xref: /freebsd/crypto/openssl/ssl/ktls.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*
2  * Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include "ssl_local.h"
11 #include "internal/ktls.h"
12 
13 #ifndef OPENSSL_NO_KTLS_RX
14  /*
15   * Count the number of records that were not processed yet from record boundary.
16   *
17   * This function assumes that there are only fully formed records read in the
18   * record layer. If read_ahead is enabled, then this might be false and this
19   * function will fail.
20   */
21 static int count_unprocessed_records(SSL *s)
22 {
23     SSL3_BUFFER *rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
24     PACKET pkt, subpkt;
25     int count = 0;
26 
27     if (!PACKET_buf_init(&pkt, rbuf->buf + rbuf->offset, rbuf->left))
28         return -1;
29 
30     while (PACKET_remaining(&pkt) > 0) {
31         /* Skip record type and version */
32         if (!PACKET_forward(&pkt, 3))
33             return -1;
34 
35         /* Read until next record */
36         if (!PACKET_get_length_prefixed_2(&pkt, &subpkt))
37             return -1;
38 
39         count += 1;
40     }
41 
42     return count;
43 }
44 
45 /*
46  * The kernel cannot offload receive if a partial TLS record has been read.
47  * Check the read buffer for unprocessed records.  If the buffer contains a
48  * partial record, fail and return 0.  Otherwise, update the sequence
49  * number at *rec_seq for the count of unprocessed records and return 1.
50  */
51 static int check_rx_read_ahead(SSL *s, unsigned char *rec_seq)
52 {
53     int bit, count_unprocessed;
54 
55     count_unprocessed = count_unprocessed_records(s);
56     if (count_unprocessed < 0)
57         return 0;
58 
59     /* increment the crypto_info record sequence */
60     while (count_unprocessed) {
61         for (bit = 7; bit >= 0; bit--) { /* increment */
62             ++rec_seq[bit];
63             if (rec_seq[bit] != 0)
64                 break;
65         }
66         count_unprocessed--;
67 
68     }
69 
70     return 1;
71 }
72 #endif
73 
74 #if defined(__FreeBSD__)
75 # include <crypto/cryptodev.h>
76 
77 /*-
78  * Check if a given cipher is supported by the KTLS interface.
79  * The kernel might still fail the setsockopt() if no suitable
80  * provider is found, but this checks if the socket option
81  * supports the cipher suite used at all.
82  */
83 int ktls_check_supported_cipher(const SSL *s, const EVP_CIPHER *c,
84                                 const EVP_CIPHER_CTX *dd)
85 {
86 
87     switch (s->version) {
88     case TLS1_VERSION:
89     case TLS1_1_VERSION:
90     case TLS1_2_VERSION:
91     case TLS1_3_VERSION:
92         break;
93     default:
94         return 0;
95     }
96 
97     switch (s->s3->tmp.new_cipher->algorithm_enc) {
98     case SSL_AES128GCM:
99     case SSL_AES256GCM:
100         return 1;
101 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
102     case SSL_CHACHA20POLY1305:
103         return 1;
104 # endif
105     case SSL_AES128:
106     case SSL_AES256:
107         if (s->ext.use_etm)
108             return 0;
109         switch (s->s3->tmp.new_cipher->algorithm_mac) {
110         case SSL_SHA1:
111         case SSL_SHA256:
112         case SSL_SHA384:
113             return 1;
114         default:
115             return 0;
116         }
117     default:
118         return 0;
119     }
120 }
121 
122 /* Function to configure kernel TLS structure */
123 int ktls_configure_crypto(SSL *s, const EVP_CIPHER *c, EVP_CIPHER_CTX *dd,
124                           void *rl_sequence, ktls_crypto_info_t *crypto_info,
125                           int is_tx, unsigned char *iv,
126                           unsigned char *key, unsigned char *mac_key,
127                           size_t mac_secret_size)
128 {
129     memset(crypto_info, 0, sizeof(*crypto_info));
130     switch (s->s3->tmp.new_cipher->algorithm_enc) {
131     case SSL_AES128GCM:
132     case SSL_AES256GCM:
133         crypto_info->cipher_algorithm = CRYPTO_AES_NIST_GCM_16;
134         if (s->version == TLS1_3_VERSION)
135             crypto_info->iv_len = EVP_CIPHER_CTX_iv_length(dd);
136         else
137             crypto_info->iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
138         break;
139 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
140     case SSL_CHACHA20POLY1305:
141         crypto_info->cipher_algorithm = CRYPTO_CHACHA20_POLY1305;
142         crypto_info->iv_len = EVP_CIPHER_CTX_iv_length(dd);
143         break;
144 # endif
145     case SSL_AES128:
146     case SSL_AES256:
147         switch (s->s3->tmp.new_cipher->algorithm_mac) {
148         case SSL_SHA1:
149             crypto_info->auth_algorithm = CRYPTO_SHA1_HMAC;
150             break;
151         case SSL_SHA256:
152             crypto_info->auth_algorithm = CRYPTO_SHA2_256_HMAC;
153             break;
154         case SSL_SHA384:
155             crypto_info->auth_algorithm = CRYPTO_SHA2_384_HMAC;
156             break;
157         default:
158             return 0;
159         }
160         crypto_info->cipher_algorithm = CRYPTO_AES_CBC;
161         crypto_info->iv_len = EVP_CIPHER_iv_length(c);
162         crypto_info->auth_key = mac_key;
163         crypto_info->auth_key_len = mac_secret_size;
164         break;
165     default:
166         return 0;
167     }
168     crypto_info->cipher_key = key;
169     crypto_info->cipher_key_len = EVP_CIPHER_key_length(c);
170     crypto_info->iv = iv;
171     crypto_info->tls_vmajor = (s->version >> 8) & 0x000000ff;
172     crypto_info->tls_vminor = (s->version & 0x000000ff);
173 # ifdef TCP_RXTLS_ENABLE
174     memcpy(crypto_info->rec_seq, rl_sequence, sizeof(crypto_info->rec_seq));
175     if (!is_tx && !check_rx_read_ahead(s, crypto_info->rec_seq))
176         return 0;
177 # else
178     if (!is_tx)
179         return 0;
180 # endif
181     return 1;
182 };
183 
184 #endif                         /* __FreeBSD__ */
185 
186 #if defined(OPENSSL_SYS_LINUX)
187 
188 /* Function to check supported ciphers in Linux */
189 int ktls_check_supported_cipher(const SSL *s, const EVP_CIPHER *c,
190                                 const EVP_CIPHER_CTX *dd)
191 {
192     switch (s->version) {
193     case TLS1_2_VERSION:
194     case TLS1_3_VERSION:
195         break;
196     default:
197         return 0;
198     }
199 
200     /* check that cipher is AES_GCM_128, AES_GCM_256, AES_CCM_128
201      * or Chacha20-Poly1305
202      */
203     switch (EVP_CIPHER_nid(c))
204     {
205 # ifdef OPENSSL_KTLS_AES_CCM_128
206     case NID_aes_128_ccm:
207         if (EVP_CIPHER_CTX_tag_length(dd) != EVP_CCM_TLS_TAG_LEN)
208           return 0;
209 # endif
210 # ifdef OPENSSL_KTLS_AES_GCM_128
211         /* Fall through */
212     case NID_aes_128_gcm:
213 # endif
214 # ifdef OPENSSL_KTLS_AES_GCM_256
215     case NID_aes_256_gcm:
216 # endif
217 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
218     case NID_chacha20_poly1305:
219 # endif
220         return 1;
221     default:
222         return 0;
223     }
224 }
225 
226 /* Function to configure kernel TLS structure */
227 int ktls_configure_crypto(SSL *s, const EVP_CIPHER *c, EVP_CIPHER_CTX *dd,
228                           void *rl_sequence, ktls_crypto_info_t *crypto_info,
229                           int is_tx, unsigned char *iv,
230                           unsigned char *key, unsigned char *mac_key,
231                           size_t mac_secret_size)
232 {
233     unsigned char geniv[12];
234     unsigned char *iiv = iv;
235 
236 # ifdef OPENSSL_NO_KTLS_RX
237     if (!is_tx)
238         return 0;
239 # endif
240 
241     if (s->version == TLS1_2_VERSION &&
242         EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE) {
243         EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_GET_IV,
244                             EVP_GCM_TLS_FIXED_IV_LEN + EVP_GCM_TLS_EXPLICIT_IV_LEN,
245                             geniv);
246         iiv = geniv;
247     }
248 
249     memset(crypto_info, 0, sizeof(*crypto_info));
250     switch (EVP_CIPHER_nid(c))
251     {
252 # ifdef OPENSSL_KTLS_AES_GCM_128
253     case NID_aes_128_gcm:
254         crypto_info->gcm128.info.cipher_type = TLS_CIPHER_AES_GCM_128;
255         crypto_info->gcm128.info.version = s->version;
256         crypto_info->tls_crypto_info_len = sizeof(crypto_info->gcm128);
257         memcpy(crypto_info->gcm128.iv, iiv + EVP_GCM_TLS_FIXED_IV_LEN,
258                 TLS_CIPHER_AES_GCM_128_IV_SIZE);
259         memcpy(crypto_info->gcm128.salt, iiv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
260         memcpy(crypto_info->gcm128.key, key, EVP_CIPHER_key_length(c));
261         memcpy(crypto_info->gcm128.rec_seq, rl_sequence,
262                 TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
263         if (!is_tx && !check_rx_read_ahead(s, crypto_info->gcm128.rec_seq))
264             return 0;
265         return 1;
266 # endif
267 # ifdef OPENSSL_KTLS_AES_GCM_256
268     case NID_aes_256_gcm:
269         crypto_info->gcm256.info.cipher_type = TLS_CIPHER_AES_GCM_256;
270         crypto_info->gcm256.info.version = s->version;
271         crypto_info->tls_crypto_info_len = sizeof(crypto_info->gcm256);
272         memcpy(crypto_info->gcm256.iv, iiv + EVP_GCM_TLS_FIXED_IV_LEN,
273                 TLS_CIPHER_AES_GCM_256_IV_SIZE);
274         memcpy(crypto_info->gcm256.salt, iiv, TLS_CIPHER_AES_GCM_256_SALT_SIZE);
275         memcpy(crypto_info->gcm256.key, key, EVP_CIPHER_key_length(c));
276         memcpy(crypto_info->gcm256.rec_seq, rl_sequence,
277                 TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
278         if (!is_tx && !check_rx_read_ahead(s, crypto_info->gcm256.rec_seq))
279             return 0;
280         return 1;
281 # endif
282 # ifdef OPENSSL_KTLS_AES_CCM_128
283     case NID_aes_128_ccm:
284         crypto_info->ccm128.info.cipher_type = TLS_CIPHER_AES_CCM_128;
285         crypto_info->ccm128.info.version = s->version;
286         crypto_info->tls_crypto_info_len = sizeof(crypto_info->ccm128);
287         memcpy(crypto_info->ccm128.iv, iiv + EVP_CCM_TLS_FIXED_IV_LEN,
288                 TLS_CIPHER_AES_CCM_128_IV_SIZE);
289         memcpy(crypto_info->ccm128.salt, iiv, TLS_CIPHER_AES_CCM_128_SALT_SIZE);
290         memcpy(crypto_info->ccm128.key, key, EVP_CIPHER_key_length(c));
291         memcpy(crypto_info->ccm128.rec_seq, rl_sequence,
292                 TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE);
293         if (!is_tx && !check_rx_read_ahead(s, crypto_info->ccm128.rec_seq))
294             return 0;
295         return 1;
296 # endif
297 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
298     case NID_chacha20_poly1305:
299         crypto_info->chacha20poly1305.info.cipher_type = TLS_CIPHER_CHACHA20_POLY1305;
300         crypto_info->chacha20poly1305.info.version = s->version;
301         crypto_info->tls_crypto_info_len = sizeof(crypto_info->chacha20poly1305);
302         memcpy(crypto_info->chacha20poly1305.iv, iiv,
303 		TLS_CIPHER_CHACHA20_POLY1305_IV_SIZE);
304         memcpy(crypto_info->chacha20poly1305.key, key, EVP_CIPHER_key_length(c));
305         memcpy(crypto_info->chacha20poly1305.rec_seq, rl_sequence,
306                 TLS_CIPHER_CHACHA20_POLY1305_REC_SEQ_SIZE);
307         if (!is_tx
308                 && !check_rx_read_ahead(s,
309                                         crypto_info->chacha20poly1305.rec_seq))
310             return 0;
311         return 1;
312 # endif
313     default:
314         return 0;
315     }
316 
317 }
318 
319 #endif /* OPENSSL_SYS_LINUX */
320