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