- markus@cvs.openbsd.org 2013/12/06 13:39:49
[authfd.c authfile.c key.c key.h myproposal.h pathnames.h readconf.c]
[servconf.c ssh-agent.c ssh-keygen.c ssh-keyscan.1 ssh-keyscan.c]
[ssh-keysign.c ssh.c ssh_config.5 sshd.8 sshd.c verify.c ssh-ed25519.c]
[sc25519.h sc25519.c hash.c ge25519_base.data ge25519.h ge25519.c]
[fe25519.h fe25519.c ed25519.c crypto_api.h blocks.c]
support ed25519 keys (hostkeys and user identities) using the public
domain ed25519 reference code from SUPERCOP, see
http://ed25519.cr.yp.to/software.html
feedback, help & ok djm@
diff --git a/ssh-ed25519.c b/ssh-ed25519.c
new file mode 100644
index 0000000..c03c163
--- /dev/null
+++ b/ssh-ed25519.c
@@ -0,0 +1,141 @@
+/* $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 <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;
+}