include/internal/ktls.h

   1 /*
   2  * Copyright 2018 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 #ifndef OPENSSL_NO_KTLS
  11 # ifndef HEADER_INTERNAL_KTLS
  12 #  define HEADER_INTERNAL_KTLS
  13
  14 #  if defined(__FreeBSD__)
  15 #   include <sys/types.h>
  16 #   include <sys/socket.h>
  17 #   include <sys/ktls.h>
  18 #   include <netinet/in.h>
  19 #   include <netinet/tcp.h>
  20 #   include <crypto/cryptodev.h>
  21
  22 /*
  23  * Only used by the tests in sslapitest.c.
  24  */
  25 #   define TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE             8
  26
  27 /*
  28  * FreeBSD does not require any additional steps to enable KTLS before
  29  * setting keys.
  30  */
  31 static ossl_inline int ktls_enable(int fd)
  32 {
  33     return 1;
  34 }
  35
  36 /*
  37  * The TCP_TXTLS_ENABLE socket option marks the outgoing socket buffer
  38  * as using TLS.  If successful, then data sent using this socket will
  39  * be encrypted and encapsulated in TLS records using the tls_en.
  40  * provided here.
  41  */
  42 static ossl_inline int ktls_start(int fd,
  43                                   struct tls_enable *tls_en,
  44                                   size_t len, int is_tx)
  45 {
  46     if (is_tx)
  47         return setsockopt(fd, IPPROTO_TCP, TCP_TXTLS_ENABLE,
  48                           tls_en, sizeof(*tls_en)) ? 0 : 1;
  49     else
  50         return 0;
  51 }
  52
  53 /*
  54  * Send a TLS record using the tls_en provided in ktls_start and use
  55  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
  56  * When the socket is non-blocking, then this call either returns EAGAIN or
  57  * the entire record is pushed to TCP. It is impossible to send a partial
  58  * record using this control message.
  59  */
  60 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
  61                                               const void *data, size_t length)
  62 {
  63     struct msghdr msg = { 0 };
  64     int cmsg_len = sizeof(record_type);
  65     struct cmsghdr *cmsg;
  66     char buf[CMSG_SPACE(cmsg_len)];
  67     struct iovec msg_iov;   /* Vector of data to send/receive into */
  68
  69     msg.msg_control = buf;
  70     msg.msg_controllen = sizeof(buf);
  71     cmsg = CMSG_FIRSTHDR(&msg);
  72     cmsg->cmsg_level = IPPROTO_TCP;
  73     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
  74     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
  75     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
  76     msg.msg_controllen = cmsg->cmsg_len;
  77
  78     msg_iov.iov_base = (void *)data;
  79     msg_iov.iov_len = length;
  80     msg.msg_iov = &msg_iov;
  81     msg.msg_iovlen = 1;
  82
  83     return sendmsg(fd, &msg, 0);
  84 }
  85
  86 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
  87 {
  88     return -1;
  89 }
  90
  91 /*
  92  * KTLS enables the sendfile system call to send data from a file over
  93  * TLS.
  94  */
  95 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off,
  96                                               size_t size, int flags)
  97 {
  98     off_t sbytes;
  99     int ret;
 100
 101     ret = sendfile(fd, s, off, size, NULL, &sbytes, flags);
 102     if (ret == -1) {
 103             if (errno == EAGAIN && sbytes != 0)
 104                     return sbytes;
 105             return -1;
 106     }
 107     return sbytes;
 108 }
 109 #  endif                         /* __FreeBSD__ */
 110
 111 #  if defined(OPENSSL_SYS_LINUX)
 112 #   include <linux/version.h>
 113
 114 #   define K_MAJ   4
 115 #   define K_MIN1  13
 116 #   define K_MIN2  0
 117 #   if LINUX_VERSION_CODE < KERNEL_VERSION(K_MAJ, K_MIN1, K_MIN2)
 118
 119 #    ifndef PEDANTIC
 120 #     warning "KTLS requires Kernel Headers >= 4.13.0"
 121 #     warning "Skipping Compilation of KTLS"
 122 #    endif
 123
 124 #    define TLS_TX                  1
 125 #    define TLS_RX                  2
 126
 127 #    define TLS_CIPHER_AES_GCM_128                          51
 128 #    define TLS_CIPHER_AES_GCM_128_IV_SIZE                  8
 129 #    define TLS_CIPHER_AES_GCM_128_KEY_SIZE                 16
 130 #    define TLS_CIPHER_AES_GCM_128_SALT_SIZE                4
 131 #    define TLS_CIPHER_AES_GCM_128_TAG_SIZE                 16
 132 #    define TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE             8
 133
 134 #    define TLS_SET_RECORD_TYPE     1
 135
 136 struct tls_crypto_info {
 137     unsigned short version;
 138     unsigned short cipher_type;
 139 };
 140
 141 struct tls12_crypto_info_aes_gcm_128 {
 142     struct tls_crypto_info info;
 143     unsigned char iv[TLS_CIPHER_AES_GCM_128_IV_SIZE];
 144     unsigned char key[TLS_CIPHER_AES_GCM_128_KEY_SIZE];
 145     unsigned char salt[TLS_CIPHER_AES_GCM_128_SALT_SIZE];
 146     unsigned char rec_seq[TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE];
 147 };
 148
 149 /* Dummy functions here */
 150 static ossl_inline int ktls_enable(int fd)
 151 {
 152     return 0;
 153 }
 154
 155 static ossl_inline int ktls_start(int fd,
 156                                   struct tls12_crypto_info_aes_gcm_128
 157                                   *crypto_info, size_t len, int is_tx)
 158 {
 159     return 0;
 160 }
 161
 162 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
 163                                               const void *data, size_t length)
 164 {
 165     return -1;
 166 }
 167
 168 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 169 {
 170     return -1;
 171 }
 172
 173 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off, size_t size, int flags)
 174 {
 175     return -1;
 176 }
 177
 178 #   else                        /* KERNEL_VERSION */
 179
 180 #    include <sys/sendfile.h>
 181 #    include <netinet/tcp.h>
 182 #    include <linux/tls.h>
 183 #    include <linux/socket.h>
 184 #    include "openssl/ssl3.h"
 185 #    include "openssl/tls1.h"
 186 #    include "openssl/evp.h"
 187
 188 #    ifndef SOL_TLS
 189 #     define SOL_TLS 282
 190 #    endif
 191
 192 #    ifndef TCP_ULP
 193 #     define TCP_ULP 31
 194 #    endif
 195
 196 #    ifndef TLS_RX
 197 #     define TLS_RX                  2
 198 #    endif
 199
 200 /*
 201  * When successful, this socket option doesn't change the behaviour of the
 202  * TCP socket, except changing the TCP setsockopt handler to enable the
 203  * processing of SOL_TLS socket options. All other functionality remains the
 204  * same.
 205  */
 206 static ossl_inline int ktls_enable(int fd)
 207 {
 208     return setsockopt(fd, SOL_TCP, TCP_ULP, "tls", sizeof("tls")) ? 0 : 1;
 209 }
 210
 211 /*
 212  * The TLS_TX socket option changes the send/sendmsg handlers of the TCP socket.
 213  * If successful, then data sent using this socket will be encrypted and
 214  * encapsulated in TLS records using the crypto_info provided here.
 215  * The TLS_RX socket option changes the recv/recvmsg handlers of the TCP socket.
 216  * If successful, then data received using this socket will be decrypted,
 217  * authenticated and decapsulated using the crypto_info provided here.
 218  */
 219 static ossl_inline int ktls_start(int fd,
 220                                   struct tls12_crypto_info_aes_gcm_128
 221                                   *crypto_info, size_t len, int is_tx)
 222 {
 223     return setsockopt(fd, SOL_TLS, is_tx ? TLS_TX : TLS_RX,
 224                       crypto_info, sizeof(*crypto_info)) ? 0 : 1;
 225 }
 226
 227 /*
 228  * Send a TLS record using the crypto_info provided in ktls_start and use
 229  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
 230  * When the socket is non-blocking, then this call either returns EAGAIN or
 231  * the entire record is pushed to TCP. It is impossible to send a partial
 232  * record using this control message.
 233  */
 234 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
 235                                               const void *data, size_t length)
 236 {
 237     struct msghdr msg;
 238     int cmsg_len = sizeof(record_type);
 239     struct cmsghdr *cmsg;
 240     union {
 241         struct cmsghdr hdr;
 242         char buf[CMSG_SPACE(sizeof(unsigned char))];
 243     } cmsgbuf;
 244     struct iovec msg_iov;       /* Vector of data to send/receive into */
 245
 246     memset(&msg, 0, sizeof(msg));
 247     msg.msg_control = cmsgbuf.buf;
 248     msg.msg_controllen = sizeof(cmsgbuf.buf);
 249     cmsg = CMSG_FIRSTHDR(&msg);
 250     cmsg->cmsg_level = SOL_TLS;
 251     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
 252     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
 253     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
 254     msg.msg_controllen = cmsg->cmsg_len;
 255
 256     msg_iov.iov_base = (void *)data;
 257     msg_iov.iov_len = length;
 258     msg.msg_iov = &msg_iov;
 259     msg.msg_iovlen = 1;
 260
 261     return sendmsg(fd, &msg, 0);
 262 }
 263
 264 /*
 265  * KTLS enables the sendfile system call to send data from a file over TLS.
 266  * @flags are ignored on Linux. (placeholder for FreeBSD sendfile)
 267  * */
 268 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off, size_t size, int flags)
 269 {
 270     return sendfile(s, fd, &off, size);
 271 }
 272
 273 #    define K_MIN1_RX  17
 274 #    if LINUX_VERSION_CODE < KERNEL_VERSION(K_MAJ, K_MIN1_RX, K_MIN2)
 275
 276 #     ifndef PEDANTIC
 277 #      warning "KTLS requires Kernel Headers >= 4.17.0 for receiving"
 278 #      warning "Skipping Compilation of KTLS receive data path"
 279 #     endif
 280
 281 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 282 {
 283     return -1;
 284 }
 285
 286 #    else
 287
 288 /*
 289  * Receive a TLS record using the crypto_info provided in ktls_start.
 290  * The kernel strips the TLS record header, IV and authentication tag,
 291  * returning only the plaintext data or an error on failure.
 292  * We add the TLS record header here to satisfy routines in rec_layer_s3.c
 293  */
 294 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
 295 {
 296     struct msghdr msg;
 297     struct cmsghdr *cmsg;
 298     union {
 299         struct cmsghdr hdr;
 300         char buf[CMSG_SPACE(sizeof(unsigned char))];
 301     } cmsgbuf;
 302     struct iovec msg_iov;
 303     int ret;
 304     unsigned char *p = data;
 305     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
 306
 307     if (length < prepend_length + EVP_GCM_TLS_TAG_LEN) {
 308         errno = EINVAL;
 309         return -1;
 310     }
 311
 312     memset(&msg, 0, sizeof(msg));
 313     msg.msg_control = cmsgbuf.buf;
 314     msg.msg_controllen = sizeof(cmsgbuf.buf);
 315
 316     msg_iov.iov_base = p + prepend_length;
 317     msg_iov.iov_len = length - prepend_length - EVP_GCM_TLS_TAG_LEN;
 318     msg.msg_iov = &msg_iov;
 319     msg.msg_iovlen = 1;
 320
 321     ret = recvmsg(fd, &msg, 0);
 322     if (ret < 0)
 323         return ret;
 324
 325     if (msg.msg_controllen > 0) {
 326         cmsg = CMSG_FIRSTHDR(&msg);
 327         if (cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
 328             p[0] = *((unsigned char *)CMSG_DATA(cmsg));
 329             p[1] = TLS1_2_VERSION_MAJOR;
 330             p[2] = TLS1_2_VERSION_MINOR;
 331             /* returned length is limited to msg_iov.iov_len above */
 332             p[3] = (ret >> 8) & 0xff;
 333             p[4] = ret & 0xff;
 334             ret += prepend_length;
 335         }
 336     }
 337
 338     return ret;
 339 }
 340
 341 #    endif
 342 #   endif
 343 #  endif
 344 # endif
 345 #endif