diff options
Diffstat (limited to 'ssh-ed25519.c')
| -rw-r--r-- | ssh-ed25519.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/ssh-ed25519.c b/ssh-ed25519.c new file mode 100644 index 0000000..5163e02 --- /dev/null +++ b/ssh-ed25519.c @@ -0,0 +1,167 @@ +/* $OpenBSD: ssh-ed25519.c,v 1.7 2016/04/21 06:08:02 djm Exp $ */ +/* + * Copyright (c) 2013 Markus Friedl <markus@openbsd.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" + +#include <sys/types.h> +#include <limits.h> + +#include "crypto_api.h" + +#include <string.h> +#include <stdarg.h> + +#include "log.h" +#include "sshbuf.h" +#define SSHKEY_INTERNAL +#include "sshkey.h" +#include "ssherr.h" +#include "ssh.h" + +int +ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, + const u_char *data, size_t datalen, u_int compat) +{ + u_char *sig = NULL; + size_t slen = 0, len; + unsigned long long smlen; + int r, ret; + struct sshbuf *b = NULL; + + if (lenp != NULL) + *lenp = 0; + if (sigp != NULL) + *sigp = NULL; + + if (key == NULL || + sshkey_type_plain(key->type) != KEY_ED25519 || + key->ed25519_sk == NULL || + datalen >= INT_MAX - crypto_sign_ed25519_BYTES) + return SSH_ERR_INVALID_ARGUMENT; + smlen = slen = datalen + crypto_sign_ed25519_BYTES; + if ((sig = malloc(slen)) == NULL) + return SSH_ERR_ALLOC_FAIL; + + if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen, + key->ed25519_sk)) != 0 || smlen <= datalen) { + r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */ + goto out; + } + /* encode signature */ + if ((b = sshbuf_new()) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + if ((r = sshbuf_put_cstring(b, "ssh-ed25519")) != 0 || + (r = sshbuf_put_string(b, sig, smlen - datalen)) != 0) + goto out; + len = sshbuf_len(b); + if (sigp != NULL) { + if ((*sigp = malloc(len)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + memcpy(*sigp, sshbuf_ptr(b), len); + } + if (lenp != NULL) + *lenp = len; + /* success */ + r = 0; + out: + sshbuf_free(b); + if (sig != NULL) { + explicit_bzero(sig, slen); + free(sig); + } + + return r; +} + +int +ssh_ed25519_verify(const struct sshkey *key, + const u_char *signature, size_t signaturelen, + const u_char *data, size_t datalen, u_int compat) +{ + struct sshbuf *b = NULL; + char *ktype = NULL; + const u_char *sigblob; + u_char *sm = NULL, *m = NULL; + size_t len; + unsigned long long smlen = 0, mlen = 0; + int r, ret; + + if (key == NULL || + sshkey_type_plain(key->type) != KEY_ED25519 || + key->ed25519_pk == NULL || + datalen >= INT_MAX - crypto_sign_ed25519_BYTES || + signature == NULL || signaturelen == 0) + return SSH_ERR_INVALID_ARGUMENT; + + if ((b = sshbuf_from(signature, signaturelen)) == NULL) + return SSH_ERR_ALLOC_FAIL; + if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 || + (r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0) + goto out; + if (strcmp("ssh-ed25519", ktype) != 0) { + r = SSH_ERR_KEY_TYPE_MISMATCH; + goto out; + } + if (sshbuf_len(b) != 0) { + r = SSH_ERR_UNEXPECTED_TRAILING_DATA; + goto out; + } + if (len > crypto_sign_ed25519_BYTES) { + r = SSH_ERR_INVALID_FORMAT; + goto out; + } + if (datalen >= SIZE_MAX - len) { + r = SSH_ERR_INVALID_ARGUMENT; + goto out; + } + smlen = len + datalen; + mlen = smlen; + if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + memcpy(sm, sigblob, len); + memcpy(sm+len, data, datalen); + if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen, + key->ed25519_pk)) != 0) { + debug2("%s: crypto_sign_ed25519_open failed: %d", + __func__, ret); + } + if (ret != 0 || mlen != datalen) { + r = SSH_ERR_SIGNATURE_INVALID; + goto out; + } + /* XXX compare 'm' and 'data' ? */ + /* success */ + r = 0; + out: + if (sm != NULL) { + explicit_bzero(sm, smlen); + free(sm); + } + if (m != NULL) { + explicit_bzero(m, smlen); /* NB mlen may be invalid if r != 0 */ + free(m); + } + sshbuf_free(b); + free(ktype); + return r; +} |