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- /* $OpenBSD: digest-openssl.c,v 1.9 2020/10/29 02:52:43 djm Exp $ */
- /*
- * Copyright (c) 2013 Damien Miller <djm@mindrot.org>
- *
- * 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"
-
- #ifdef WITH_OPENSSL
-
- #include <sys/types.h>
- #include <limits.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include <openssl/evp.h>
-
- #include "openbsd-compat/openssl-compat.h"
-
- #include "sshbuf.h"
- #include "digest.h"
- #include "ssherr.h"
-
- #ifndef HAVE_EVP_SHA256
- # define EVP_sha256 NULL
- #endif
- #ifndef HAVE_EVP_SHA384
- # define EVP_sha384 NULL
- #endif
- #ifndef HAVE_EVP_SHA512
- # define EVP_sha512 NULL
- #endif
-
- struct ssh_digest_ctx {
- int alg;
- EVP_MD_CTX *mdctx;
- };
-
- struct ssh_digest {
- int id;
- const char *name;
- size_t digest_len;
- const EVP_MD *(*mdfunc)(void);
- };
-
- /* NB. Indexed directly by algorithm number */
- const struct ssh_digest digests[] = {
- { SSH_DIGEST_MD5, "MD5", 16, EVP_md5 },
- { SSH_DIGEST_SHA1, "SHA1", 20, EVP_sha1 },
- { SSH_DIGEST_SHA256, "SHA256", 32, EVP_sha256 },
- { SSH_DIGEST_SHA384, "SHA384", 48, EVP_sha384 },
- { SSH_DIGEST_SHA512, "SHA512", 64, EVP_sha512 },
- { -1, NULL, 0, NULL },
- };
-
- static const struct ssh_digest *
- ssh_digest_by_alg(int alg)
- {
- if (alg < 0 || alg >= SSH_DIGEST_MAX)
- return NULL;
- if (digests[alg].id != alg) /* sanity */
- return NULL;
- if (digests[alg].mdfunc == NULL)
- return NULL;
- return &(digests[alg]);
- }
-
- int
- ssh_digest_alg_by_name(const char *name)
- {
- int alg;
-
- for (alg = 0; digests[alg].id != -1; alg++) {
- if (strcasecmp(name, digests[alg].name) == 0)
- return digests[alg].id;
- }
- return -1;
- }
-
- const char *
- ssh_digest_alg_name(int alg)
- {
- const struct ssh_digest *digest = ssh_digest_by_alg(alg);
-
- return digest == NULL ? NULL : digest->name;
- }
-
- size_t
- ssh_digest_bytes(int alg)
- {
- const struct ssh_digest *digest = ssh_digest_by_alg(alg);
-
- return digest == NULL ? 0 : digest->digest_len;
- }
-
- size_t
- ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
- {
- return EVP_MD_CTX_block_size(ctx->mdctx);
- }
-
- struct ssh_digest_ctx *
- ssh_digest_start(int alg)
- {
- const struct ssh_digest *digest = ssh_digest_by_alg(alg);
- struct ssh_digest_ctx *ret;
-
- if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL))
- return NULL;
- ret->alg = alg;
- if ((ret->mdctx = EVP_MD_CTX_new()) == NULL) {
- free(ret);
- return NULL;
- }
- if (EVP_DigestInit_ex(ret->mdctx, digest->mdfunc(), NULL) != 1) {
- ssh_digest_free(ret);
- return NULL;
- }
- return ret;
- }
-
- int
- ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
- {
- if (from->alg != to->alg)
- return SSH_ERR_INVALID_ARGUMENT;
- /* we have bcopy-style order while openssl has memcpy-style */
- if (!EVP_MD_CTX_copy_ex(to->mdctx, from->mdctx))
- return SSH_ERR_LIBCRYPTO_ERROR;
- return 0;
- }
-
- int
- ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
- {
- if (EVP_DigestUpdate(ctx->mdctx, m, mlen) != 1)
- return SSH_ERR_LIBCRYPTO_ERROR;
- return 0;
- }
-
- int
- ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
- {
- return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
- }
-
- int
- ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
- {
- const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
- u_int l = dlen;
-
- if (digest == NULL || dlen > UINT_MAX)
- return SSH_ERR_INVALID_ARGUMENT;
- if (dlen < digest->digest_len) /* No truncation allowed */
- return SSH_ERR_INVALID_ARGUMENT;
- if (EVP_DigestFinal_ex(ctx->mdctx, d, &l) != 1)
- return SSH_ERR_LIBCRYPTO_ERROR;
- if (l != digest->digest_len) /* sanity */
- return SSH_ERR_INTERNAL_ERROR;
- return 0;
- }
-
- void
- ssh_digest_free(struct ssh_digest_ctx *ctx)
- {
- if (ctx == NULL)
- return;
- EVP_MD_CTX_free(ctx->mdctx);
- freezero(ctx, sizeof(*ctx));
- }
-
- int
- ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
- {
- const struct ssh_digest *digest = ssh_digest_by_alg(alg);
- u_int mdlen;
-
- if (digest == NULL)
- return SSH_ERR_INVALID_ARGUMENT;
- if (dlen > UINT_MAX)
- return SSH_ERR_INVALID_ARGUMENT;
- if (dlen < digest->digest_len)
- return SSH_ERR_INVALID_ARGUMENT;
- mdlen = dlen;
- if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL))
- return SSH_ERR_LIBCRYPTO_ERROR;
- return 0;
- }
-
- int
- ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
- {
- return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
- }
- #endif /* WITH_OPENSSL */
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