char *e, size_t elen) +{ + struct ssh_hmac_ctx *ctx; + size_t i; + u_char digest[16]; + + if ((ctx = ssh_hmac_start(SSH_DIGEST_MD5)) == NULL) + printf("ssh_hmac_start failed"); + if (ssh_hmac_init(ctx, key, klen) < 0 || + ssh_hmac_update(ctx, m, mlen) < 0 || + ssh_hmac_final(ctx, digest, sizeof(digest)) < 0) + printf("ssh_hmac_xxx failed"); + ssh_hmac_free(ctx); + + if (memcmp(e, digest, elen)) { + for (i = 0; i < elen; i++) + printf("[%zu] %2.2x %2.2x\n", i, e[i], digest[i]); + printf("mismatch\n"); + } else + printf("ok\n"); +} + +int +main(int argc, char **argv) +{ + /* try test vectors from RFC 2104 */ + + u_char key1[16] = { + 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, + 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb, 0xb }; + u_char *data1 = "Hi There"; + u_char dig1[16] = { + 0x92, 0x94, 0x72, 0x7a, 0x36, 0x38, 0xbb, 0x1c, + 0x13, 0xf4, 0x8e, 0xf8, 0x15, 0x8b, 0xfc, 0x9d }; + + u_char *key2 = "Jefe"; + u_char *data2 = "what do ya want for nothing?"; + u_char dig2[16] = { + 0x75, 0x0c, 0x78, 0x3e, 0x6a, 0xb0, 0xb5, 0x03, + 0xea, 0xa8, 0x6e, 0x31, 0x0a, 0x5d, 0xb7, 0x38 }; + + u_char key3[16]; + u_char data3[50]; + u_char dig3[16] = { + 0x56, 0xbe, 0x34, 0x52, 0x1d, 0x14, 0x4c, 0x88, + 0xdb, 0xb8, 0xc7, 0x33, 0xf0, 0xe8, 0xb3, 0xf6 }; + memset(key3, 0xaa, sizeof(key3)); + memset(data3, 0xdd, sizeof(data3)); + + hmac_test(key1, sizeof(key1), data1, strlen(data1), dig1, sizeof(dig1)); + hmac_test(key2, strlen(key2), data2, strlen(data2), dig2, sizeof(dig2)); + hmac_test(key3, sizeof(key3), data3, sizeof(data3), dig3, sizeof(dig3)); + + return 0; +} + +#endif |