diff options
Diffstat (limited to 'crypto/openssh/ssh-ecdsa.c')
| -rw-r--r-- | crypto/openssh/ssh-ecdsa.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/crypto/openssh/ssh-ecdsa.c b/crypto/openssh/ssh-ecdsa.c new file mode 100644 index 0000000..c8276b4 --- /dev/null +++ b/crypto/openssh/ssh-ecdsa.c @@ -0,0 +1,168 @@ +/* $OpenBSD: ssh-ecdsa.c,v 1.4 2010/09/10 01:04:10 djm Exp $ */ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * Copyright (c) 2010 Damien Miller. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef OPENSSL_HAS_ECC + +#include <sys/types.h> + +#include <openssl/bn.h> +#include <openssl/ec.h> +#include <openssl/ecdsa.h> +#include <openssl/evp.h> + +#include <string.h> + +#include "xmalloc.h" +#include "buffer.h" +#include "compat.h" +#include "log.h" +#include "key.h" + +int +ssh_ecdsa_sign(const Key *key, u_char **sigp, u_int *lenp, + const u_char *data, u_int datalen) +{ + ECDSA_SIG *sig; + const EVP_MD *evp_md; + EVP_MD_CTX md; + u_char digest[EVP_MAX_MD_SIZE]; + u_int len, dlen; + Buffer b, bb; + + if (key == NULL || key->ecdsa == NULL || + (key->type != KEY_ECDSA && key->type != KEY_ECDSA_CERT)) { + error("%s: no ECDSA key", __func__); + return -1; + } + evp_md = key_ec_nid_to_evpmd(key->ecdsa_nid); + EVP_DigestInit(&md, evp_md); + EVP_DigestUpdate(&md, data, datalen); + EVP_DigestFinal(&md, digest, &dlen); + + sig = ECDSA_do_sign(digest, dlen, key->ecdsa); + memset(digest, 'd', sizeof(digest)); + + if (sig == NULL) { + error("%s: sign failed", __func__); + return -1; + } + + buffer_init(&bb); + buffer_put_bignum2(&bb, sig->r); + buffer_put_bignum2(&bb, sig->s); + ECDSA_SIG_free(sig); + + buffer_init(&b); + buffer_put_cstring(&b, key_ssh_name_plain(key)); + buffer_put_string(&b, buffer_ptr(&bb), buffer_len(&bb)); + buffer_free(&bb); + len = buffer_len(&b); + if (lenp != NULL) + *lenp = len; + if (sigp != NULL) { + *sigp = xmalloc(len); + memcpy(*sigp, buffer_ptr(&b), len); + } + buffer_free(&b); + + return 0; +} +int +ssh_ecdsa_verify(const Key *key, const u_char *signature, u_int signaturelen, + const u_char *data, u_int datalen) +{ + ECDSA_SIG *sig; + const EVP_MD *evp_md; + EVP_MD_CTX md; + u_char digest[EVP_MAX_MD_SIZE], *sigblob; + u_int len, dlen; + int rlen, ret; + Buffer b, bb; + char *ktype; + + if (key == NULL || key->ecdsa == NULL || + (key->type != KEY_ECDSA && key->type != KEY_ECDSA_CERT)) { + error("%s: no ECDSA key", __func__); + return -1; + } + evp_md = key_ec_nid_to_evpmd(key->ecdsa_nid); + + /* fetch signature */ + buffer_init(&b); + buffer_append(&b, signature, signaturelen); + ktype = buffer_get_string(&b, NULL); + if (strcmp(key_ssh_name_plain(key), ktype) != 0) { + error("%s: cannot handle type %s", __func__, ktype); + buffer_free(&b); + xfree(ktype); + return -1; + } + xfree(ktype); + sigblob = buffer_get_string(&b, &len); + rlen = buffer_len(&b); + buffer_free(&b); + if (rlen != 0) { + error("%s: remaining bytes in signature %d", __func__, rlen); + xfree(sigblob); + return -1; + } + + /* parse signature */ + if ((sig = ECDSA_SIG_new()) == NULL) + fatal("%s: ECDSA_SIG_new failed", __func__); + if ((sig->r = BN_new()) == NULL || + (sig->s = BN_new()) == NULL) + fatal("%s: BN_new failed", __func__); + + buffer_init(&bb); + buffer_append(&bb, sigblob, len); + buffer_get_bignum2(&bb, sig->r); + buffer_get_bignum2(&bb, sig->s); + if (buffer_len(&bb) != 0) + fatal("%s: remaining bytes in inner sigblob", __func__); + + /* clean up */ + memset(sigblob, 0, len); + xfree(sigblob); + + /* hash the data */ + EVP_DigestInit(&md, evp_md); + EVP_DigestUpdate(&md, data, datalen); + EVP_DigestFinal(&md, digest, &dlen); + + ret = ECDSA_do_verify(digest, dlen, sig, key->ecdsa); + memset(digest, 'd', sizeof(digest)); + + ECDSA_SIG_free(sig); + + debug("%s: signature %s", __func__, + ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error"); + return ret; +} + +#endif /* OPENSSL_HAS_ECC */ |
