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authormarkus@openbsd.org <markus@openbsd.org>2019-11-12 19:29:24 +0000
committerDamien Miller <djm@mindrot.org>2019-11-13 08:48:48 +1100
commit7c096c456f33f3d2682736d4735cc10e790276e9 (patch)
tree50728b70f2b5a793fe6eb63c6da51256fd135add
parentba5fb02bed1e556d0ce7b1740ae8a5f87b737491 (diff)
upstream: implement ssh-ed25519-sk verification; ok djm@
OpenBSD-Commit-ID: 37906d93948a1e3d237c20e713d6ca8fbf7d13f6
-rw-r--r--Makefile.in2
-rw-r--r--ssh-ed25519-sk.c130
-rw-r--r--sshkey.c6
-rw-r--r--sshkey.h7
4 files changed, 142 insertions, 3 deletions
diff --git a/Makefile.in b/Makefile.in
index fddc8257..3acfab5c 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -94,7 +94,7 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
readpass.o ttymodes.o xmalloc.o addrmatch.o \
atomicio.o dispatch.o mac.o misc.o utf8.o \
monitor_fdpass.o rijndael.o ssh-dss.o ssh-ecdsa.o ssh-ecdsa-sk.o \
- ssh-rsa.o dh.o \
+ ssh-ed25519-sk.o ssh-rsa.o dh.o \
msg.o progressmeter.o dns.o entropy.o gss-genr.o umac.o umac128.o \
ssh-pkcs11.o smult_curve25519_ref.o \
poly1305.o chacha.o cipher-chachapoly.o \
diff --git a/ssh-ed25519-sk.c b/ssh-ed25519-sk.c
new file mode 100644
index 00000000..f42c8830
--- /dev/null
+++ b/ssh-ed25519-sk.c
@@ -0,0 +1,130 @@
+/* $OpenBSD: ssh-ed25519-sk.c,v 1.1 2019/11/12 19:29:24 markus Exp $ */
+/*
+ * Copyright (c) 2019 Markus Friedl. All rights reserved.
+ *
+ * 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.
+ */
+#define SSHKEY_INTERNAL
+#include <sys/types.h>
+#include <limits.h>
+
+#include "crypto_api.h"
+
+#include <string.h>
+#include <stdarg.h>
+
+#include "log.h"
+#include "sshbuf.h"
+#include "sshkey.h"
+#include "ssherr.h"
+#include "ssh.h"
+#include "digest.h"
+
+int
+ssh_ed25519_sk_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;
+ struct sshbuf *sigbuf = NULL;
+ struct sshbuf *encoded = NULL;
+ char *ktype = NULL;
+ const u_char *sigblob;
+ const u_char *sm;
+ u_char *m = NULL;
+ u_char apphash[32];
+ u_char msghash[32];
+ u_char sig_flags;
+ u_int sig_counter;
+ size_t len;
+ unsigned long long smlen = 0, mlen = 0;
+ int r = SSH_ERR_INTERNAL_ERROR;
+ int ret;
+
+ if (key == NULL ||
+ sshkey_type_plain(key->type) != KEY_ED25519_SK ||
+ key->ed25519_pk == NULL ||
+ signature == NULL || signaturelen == 0)
+ return SSH_ERR_INVALID_ARGUMENT;
+
+ if ((b = sshbuf_from(signature, signaturelen)) == NULL)
+ return SSH_ERR_ALLOC_FAIL;
+ if (sshbuf_get_cstring(b, &ktype, NULL) != 0 ||
+ sshbuf_froms(b, &sigbuf) != 0 ||
+ sshbuf_get_string_direct(sigbuf, &sigblob, &len) != 0 ||
+ sshbuf_get_u8(sigbuf, &sig_flags) != 0 ||
+ sshbuf_get_u32(sigbuf, &sig_counter) != 0) {
+ r = SSH_ERR_INVALID_FORMAT;
+ goto out;
+ }
+ if (strcmp(sshkey_ssh_name_plain(key), 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 (ssh_digest_memory(SSH_DIGEST_SHA256, key->sk_application,
+ strlen(key->sk_application), apphash, sizeof(apphash)) != 0 ||
+ ssh_digest_memory(SSH_DIGEST_SHA256, data, datalen,
+ msghash, sizeof(msghash)) != 0) {
+ r = SSH_ERR_INVALID_ARGUMENT;
+ goto out;
+ }
+ if ((encoded = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if (sshbuf_put(encoded, sigblob, len) != 0 ||
+ sshbuf_put(encoded, apphash, sizeof(apphash)) != 0 ||
+ sshbuf_put_u8(encoded, sig_flags) != 0 ||
+ sshbuf_put_u32(encoded, sig_counter) != 0 ||
+ sshbuf_put(encoded, msghash, sizeof(msghash)) != 0) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ sm = sshbuf_ptr(encoded);
+ smlen = sshbuf_len(encoded);
+ mlen = smlen;
+ if ((m = malloc(smlen)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ 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 != smlen - len) {
+ r = SSH_ERR_SIGNATURE_INVALID;
+ goto out;
+ }
+ /* XXX compare 'm' and 'sm + len' ? */
+ /* success */
+ r = 0;
+ out:
+ if (m != NULL) {
+ explicit_bzero(m, smlen); /* NB mlen may be invalid if r != 0 */
+ free(m);
+ }
+ sshbuf_free(b);
+ sshbuf_free(sigbuf);
+ sshbuf_free(encoded);
+ free(ktype);
+ return r;
+}
diff --git a/sshkey.c b/sshkey.c
index 861d7768..b72f38a2 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.86 2019/10/31 21:23:19 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.87 2019/11/12 19:29:24 markus Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2008 Alexander von Gernler. All rights reserved.
@@ -2750,6 +2750,10 @@ sshkey_verify(const struct sshkey *key,
case KEY_ED25519:
case KEY_ED25519_CERT:
return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat);
+ case KEY_ED25519_SK:
+ case KEY_ED25519_SK_CERT:
+ return ssh_ed25519_sk_verify(key, sig, siglen, data, dlen,
+ compat);
#ifdef WITH_XMSS
case KEY_XMSS:
case KEY_XMSS_CERT:
diff --git a/sshkey.h b/sshkey.h
index 1d36a24a..8cd12bd9 100644
--- a/sshkey.h
+++ b/sshkey.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.h,v 1.36 2019/10/31 21:23:19 djm Exp $ */
+/* $OpenBSD: sshkey.h,v 1.37 2019/11/12 19:29:25 markus Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
@@ -67,6 +67,8 @@ enum sshkey_types {
KEY_XMSS_CERT,
KEY_ECDSA_SK,
KEY_ECDSA_SK_CERT,
+ KEY_ED25519_SK,
+ KEY_ED25519_SK_CERT,
KEY_UNSPEC
};
@@ -291,6 +293,9 @@ int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
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);
+int ssh_ed25519_sk_verify(const struct sshkey *key,
+ const u_char *signature, size_t signaturelen,
+ const u_char *data, size_t datalen, u_int compat);
int ssh_xmss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
const u_char *data, size_t datalen, u_int compat);
int ssh_xmss_verify(const struct sshkey *key,