Bug Summary

File:src/lib/libcrypto/des/cfb_enc.c
Warning:line 187, column 11
Although the value stored to 'd1' is used in the enclosing expression, the value is never actually read from 'd1'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name cfb_enc.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -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 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -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/lib/clang/13.0.0 -D LIBRESSL_INTERNAL -D LIBRESSL_CRYPTO_INTERNAL -D DSO_DLFCN -D HAVE_DLFCN_H -D HAVE_FUNOPEN -D OPENSSL_NO_HW_PADLOCK -I /usr/src/lib/libcrypto -I /usr/src/lib/libcrypto/asn1 -I /usr/src/lib/libcrypto/bio -I /usr/src/lib/libcrypto/bn -I /usr/src/lib/libcrypto/bytestring -I /usr/src/lib/libcrypto/dh -I /usr/src/lib/libcrypto/dsa -I /usr/src/lib/libcrypto/ec -I /usr/src/lib/libcrypto/ecdh -I /usr/src/lib/libcrypto/ecdsa -I /usr/src/lib/libcrypto/evp -I /usr/src/lib/libcrypto/hmac -I /usr/src/lib/libcrypto/modes -I /usr/src/lib/libcrypto/ocsp -I /usr/src/lib/libcrypto/rsa -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 OPENSSL_BN_ASM_GF2m -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 -D PIC -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libcrypto/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -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/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/lib/libcrypto/des/cfb_enc.c
1/* $OpenBSD: cfb_enc.c,v 1.14 2021/11/09 18:40:21 bcook Exp $ */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include "des_locl.h"
60#include <endian.h>
61
62/* The input and output are loaded in multiples of 8 bits.
63 * What this means is that if you hame numbits=12 and length=2
64 * the first 12 bits will be retrieved from the first byte and half
65 * the second. The second 12 bits will come from the 3rd and half the 4th
66 * byte.
67 */
68/* Until Aug 1 2003 this function did not correctly implement CFB-r, so it
69 * will not be compatible with any encryption prior to that date. Ben. */
70void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
71 long length, DES_key_schedule *schedule, DES_cblock *ivec,
72 int enc)
73 {
74 DES_LONGunsigned int d0,d1,v0,v1;
75 unsigned long l=length;
76 int num=numbits/8,n=(numbits+7)/8,i,rem=numbits%8;
77 DES_LONGunsigned int ti[2];
78 unsigned char *iv;
79#if BYTE_ORDER1234 != LITTLE_ENDIAN1234
80 unsigned char ovec[16];
81#else
82 unsigned int sh[4];
83 unsigned char *ovec=(unsigned char *)sh;
84#endif
85
86 if (numbits<=0 || numbits > 64) return;
87 iv = &(*ivec)[0];
88 c2l(iv,v0)(v0 =((unsigned int)(*((iv)++))) , v0|=((unsigned int)(*((iv)
++)))<< 8L, v0|=((unsigned int)(*((iv)++)))<<16L,
v0|=((unsigned int)(*((iv)++)))<<24L);
89 c2l(iv,v1)(v1 =((unsigned int)(*((iv)++))) , v1|=((unsigned int)(*((iv)
++)))<< 8L, v1|=((unsigned int)(*((iv)++)))<<16L,
v1|=((unsigned int)(*((iv)++)))<<24L);
90 if (enc)
91 {
92 while (l >= (unsigned long)n)
93 {
94 l-=n;
95 ti[0]=v0;
96 ti[1]=v1;
97 DES_encrypt1((DES_LONGunsigned int *)ti,schedule,DES_ENCRYPT1);
98 c2ln(in,d0,d1,n){ in+=n; d0=d1=0; switch (n) { case 8: d1 =((unsigned int)(*(
--(in))))<<24L; case 7: d1|=((unsigned int)(*(--(in))))
<<16L; case 6: d1|=((unsigned int)(*(--(in))))<< 8L
; case 5: d1|=((unsigned int)(*(--(in)))); case 4: d0 =((unsigned
int)(*(--(in))))<<24L; case 3: d0|=((unsigned int)(*(--
(in))))<<16L; case 2: d0|=((unsigned int)(*(--(in))))<<
8L; case 1: d0|=((unsigned int)(*(--(in)))); } };
99 in+=n;
100 d0^=ti[0];
101 d1^=ti[1];
102 l2cn(d0,d1,out,n){ out+=n; switch (n) { case 8: *(--(out))=(unsigned char)(((d1
)>>24L)&0xff); case 7: *(--(out))=(unsigned char)((
(d1)>>16L)&0xff); case 6: *(--(out))=(unsigned char
)(((d1)>> 8L)&0xff); case 5: *(--(out))=(unsigned char
)(((d1) )&0xff); case 4: *(--(out))=(unsigned char)(((d0)
>>24L)&0xff); case 3: *(--(out))=(unsigned char)(((
d0)>>16L)&0xff); case 2: *(--(out))=(unsigned char)
(((d0)>> 8L)&0xff); case 1: *(--(out))=(unsigned char
)(((d0) )&0xff); } };
103 out+=n;
104 /* 30-08-94 - eay - changed because l>>32 and
105 * l<<32 are bad under gcc :-( */
106 if (numbits == 32)
107 { v0=v1; v1=d0; }
108 else if (numbits == 64)
109 { v0=d0; v1=d1; }
110 else
111 {
112#if BYTE_ORDER1234 != LITTLE_ENDIAN1234
113 iv=&ovec[0];
114 l2c(v0,iv)(*((iv)++)=(unsigned char)(((v0) )&0xff), *((iv)++)=(unsigned
char)(((v0)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((v0)>>16L)&0xff), *((iv)++)=(unsigned char)(((v0)
>>24L)&0xff));
115 l2c(v1,iv)(*((iv)++)=(unsigned char)(((v1) )&0xff), *((iv)++)=(unsigned
char)(((v1)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((v1)>>16L)&0xff), *((iv)++)=(unsigned char)(((v1)
>>24L)&0xff));
116 l2c(d0,iv)(*((iv)++)=(unsigned char)(((d0) )&0xff), *((iv)++)=(unsigned
char)(((d0)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((d0)>>16L)&0xff), *((iv)++)=(unsigned char)(((d0)
>>24L)&0xff));
117 l2c(d1,iv)(*((iv)++)=(unsigned char)(((d1) )&0xff), *((iv)++)=(unsigned
char)(((d1)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((d1)>>16L)&0xff), *((iv)++)=(unsigned char)(((d1)
>>24L)&0xff));
118#else
119 sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1;
120#endif
121 if (rem==0)
122 memmove(ovec,ovec+num,8);
123 else
124 for(i=0 ; i < 8 ; ++i)
125 ovec[i]=ovec[i+num]<<rem |
126 ovec[i+num+1]>>(8-rem);
127#if BYTE_ORDER1234 == LITTLE_ENDIAN1234
128 v0=sh[0], v1=sh[1];
129#else
130 iv=&ovec[0];
131 c2l(iv,v0)(v0 =((unsigned int)(*((iv)++))) , v0|=((unsigned int)(*((iv)
++)))<< 8L, v0|=((unsigned int)(*((iv)++)))<<16L,
v0|=((unsigned int)(*((iv)++)))<<24L);
132 c2l(iv,v1)(v1 =((unsigned int)(*((iv)++))) , v1|=((unsigned int)(*((iv)
++)))<< 8L, v1|=((unsigned int)(*((iv)++)))<<16L,
v1|=((unsigned int)(*((iv)++)))<<24L);
133#endif
134 }
135 }
136 }
137 else
138 {
139 while (l >= (unsigned long)n)
140 {
141 l-=n;
142 ti[0]=v0;
143 ti[1]=v1;
144 DES_encrypt1((DES_LONGunsigned int *)ti,schedule,DES_ENCRYPT1);
145 c2ln(in,d0,d1,n){ in+=n; d0=d1=0; switch (n) { case 8: d1 =((unsigned int)(*(
--(in))))<<24L; case 7: d1|=((unsigned int)(*(--(in))))
<<16L; case 6: d1|=((unsigned int)(*(--(in))))<< 8L
; case 5: d1|=((unsigned int)(*(--(in)))); case 4: d0 =((unsigned
int)(*(--(in))))<<24L; case 3: d0|=((unsigned int)(*(--
(in))))<<16L; case 2: d0|=((unsigned int)(*(--(in))))<<
8L; case 1: d0|=((unsigned int)(*(--(in)))); } };
146 in+=n;
147 /* 30-08-94 - eay - changed because l>>32 and
148 * l<<32 are bad under gcc :-( */
149 if (numbits == 32)
150 { v0=v1; v1=d0; }
151 else if (numbits == 64)
152 { v0=d0; v1=d1; }
153 else
154 {
155#if BYTE_ORDER1234 != LITTLE_ENDIAN1234
156 iv=&ovec[0];
157 l2c(v0,iv)(*((iv)++)=(unsigned char)(((v0) )&0xff), *((iv)++)=(unsigned
char)(((v0)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((v0)>>16L)&0xff), *((iv)++)=(unsigned char)(((v0)
>>24L)&0xff));
158 l2c(v1,iv)(*((iv)++)=(unsigned char)(((v1) )&0xff), *((iv)++)=(unsigned
char)(((v1)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((v1)>>16L)&0xff), *((iv)++)=(unsigned char)(((v1)
>>24L)&0xff));
159 l2c(d0,iv)(*((iv)++)=(unsigned char)(((d0) )&0xff), *((iv)++)=(unsigned
char)(((d0)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((d0)>>16L)&0xff), *((iv)++)=(unsigned char)(((d0)
>>24L)&0xff));
160 l2c(d1,iv)(*((iv)++)=(unsigned char)(((d1) )&0xff), *((iv)++)=(unsigned
char)(((d1)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((d1)>>16L)&0xff), *((iv)++)=(unsigned char)(((d1)
>>24L)&0xff));
161#else
162 sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1;
163#endif
164 if (rem==0)
165 memmove(ovec,ovec+num,8);
166 else
167 for(i=0 ; i < 8 ; ++i)
168 ovec[i]=ovec[i+num]<<rem |
169 ovec[i+num+1]>>(8-rem);
170#if BYTE_ORDER1234 == LITTLE_ENDIAN1234
171 v0=sh[0], v1=sh[1];
172#else
173 iv=&ovec[0];
174 c2l(iv,v0)(v0 =((unsigned int)(*((iv)++))) , v0|=((unsigned int)(*((iv)
++)))<< 8L, v0|=((unsigned int)(*((iv)++)))<<16L,
v0|=((unsigned int)(*((iv)++)))<<24L);
175 c2l(iv,v1)(v1 =((unsigned int)(*((iv)++))) , v1|=((unsigned int)(*((iv)
++)))<< 8L, v1|=((unsigned int)(*((iv)++)))<<16L,
v1|=((unsigned int)(*((iv)++)))<<24L);
176#endif
177 }
178 d0^=ti[0];
179 d1^=ti[1];
180 l2cn(d0,d1,out,n){ out+=n; switch (n) { case 8: *(--(out))=(unsigned char)(((d1
)>>24L)&0xff); case 7: *(--(out))=(unsigned char)((
(d1)>>16L)&0xff); case 6: *(--(out))=(unsigned char
)(((d1)>> 8L)&0xff); case 5: *(--(out))=(unsigned char
)(((d1) )&0xff); case 4: *(--(out))=(unsigned char)(((d0)
>>24L)&0xff); case 3: *(--(out))=(unsigned char)(((
d0)>>16L)&0xff); case 2: *(--(out))=(unsigned char)
(((d0)>> 8L)&0xff); case 1: *(--(out))=(unsigned char
)(((d0) )&0xff); } };
181 out+=n;
182 }
183 }
184 iv = &(*ivec)[0];
185 l2c(v0,iv)(*((iv)++)=(unsigned char)(((v0) )&0xff), *((iv)++)=(unsigned
char)(((v0)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((v0)>>16L)&0xff), *((iv)++)=(unsigned char)(((v0)
>>24L)&0xff));
186 l2c(v1,iv)(*((iv)++)=(unsigned char)(((v1) )&0xff), *((iv)++)=(unsigned
char)(((v1)>> 8L)&0xff), *((iv)++)=(unsigned char)
(((v1)>>16L)&0xff), *((iv)++)=(unsigned char)(((v1)
>>24L)&0xff));
187 v0=v1=d0=d1=ti[0]=ti[1]=0;
Although the value stored to 'd1' is used in the enclosing expression, the value is never actually read from 'd1'
188 }
189