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-rw-r--r--ChangeLog2
-rw-r--r--kexc25519.c127
-rw-r--r--kexc25519c.c128
-rw-r--r--kexc25519s.c123
4 files changed, 380 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index e7b773de8..1d3e74671 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -24,6 +24,8 @@
24 [roaming_common.c] 24 [roaming_common.c]
25 fix a couple of function definitions foo() -> foo(void) 25 fix a couple of function definitions foo() -> foo(void)
26 (-Wold-style-definition) 26 (-Wold-style-definition)
27 - (djm) [kexc25519.c kexc25519c.c kexc25519s.c] Import missed files from
28 KEX/curve25519 change
27 29
2820131103 3020131103
29 - (dtucker) [openbsd-compat/bsd-misc.c] Include time.h for nanosleep. 31 - (dtucker) [openbsd-compat/bsd-misc.c] Include time.h for nanosleep.
diff --git a/kexc25519.c b/kexc25519.c
new file mode 100644
index 000000000..348a7d50d
--- /dev/null
+++ b/kexc25519.c
@@ -0,0 +1,127 @@
1/* $OpenBSD: kexc25519.c,v 1.2 2013/11/02 22:02:14 markus Exp $ */
2/*
3 * Copyright (c) 2001, 2013 Markus Friedl. All rights reserved.
4 * Copyright (c) 2010 Damien Miller. All rights reserved.
5 * Copyright (c) 2013 Aris Adamantiadis. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "includes.h"
29
30#include <sys/types.h>
31
32#include <signal.h>
33#include <string.h>
34
35#include <openssl/bn.h>
36#include <openssl/evp.h>
37
38#include "buffer.h"
39#include "ssh2.h"
40#include "key.h"
41#include "cipher.h"
42#include "kex.h"
43#include "log.h"
44
45extern int crypto_scalarmult_curve25519(u_char a[CURVE25519_SIZE],
46 const u_char b[CURVE25519_SIZE], const u_char c[CURVE25519_SIZE])
47 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
48 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)))
49 __attribute__((__bounded__(__minbytes__, 3, CURVE25519_SIZE)));
50
51void
52kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
53{
54 static const u_char basepoint[CURVE25519_SIZE] = {9};
55
56 arc4random_buf(key, CURVE25519_SIZE);
57 crypto_scalarmult_curve25519(pub, key, basepoint);
58}
59
60BIGNUM *
61kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
62 const u_char pub[CURVE25519_SIZE])
63{
64 u_char shared_key[CURVE25519_SIZE];
65 BIGNUM *shared_secret;
66
67 crypto_scalarmult_curve25519(shared_key, key, pub);
68#ifdef DEBUG_KEXECDH
69 dump_digest("shared secret", shared_key, CURVE25519_SIZE);
70#endif
71 if ((shared_secret = BN_new()) == NULL)
72 fatal("%s: BN_new failed", __func__);
73 if (BN_bin2bn(shared_key, sizeof(shared_key), shared_secret) == NULL)
74 fatal("%s: BN_bin2bn failed", __func__);
75 memset(shared_key, 0, CURVE25519_SIZE); /* XXX explicit_bzero() */
76 return (shared_secret);
77}
78
79void
80kex_c25519_hash(
81 const EVP_MD *evp_md,
82 char *client_version_string,
83 char *server_version_string,
84 char *ckexinit, int ckexinitlen,
85 char *skexinit, int skexinitlen,
86 u_char *serverhostkeyblob, int sbloblen,
87 const u_char client_dh_pub[CURVE25519_SIZE],
88 const u_char server_dh_pub[CURVE25519_SIZE],
89 const BIGNUM *shared_secret,
90 u_char **hash, u_int *hashlen)
91{
92 Buffer b;
93 EVP_MD_CTX md;
94 static u_char digest[EVP_MAX_MD_SIZE];
95
96 buffer_init(&b);
97 buffer_put_cstring(&b, client_version_string);
98 buffer_put_cstring(&b, server_version_string);
99
100 /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
101 buffer_put_int(&b, ckexinitlen+1);
102 buffer_put_char(&b, SSH2_MSG_KEXINIT);
103 buffer_append(&b, ckexinit, ckexinitlen);
104 buffer_put_int(&b, skexinitlen+1);
105 buffer_put_char(&b, SSH2_MSG_KEXINIT);
106 buffer_append(&b, skexinit, skexinitlen);
107
108 buffer_put_string(&b, serverhostkeyblob, sbloblen);
109 buffer_put_string(&b, client_dh_pub, CURVE25519_SIZE);
110 buffer_put_string(&b, server_dh_pub, CURVE25519_SIZE);
111 buffer_put_bignum2(&b, shared_secret);
112
113#ifdef DEBUG_KEX
114 buffer_dump(&b);
115#endif
116 EVP_DigestInit(&md, evp_md);
117 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
118 EVP_DigestFinal(&md, digest, NULL);
119
120 buffer_free(&b);
121
122#ifdef DEBUG_KEX
123 dump_digest("hash", digest, EVP_MD_size(evp_md));
124#endif
125 *hash = digest;
126 *hashlen = EVP_MD_size(evp_md);
127}
diff --git a/kexc25519c.c b/kexc25519c.c
new file mode 100644
index 000000000..f741566cc
--- /dev/null
+++ b/kexc25519c.c
@@ -0,0 +1,128 @@
1/* $OpenBSD: kexc25519c.c,v 1.2 2013/11/02 22:02:14 markus Exp $ */
2/*
3 * Copyright (c) 2001 Markus Friedl. All rights reserved.
4 * Copyright (c) 2010 Damien Miller. All rights reserved.
5 * Copyright (c) 2013 Aris Adamantiadis. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "includes.h"
29
30#include <sys/types.h>
31
32#include <stdio.h>
33#include <string.h>
34#include <signal.h>
35
36#include "xmalloc.h"
37#include "buffer.h"
38#include "key.h"
39#include "cipher.h"
40#include "kex.h"
41#include "log.h"
42#include "packet.h"
43#include "ssh2.h"
44
45void
46kexc25519_client(Kex *kex)
47{
48 BIGNUM *shared_secret;
49 Key *server_host_key;
50 u_char client_key[CURVE25519_SIZE];
51 u_char client_pubkey[CURVE25519_SIZE];
52 u_char *server_pubkey = NULL;
53 u_char *server_host_key_blob = NULL, *signature = NULL;
54 u_char *hash;
55 u_int slen, sbloblen, hashlen;
56
57 kexc25519_keygen(client_key, client_pubkey);
58
59 packet_start(SSH2_MSG_KEX_ECDH_INIT);
60 packet_put_string(client_pubkey, sizeof(client_pubkey));
61 packet_send();
62 debug("sending SSH2_MSG_KEX_ECDH_INIT");
63
64#ifdef DEBUG_KEXECDH
65 dump_digest("client private key:", client_key, sizeof(client_key));
66#endif
67
68 debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
69 packet_read_expect(SSH2_MSG_KEX_ECDH_REPLY);
70
71 /* hostkey */
72 server_host_key_blob = packet_get_string(&sbloblen);
73 server_host_key = key_from_blob(server_host_key_blob, sbloblen);
74 if (server_host_key == NULL)
75 fatal("cannot decode server_host_key_blob");
76 if (server_host_key->type != kex->hostkey_type)
77 fatal("type mismatch for decoded server_host_key_blob");
78 if (kex->verify_host_key == NULL)
79 fatal("cannot verify server_host_key");
80 if (kex->verify_host_key(server_host_key) == -1)
81 fatal("server_host_key verification failed");
82
83 /* Q_S, server public key */
84 server_pubkey = packet_get_string(&slen);
85 if (slen != CURVE25519_SIZE)
86 fatal("Incorrect size for server Curve25519 pubkey: %d", slen);
87
88#ifdef DEBUG_KEXECDH
89 dump_digest("server public key:", server_pubkey, CURVE25519_SIZE);
90#endif
91
92 /* signed H */
93 signature = packet_get_string(&slen);
94 packet_check_eom();
95
96 shared_secret = kexc25519_shared_key(client_key, server_pubkey);
97
98 /* calc and verify H */
99 kex_c25519_hash(
100 kex->evp_md,
101 kex->client_version_string,
102 kex->server_version_string,
103 buffer_ptr(&kex->my), buffer_len(&kex->my),
104 buffer_ptr(&kex->peer), buffer_len(&kex->peer),
105 server_host_key_blob, sbloblen,
106 client_pubkey,
107 server_pubkey,
108 shared_secret,
109 &hash, &hashlen
110 );
111 free(server_host_key_blob);
112 free(server_pubkey);
113 if (key_verify(server_host_key, signature, slen, hash, hashlen) != 1)
114 fatal("key_verify failed for server_host_key");
115 key_free(server_host_key);
116 free(signature);
117
118 /* save session id */
119 if (kex->session_id == NULL) {
120 kex->session_id_len = hashlen;
121 kex->session_id = xmalloc(kex->session_id_len);
122 memcpy(kex->session_id, hash, kex->session_id_len);
123 }
124
125 kex_derive_keys(kex, hash, hashlen, shared_secret);
126 BN_clear_free(shared_secret);
127 kex_finish(kex);
128}
diff --git a/kexc25519s.c b/kexc25519s.c
new file mode 100644
index 000000000..784841b82
--- /dev/null
+++ b/kexc25519s.c
@@ -0,0 +1,123 @@
1/* $OpenBSD: kexc25519s.c,v 1.2 2013/11/02 22:02:14 markus Exp $ */
2/*
3 * Copyright (c) 2001 Markus Friedl. All rights reserved.
4 * Copyright (c) 2010 Damien Miller. All rights reserved.
5 * Copyright (c) 2013 Aris Adamantiadis. All rights reserved.
6 *
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
28
29#include <sys/types.h>
30#include <string.h>
31#include <signal.h>
32
33#include "xmalloc.h"
34#include "buffer.h"
35#include "key.h"
36#include "cipher.h"
37#include "kex.h"
38#include "log.h"
39#include "packet.h"
40#include "ssh2.h"
41
42void
43kexc25519_server(Kex *kex)
44{
45 BIGNUM *shared_secret;
46 Key *server_host_private, *server_host_public;
47 u_char *server_host_key_blob = NULL, *signature = NULL;
48 u_char server_key[CURVE25519_SIZE];
49 u_char *client_pubkey = NULL;
50 u_char server_pubkey[CURVE25519_SIZE];
51 u_char *hash;
52 u_int slen, sbloblen, hashlen;
53
54 /* generate private key */
55 kexc25519_keygen(server_key, server_pubkey);
56#ifdef DEBUG_KEXECDH
57 dump_digest("server private key:", server_key, sizeof(server_key));
58#endif
59
60 if (kex->load_host_public_key == NULL ||
61 kex->load_host_private_key == NULL)
62 fatal("Cannot load hostkey");
63 server_host_public = kex->load_host_public_key(kex->hostkey_type);
64 if (server_host_public == NULL)
65 fatal("Unsupported hostkey type %d", kex->hostkey_type);
66 server_host_private = kex->load_host_private_key(kex->hostkey_type);
67
68 debug("expecting SSH2_MSG_KEX_ECDH_INIT");
69 packet_read_expect(SSH2_MSG_KEX_ECDH_INIT);
70 client_pubkey = packet_get_string(&slen);
71 if (slen != CURVE25519_SIZE)
72 fatal("Incorrect size for server Curve25519 pubkey: %d", slen);
73 packet_check_eom();
74
75#ifdef DEBUG_KEXECDH
76 dump_digest("client public key:", client_pubkey, CURVE25519_SIZE);
77#endif
78
79 shared_secret = kexc25519_shared_key(server_key, client_pubkey);
80
81 /* calc H */
82 key_to_blob(server_host_public, &server_host_key_blob, &sbloblen);
83 kex_c25519_hash(
84 kex->evp_md,
85 kex->client_version_string,
86 kex->server_version_string,
87 buffer_ptr(&kex->peer), buffer_len(&kex->peer),
88 buffer_ptr(&kex->my), buffer_len(&kex->my),
89 server_host_key_blob, sbloblen,
90 client_pubkey,
91 server_pubkey,
92 shared_secret,
93 &hash, &hashlen
94 );
95
96 /* save session id := H */
97 if (kex->session_id == NULL) {
98 kex->session_id_len = hashlen;
99 kex->session_id = xmalloc(kex->session_id_len);
100 memcpy(kex->session_id, hash, kex->session_id_len);
101 }
102
103 /* sign H */
104 kex->sign(server_host_private, server_host_public, &signature, &slen,
105 hash, hashlen);
106
107 /* destroy_sensitive_data(); */
108
109 /* send server hostkey, ECDH pubkey 'Q_S' and signed H */
110 packet_start(SSH2_MSG_KEX_ECDH_REPLY);
111 packet_put_string(server_host_key_blob, sbloblen);
112 packet_put_string(server_pubkey, sizeof(server_pubkey));
113 packet_put_string(signature, slen);
114 packet_send();
115
116 free(signature);
117 free(server_host_key_blob);
118 /* have keys, free server key */
119 free(client_pubkey);
120 kex_derive_keys(kex, hash, hashlen, shared_secret);
121 BN_clear_free(shared_secret);
122 kex_finish(kex);
123}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 12:02:14 +0000