summaryrefslogtreecommitdiff
path: root/security/nss/lib/ssl/sslspec.c
blob: def3c67505d8d89c1a940b2da677cb3f30206c9b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
/* -*- 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 "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);

    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);
    }
}