Bug Summary

File:src/lib/libcrypto/asn1/bio_ndef.c
Warning:line 185, column 7
Although the value stored to 'derlen' is used in the enclosing expression, the value is never actually read from 'derlen'

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name bio_ndef.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 -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/lib/libcrypto/obj -resource-dir /usr/local/llvm16/lib/clang/16 -D LIBRESSL_INTERNAL -D HAVE_FUNOPEN -I /usr/src/lib/libcrypto -I /usr/src/lib/libcrypto/arch/amd64 -I /usr/src/lib/libcrypto/asn1 -I /usr/src/lib/libcrypto/bio -I /usr/src/lib/libcrypto/bn -I /usr/src/lib/libcrypto/bn/arch/amd64 -I /usr/src/lib/libcrypto/bytestring -I /usr/src/lib/libcrypto/curve25519 -I /usr/src/lib/libcrypto/dh -I /usr/src/lib/libcrypto/dsa -I /usr/src/lib/libcrypto/ec -I /usr/src/lib/libcrypto/ecdsa -I /usr/src/lib/libcrypto/evp -I /usr/src/lib/libcrypto/hidden -I /usr/src/lib/libcrypto/hmac -I /usr/src/lib/libcrypto/kdf -I /usr/src/lib/libcrypto/modes -I /usr/src/lib/libcrypto/ocsp -I /usr/src/lib/libcrypto/pkcs12 -I /usr/src/lib/libcrypto/rsa -I /usr/src/lib/libcrypto/sha -I /usr/src/lib/libcrypto/ts -I /usr/src/lib/libcrypto/x509 -I /usr/src/lib/libcrypto/obj -D AES_ASM -D BSAES_ASM -D VPAES_ASM -D OPENSSL_IA32_SSE2 -D RSA_ASM -D OPENSSL_BN_ASM_MONT -D OPENSSL_BN_ASM_MONT5 -D MD5_ASM -D GHASH_ASM -D RC4_MD5_ASM -D SHA1_ASM -D SHA256_ASM -D SHA512_ASM -D WHIRLPOOL_ASM -D OPENSSL_CPUID_OBJ -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libcrypto/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/scan/2024-01-11-140451-98009-1 -x c /usr/src/lib/libcrypto/asn1/bio_ndef.c
1/* $OpenBSD: bio_ndef.c,v 1.24 2023/07/28 09:58:30 tb Exp $ */
2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project.
4 */
5/* ====================================================================
6 * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 */
54
55#include <stdio.h>
56
57#include <openssl/asn1.h>
58#include <openssl/asn1t.h>
59#include <openssl/bio.h>
60#include <openssl/err.h>
61
62#include "asn1_local.h"
63
64int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix, asn1_ps_func *prefix_free);
65int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix, asn1_ps_func *suffix_free);
66
67/* Experimental NDEF ASN1 BIO support routines */
68
69/* The usage is quite simple, initialize an ASN1 structure,
70 * get a BIO from it then any data written through the BIO
71 * will end up translated to approptiate format on the fly.
72 * The data is streamed out and does *not* need to be
73 * all held in memory at once.
74 *
75 * When the BIO is flushed the output is finalized and any
76 * signatures etc written out.
77 *
78 * The BIO is a 'proper' BIO and can handle non blocking I/O
79 * correctly.
80 *
81 * The usage is simple. The implementation is *not*...
82 */
83
84/* BIO support data stored in the ASN1 BIO ex_arg */
85
86typedef struct ndef_aux_st {
87 /* ASN1 structure this BIO refers to */
88 ASN1_VALUE *val;
89 const ASN1_ITEM *it;
90 /* Top of the BIO chain */
91 BIO *ndef_bio;
92 /* Output BIO */
93 BIO *out;
94 /* Boundary where content is inserted */
95 unsigned char **boundary;
96 /* DER buffer start */
97 unsigned char *derbuf;
98} NDEF_SUPPORT;
99
100static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
101static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg);
102static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
103static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg);
104
105BIO *
106BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
107{
108 NDEF_SUPPORT *ndef_aux = NULL((void *)0);
109 BIO *asn_bio = NULL((void *)0), *pop_bio = NULL((void *)0);
110 const ASN1_AUX *aux = it->funcs;
111 ASN1_STREAM_ARG sarg;
112
113 if (aux == NULL((void *)0) || aux->asn1_cb == NULL((void *)0)) {
114 ASN1error(ASN1_R_STREAMING_NOT_SUPPORTED)ERR_put_error(13,(0xfff),(202),"/usr/src/lib/libcrypto/asn1/bio_ndef.c"
,114);
115 goto err;
116 }
117
118 if ((asn_bio = BIO_new(BIO_f_asn1())) == NULL((void *)0))
119 goto err;
120
121 if (BIO_push(asn_bio, out) == NULL((void *)0))
122 goto err;
123 pop_bio = asn_bio;
124
125 /*
126 * Set up prefix and suffix handlers first. This ensures that ndef_aux
127 * is freed as part of asn_bio once it is the asn_bio's ex_arg.
128 */
129 if (BIO_asn1_set_prefix(asn_bio, ndef_prefix, ndef_prefix_free) <= 0)
130 goto err;
131 if (BIO_asn1_set_suffix(asn_bio, ndef_suffix, ndef_suffix_free) <= 0)
132 goto err;
133
134 /*
135 * Allocate early to avoid the tricky cleanup after the asn1_cb().
136 * Ownership of ndef_aux is transferred to asn_bio in BIO_ctrl().
137 * Keep a reference to populate it after callback success.
138 */
139 if ((ndef_aux = calloc(1, sizeof(*ndef_aux))) == NULL((void *)0))
140 goto err;
141 if (BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG153, 0, ndef_aux) <= 0) {
142 free(ndef_aux);
143 goto err;
144 }
145
146 /*
147 * The callback prepends BIOs to the chain starting at asn_bio for
148 * digest, cipher, etc. The resulting chain starts at sarg.ndef_bio.
149 */
150
151 sarg.out = asn_bio;
152 sarg.ndef_bio = NULL((void *)0);
153 sarg.boundary = NULL((void *)0);
154
155 if (aux->asn1_cb(ASN1_OP_STREAM_PRE10, &val, it, &sarg) <= 0)
156 goto err;
157
158 ndef_aux->val = val;
159 ndef_aux->it = it;
160 ndef_aux->ndef_bio = sarg.ndef_bio;
161 ndef_aux->boundary = sarg.boundary;
162 ndef_aux->out = asn_bio;
163
164 return sarg.ndef_bio;
165
166 err:
167 BIO_pop(pop_bio);
168 BIO_free(asn_bio);
169
170 return NULL((void *)0);
171}
172
173static int
174ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
175{
176 NDEF_SUPPORT *ndef_aux;
177 unsigned char *p = NULL((void *)0);
178 int derlen;
179
180 if (!parg)
181 return 0;
182
183 ndef_aux = *(NDEF_SUPPORT **)parg;
184
185 if ((derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it)) <= 0)
Although the value stored to 'derlen' is used in the enclosing expression, the value is never actually read from 'derlen'
186 return 0;
187
188 ndef_aux->derbuf = p;
189 *pbuf = p;
190
191 if (*ndef_aux->boundary == NULL((void *)0))
192 return 0;
193
194 *plen = *ndef_aux->boundary - *pbuf;
195
196 return 1;
197}
198
199static int
200ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg)
201{
202 NDEF_SUPPORT **pndef_aux = parg;
203
204 if (pndef_aux == NULL((void *)0) || *pndef_aux == NULL((void *)0))
205 return 0;
206
207 free((*pndef_aux)->derbuf);
208 (*pndef_aux)->derbuf = NULL((void *)0);
209
210 *pbuf = NULL((void *)0);
211 *plen = 0;
212
213 return 1;
214}
215
216static int
217ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg)
218{
219 NDEF_SUPPORT **pndef_aux = parg;
220
221 /* Ensure ndef_prefix_free() won't fail, so we won't leak *pndef_aux. */
222 if (pndef_aux == NULL((void *)0) || *pndef_aux == NULL((void *)0))
223 return 0;
224 if (!ndef_prefix_free(b, pbuf, plen, parg))
225 return 0;
226
227 free(*pndef_aux);
228 *pndef_aux = NULL((void *)0);
229
230 return 1;
231}
232
233static int
234ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
235{
236 NDEF_SUPPORT *ndef_aux;
237 unsigned char *p = NULL((void *)0);
238 int derlen;
239 const ASN1_AUX *aux;
240 ASN1_STREAM_ARG sarg;
241
242 if (!parg)
243 return 0;
244
245 ndef_aux = *(NDEF_SUPPORT **)parg;
246
247 aux = ndef_aux->it->funcs;
248
249 /* Finalize structures */
250 sarg.ndef_bio = ndef_aux->ndef_bio;
251 sarg.out = ndef_aux->out;
252 sarg.boundary = ndef_aux->boundary;
253 if (aux->asn1_cb(ASN1_OP_STREAM_POST11,
254 &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
255 return 0;
256
257 if ((derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it)) <= 0)
258 return 0;
259
260 ndef_aux->derbuf = p;
261 *pbuf = p;
262
263 if (*ndef_aux->boundary == NULL((void *)0))
264 return 0;
265
266 *pbuf = *ndef_aux->boundary;
267 *plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
268
269 return 1;
270}