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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* Handling of cipher specs.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "ssl.h"
#include "sslexp.h"
#include "sslimpl.h"
#include "sslproto.h"
#include "pk11func.h"
#include "secitem.h"
#include "sslimpl.h"
/* Record protection algorithms, indexed by SSL3BulkCipher.
*
* The |max_records| field (|mr| below) is set to a number that is higher than
* recommended in some literature (esp. TLS 1.3) because we currently abort the
* connection when this limit is reached and we want to ensure that we only
* rarely hit this limit. See bug 1268745 for details.
*/
#define MR_MAX RECORD_SEQ_MAX /* 2^48-1 */
#define MR_128 (0x5aULL << 28) /* For AES and similar. */
#define MR_LOW (1ULL << 20) /* For weak ciphers. */
/* clang-format off */
static const ssl3BulkCipherDef ssl_bulk_cipher_defs[] = {
/* |--------- Lengths ---------| */
/* cipher calg : s : */
/* : e b n */
/* oid short_name mr : c l o */
/* k r o t n */
/* e e i c a c */
/* y t type v k g e */
{cipher_null, ssl_calg_null, 0, 0, type_stream, 0, 0, 0, 0,
SEC_OID_NULL_CIPHER, "NULL", MR_MAX},
{cipher_rc4, ssl_calg_rc4, 16,16, type_stream, 0, 0, 0, 0,
SEC_OID_RC4, "RC4", MR_LOW},
{cipher_des, ssl_calg_des, 8, 8, type_block, 8, 8, 0, 0,
SEC_OID_DES_CBC, "DES-CBC", MR_LOW},
{cipher_3des, ssl_calg_3des, 24,24, type_block, 8, 8, 0, 0,
SEC_OID_DES_EDE3_CBC, "3DES-EDE-CBC", MR_LOW},
{cipher_aes_128, ssl_calg_aes, 16,16, type_block, 16,16, 0, 0,
SEC_OID_AES_128_CBC, "AES-128", MR_128},
{cipher_aes_256, ssl_calg_aes, 32,32, type_block, 16,16, 0, 0,
SEC_OID_AES_256_CBC, "AES-256", MR_128},
{cipher_camellia_128, ssl_calg_camellia, 16,16, type_block, 16,16, 0, 0,
SEC_OID_CAMELLIA_128_CBC, "Camellia-128", MR_128},
{cipher_camellia_256, ssl_calg_camellia, 32,32, type_block, 16,16, 0, 0,
SEC_OID_CAMELLIA_256_CBC, "Camellia-256", MR_128},
{cipher_seed, ssl_calg_seed, 16,16, type_block, 16,16, 0, 0,
SEC_OID_SEED_CBC, "SEED-CBC", MR_128},
{cipher_aes_128_gcm, ssl_calg_aes_gcm, 16,16, type_aead, 4, 0,16, 8,
SEC_OID_AES_128_GCM, "AES-128-GCM", MR_128},
{cipher_aes_256_gcm, ssl_calg_aes_gcm, 32,32, type_aead, 4, 0,16, 8,
SEC_OID_AES_256_GCM, "AES-256-GCM", MR_128},
{cipher_chacha20, ssl_calg_chacha20, 32,32, type_aead, 12, 0,16, 0,
SEC_OID_CHACHA20_POLY1305, "ChaCha20-Poly1305", MR_MAX},
{cipher_missing, ssl_calg_null, 0, 0, type_stream, 0, 0, 0, 0,
SEC_OID_UNKNOWN, "missing", 0U},
};
/* clang-format on */
const ssl3BulkCipherDef *
ssl_GetBulkCipherDef(const ssl3CipherSuiteDef *suiteDef)
{
SSL3BulkCipher bulkCipher = suiteDef->bulk_cipher_alg;
PORT_Assert(bulkCipher < PR_ARRAY_SIZE(ssl_bulk_cipher_defs));
PORT_Assert(ssl_bulk_cipher_defs[bulkCipher].cipher == bulkCipher);
return &ssl_bulk_cipher_defs[bulkCipher];
}
/* indexed by SSL3MACAlgorithm */
static const ssl3MACDef ssl_mac_defs[] = {
/* pad_size is only used for SSL 3.0 MAC. See RFC 6101 Sec. 5.2.3.1. */
/* mac mmech pad_size mac_size */
{ ssl_mac_null, CKM_INVALID_MECHANISM, 0, 0, 0 },
{ ssl_mac_md5, CKM_SSL3_MD5_MAC, 48, MD5_LENGTH, SEC_OID_HMAC_MD5 },
{ ssl_mac_sha, CKM_SSL3_SHA1_MAC, 40, SHA1_LENGTH, SEC_OID_HMAC_SHA1 },
{ ssl_hmac_md5, CKM_MD5_HMAC, 0, MD5_LENGTH, SEC_OID_HMAC_MD5 },
{ ssl_hmac_sha, CKM_SHA_1_HMAC, 0, SHA1_LENGTH, SEC_OID_HMAC_SHA1 },
{ ssl_hmac_sha256, CKM_SHA256_HMAC, 0, SHA256_LENGTH, SEC_OID_HMAC_SHA256 },
{ ssl_mac_aead, CKM_INVALID_MECHANISM, 0, 0, 0 },
{ ssl_hmac_sha384, CKM_SHA384_HMAC, 0, SHA384_LENGTH, SEC_OID_HMAC_SHA384 }
};
const ssl3MACDef *
ssl_GetMacDefByAlg(SSL3MACAlgorithm mac)
{
/* Cast here for clang: https://bugs.llvm.org/show_bug.cgi?id=16154 */
PORT_Assert((size_t)mac < PR_ARRAY_SIZE(ssl_mac_defs));
PORT_Assert(ssl_mac_defs[mac].mac == mac);
return &ssl_mac_defs[mac];
}
const ssl3MACDef *
ssl_GetMacDef(const sslSocket *ss, const ssl3CipherSuiteDef *suiteDef)
{
SSL3MACAlgorithm mac = suiteDef->mac_alg;
if (ss->version > SSL_LIBRARY_VERSION_3_0) {
switch (mac) {
case ssl_mac_md5:
mac = ssl_hmac_md5;
break;
case ssl_mac_sha:
mac = ssl_hmac_sha;
break;
default:
break;
}
}
return ssl_GetMacDefByAlg(mac);
}
ssl3CipherSpec *
ssl_FindCipherSpecByEpoch(sslSocket *ss, SSLSecretDirection direction,
DTLSEpoch epoch)
{
PRCList *cur_p;
for (cur_p = PR_LIST_HEAD(&ss->ssl3.hs.cipherSpecs);
cur_p != &ss->ssl3.hs.cipherSpecs;
cur_p = PR_NEXT_LINK(cur_p)) {
ssl3CipherSpec *spec = (ssl3CipherSpec *)cur_p;
if (spec->epoch != epoch) {
continue;
}
if (direction != spec->direction) {
continue;
}
return spec;
}
return NULL;
}
ssl3CipherSpec *
ssl_CreateCipherSpec(sslSocket *ss, SSLSecretDirection direction)
{
ssl3CipherSpec *spec = PORT_ZNew(ssl3CipherSpec);
if (!spec) {
return NULL;
}
spec->refCt = 1;
spec->version = ss->version;
spec->direction = direction;
spec->recordSizeLimit = MAX_FRAGMENT_LENGTH;
SSL_TRC(10, ("%d: SSL[%d]: new %s spec %d ct=%d",
SSL_GETPID(), ss->fd, SPEC_DIR(spec), spec,
spec->refCt));
return spec;
}
void
ssl_SaveCipherSpec(sslSocket *ss, ssl3CipherSpec *spec)
{
PR_APPEND_LINK(&spec->link, &ss->ssl3.hs.cipherSpecs);
}
/* Called from ssl3_InitState. */
/* Caller must hold the SpecWriteLock. */
SECStatus
ssl_SetupNullCipherSpec(sslSocket *ss, SSLSecretDirection dir)
{
ssl3CipherSpec *spec;
PORT_Assert(ss->opt.noLocks || ssl_HaveSpecWriteLock(ss));
spec = ssl_CreateCipherSpec(ss, dir);
if (!spec) {
return SECFailure;
}
/* Set default versions. This value will be used to generate and send
* alerts if a version is not negotiated. These values are overridden when
* sending a ClientHello and when a version is negotiated. */
spec->version = SSL_LIBRARY_VERSION_TLS_1_0;
spec->recordVersion = IS_DTLS(ss)
? SSL_LIBRARY_VERSION_DTLS_1_0_WIRE
: SSL_LIBRARY_VERSION_TLS_1_0;
spec->cipherDef = &ssl_bulk_cipher_defs[cipher_null];
PORT_Assert(spec->cipherDef->cipher == cipher_null);
spec->macDef = &ssl_mac_defs[ssl_mac_null];
PORT_Assert(spec->macDef->mac == ssl_mac_null);
spec->cipher = Null_Cipher;
spec->phase = "cleartext";
dtls_InitRecvdRecords(&spec->recvdRecords);
ssl_SaveCipherSpec(ss, spec);
if (dir == ssl_secret_read) {
ss->ssl3.crSpec = spec;
} else {
ss->ssl3.cwSpec = spec;
}
return SECSuccess;
}
void
ssl_CipherSpecAddRef(ssl3CipherSpec *spec)
{
++spec->refCt;
SSL_TRC(10, ("%d: SSL[-]: Increment ref ct for %s spec %d. new ct = %d",
SSL_GETPID(), SPEC_DIR(spec), spec, spec->refCt));
}
void
ssl_DestroyKeyMaterial(ssl3KeyMaterial *keyMaterial)
{
PK11_FreeSymKey(keyMaterial->key);
PK11_FreeSymKey(keyMaterial->macKey);
if (keyMaterial->macContext != NULL) {
PK11_DestroyContext(keyMaterial->macContext, PR_TRUE);
}
}
static void
ssl_FreeCipherSpec(ssl3CipherSpec *spec)
{
SSL_TRC(10, ("%d: SSL[-]: Freeing %s spec %d. epoch=%d",
SSL_GETPID(), SPEC_DIR(spec), spec, spec->epoch));
PR_REMOVE_LINK(&spec->link);
/* PORT_Assert( ss->opt.noLocks || ssl_HaveSpecWriteLock(ss)); Don't have ss! */
if (spec->cipherContext) {
PK11_DestroyContext(spec->cipherContext, PR_TRUE);
}
PK11_FreeSymKey(spec->masterSecret);
ssl_DestroyKeyMaterial(&spec->keyMaterial);
ssl_DestroyMaskingContextInner(spec->maskContext);
PORT_ZFree(spec, sizeof(*spec));
}
/* This function is never called on a spec which is on the
* cipherSpecs list. */
void
ssl_CipherSpecRelease(ssl3CipherSpec *spec)
{
if (!spec) {
return;
}
PORT_Assert(spec->refCt > 0);
--spec->refCt;
SSL_TRC(10, ("%d: SSL[-]: decrement refct for %s spec %d. epoch=%d new ct = %d",
SSL_GETPID(), SPEC_DIR(spec), spec, spec->epoch, spec->refCt));
if (!spec->refCt) {
ssl_FreeCipherSpec(spec);
}
}
void
ssl_DestroyCipherSpecs(PRCList *list)
{
while (!PR_CLIST_IS_EMPTY(list)) {
ssl3CipherSpec *spec = (ssl3CipherSpec *)PR_LIST_TAIL(list);
ssl_FreeCipherSpec(spec);
}
}
void
ssl_CipherSpecReleaseByEpoch(sslSocket *ss, SSLSecretDirection dir,
DTLSEpoch epoch)
{
ssl3CipherSpec *spec;
SSL_TRC(10, ("%d: SSL[%d]: releasing %s cipher spec for epoch %d",
SSL_GETPID(), ss->fd,
(dir == ssl_secret_read) ? "read" : "write", epoch));
spec = ssl_FindCipherSpecByEpoch(ss, dir, epoch);
if (spec) {
ssl_CipherSpecRelease(spec);
}
}