pineapple/externals/libressl/ssl/ssl_ciphers.c
2020-12-28 15:15:37 +00:00

296 lines
6.8 KiB
C
Executable file

/* $OpenBSD: ssl_ciphers.c,v 1.9 2020/09/15 15:28:38 schwarze Exp $ */
/*
* Copyright (c) 2015-2017 Doug Hogan <doug@openbsd.org>
* Copyright (c) 2015-2018, 2020 Joel Sing <jsing@openbsd.org>
* Copyright (c) 2019 Theo Buehler <tb@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <openssl/safestack.h>
#include "bytestring.h"
#include "ssl_locl.h"
int
ssl_cipher_in_list(STACK_OF(SSL_CIPHER) *ciphers, const SSL_CIPHER *cipher)
{
int i;
for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
if (sk_SSL_CIPHER_value(ciphers, i)->id == cipher->id)
return 1;
}
return 0;
}
int
ssl_cipher_allowed_in_version_range(const SSL_CIPHER *cipher, uint16_t min_ver,
uint16_t max_ver)
{
/* XXX: We only support DTLSv1 which is effectively TLSv1.1 */
if (min_ver == DTLS1_VERSION || max_ver == DTLS1_VERSION)
min_ver = max_ver = TLS1_1_VERSION;
switch(cipher->algorithm_ssl) {
case SSL_SSLV3:
if (min_ver <= TLS1_2_VERSION)
return 1;
break;
case SSL_TLSV1_2:
if (min_ver <= TLS1_2_VERSION && TLS1_2_VERSION <= max_ver)
return 1;
break;
case SSL_TLSV1_3:
if (min_ver <= TLS1_3_VERSION && TLS1_3_VERSION <= max_ver)
return 1;
break;
}
return 0;
}
int
ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *ciphers, CBB *cbb)
{
SSL_CIPHER *cipher;
int num_ciphers = 0;
uint16_t min_vers, max_vers;
int i;
if (ciphers == NULL)
return 0;
if (!ssl_supported_version_range(s, &min_vers, &max_vers))
return 0;
for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
if ((cipher = sk_SSL_CIPHER_value(ciphers, i)) == NULL)
return 0;
if (!ssl_cipher_allowed_in_version_range(cipher, min_vers,
max_vers))
continue;
if (!CBB_add_u16(cbb, ssl3_cipher_get_value(cipher)))
return 0;
num_ciphers++;
}
/* Add SCSV if there are other ciphers and we're not renegotiating. */
if (num_ciphers > 0 && !s->internal->renegotiate) {
if (!CBB_add_u16(cbb, SSL3_CK_SCSV & SSL3_CK_VALUE_MASK))
return 0;
}
if (!CBB_flush(cbb))
return 0;
return 1;
}
STACK_OF(SSL_CIPHER) *
ssl_bytes_to_cipher_list(SSL *s, CBS *cbs)
{
STACK_OF(SSL_CIPHER) *ciphers = NULL;
const SSL_CIPHER *cipher;
uint16_t cipher_value, max_version;
unsigned long cipher_id;
S3I(s)->send_connection_binding = 0;
if ((ciphers = sk_SSL_CIPHER_new_null()) == NULL) {
SSLerror(s, ERR_R_MALLOC_FAILURE);
goto err;
}
while (CBS_len(cbs) > 0) {
if (!CBS_get_u16(cbs, &cipher_value)) {
SSLerror(s, SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
goto err;
}
cipher_id = SSL3_CK_ID | cipher_value;
if (cipher_id == SSL3_CK_SCSV) {
/*
* TLS_EMPTY_RENEGOTIATION_INFO_SCSV is fatal if
* renegotiating.
*/
if (s->internal->renegotiate) {
SSLerror(s, SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING);
ssl3_send_alert(s, SSL3_AL_FATAL,
SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
S3I(s)->send_connection_binding = 1;
continue;
}
if (cipher_id == SSL3_CK_FALLBACK_SCSV) {
/*
* TLS_FALLBACK_SCSV indicates that the client
* previously tried a higher protocol version.
* Fail if the current version is an unexpected
* downgrade.
*/
if (!ssl_downgrade_max_version(s, &max_version))
goto err;
if (s->version < max_version) {
SSLerror(s, SSL_R_INAPPROPRIATE_FALLBACK);
ssl3_send_alert(s, SSL3_AL_FATAL,
SSL_AD_INAPPROPRIATE_FALLBACK);
goto err;
}
continue;
}
if ((cipher = ssl3_get_cipher_by_value(cipher_value)) != NULL) {
if (!sk_SSL_CIPHER_push(ciphers, cipher)) {
SSLerror(s, ERR_R_MALLOC_FAILURE);
goto err;
}
}
}
return (ciphers);
err:
sk_SSL_CIPHER_free(ciphers);
return (NULL);
}
struct ssl_tls13_ciphersuite {
const char *name;
const char *alias;
unsigned long cid;
};
static const struct ssl_tls13_ciphersuite ssl_tls13_ciphersuites[] = {
{
.name = TLS1_3_TXT_AES_128_GCM_SHA256,
.alias = "TLS_AES_128_GCM_SHA256",
.cid = TLS1_3_CK_AES_128_GCM_SHA256,
},
{
.name = TLS1_3_TXT_AES_256_GCM_SHA384,
.alias = "TLS_AES_256_GCM_SHA384",
.cid = TLS1_3_CK_AES_256_GCM_SHA384,
},
{
.name = TLS1_3_TXT_CHACHA20_POLY1305_SHA256,
.alias = "TLS_CHACHA20_POLY1305_SHA256",
.cid = TLS1_3_CK_CHACHA20_POLY1305_SHA256,
},
{
.name = TLS1_3_TXT_AES_128_CCM_SHA256,
.alias = "TLS_AES_128_CCM_SHA256",
.cid = TLS1_3_CK_AES_128_CCM_SHA256,
},
{
.name = TLS1_3_TXT_AES_128_CCM_8_SHA256,
.alias = "TLS_AES_128_CCM_8_SHA256",
.cid = TLS1_3_CK_AES_128_CCM_8_SHA256,
},
{
.name = NULL,
},
};
int
ssl_parse_ciphersuites(STACK_OF(SSL_CIPHER) **out_ciphers, const char *str)
{
const struct ssl_tls13_ciphersuite *ciphersuite;
STACK_OF(SSL_CIPHER) *ciphers;
const SSL_CIPHER *cipher;
char *s = NULL;
char *p, *q;
int i;
int ret = 0;
if ((ciphers = sk_SSL_CIPHER_new_null()) == NULL)
goto err;
/* An empty string is valid and means no ciphers. */
if (strcmp(str, "") == 0)
goto done;
if ((s = strdup(str)) == NULL)
goto err;
q = s;
while ((p = strsep(&q, ":")) != NULL) {
ciphersuite = &ssl_tls13_ciphersuites[0];
for (i = 0; ciphersuite->name != NULL; i++) {
if (strcmp(p, ciphersuite->name) == 0)
break;
if (strcmp(p, ciphersuite->alias) == 0)
break;
ciphersuite = &ssl_tls13_ciphersuites[i];
}
if (ciphersuite->name == NULL)
goto err;
/* We know about the cipher suite, but it is not supported. */
if ((cipher = ssl3_get_cipher_by_id(ciphersuite->cid)) == NULL)
continue;
if (!sk_SSL_CIPHER_push(ciphers, cipher))
goto err;
}
done:
sk_SSL_CIPHER_free(*out_ciphers);
*out_ciphers = ciphers;
ciphers = NULL;
ret = 1;
err:
sk_SSL_CIPHER_free(ciphers);
free(s);
return ret;
}
int
ssl_merge_cipherlists(STACK_OF(SSL_CIPHER) *cipherlist,
STACK_OF(SSL_CIPHER) *cipherlist_tls13,
STACK_OF(SSL_CIPHER) **out_cipherlist)
{
STACK_OF(SSL_CIPHER) *ciphers = NULL;
const SSL_CIPHER *cipher;
int i, ret = 0;
if ((ciphers = sk_SSL_CIPHER_dup(cipherlist_tls13)) == NULL)
goto err;
for (i = 0; i < sk_SSL_CIPHER_num(cipherlist); i++) {
cipher = sk_SSL_CIPHER_value(cipherlist, i);
if (cipher->algorithm_ssl == SSL_TLSV1_3)
continue;
if (!sk_SSL_CIPHER_push(ciphers, cipher))
goto err;
}
sk_SSL_CIPHER_free(*out_cipherlist);
*out_cipherlist = ciphers;
ciphers = NULL;
ret = 1;
err:
sk_SSL_CIPHER_free(ciphers);
return ret;
}