freebsd-src/crypto/openssl/ssl/ktls.c
John Baldwin eee55a22b2 KTLS: Check for unprocessed receive records in ktls_configure_crypto.
KTLS implementations currently assume that the start of the in-kernel
socket buffer is aligned with the start of a TLS record for the
receive side.  The socket option to enable KTLS specifies the TLS
sequence number of this initial record.

When read ahead is enabled, data can be pending in the SSL read buffer
after negotiating session keys.  This pending data must be examined to
ensurs that the kernel's socket buffer does not contain a partial TLS
record as well as to determine the correct sequence number of the
first TLS record to be processed by the kernel.

In preparation for enabling receive kernel offload for TLS 1.3, move
the existing logic to handle read ahead from t1_enc.c into ktls.c and
invoke it from ktls_configure_crypto().

Obtained from:	OpenSSL commit 85773128d0e80cd8dcc772a6931d385b8cf4acd1
2023-10-19 11:34:58 -07:00

326 lines
10 KiB
C

/*
* Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "ssl_local.h"
#include "internal/ktls.h"
#ifndef OPENSSL_NO_KTLS_RX
/*
* Count the number of records that were not processed yet from record boundary.
*
* This function assumes that there are only fully formed records read in the
* record layer. If read_ahead is enabled, then this might be false and this
* function will fail.
*/
static int count_unprocessed_records(SSL *s)
{
SSL3_BUFFER *rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
PACKET pkt, subpkt;
int count = 0;
if (!PACKET_buf_init(&pkt, rbuf->buf + rbuf->offset, rbuf->left))
return -1;
while (PACKET_remaining(&pkt) > 0) {
/* Skip record type and version */
if (!PACKET_forward(&pkt, 3))
return -1;
/* Read until next record */
if (!PACKET_get_length_prefixed_2(&pkt, &subpkt))
return -1;
count += 1;
}
return count;
}
/*
* The kernel cannot offload receive if a partial TLS record has been read.
* Check the read buffer for unprocessed records. If the buffer contains a
* partial record, fail and return 0. Otherwise, update the sequence
* number at *rec_seq for the count of unprocessed records and return 1.
*/
static int check_rx_read_ahead(SSL *s, unsigned char *rec_seq)
{
int bit, count_unprocessed;
count_unprocessed = count_unprocessed_records(s);
if (count_unprocessed < 0)
return 0;
/* increment the crypto_info record sequence */
while (count_unprocessed) {
for (bit = 7; bit >= 0; bit--) { /* increment */
++rec_seq[bit];
if (rec_seq[bit] != 0)
break;
}
count_unprocessed--;
}
return 1;
}
#endif
#if defined(__FreeBSD__)
# include "crypto/cryptodev.h"
/*-
* Check if a given cipher is supported by the KTLS interface.
* The kernel might still fail the setsockopt() if no suitable
* provider is found, but this checks if the socket option
* supports the cipher suite used at all.
*/
int ktls_check_supported_cipher(const SSL *s, const EVP_CIPHER *c,
const EVP_CIPHER_CTX *dd)
{
switch (s->version) {
case TLS1_VERSION:
case TLS1_1_VERSION:
case TLS1_2_VERSION:
case TLS1_3_VERSION:
break;
default:
return 0;
}
switch (s->s3.tmp.new_cipher->algorithm_enc) {
case SSL_AES128GCM:
case SSL_AES256GCM:
return 1;
# ifdef OPENSSL_KTLS_CHACHA20_POLY1305
case SSL_CHACHA20POLY1305:
return 1;
# endif
case SSL_AES128:
case SSL_AES256:
if (s->ext.use_etm)
return 0;
switch (s->s3.tmp.new_cipher->algorithm_mac) {
case SSL_SHA1:
case SSL_SHA256:
case SSL_SHA384:
return 1;
default:
return 0;
}
default:
return 0;
}
}
/* Function to configure kernel TLS structure */
int ktls_configure_crypto(SSL *s, const EVP_CIPHER *c, EVP_CIPHER_CTX *dd,
void *rl_sequence, ktls_crypto_info_t *crypto_info,
int is_tx, unsigned char *iv,
unsigned char *key, unsigned char *mac_key,
size_t mac_secret_size)
{
memset(crypto_info, 0, sizeof(*crypto_info));
switch (s->s3.tmp.new_cipher->algorithm_enc) {
case SSL_AES128GCM:
case SSL_AES256GCM:
crypto_info->cipher_algorithm = CRYPTO_AES_NIST_GCM_16;
if (s->version == TLS1_3_VERSION) {
crypto_info->iv_len = EVP_CIPHER_CTX_get_iv_length(dd);
if (crypto_info->iv_len < 0)
return 0;
}
else
crypto_info->iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
break;
# ifdef OPENSSL_KTLS_CHACHA20_POLY1305
case SSL_CHACHA20POLY1305:
crypto_info->cipher_algorithm = CRYPTO_CHACHA20_POLY1305;
crypto_info->iv_len = EVP_CIPHER_CTX_get_iv_length(dd);
break;
# endif
case SSL_AES128:
case SSL_AES256:
switch (s->s3.tmp.new_cipher->algorithm_mac) {
case SSL_SHA1:
crypto_info->auth_algorithm = CRYPTO_SHA1_HMAC;
break;
case SSL_SHA256:
crypto_info->auth_algorithm = CRYPTO_SHA2_256_HMAC;
break;
case SSL_SHA384:
crypto_info->auth_algorithm = CRYPTO_SHA2_384_HMAC;
break;
default:
return 0;
}
crypto_info->cipher_algorithm = CRYPTO_AES_CBC;
crypto_info->iv_len = EVP_CIPHER_get_iv_length(c);
crypto_info->auth_key = mac_key;
crypto_info->auth_key_len = mac_secret_size;
break;
default:
return 0;
}
crypto_info->cipher_key = key;
crypto_info->cipher_key_len = EVP_CIPHER_get_key_length(c);
crypto_info->iv = iv;
crypto_info->tls_vmajor = (s->version >> 8) & 0x000000ff;
crypto_info->tls_vminor = (s->version & 0x000000ff);
# ifdef TCP_RXTLS_ENABLE
memcpy(crypto_info->rec_seq, rl_sequence, sizeof(crypto_info->rec_seq));
if (!is_tx && !check_rx_read_ahead(s, crypto_info->rec_seq))
return 0;
# else
if (!is_tx)
return 0;
# endif
return 1;
};
#endif /* __FreeBSD__ */
#if defined(OPENSSL_SYS_LINUX)
/* Function to check supported ciphers in Linux */
int ktls_check_supported_cipher(const SSL *s, const EVP_CIPHER *c,
const EVP_CIPHER_CTX *dd)
{
switch (s->version) {
case TLS1_2_VERSION:
case TLS1_3_VERSION:
break;
default:
return 0;
}
/* check that cipher is AES_GCM_128, AES_GCM_256, AES_CCM_128
* or Chacha20-Poly1305
*/
# ifdef OPENSSL_KTLS_AES_CCM_128
if (EVP_CIPHER_is_a(c, "AES-128-CCM")) {
if (s->version == TLS_1_3_VERSION /* broken on 5.x kernels */
|| EVP_CIPHER_CTX_get_tag_length(dd) != EVP_CCM_TLS_TAG_LEN)
return 0;
return 1;
} else
# endif
if (0
# ifdef OPENSSL_KTLS_AES_GCM_128
|| EVP_CIPHER_is_a(c, "AES-128-GCM")
# endif
# ifdef OPENSSL_KTLS_AES_GCM_256
|| EVP_CIPHER_is_a(c, "AES-256-GCM")
# endif
# ifdef OPENSSL_KTLS_CHACHA20_POLY1305
|| EVP_CIPHER_is_a(c, "ChaCha20-Poly1305")
# endif
) {
return 1;
}
return 0;
}
/* Function to configure kernel TLS structure */
int ktls_configure_crypto(SSL *s, const EVP_CIPHER *c, EVP_CIPHER_CTX *dd,
void *rl_sequence, ktls_crypto_info_t *crypto_info,
int is_tx, unsigned char *iv,
unsigned char *key, unsigned char *mac_key,
size_t mac_secret_size)
{
unsigned char geniv[12];
unsigned char *iiv = iv;
# ifdef OPENSSL_NO_KTLS_RX
if (!is_tx)
return 0;
# endif
if (s->version == TLS1_2_VERSION &&
EVP_CIPHER_get_mode(c) == EVP_CIPH_GCM_MODE) {
if (!EVP_CIPHER_CTX_get_updated_iv(dd, geniv,
EVP_GCM_TLS_FIXED_IV_LEN
+ EVP_GCM_TLS_EXPLICIT_IV_LEN))
return 0;
iiv = geniv;
}
memset(crypto_info, 0, sizeof(*crypto_info));
switch (EVP_CIPHER_get_nid(c))
{
# ifdef OPENSSL_KTLS_AES_GCM_128
case NID_aes_128_gcm:
crypto_info->gcm128.info.cipher_type = TLS_CIPHER_AES_GCM_128;
crypto_info->gcm128.info.version = s->version;
crypto_info->tls_crypto_info_len = sizeof(crypto_info->gcm128);
memcpy(crypto_info->gcm128.iv, iiv + EVP_GCM_TLS_FIXED_IV_LEN,
TLS_CIPHER_AES_GCM_128_IV_SIZE);
memcpy(crypto_info->gcm128.salt, iiv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
memcpy(crypto_info->gcm128.key, key, EVP_CIPHER_get_key_length(c));
memcpy(crypto_info->gcm128.rec_seq, rl_sequence,
TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
if (!is_tx && !check_rx_read_ahead(s, crypto_info->gcm128.rec_seq))
return 0;
return 1;
# endif
# ifdef OPENSSL_KTLS_AES_GCM_256
case NID_aes_256_gcm:
crypto_info->gcm256.info.cipher_type = TLS_CIPHER_AES_GCM_256;
crypto_info->gcm256.info.version = s->version;
crypto_info->tls_crypto_info_len = sizeof(crypto_info->gcm256);
memcpy(crypto_info->gcm256.iv, iiv + EVP_GCM_TLS_FIXED_IV_LEN,
TLS_CIPHER_AES_GCM_256_IV_SIZE);
memcpy(crypto_info->gcm256.salt, iiv, TLS_CIPHER_AES_GCM_256_SALT_SIZE);
memcpy(crypto_info->gcm256.key, key, EVP_CIPHER_get_key_length(c));
memcpy(crypto_info->gcm256.rec_seq, rl_sequence,
TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
if (!is_tx && !check_rx_read_ahead(s, crypto_info->gcm256.rec_seq))
return 0;
return 1;
# endif
# ifdef OPENSSL_KTLS_AES_CCM_128
case NID_aes_128_ccm:
crypto_info->ccm128.info.cipher_type = TLS_CIPHER_AES_CCM_128;
crypto_info->ccm128.info.version = s->version;
crypto_info->tls_crypto_info_len = sizeof(crypto_info->ccm128);
memcpy(crypto_info->ccm128.iv, iiv + EVP_CCM_TLS_FIXED_IV_LEN,
TLS_CIPHER_AES_CCM_128_IV_SIZE);
memcpy(crypto_info->ccm128.salt, iiv, TLS_CIPHER_AES_CCM_128_SALT_SIZE);
memcpy(crypto_info->ccm128.key, key, EVP_CIPHER_get_key_length(c));
memcpy(crypto_info->ccm128.rec_seq, rl_sequence,
TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE);
if (!is_tx && !check_rx_read_ahead(s, crypto_info->ccm128.rec_seq))
return 0;
return 1;
# endif
# ifdef OPENSSL_KTLS_CHACHA20_POLY1305
case NID_chacha20_poly1305:
crypto_info->chacha20poly1305.info.cipher_type = TLS_CIPHER_CHACHA20_POLY1305;
crypto_info->chacha20poly1305.info.version = s->version;
crypto_info->tls_crypto_info_len = sizeof(crypto_info->chacha20poly1305);
memcpy(crypto_info->chacha20poly1305.iv, iiv,
TLS_CIPHER_CHACHA20_POLY1305_IV_SIZE);
memcpy(crypto_info->chacha20poly1305.key, key,
EVP_CIPHER_get_key_length(c));
memcpy(crypto_info->chacha20poly1305.rec_seq, rl_sequence,
TLS_CIPHER_CHACHA20_POLY1305_REC_SEQ_SIZE);
if (!is_tx
&& !check_rx_read_ahead(s,
crypto_info->chacha20poly1305.rec_seq))
return 0;
return 1;
# endif
default:
return 0;
}
}
#endif /* OPENSSL_SYS_LINUX */