1 files changed, 143 insertions, 0 deletions

diff --git a/ssh-ed25519.c b/ssh-ed25519.c
new file mode 100644
index 000000000..1aedcf83a
--- /dev/null
+++ b/ssh-ed25519.c
@@ -0,0 +1,143 @@
+/* $OpenBSD: ssh-ed25519.c,v 1.1 2013/12/06 13:39:49 markus 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 "crypto_api.h"
+
+#include <string.h>
+#include <stdarg.h>
+
+#include "xmalloc.h"
+#include "log.h"
+#include "buffer.h"
+#include "key.h"
+#include "ssh.h"
+
+int
+ssh_ed25519_sign(const Key *key, u_char **sigp, u_int *lenp,
+    const u_char *data, u_int datalen)
+{
+        u_char *sig;
+        u_int slen, len;
+        unsigned long long smlen;
+        int ret;
+        Buffer b;
+
+        if (key == NULL || key_type_plain(key->type) != KEY_ED25519 ||
+            key->ed25519_sk == NULL) {
+                error("%s: no ED25519 key", __func__);
+                return -1;
+        }
+        smlen = slen = datalen + crypto_sign_ed25519_BYTES;
+        sig = xmalloc(slen);
+
+        if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen,
+            key->ed25519_sk)) != 0 || smlen <= datalen) {
+                error("%s: crypto_sign_ed25519 failed: %d", __func__, ret);
+                free(sig);
+                return -1;
+        }
+        /* encode signature */
+        buffer_init(&b);
+        buffer_put_cstring(&b, "ssh-ed25519");
+        buffer_put_string(&b, sig, smlen - datalen);
+        len = buffer_len(&b);
+        if (lenp != NULL)
+                *lenp = len;
+        if (sigp != NULL) {
+                *sigp = xmalloc(len);
+                memcpy(*sigp, buffer_ptr(&b), len);
+        }
+        buffer_free(&b);
+        memset(sig, 's', slen);
+        free(sig);
+
+        return 0;
+}
+
+int
+ssh_ed25519_verify(const Key *key, const u_char *signature, u_int signaturelen,
+    const u_char *data, u_int datalen)
+{
+        Buffer b;
+        char *ktype;
+        u_char *sigblob, *sm, *m;
+        u_int len;
+        unsigned long long smlen, mlen;
+        int rlen, ret;
+
+        if (key == NULL || key_type_plain(key->type) != KEY_ED25519 ||
+            key->ed25519_pk == NULL) {
+                error("%s: no ED25519 key", __func__);
+                return -1;
+        }
+        buffer_init(&b);
+        buffer_append(&b, signature, signaturelen);
+        ktype = buffer_get_cstring(&b, NULL);
+        if (strcmp("ssh-ed25519", ktype) != 0) {
+                error("%s: cannot handle type %s", __func__, ktype);
+                buffer_free(&b);
+                free(ktype);
+                return -1;
+        }
+        free(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);
+                free(sigblob);
+                return -1;
+        }
+        if (len > crypto_sign_ed25519_BYTES) {
+                error("%s: len %u > crypto_sign_ed25519_BYTES %u", __func__,
+                    len, crypto_sign_ed25519_BYTES);
+                free(sigblob);
+                return -1;
+        }
+        smlen = len + datalen;
+        sm = xmalloc(smlen);
+        memcpy(sm, sigblob, len);
+        memcpy(sm+len, data, datalen);
+        mlen = smlen;
+        m = xmalloc(mlen);
+        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) {
+                debug2("%s: crypto_sign_ed25519_open "
+                    "mlen != datalen (%llu != %u)", __func__, mlen, datalen);
+                ret = -1;
+        }
+        /* XXX compare 'm' and 'data' ? */
+
+        memset(sigblob, 's', len);
+        memset(sm, 'S', smlen);
+        memset(m, 'm', smlen); /* NB. mlen may be invalid if ret != 0 */
+        free(sigblob);
+        free(sm);
+        free(m);
+        debug("%s: signature %scorrect", __func__, (ret != 0) ? "in" : "");
+
+        /* translate return code carefully */
+        return (ret == 0) ? 1 : -1;
+}