Return to ssh-ed25519.c CVS log

Up to [local] / src / usr.bin / ssh

Annotation of src/usr.bin/ssh/ssh-ed25519.c, Revision 1.2

1.2     ! djm         1: /* $OpenBSD: ssh-ed25519.c,v 1.1 2013/12/06 13:39:49 markus Exp $ */
1.1       markus      2: /*
                      3:  * Copyright (c) 2013 Markus Friedl <markus@openbsd.org>
                      4:  *
                      5:  * Permission to use, copy, modify, and distribute this software for any
                      6:  * purpose with or without fee is hereby granted, provided that the above
                      7:  * copyright notice and this permission notice appear in all copies.
                      8:  *
                      9:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
                     10:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
                     11:  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
                     12:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
                     13:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
                     14:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
                     15:  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
                     16:  */
                     17:
                     18: #include <sys/types.h>
                     19:
                     20: #include "crypto_api.h"
                     21:
                     22: #include <string.h>
                     23: #include <stdarg.h>
                     24:
                     25: #include "xmalloc.h"
                     26: #include "log.h"
                     27: #include "buffer.h"
                     28: #include "key.h"
                     29: #include "ssh.h"
                     30:
                     31: int
                     32: ssh_ed25519_sign(const Key *key, u_char **sigp, u_int *lenp,
                     33:     const u_char *data, u_int datalen)
                     34: {
                     35:        u_char *sig;
                     36:        u_int slen, len;
                     37:        unsigned long long smlen;
                     38:        int ret;
                     39:        Buffer b;
                     40:
                     41:        if (key == NULL || key_type_plain(key->type) != KEY_ED25519 ||
                     42:            key->ed25519_sk == NULL) {
                     43:                error("%s: no ED25519 key", __func__);
                     44:                return -1;
                     45:        }
                     46:        smlen = slen = datalen + crypto_sign_ed25519_BYTES;
                     47:        sig = xmalloc(slen);
                     48:
                     49:        if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen,
                     50:            key->ed25519_sk)) != 0 || smlen <= datalen) {
                     51:                error("%s: crypto_sign_ed25519 failed: %d", __func__, ret);
                     52:                free(sig);
                     53:                return -1;
                     54:        }
                     55:        /* encode signature */
                     56:        buffer_init(&b);
                     57:        buffer_put_cstring(&b, "ssh-ed25519");
                     58:        buffer_put_string(&b, sig, smlen - datalen);
                     59:        len = buffer_len(&b);
                     60:        if (lenp != NULL)
                     61:                *lenp = len;
                     62:        if (sigp != NULL) {
                     63:                *sigp = xmalloc(len);
                     64:                memcpy(*sigp, buffer_ptr(&b), len);
                     65:        }
                     66:        buffer_free(&b);
1.2     ! djm        67:        explicit_bzero(sig, slen);
1.1       markus     68:        free(sig);
                     69:
                     70:        return 0;
                     71: }
                     72:
                     73: int
                     74: ssh_ed25519_verify(const Key *key, const u_char *signature, u_int signaturelen,
                     75:     const u_char *data, u_int datalen)
                     76: {
                     77:        Buffer b;
                     78:        char *ktype;
                     79:        u_char *sigblob, *sm, *m;
                     80:        u_int len;
                     81:        unsigned long long smlen, mlen;
                     82:        int rlen, ret;
                     83:
                     84:        if (key == NULL || key_type_plain(key->type) != KEY_ED25519 ||
                     85:            key->ed25519_pk == NULL) {
                     86:                error("%s: no ED25519 key", __func__);
                     87:                return -1;
                     88:        }
                     89:        buffer_init(&b);
                     90:        buffer_append(&b, signature, signaturelen);
                     91:        ktype = buffer_get_cstring(&b, NULL);
                     92:        if (strcmp("ssh-ed25519", ktype) != 0) {
                     93:                error("%s: cannot handle type %s", __func__, ktype);
                     94:                buffer_free(&b);
                     95:                free(ktype);
                     96:                return -1;
                     97:        }
                     98:        free(ktype);
                     99:        sigblob = buffer_get_string(&b, &len);
                    100:        rlen = buffer_len(&b);
                    101:        buffer_free(&b);
                    102:        if (rlen != 0) {
                    103:                error("%s: remaining bytes in signature %d", __func__, rlen);
                    104:                free(sigblob);
                    105:                return -1;
                    106:        }
                    107:        if (len > crypto_sign_ed25519_BYTES) {
                    108:                error("%s: len %u > crypto_sign_ed25519_BYTES %u", __func__,
                    109:                    len, crypto_sign_ed25519_BYTES);
                    110:                free(sigblob);
                    111:                return -1;
                    112:        }
                    113:        smlen = len + datalen;
                    114:        sm = xmalloc(smlen);
                    115:        memcpy(sm, sigblob, len);
                    116:        memcpy(sm+len, data, datalen);
                    117:        mlen = smlen;
                    118:        m = xmalloc(mlen);
                    119:        if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen,
                    120:            key->ed25519_pk)) != 0) {
                    121:                debug2("%s: crypto_sign_ed25519_open failed: %d",
                    122:                    __func__, ret);
                    123:        }
                    124:        if (ret == 0 && mlen != datalen) {
                    125:                debug2("%s: crypto_sign_ed25519_open "
                    126:                    "mlen != datalen (%llu != %u)", __func__, mlen, datalen);
                    127:                ret = -1;
                    128:        }
                    129:        /* XXX compare 'm' and 'data' ? */
                    130:
1.2     ! djm       131:        explicit_bzero(sigblob, len);
        !           132:        explicit_bzero(sm, smlen);
        !           133:        explicit_bzero(m, smlen); /* NB. mlen may be invalid if ret != 0 */
1.1       markus    134:        free(sigblob);
                    135:        free(sm);
                    136:        free(m);
                    137:        debug("%s: signature %scorrect", __func__, (ret != 0) ? "in" : "");
                    138:
                    139:        /* translate return code carefully */
                    140:        return (ret == 0) ? 1 : -1;
                    141: }