xref: /freebsd/crypto/openssl/ssl/ktls.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*
2  * Copyright 2018-2022 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_get_iv_length(dd);
136             if (crypto_info->iv_len < 0)
137                 return 0;
138         }
139         else
140             crypto_info->iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
141         break;
142 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
143     case SSL_CHACHA20POLY1305:
144         crypto_info->cipher_algorithm = CRYPTO_CHACHA20_POLY1305;
145         crypto_info->iv_len = EVP_CIPHER_CTX_get_iv_length(dd);
146         break;
147 # endif
148     case SSL_AES128:
149     case SSL_AES256:
150         switch (s->s3.tmp.new_cipher->algorithm_mac) {
151         case SSL_SHA1:
152             crypto_info->auth_algorithm = CRYPTO_SHA1_HMAC;
153             break;
154         case SSL_SHA256:
155             crypto_info->auth_algorithm = CRYPTO_SHA2_256_HMAC;
156             break;
157         case SSL_SHA384:
158             crypto_info->auth_algorithm = CRYPTO_SHA2_384_HMAC;
159             break;
160         default:
161             return 0;
162         }
163         crypto_info->cipher_algorithm = CRYPTO_AES_CBC;
164         crypto_info->iv_len = EVP_CIPHER_get_iv_length(c);
165         crypto_info->auth_key = mac_key;
166         crypto_info->auth_key_len = mac_secret_size;
167         break;
168     default:
169         return 0;
170     }
171     crypto_info->cipher_key = key;
172     crypto_info->cipher_key_len = EVP_CIPHER_get_key_length(c);
173     crypto_info->iv = iv;
174     crypto_info->tls_vmajor = (s->version >> 8) & 0x000000ff;
175     crypto_info->tls_vminor = (s->version & 0x000000ff);
176 # ifdef TCP_RXTLS_ENABLE
177     memcpy(crypto_info->rec_seq, rl_sequence, sizeof(crypto_info->rec_seq));
178     if (!is_tx && !check_rx_read_ahead(s, crypto_info->rec_seq))
179         return 0;
180 # else
181     if (!is_tx)
182         return 0;
183 # endif
184     return 1;
185 };
186 
187 #endif                         /* __FreeBSD__ */
188 
189 #if defined(OPENSSL_SYS_LINUX)
190 
191 /* Function to check supported ciphers in Linux */
192 int ktls_check_supported_cipher(const SSL *s, const EVP_CIPHER *c,
193                                 const EVP_CIPHER_CTX *dd)
194 {
195     switch (s->version) {
196     case TLS1_2_VERSION:
197     case TLS1_3_VERSION:
198         break;
199     default:
200         return 0;
201     }
202 
203     /* check that cipher is AES_GCM_128, AES_GCM_256, AES_CCM_128
204      * or Chacha20-Poly1305
205      */
206 # ifdef OPENSSL_KTLS_AES_CCM_128
207     if (EVP_CIPHER_is_a(c, "AES-128-CCM")) {
208         if (s->version == TLS_1_3_VERSION /* broken on 5.x kernels */
209             || EVP_CIPHER_CTX_get_tag_length(dd) != EVP_CCM_TLS_TAG_LEN)
210             return 0;
211         return 1;
212     } else
213 # endif
214     if (0
215 # ifdef OPENSSL_KTLS_AES_GCM_128
216         || EVP_CIPHER_is_a(c, "AES-128-GCM")
217 # endif
218 # ifdef OPENSSL_KTLS_AES_GCM_256
219         || EVP_CIPHER_is_a(c, "AES-256-GCM")
220 # endif
221 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
222         || EVP_CIPHER_is_a(c, "ChaCha20-Poly1305")
223 # endif
224         ) {
225         return 1;
226     }
227     return 0;
228 }
229 
230 /* Function to configure kernel TLS structure */
231 int ktls_configure_crypto(SSL *s, const EVP_CIPHER *c, EVP_CIPHER_CTX *dd,
232                           void *rl_sequence, ktls_crypto_info_t *crypto_info,
233                           int is_tx, unsigned char *iv,
234                           unsigned char *key, unsigned char *mac_key,
235                           size_t mac_secret_size)
236 {
237     unsigned char geniv[12];
238     unsigned char *iiv = iv;
239 
240 # ifdef OPENSSL_NO_KTLS_RX
241     if (!is_tx)
242         return 0;
243 # endif
244 
245     if (s->version == TLS1_2_VERSION &&
246         EVP_CIPHER_get_mode(c) == EVP_CIPH_GCM_MODE) {
247         if (!EVP_CIPHER_CTX_get_updated_iv(dd, geniv,
248                                            EVP_GCM_TLS_FIXED_IV_LEN
249                                            + EVP_GCM_TLS_EXPLICIT_IV_LEN))
250             return 0;
251         iiv = geniv;
252     }
253 
254     memset(crypto_info, 0, sizeof(*crypto_info));
255     switch (EVP_CIPHER_get_nid(c))
256     {
257 # ifdef OPENSSL_KTLS_AES_GCM_128
258     case NID_aes_128_gcm:
259         crypto_info->gcm128.info.cipher_type = TLS_CIPHER_AES_GCM_128;
260         crypto_info->gcm128.info.version = s->version;
261         crypto_info->tls_crypto_info_len = sizeof(crypto_info->gcm128);
262         memcpy(crypto_info->gcm128.iv, iiv + EVP_GCM_TLS_FIXED_IV_LEN,
263                TLS_CIPHER_AES_GCM_128_IV_SIZE);
264         memcpy(crypto_info->gcm128.salt, iiv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
265         memcpy(crypto_info->gcm128.key, key, EVP_CIPHER_get_key_length(c));
266         memcpy(crypto_info->gcm128.rec_seq, rl_sequence,
267                TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
268         if (!is_tx && !check_rx_read_ahead(s, crypto_info->gcm128.rec_seq))
269             return 0;
270         return 1;
271 # endif
272 # ifdef OPENSSL_KTLS_AES_GCM_256
273     case NID_aes_256_gcm:
274         crypto_info->gcm256.info.cipher_type = TLS_CIPHER_AES_GCM_256;
275         crypto_info->gcm256.info.version = s->version;
276         crypto_info->tls_crypto_info_len = sizeof(crypto_info->gcm256);
277         memcpy(crypto_info->gcm256.iv, iiv + EVP_GCM_TLS_FIXED_IV_LEN,
278                TLS_CIPHER_AES_GCM_256_IV_SIZE);
279         memcpy(crypto_info->gcm256.salt, iiv, TLS_CIPHER_AES_GCM_256_SALT_SIZE);
280         memcpy(crypto_info->gcm256.key, key, EVP_CIPHER_get_key_length(c));
281         memcpy(crypto_info->gcm256.rec_seq, rl_sequence,
282                TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
283         if (!is_tx && !check_rx_read_ahead(s, crypto_info->gcm256.rec_seq))
284             return 0;
285         return 1;
286 # endif
287 # ifdef OPENSSL_KTLS_AES_CCM_128
288     case NID_aes_128_ccm:
289         crypto_info->ccm128.info.cipher_type = TLS_CIPHER_AES_CCM_128;
290         crypto_info->ccm128.info.version = s->version;
291         crypto_info->tls_crypto_info_len = sizeof(crypto_info->ccm128);
292         memcpy(crypto_info->ccm128.iv, iiv + EVP_CCM_TLS_FIXED_IV_LEN,
293                TLS_CIPHER_AES_CCM_128_IV_SIZE);
294         memcpy(crypto_info->ccm128.salt, iiv, TLS_CIPHER_AES_CCM_128_SALT_SIZE);
295         memcpy(crypto_info->ccm128.key, key, EVP_CIPHER_get_key_length(c));
296         memcpy(crypto_info->ccm128.rec_seq, rl_sequence,
297                TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE);
298         if (!is_tx && !check_rx_read_ahead(s, crypto_info->ccm128.rec_seq))
299             return 0;
300         return 1;
301 # endif
302 # ifdef OPENSSL_KTLS_CHACHA20_POLY1305
303     case NID_chacha20_poly1305:
304         crypto_info->chacha20poly1305.info.cipher_type = TLS_CIPHER_CHACHA20_POLY1305;
305         crypto_info->chacha20poly1305.info.version = s->version;
306         crypto_info->tls_crypto_info_len = sizeof(crypto_info->chacha20poly1305);
307         memcpy(crypto_info->chacha20poly1305.iv, iiv,
308                TLS_CIPHER_CHACHA20_POLY1305_IV_SIZE);
309         memcpy(crypto_info->chacha20poly1305.key, key,
310                EVP_CIPHER_get_key_length(c));
311         memcpy(crypto_info->chacha20poly1305.rec_seq, rl_sequence,
312                TLS_CIPHER_CHACHA20_POLY1305_REC_SEQ_SIZE);
313         if (!is_tx
314                 && !check_rx_read_ahead(s,
315                                         crypto_info->chacha20poly1305.rec_seq))
316             return 0;
317         return 1;
318 # endif
319     default:
320         return 0;
321     }
322 
323 }
324 
325 #endif /* OPENSSL_SYS_LINUX */
326