libssh: crypto.h Source File

libssh 0.11.1 The SSH library

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crypto.h
1/*
2 * This file is part of the SSH Library
3 *
4 * Copyright (c) 2003-2009 by Aris Adamantiadis
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/*
22 * crypto.h is an include file for internal cryptographic structures of libssh
23 */
24
25#ifndef _CRYPTO_H_
26#define _CRYPTO_H_
27
28#include <stdbool.h>
29#include "config.h"
30
31#ifdef HAVE_LIBGCRYPT
32#include <gcrypt.h>
33#elif defined(HAVE_LIBMBEDCRYPTO)
34#include <mbedtls/gcm.h>
35#endif
36#include "libssh/wrapper.h"
37
38#ifdef cbc_encrypt
39#undef cbc_encrypt
40#endif
41#ifdef cbc_decrypt
42#undef cbc_decrypt
43#endif
44
45#ifdef HAVE_OPENSSL_ECDH_H
46#include <openssl/ecdh.h>
47#endif
48#include "libssh/dh.h"
49#include "libssh/ecdh.h"
50#include "libssh/kex.h"
51#include "libssh/curve25519.h"
52
53#define DIGEST_MAX_LEN 64
54
55#define AES_GCM_TAGLEN 16
56#define AES_GCM_IVLEN 12
57
58enum ssh_key_exchange_e {
59 /* diffie-hellman-group1-sha1 */
60 SSH_KEX_DH_GROUP1_SHA1=1,
61 /* diffie-hellman-group14-sha1 */
62 SSH_KEX_DH_GROUP14_SHA1,
63#ifdef WITH_GEX
64 /* diffie-hellman-group-exchange-sha1 */
65 SSH_KEX_DH_GEX_SHA1,
66 /* diffie-hellman-group-exchange-sha256 */
67 SSH_KEX_DH_GEX_SHA256,
68#endif /* WITH_GEX */
69 /* ecdh-sha2-nistp256 */
70 SSH_KEX_ECDH_SHA2_NISTP256,
71 /* ecdh-sha2-nistp384 */
72 SSH_KEX_ECDH_SHA2_NISTP384,
73 /* ecdh-sha2-nistp521 */
74 SSH_KEX_ECDH_SHA2_NISTP521,
75 /* curve25519-sha256@libssh.org */
76 SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG,
77 /* curve25519-sha256 */
78 SSH_KEX_CURVE25519_SHA256,
79 /* diffie-hellman-group16-sha512 */
80 SSH_KEX_DH_GROUP16_SHA512,
81 /* diffie-hellman-group18-sha512 */
82 SSH_KEX_DH_GROUP18_SHA512,
83 /* diffie-hellman-group14-sha256 */
84 SSH_KEX_DH_GROUP14_SHA256,
85};
86
87enum ssh_cipher_e {
88 SSH_NO_CIPHER=0,
89#ifdef HAVE_BLOWFISH
90 SSH_BLOWFISH_CBC,
91#endif /* HAVE_BLOWFISH */
92 SSH_3DES_CBC,
93 SSH_AES128_CBC,
94 SSH_AES192_CBC,
95 SSH_AES256_CBC,
96 SSH_AES128_CTR,
97 SSH_AES192_CTR,
98 SSH_AES256_CTR,
99 SSH_AEAD_AES128_GCM,
100 SSH_AEAD_AES256_GCM,
101 SSH_AEAD_CHACHA20_POLY1305
102};
103
104struct dh_ctx;
105
106struct ssh_crypto_struct {
107 bignum shared_secret;
108 struct dh_ctx *dh_ctx;
109#ifdef WITH_GEX
110 size_t dh_pmin; size_t dh_pn; size_t dh_pmax; /* preferred group parameters */
111#endif /* WITH_GEX */
112#ifdef HAVE_ECDH
113#ifdef HAVE_OPENSSL_ECC
114#if OPENSSL_VERSION_NUMBER < 0x30000000L
115 EC_KEY *ecdh_privkey;
116#else
117 EVP_PKEY *ecdh_privkey;
118#endif /* OPENSSL_VERSION_NUMBER */
119#elif defined HAVE_GCRYPT_ECC
120 gcry_sexp_t ecdh_privkey;
121#elif defined HAVE_LIBMBEDCRYPTO
122 mbedtls_ecp_keypair *ecdh_privkey;
123#endif
124 ssh_string ecdh_client_pubkey;
125 ssh_string ecdh_server_pubkey;
126#endif
127#ifdef HAVE_CURVE25519
128 ssh_curve25519_privkey curve25519_privkey;
129 ssh_curve25519_pubkey curve25519_client_pubkey;
130 ssh_curve25519_pubkey curve25519_server_pubkey;
131#endif
132 ssh_string dh_server_signature; /* information used by dh_handshake. */
133 size_t session_id_len;
134 unsigned char *session_id;
135 size_t digest_len; /* len of the secret hash */
136 unsigned char *secret_hash; /* Secret hash is same as session id until re-kex */
137 unsigned char *encryptIV;
138 unsigned char *decryptIV;
139 unsigned char *decryptkey;
140 unsigned char *encryptkey;
141 unsigned char *encryptMAC;
142 unsigned char *decryptMAC;
143 unsigned char hmacbuf[DIGEST_MAX_LEN];
144 struct ssh_cipher_struct *in_cipher, *out_cipher; /* the cipher structures/objects */
145 enum ssh_hmac_e in_hmac, out_hmac; /* the MAC algorithms used */
146 bool in_hmac_etm, out_hmac_etm; /* Whether EtM mode is used or not */
147
148 ssh_key server_pubkey;
149 int do_compress_out; /* idem */
150 int do_compress_in; /* don't set them, set the option instead */
151 int delayed_compress_in; /* Use of zlib@openssh.org */
152 int delayed_compress_out;
153 void *compress_out_ctx; /* don't touch it */
154 void *compress_in_ctx; /* really, don't */
155 /* kex sent by server, client, and mutually elected methods */
156 struct ssh_kex_struct server_kex;
157 struct ssh_kex_struct client_kex;
158 char *kex_methods[SSH_KEX_METHODS];
159 enum ssh_key_exchange_e kex_type;
160 enum ssh_kdf_digest digest_type; /* Digest type for session keys derivation */
161 enum ssh_crypto_direction_e used; /* Is this crypto still used for either of directions? */
162};
163
164struct ssh_cipher_struct {
165 const char *name; /* ssh name of the algorithm */
166 unsigned int blocksize; /* blocksize of the algo */
167 enum ssh_cipher_e ciphertype;
168 uint32_t lenfield_blocksize; /* blocksize of the packet length field */
169 size_t keylen; /* length of the key structure */
170#ifdef HAVE_LIBGCRYPT
171 gcry_cipher_hd_t *key;
172 unsigned char last_iv[AES_GCM_IVLEN];
173#elif defined HAVE_LIBCRYPTO
174 struct ssh_3des_key_schedule *des3_key;
175 struct ssh_aes_key_schedule *aes_key;
176 const EVP_CIPHER *cipher;
177 EVP_CIPHER_CTX *ctx;
178#elif defined HAVE_LIBMBEDCRYPTO
179 mbedtls_cipher_context_t encrypt_ctx;
180 mbedtls_cipher_context_t decrypt_ctx;
181 mbedtls_cipher_type_t type;
182#ifdef MBEDTLS_GCM_C
183 mbedtls_gcm_context gcm_ctx;
184 unsigned char last_iv[AES_GCM_IVLEN];
185#endif /* MBEDTLS_GCM_C */
186#endif
187 struct chacha20_poly1305_keysched *chacha20_schedule;
188 unsigned int keysize; /* bytes of key used. != keylen */
189 size_t tag_size; /* overhead required for tag */
190 /* Counters for rekeying initialization */
191 uint32_t packets;
192 uint64_t blocks;
193 /* Rekeying limit for the cipher or manually enforced */
194 uint64_t max_blocks;
195 /* sets the new key for immediate use */
196 int (*set_encrypt_key)(struct ssh_cipher_struct *cipher, void *key, void *IV);
197 int (*set_decrypt_key)(struct ssh_cipher_struct *cipher, void *key, void *IV);
198 void (*encrypt)(struct ssh_cipher_struct *cipher,
199 void *in,
200 void *out,
201 size_t len);
202 void (*decrypt)(struct ssh_cipher_struct *cipher,
203 void *in,
204 void *out,
205 size_t len);
206 void (*aead_encrypt)(struct ssh_cipher_struct *cipher, void *in, void *out,
207 size_t len, uint8_t *mac, uint64_t seq);
208 int (*aead_decrypt_length)(struct ssh_cipher_struct *cipher, void *in,
209 uint8_t *out, size_t len, uint64_t seq);
210 int (*aead_decrypt)(struct ssh_cipher_struct *cipher, void *complete_packet, uint8_t *out,
211 size_t encrypted_size, uint64_t seq);
212 void (*cleanup)(struct ssh_cipher_struct *cipher);
213};
214
215#ifdef __cplusplus
216extern "C" {
217#endif
218
219const struct ssh_cipher_struct *ssh_get_chacha20poly1305_cipher(void);
220int sshkdf_derive_key(struct ssh_crypto_struct *crypto,
221 unsigned char *key, size_t key_len,
222 uint8_t key_type, unsigned char *output,
223 size_t requested_len);
224
225int secure_memcmp(const void *s1, const void *s2, size_t n);
226#if defined(HAVE_LIBCRYPTO) && !defined(WITH_PKCS11_PROVIDER)
227ENGINE *pki_get_engine(void);
228#endif /* HAVE_LIBCRYPTO */
229
230#ifdef __cplusplus
231}
232#endif
233
234#endif /* _CRYPTO_H_ */