include/internal/ktls.h

   1 /*
   2  * Copyright 2018-2021 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 #if defined(OPENSSL_SYS_LINUX)
  11 # ifndef OPENSSL_NO_KTLS
  12 #  include <linux/version.h>
  13 #  if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0)
  14 #   define OPENSSL_NO_KTLS
  15 #   ifndef PEDANTIC
  16 #    warning "KTLS requires Kernel Headers >= 4.13.0"
  17 #    warning "Skipping Compilation of KTLS"
  18 #   endif
  19 #  endif
  20 # endif
  21 #endif
  22
  23 #ifndef HEADER_INTERNAL_KTLS
  24 # define HEADER_INTERNAL_KTLS
  25 # pragma once
  26
  27 # ifndef OPENSSL_NO_KTLS
  28
  29 #  if defined(__FreeBSD__)
  30 #   include <sys/types.h>
  31 #   include <sys/socket.h>
  32 #   include <sys/ktls.h>
  33 #   include <netinet/in.h>
  34 #   include <netinet/tcp.h>
  35 #   include <openssl/ssl3.h>
  36
  37 #   ifndef TCP_RXTLS_ENABLE
  38 #    define OPENSSL_NO_KTLS_RX
  39 #   endif
  40 #   define OPENSSL_KTLS_AES_GCM_128
  41 #   define OPENSSL_KTLS_AES_GCM_256
  42 #   define OPENSSL_KTLS_TLS13
  43
  44 /*
  45  * Only used by the tests in sslapitest.c.
  46  */
  47 #   define TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE             8
  48 #   define TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE             8
  49
  50 typedef struct tls_enable ktls_crypto_info_t;
  51
  52 /*
  53  * FreeBSD does not require any additional steps to enable KTLS before
  54  * setting keys.
  55  */
  56 static ossl_inline int ktls_enable(int fd)
  57 {
  58     return 1;
  59 }
  60
  61 /*
  62  * The TCP_TXTLS_ENABLE socket option marks the outgoing socket buffer
  63  * as using TLS.  If successful, then data sent using this socket will
  64  * be encrypted and encapsulated in TLS records using the tls_en
  65  * provided here.
  66  *
  67  * The TCP_RXTLS_ENABLE socket option marks the incoming socket buffer
  68  * as using TLS.  If successful, then data received for this socket will
  69  * be authenticated and decrypted using the tls_en provided here.
  70  */
  71 static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *tls_en, int is_tx)
  72 {
  73     if (is_tx)
  74         return setsockopt(fd, IPPROTO_TCP, TCP_TXTLS_ENABLE,
  75                           tls_en, sizeof(*tls_en)) ? 0 : 1;
  76 #   ifndef OPENSSL_NO_KTLS_RX
  77     return setsockopt(fd, IPPROTO_TCP, TCP_RXTLS_ENABLE, tls_en,
  78                       sizeof(*tls_en)) ? 0 : 1;
  79 #   else
  80     return 0;
  81 #   endif
  82 }
  83
  84 /*
  85  * Send a TLS record using the tls_en provided in ktls_start and use
  86  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
  87  * When the socket is non-blocking, then this call either returns EAGAIN or
  88  * the entire record is pushed to TCP. It is impossible to send a partial
  89  * record using this control message.
  90  */
  91 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
  92                                               const void *data, size_t length)
  93 {
  94     struct msghdr msg = { 0 };
  95     int cmsg_len = sizeof(record_type);
  96     struct cmsghdr *cmsg;
  97     char buf[CMSG_SPACE(cmsg_len)];
  98     struct iovec msg_iov;   /* Vector of data to send/receive into */
  99
 100     msg.msg_control = buf;
 101     msg.msg_controllen = sizeof(buf);
 102     cmsg = CMSG_FIRSTHDR(&msg);
 103     cmsg->cmsg_level = IPPROTO_TCP;
 104     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
 105     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
 106     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
 107     msg.msg_controllen = cmsg->cmsg_len;
 108
 109     msg_iov.iov_base = (void *)data;
 110     msg_iov.iov_len = length;
 111     msg.msg_iov = &msg_iov;
 112     msg.msg_iovlen = 1;
 113
 114     return sendmsg(fd, &msg, 0);
 115 }
 116
 117 #   ifdef OPENSSL_NO_KTLS_RX
 118
 119 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 120 {
 121     return -1;
 122 }
 123
 124 #   else /* !defined(OPENSSL_NO_KTLS_RX) */
 125
 126 /*
 127  * Receive a TLS record using the tls_en provided in ktls_start.  The
 128  * kernel strips any explicit IV and authentication tag, but provides
 129  * the TLS record header via a control message.  If there is an error
 130  * with the TLS record such as an invalid header, invalid padding, or
 131  * authentication failure recvmsg() will fail with an error.
 132  */
 133 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 134 {
 135     struct msghdr msg = { 0 };
 136     int cmsg_len = sizeof(struct tls_get_record);
 137     struct tls_get_record *tgr;
 138     struct cmsghdr *cmsg;
 139     char buf[CMSG_SPACE(cmsg_len)];
 140     struct iovec msg_iov;   /* Vector of data to send/receive into */
 141     int ret;
 142     unsigned char *p = data;
 143     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
 144
 145     if (length <= prepend_length) {
 146         errno = EINVAL;
 147         return -1;
 148     }
 149
 150     msg.msg_control = buf;
 151     msg.msg_controllen = sizeof(buf);
 152
 153     msg_iov.iov_base = p + prepend_length;
 154     msg_iov.iov_len = length - prepend_length;
 155     msg.msg_iov = &msg_iov;
 156     msg.msg_iovlen = 1;
 157
 158     ret = recvmsg(fd, &msg, 0);
 159     if (ret <= 0)
 160         return ret;
 161
 162     if ((msg.msg_flags & (MSG_EOR | MSG_CTRUNC)) != MSG_EOR) {
 163         errno = EMSGSIZE;
 164         return -1;
 165     }
 166
 167     if (msg.msg_controllen == 0) {
 168         errno = EBADMSG;
 169         return -1;
 170     }
 171
 172     cmsg = CMSG_FIRSTHDR(&msg);
 173     if (cmsg->cmsg_level != IPPROTO_TCP || cmsg->cmsg_type != TLS_GET_RECORD
 174         || cmsg->cmsg_len != CMSG_LEN(cmsg_len)) {
 175         errno = EBADMSG;
 176         return -1;
 177     }
 178
 179     tgr = (struct tls_get_record *)CMSG_DATA(cmsg);
 180     p[0] = tgr->tls_type;
 181     p[1] = tgr->tls_vmajor;
 182     p[2] = tgr->tls_vminor;
 183     *(uint16_t *)(p + 3) = htons(ret);
 184
 185     return ret + prepend_length;
 186 }
 187
 188 #   endif /* OPENSSL_NO_KTLS_RX */
 189
 190 /*
 191  * KTLS enables the sendfile system call to send data from a file over
 192  * TLS.
 193  */
 194 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off,
 195                                               size_t size, int flags)
 196 {
 197     off_t sbytes = 0;
 198     int ret;
 199
 200     ret = sendfile(fd, s, off, size, NULL, &sbytes, flags);
 201     if (ret == -1 && sbytes == 0)
 202         return -1;
 203     return sbytes;
 204 }
 205
 206 #  endif                         /* __FreeBSD__ */
 207
 208 #  if defined(OPENSSL_SYS_LINUX)
 209
 210 #   include <linux/tls.h>
 211 #   if LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0)
 212 #    define OPENSSL_NO_KTLS_RX
 213 #    ifndef PEDANTIC
 214 #     warning "KTLS requires Kernel Headers >= 4.17.0 for receiving"
 215 #     warning "Skipping Compilation of KTLS receive data path"
 216 #    endif
 217 #   endif
 218 #   define OPENSSL_KTLS_AES_GCM_128
 219 #   if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
 220 #    define OPENSSL_KTLS_AES_GCM_256
 221 #    define OPENSSL_KTLS_TLS13
 222 #    if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
 223 #     define OPENSSL_KTLS_AES_CCM_128
 224 #     if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 11, 0)
 225 #      ifndef OPENSSL_NO_CHACHA
 226 #       define OPENSSL_KTLS_CHACHA20_POLY1305
 227 #      endif
 228 #     endif
 229 #    endif
 230 #   endif
 231
 232 #   include <sys/sendfile.h>
 233 #   include <netinet/tcp.h>
 234 #   include <linux/socket.h>
 235 #   include <openssl/ssl3.h>
 236 #   include <openssl/tls1.h>
 237 #   include <openssl/evp.h>
 238
 239 #   ifndef SOL_TLS
 240 #    define SOL_TLS 282
 241 #   endif
 242
 243 #   ifndef TCP_ULP
 244 #    define TCP_ULP 31
 245 #   endif
 246
 247 #   ifndef TLS_RX
 248 #    define TLS_RX                  2
 249 #   endif
 250
 251 struct tls_crypto_info_all {
 252     union {
 253 #   ifdef OPENSSL_KTLS_AES_GCM_128
 254         struct tls12_crypto_info_aes_gcm_128 gcm128;
 255 #   endif
 256 #   ifdef OPENSSL_KTLS_AES_GCM_256
 257         struct tls12_crypto_info_aes_gcm_256 gcm256;
 258 #   endif
 259 #   ifdef OPENSSL_KTLS_AES_CCM_128
 260         struct tls12_crypto_info_aes_ccm_128 ccm128;
 261 #   endif
 262 #   ifdef OPENSSL_KTLS_CHACHA20_POLY1305
 263         struct tls12_crypto_info_chacha20_poly1305 chacha20poly1305;
 264 #   endif
 265     };
 266     size_t tls_crypto_info_len;
 267 };
 268
 269 typedef struct tls_crypto_info_all ktls_crypto_info_t;
 270
 271 /*
 272  * When successful, this socket option doesn't change the behaviour of the
 273  * TCP socket, except changing the TCP setsockopt handler to enable the
 274  * processing of SOL_TLS socket options. All other functionality remains the
 275  * same.
 276  */
 277 static ossl_inline int ktls_enable(int fd)
 278 {
 279     return setsockopt(fd, SOL_TCP, TCP_ULP, "tls", sizeof("tls")) ? 0 : 1;
 280 }
 281
 282 /*
 283  * The TLS_TX socket option changes the send/sendmsg handlers of the TCP socket.
 284  * If successful, then data sent using this socket will be encrypted and
 285  * encapsulated in TLS records using the crypto_info provided here.
 286  * The TLS_RX socket option changes the recv/recvmsg handlers of the TCP socket.
 287  * If successful, then data received using this socket will be decrypted,
 288  * authenticated and decapsulated using the crypto_info provided here.
 289  */
 290 static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *crypto_info,
 291                                   int is_tx)
 292 {
 293     return setsockopt(fd, SOL_TLS, is_tx ? TLS_TX : TLS_RX,
 294                       crypto_info, crypto_info->tls_crypto_info_len) ? 0 : 1;
 295 }
 296
 297 /*
 298  * Send a TLS record using the crypto_info provided in ktls_start and use
 299  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
 300  * When the socket is non-blocking, then this call either returns EAGAIN or
 301  * the entire record is pushed to TCP. It is impossible to send a partial
 302  * record using this control message.
 303  */
 304 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
 305                                               const void *data, size_t length)
 306 {
 307     struct msghdr msg;
 308     int cmsg_len = sizeof(record_type);
 309     struct cmsghdr *cmsg;
 310     union {
 311         struct cmsghdr hdr;
 312         char buf[CMSG_SPACE(sizeof(unsigned char))];
 313     } cmsgbuf;
 314     struct iovec msg_iov;       /* Vector of data to send/receive into */
 315
 316     memset(&msg, 0, sizeof(msg));
 317     msg.msg_control = cmsgbuf.buf;
 318     msg.msg_controllen = sizeof(cmsgbuf.buf);
 319     cmsg = CMSG_FIRSTHDR(&msg);
 320     cmsg->cmsg_level = SOL_TLS;
 321     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
 322     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
 323     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
 324     msg.msg_controllen = cmsg->cmsg_len;
 325
 326     msg_iov.iov_base = (void *)data;
 327     msg_iov.iov_len = length;
 328     msg.msg_iov = &msg_iov;
 329     msg.msg_iovlen = 1;
 330
 331     return sendmsg(fd, &msg, 0);
 332 }
 333
 334 /*
 335  * KTLS enables the sendfile system call to send data from a file over TLS.
 336  * @flags are ignored on Linux. (placeholder for FreeBSD sendfile)
 337  * */
 338 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off, size_t size, int flags)
 339 {
 340     return sendfile(s, fd, &off, size);
 341 }
 342
 343 #   ifdef OPENSSL_NO_KTLS_RX
 344
 345
 346 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 347 {
 348     return -1;
 349 }
 350
 351 #   else /* !defined(OPENSSL_NO_KTLS_RX) */
 352
 353 /*
 354  * Receive a TLS record using the crypto_info provided in ktls_start.
 355  * The kernel strips the TLS record header, IV and authentication tag,
 356  * returning only the plaintext data or an error on failure.
 357  * We add the TLS record header here to satisfy routines in rec_layer_s3.c
 358  */
 359 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 360 {
 361     struct msghdr msg;
 362     struct cmsghdr *cmsg;
 363     union {
 364         struct cmsghdr hdr;
 365         char buf[CMSG_SPACE(sizeof(unsigned char))];
 366     } cmsgbuf;
 367     struct iovec msg_iov;
 368     int ret;
 369     unsigned char *p = data;
 370     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
 371
 372     if (length < prepend_length + EVP_GCM_TLS_TAG_LEN) {
 373         errno = EINVAL;
 374         return -1;
 375     }
 376
 377     memset(&msg, 0, sizeof(msg));
 378     msg.msg_control = cmsgbuf.buf;
 379     msg.msg_controllen = sizeof(cmsgbuf.buf);
 380
 381     msg_iov.iov_base = p + prepend_length;
 382     msg_iov.iov_len = length - prepend_length - EVP_GCM_TLS_TAG_LEN;
 383     msg.msg_iov = &msg_iov;
 384     msg.msg_iovlen = 1;
 385
 386     ret = recvmsg(fd, &msg, 0);
 387     if (ret < 0)
 388         return ret;
 389
 390     if (msg.msg_controllen > 0) {
 391         cmsg = CMSG_FIRSTHDR(&msg);
 392         if (cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
 393             p[0] = *((unsigned char *)CMSG_DATA(cmsg));
 394             p[1] = TLS1_2_VERSION_MAJOR;
 395             p[2] = TLS1_2_VERSION_MINOR;
 396             /* returned length is limited to msg_iov.iov_len above */
 397             p[3] = (ret >> 8) & 0xff;
 398             p[4] = ret & 0xff;
 399             ret += prepend_length;
 400         }
 401     }
 402
 403     return ret;
 404 }
 405
 406 #   endif /* OPENSSL_NO_KTLS_RX */
 407
 408 #  endif /* OPENSSL_SYS_LINUX */
 409 # endif /* OPENSSL_NO_KTLS */
 410 #endif /* HEADER_INTERNAL_KTLS */