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authordjm@openbsd.org <djm@openbsd.org>2019-01-21 10:20:12 +0000
committerDamien Miller <djm@mindrot.org>2019-01-21 22:07:02 +1100
commitdfd591618cdf2c96727ac0eb65f89cf54af0d97e (patch)
tree59700563da0dc6f1de649394ffb4c787710eda5a /kexc25519.c
parentb1b2ff4ed559051d1035419f8f236275fa66d5d6 (diff)
upstream: Add support for a PQC KEX/KEM:
sntrup4591761x25519-sha512@tinyssh.org using the Streamlined NTRU Prime 4591^761 implementation from SUPERCOP coupled with X25519 as a stop-loss. Not enabled by default. introduce KEM API; a simplified framework for DH-ish KEX methods. from markus@ feedback & ok djm@ OpenBSD-Commit-ID: d687f76cffd3561dd73eb302d17a1c3bf321d1a7
Diffstat (limited to 'kexc25519.c')
-rw-r--r--kexc25519.c47
1 files changed, 28 insertions, 19 deletions
diff --git a/kexc25519.c b/kexc25519.c
index acddcab3..3911baf1 100644
--- a/kexc25519.c
+++ b/kexc25519.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexc25519.c,v 1.12 2019/01/21 09:49:37 djm Exp $ */
+/* $OpenBSD: kexc25519.c,v 1.13 2019/01/21 10:20:12 djm Exp $ */
/*
* Copyright (c) 2001, 2013 Markus Friedl. All rights reserved.
* Copyright (c) 2010 Damien Miller. All rights reserved.
@@ -60,8 +60,8 @@ kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
}
int
-kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
- const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
+kexc25519_shared_key_ext(const u_char key[CURVE25519_SIZE],
+ const u_char pub[CURVE25519_SIZE], struct sshbuf *out, int raw)
{
u_char shared_key[CURVE25519_SIZE];
u_char zero[CURVE25519_SIZE];
@@ -77,13 +77,22 @@ kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
#ifdef DEBUG_KEXECDH
dump_digest("shared secret", shared_key, CURVE25519_SIZE);
#endif
- sshbuf_reset(out);
- r = sshbuf_put_bignum2_bytes(out, shared_key, CURVE25519_SIZE);
+ if (raw)
+ r = sshbuf_put(out, shared_key, CURVE25519_SIZE);
+ else
+ r = sshbuf_put_bignum2_bytes(out, shared_key, CURVE25519_SIZE);
explicit_bzero(shared_key, CURVE25519_SIZE);
return r;
}
int
+kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
+ const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
+{
+ return kexc25519_shared_key_ext(key, pub, out, 0);
+}
+
+int
kex_c25519_hash(
int hash_alg,
const struct sshbuf *client_version,
@@ -91,8 +100,8 @@ kex_c25519_hash(
const u_char *ckexinit, size_t ckexinitlen,
const u_char *skexinit, size_t skexinitlen,
const u_char *serverhostkeyblob, size_t sbloblen,
- const u_char client_dh_pub[CURVE25519_SIZE],
- const u_char server_dh_pub[CURVE25519_SIZE],
+ const u_char *client_pub, size_t client_pub_len,
+ const u_char *server_pub, size_t server_pub_len,
const u_char *shared_secret, size_t secretlen,
u_char *hash, size_t *hashlen)
{
@@ -103,19 +112,19 @@ kex_c25519_hash(
return SSH_ERR_INVALID_ARGUMENT;
if ((b = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
- if ((r = sshbuf_put_stringb(b, client_version)) < 0 ||
- (r = sshbuf_put_stringb(b, server_version)) < 0 ||
+ if ((r = sshbuf_put_stringb(b, client_version)) != 0 ||
+ (r = sshbuf_put_stringb(b, server_version)) != 0 ||
/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
- (r = sshbuf_put_u32(b, ckexinitlen+1)) < 0 ||
- (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) < 0 ||
- (r = sshbuf_put(b, ckexinit, ckexinitlen)) < 0 ||
- (r = sshbuf_put_u32(b, skexinitlen+1)) < 0 ||
- (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) < 0 ||
- (r = sshbuf_put(b, skexinit, skexinitlen)) < 0 ||
- (r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) < 0 ||
- (r = sshbuf_put_string(b, client_dh_pub, CURVE25519_SIZE)) < 0 ||
- (r = sshbuf_put_string(b, server_dh_pub, CURVE25519_SIZE)) < 0 ||
- (r = sshbuf_put(b, shared_secret, secretlen)) < 0) {
+ (r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 ||
+ (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
+ (r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 ||
+ (r = sshbuf_put_u32(b, skexinitlen+1)) != 0 ||
+ (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||
+ (r = sshbuf_put(b, skexinit, skexinitlen)) != 0 ||
+ (r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 ||
+ (r = sshbuf_put_string(b, client_pub, client_pub_len)) != 0 ||
+ (r = sshbuf_put_string(b, server_pub, server_pub_len)) != 0 ||
+ (r = sshbuf_put(b, shared_secret, secretlen)) != 0) {
sshbuf_free(b);
return r;
}