Bug Summary

File:root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c
Warning:line 19, column 14
Excessive padding in 'struct (unnamed at /root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c:19:14)' (8 padding bytes, where 0 is optimal). Optimal fields order: pkcs11Mech, hash, hashSize, consider reordering the fields or adding explicit padding members

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name tls13hkdf.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -ffp-contract=off -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/root/firefox-clang/obj-x86_64-pc-linux-gnu/security/nss/lib/ssl/ssl_ssl -fcoverage-compilation-dir=/root/firefox-clang/obj-x86_64-pc-linux-gnu/security/nss/lib/ssl/ssl_ssl -resource-dir /usr/lib/llvm-21/lib/clang/21 -include /root/firefox-clang/obj-x86_64-pc-linux-gnu/mozilla-config.h -U _FORTIFY_SOURCE -D _FORTIFY_SOURCE=2 -D _GLIBCXX_ASSERTIONS -D DEBUG -D NSS_FIPS_DISABLED -D NSS_NO_INIT_SUPPORT -D NSS_X86_OR_X64 -D NSS_X64 -D NSS_USE_64 -D NSS_ALLOW_SSLKEYLOGFILE -D USE_UTIL_DIRECTLY -D NO_NSPR_10_SUPPORT -D SSL_DISABLE_DEPRECATED_CIPHER_SUITE_NAMES -D LINUX2_1 -D LINUX -D linux -D _DEFAULT_SOURCE -D _BSD_SOURCE -D _POSIX_SOURCE -D SDB_MEASURE_USE_TEMP_DIR -D HAVE_STRERROR -D XP_UNIX -D _REENTRANT -D NSS_DISABLE_DBM -D NSS_DISABLE_LIBPKIX -I /root/firefox-clang/security/nss/lib/ssl -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/security/nss/lib/ssl/ssl_ssl -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/nspr -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/private/nss -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/nss -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include -D MOZILLA_CLIENT -internal-isystem /usr/lib/llvm-21/lib/clang/21/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-error=tautological-type-limit-compare -Wno-range-loop-analysis -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wno-error=atomic-alignment -Wno-error=deprecated-builtins -Wno-psabi -Wno-error=builtin-macro-redefined -Wno-unknown-warning-option -ferror-limit 19 -fstrict-flex-arrays=1 -stack-protector 2 -fstack-clash-protection -ftrivial-auto-var-init=pattern -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2025-06-30-093548-1913035-1 -x c /root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c
1/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2/*
3 * TLS 1.3 Protocol
4 *
5 * This Source Code Form is subject to the terms of the Mozilla Public
6 * License, v. 2.0. If a copy of the MPL was not distributed with this
7 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
8
9#include "keyhi.h"
10#include "pk11func.h"
11#include "secitem.h"
12#include "ssl.h"
13#include "sslt.h"
14#include "sslerr.h"
15#include "sslimpl.h"
16
17/* This table contains the mapping between TLS hash identifiers and the
18 * PKCS#11 identifiers */
19static const struct {
Excessive padding in 'struct (unnamed at /root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c:19:14)' (8 padding bytes, where 0 is optimal). Optimal fields order: pkcs11Mech, hash, hashSize, consider reordering the fields or adding explicit padding members
20 SSLHashType hash;
21 CK_MECHANISM_TYPE pkcs11Mech;
22 unsigned int hashSize;
23} kTlsHkdfInfo[] = {
24 { ssl_hash_none, 0, 0 },
25 { ssl_hash_md5, 0, 0 },
26 { ssl_hash_sha1, 0, 0 },
27 { ssl_hash_sha224, 0 },
28 { ssl_hash_sha256, CKM_SHA2560x00000250UL, 32 },
29 { ssl_hash_sha384, CKM_SHA3840x00000260UL, 48 },
30 { ssl_hash_sha512, CKM_SHA5120x00000270UL, 64 }
31};
32
33SECStatus
34tls13_HkdfExtract(PK11SymKey *ikm1, PK11SymKey *ikm2, SSLHashType baseHash,
35 PK11SymKey **prkp)
36{
37 CK_HKDF_PARAMS params;
38 SECItem paramsi;
39 PK11SymKey *prk;
40 static const PRUint8 zeroKeyBuf[HASH_LENGTH_MAX64];
41 SECItem zeroKeyItem = { siBuffer, CONST_CAST(PRUint8, zeroKeyBuf)((PRUint8 *)(zeroKeyBuf)), kTlsHkdfInfo[baseHash].hashSize };
42 PK11SlotInfo *slot = NULL((void*)0);
43 PK11SymKey *newIkm2 = NULL((void*)0);
44 PK11SymKey *newIkm1 = NULL((void*)0);
45 SECStatus rv;
46
47 params.bExtract = CK_TRUE1;
48 params.bExpand = CK_FALSE0;
49 params.prfHashMechanism = kTlsHkdfInfo[baseHash].pkcs11Mech;
50 params.pInfo = NULL((void*)0);
51 params.ulInfoLen = 0UL;
52 params.pSalt = NULL((void*)0);
53 params.ulSaltLen = 0UL;
54 params.hSaltKey = CK_INVALID_HANDLE0;
55
56 if (!ikm1) {
57 /* PKCS #11 v3.0 has and explict NULL value, which equates to
58 * a sequence of zeros equal in length to the HMAC. */
59 params.ulSaltType = CKF_HKDF_SALT_NULL0x00000001UL;
60 } else {
61 /* PKCS #11 v3.0 can take the salt as a key handle */
62 params.hSaltKey = PK11_GetSymKeyHandle(ikm1);
63 params.ulSaltType = CKF_HKDF_SALT_KEY0x00000004UL;
64
65 /* if we have both keys, make sure they are in the same slot */
66 if (ikm2) {
67 rv = PK11_SymKeysToSameSlot(CKM_HKDF_DERIVE0x0000402aUL,
68 CKA_DERIVE0x0000010CUL, CKA_DERIVE0x0000010CUL,
69 ikm2, ikm1, &newIkm2, &newIkm1);
70 if (rv != SECSuccess) {
71 SECItem *salt;
72 /* couldn't move the keys, try extracting the salt */
73 rv = PK11_ExtractKeyValue(ikm1);
74 if (rv != SECSuccess)
75 return rv;
76 salt = PK11_GetKeyData(ikm1);
77 if (!salt)
78 return SECFailure;
79 PORT_Assert(salt->len > 0)((salt->len > 0)?((void)0):PR_Assert("salt->len > 0"
,"/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c",79))
;
80 /* Set up for Salt as Data instead of Salt as key */
81 params.pSalt = salt->data;
82 params.ulSaltLen = salt->len;
83 params.ulSaltType = CKF_HKDF_SALT_DATA0x00000002UL;
84 }
85 /* use the new keys */
86 if (newIkm1) {
87 /* we've moved the key, get the handle for the new key */
88 params.hSaltKey = PK11_GetSymKeyHandle(newIkm1);
89 /* we don't use ikm1 after this, so don't bother setting it */
90 }
91 if (newIkm2) {
92 /* new ikm2 key, use the new key */
93 ikm2 = newIkm2;
94 }
95 }
96 }
97 paramsi.data = (unsigned char *)&params;
98 paramsi.len = sizeof(params);
99
100 PORT_Assert(kTlsHkdfInfo[baseHash].pkcs11Mech)((kTlsHkdfInfo[baseHash].pkcs11Mech)?((void)0):PR_Assert("kTlsHkdfInfo[baseHash].pkcs11Mech"
,"/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c",100))
;
101 PORT_Assert(kTlsHkdfInfo[baseHash].hashSize)((kTlsHkdfInfo[baseHash].hashSize)?((void)0):PR_Assert("kTlsHkdfInfo[baseHash].hashSize"
,"/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c",101))
;
102 PORT_Assert(kTlsHkdfInfo[baseHash].hash == baseHash)((kTlsHkdfInfo[baseHash].hash == baseHash)?((void)0):PR_Assert
("kTlsHkdfInfo[baseHash].hash == baseHash","/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c"
,102))
;
103
104 /* A zero ikm2 is a key of hash-length 0s. */
105 if (!ikm2) {
106 /* if we have ikm1, put the zero key in the same slot */
107 slot = ikm1 ? PK11_GetSlotFromKey(ikm1) : PK11_GetBestSlot(CKM_HKDF_DERIVE0x0000402aUL, NULL((void*)0));
108 if (!slot) {
109 return SECFailure;
110 }
111
112 newIkm2 = PK11_ImportDataKey(slot, CKM_HKDF_DERIVE0x0000402aUL, PK11_OriginUnwrap,
113 CKA_DERIVE0x0000010CUL, &zeroKeyItem, NULL((void*)0));
114 if (!newIkm2) {
115 return SECFailure;
116 }
117 ikm2 = newIkm2;
118 }
119 PORT_Assert(ikm2)((ikm2)?((void)0):PR_Assert("ikm2","/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c"
,119))
;
120
121 PRINT_BUF(50, (NULL, "HKDF Extract: IKM1/Salt", params.pSalt, params.ulSaltLen))if (ssl_trace >= (50)) ssl_PrintBuf (((void*)0), "HKDF Extract: IKM1/Salt"
, params.pSalt, params.ulSaltLen)
;
122 PRINT_KEY(50, (NULL, "HKDF Extract: IKM2", ikm2))if (ssl_trace >= (50)) ssl_PrintKey (((void*)0), "HKDF Extract: IKM2"
, ikm2)
;
123
124 prk = PK11_Derive(ikm2, CKM_HKDF_DERIVE0x0000402aUL, &paramsi, CKM_HKDF_DERIVE0x0000402aUL,
125 CKA_DERIVE0x0000010CUL, 0);
126 PK11_FreeSymKey(newIkm2);
127 PK11_FreeSymKey(newIkm1);
128 if (slot)
129 PK11_FreeSlot(slot);
130 if (!prk) {
131 return SECFailure;
132 }
133
134 PRINT_KEY(50, (NULL, "HKDF Extract", prk))if (ssl_trace >= (50)) ssl_PrintKey (((void*)0), "HKDF Extract"
, prk)
;
135 *prkp = prk;
136
137 return SECSuccess;
138}
139
140SECStatus
141tls13_HkdfExpandLabelGeneral(CK_MECHANISM_TYPE deriveMech, PK11SymKey *prk,
142 SSLHashType baseHash,
143 const PRUint8 *handshakeHash, unsigned int handshakeHashLen,
144 const char *label, unsigned int labelLen,
145 CK_MECHANISM_TYPE algorithm, unsigned int keySize,
146 SSLProtocolVariant variant, PK11SymKey **keyp)
147{
148 CK_HKDF_PARAMS params;
149 SECItem paramsi = { siBuffer, NULL((void*)0), 0 };
150 /* Size of info array needs to be big enough to hold the maximum Prefix,
151 * Label, plus HandshakeHash. If it's ever to small, the code will abort.
152 */
153 PRUint8 info[256];
154 sslBuffer infoBuf = SSL_BUFFER(info){ info, 0, sizeof(info), 1 };
155 PK11SymKey *derived;
156 SECStatus rv;
157 const char *kLabelPrefixTls = "tls13 ";
158 const char *kLabelPrefixDtls = "dtls13";
159 const unsigned int kLabelPrefixLen =
160 (variant == ssl_variant_stream) ? strlen(kLabelPrefixTls) : strlen(kLabelPrefixDtls);
161 const char *kLabelPrefix =
162 (variant == ssl_variant_stream) ? kLabelPrefixTls : kLabelPrefixDtls;
163
164 PORT_Assert(prk)((prk)?((void)0):PR_Assert("prk","/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c"
,164))
;
165 PORT_Assert(keyp)((keyp)?((void)0):PR_Assert("keyp","/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c"
,165))
;
166 if ((handshakeHashLen > 255) ||
167 (handshakeHash == NULL((void*)0) && handshakeHashLen > 0) ||
168 (labelLen + kLabelPrefixLen > 255)) {
169 PORT_SetErrorPORT_SetError_Util(SEC_ERROR_INVALID_ARGS);
170 return SECFailure;
171 }
172
173 /*
174 * [draft-ietf-tls-tls13-11] Section 7.1:
175 *
176 * HKDF-Expand-Label(Secret, Label, HashValue, Length) =
177 * HKDF-Expand(Secret, HkdfLabel, Length)
178 *
179 * Where HkdfLabel is specified as:
180 *
181 * struct HkdfLabel {
182 * uint16 length;
183 * opaque label<9..255>;
184 * opaque hash_value<0..255>;
185 * };
186 *
187 * Where:
188 * - HkdfLabel.length is Length
189 * - HkdfLabel.hash_value is HashValue.
190 * - HkdfLabel.label is "TLS 1.3, " + Label
191 *
192 */
193 rv = sslBuffer_AppendNumber(&infoBuf, keySize, 2);
194 if (rv != SECSuccess) {
195 return SECFailure;
196 }
197 rv = sslBuffer_AppendNumber(&infoBuf, labelLen + kLabelPrefixLen, 1);
198 if (rv != SECSuccess) {
199 return SECFailure;
200 }
201 rv = sslBuffer_Append(&infoBuf, kLabelPrefix, kLabelPrefixLen);
202 if (rv != SECSuccess) {
203 return SECFailure;
204 }
205 rv = sslBuffer_Append(&infoBuf, label, labelLen);
206 if (rv != SECSuccess) {
207 return SECFailure;
208 }
209 rv = sslBuffer_AppendVariable(&infoBuf, handshakeHash, handshakeHashLen, 1);
210 if (rv != SECSuccess) {
211 return SECFailure;
212 }
213
214 params.bExtract = CK_FALSE0;
215 params.bExpand = CK_TRUE1;
216 params.prfHashMechanism = kTlsHkdfInfo[baseHash].pkcs11Mech;
217 params.pInfo = SSL_BUFFER_BASE(&infoBuf)((&infoBuf)->buf);
218 params.ulInfoLen = SSL_BUFFER_LEN(&infoBuf)((&infoBuf)->len);
219 paramsi.data = (unsigned char *)&params;
220 paramsi.len = sizeof(params);
221 derived = PK11_DeriveWithFlags(prk, deriveMech,
222 &paramsi, algorithm,
223 CKA_DERIVE0x0000010CUL, keySize,
224 CKF_SIGN0x00000800UL | CKF_VERIFY0x00002000);
225 if (!derived) {
226 return SECFailure;
227 }
228
229 *keyp = derived;
230
231#ifdef TRACE
232 if (ssl_trace >= 50) {
233 /* Make sure the label is null terminated. */
234 char labelStr[100];
235 PORT_Memcpymemcpy(labelStr, label, labelLen);
236 labelStr[labelLen] = 0;
237 SSL_TRC(50, ("HKDF Expand: label='tls13 %s',requested length=%d",if (ssl_trace >= (50)) ssl_Trace ("HKDF Expand: label='tls13 %s',requested length=%d"
, labelStr, keySize)
238 labelStr, keySize))if (ssl_trace >= (50)) ssl_Trace ("HKDF Expand: label='tls13 %s',requested length=%d"
, labelStr, keySize)
;
239 }
240 PRINT_KEY(50, (NULL, "PRK", prk))if (ssl_trace >= (50)) ssl_PrintKey (((void*)0), "PRK", prk
)
;
241 PRINT_BUF(50, (NULL, "Hash", handshakeHash, handshakeHashLen))if (ssl_trace >= (50)) ssl_PrintBuf (((void*)0), "Hash", handshakeHash
, handshakeHashLen)
;
242 PRINT_BUF(50, (NULL, "Info", SSL_BUFFER_BASE(&infoBuf),if (ssl_trace >= (50)) ssl_PrintBuf (((void*)0), "Info", (
(&infoBuf)->buf), ((&infoBuf)->len))
243 SSL_BUFFER_LEN(&infoBuf)))if (ssl_trace >= (50)) ssl_PrintBuf (((void*)0), "Info", (
(&infoBuf)->buf), ((&infoBuf)->len))
;
244 PRINT_KEY(50, (NULL, "Derived key", derived))if (ssl_trace >= (50)) ssl_PrintKey (((void*)0), "Derived key"
, derived)
;
245#endif
246
247 return SECSuccess;
248}
249
250SECStatus
251tls13_HkdfExpandLabel(PK11SymKey *prk, SSLHashType baseHash,
252 const PRUint8 *handshakeHash, unsigned int handshakeHashLen,
253 const char *label, unsigned int labelLen,
254 CK_MECHANISM_TYPE algorithm, unsigned int keySize,
255 SSLProtocolVariant variant, PK11SymKey **keyp)
256{
257 return tls13_HkdfExpandLabelGeneral(CKM_HKDF_DERIVE0x0000402aUL, prk, baseHash,
258 handshakeHash, handshakeHashLen,
259 label, labelLen, algorithm, keySize,
260 variant, keyp);
261}
262
263SECStatus
264tls13_HkdfExpandLabelRaw(PK11SymKey *prk, SSLHashType baseHash,
265 const PRUint8 *handshakeHash, unsigned int handshakeHashLen,
266 const char *label, unsigned int labelLen,
267 SSLProtocolVariant variant, unsigned char *output,
268 unsigned int outputLen)
269{
270 PK11SymKey *derived = NULL((void*)0);
271 SECItem *rawkey;
272 SECStatus rv;
273
274 /* the result is not really a key, it's a data object */
275 rv = tls13_HkdfExpandLabelGeneral(CKM_HKDF_DATA0x0000402bUL, prk, baseHash,
276 handshakeHash, handshakeHashLen,
277 label, labelLen, CKM_HKDF_DERIVE0x0000402aUL, outputLen,
278 variant, &derived);
279 if (rv != SECSuccess || !derived) {
280 goto abort;
281 }
282
283 rv = PK11_ExtractKeyValue(derived);
284 if (rv != SECSuccess) {
285 goto abort;
286 }
287
288 rawkey = PK11_GetKeyData(derived);
289 if (!rawkey) {
290 goto abort;
291 }
292
293 PORT_Assert(rawkey->len == outputLen)((rawkey->len == outputLen)?((void)0):PR_Assert("rawkey->len == outputLen"
,"/root/firefox-clang/security/nss/lib/ssl/tls13hkdf.c",293))
;
294 memcpy(output, rawkey->data, outputLen);
295 PK11_FreeSymKey(derived);
296
297 return SECSuccess;
298
299abort:
300 if (derived) {
301 PK11_FreeSymKey(derived);
302 }
303 PORT_SetErrorPORT_SetError_Util(SSL_ERROR_SYM_KEY_CONTEXT_FAILURE);
304 return SECFailure;
305}