Bug Summary

File:src/lib/libcrypto/des/ofb_enc.c
Warning:line 132, column 7
Although the value stored to 'v1' is used in the enclosing expression, the value is never actually read from 'v1'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name ofb_enc.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/des/ofb_enc.c
1/* $OpenBSD: ofb_enc.c,v 1.8 2023/07/08 07:11:07 beck 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_local.h"
60
61/* The input and output are loaded in multiples of 8 bits.
62 * What this means is that if you hame numbits=12 and length=2
63 * the first 12 bits will be retrieved from the first byte and half
64 * the second. The second 12 bits will come from the 3rd and half the 4th
65 * byte.
66 */
67void
68DES_ofb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
69 long length, DES_key_schedule *schedule,
70 DES_cblock *ivec)
71{
72 DES_LONGunsigned int d0, d1, vv0, vv1, v0, v1, n = (numbits + 7)/8;
73 DES_LONGunsigned int mask0, mask1;
74 long l = length;
75 int num = numbits;
76 DES_LONGunsigned int ti[2];
77 unsigned char *iv;
78
79 if (num > 64)
80 return;
81 if (num > 32) {
82 mask0 = 0xffffffffL;
83 if (num >= 64)
84 mask1 = mask0;
85 else
86 mask1 = (1L << (num - 32)) - 1;
87 } else {
88 if (num == 32)
89 mask0 = 0xffffffffL;
90 else
91 mask0 = (1L << num) - 1;
92 mask1 = 0x00000000L;
93 }
94
95 iv = &(*ivec)[0];
96 c2l(iv, v0)(v0 =((unsigned int)(*((iv)++))) , v0|=((unsigned int)(*((iv)
++)))<< 8L, v0|=((unsigned int)(*((iv)++)))<<16L,
v0|=((unsigned int)(*((iv)++)))<<24L)
;
97 c2l(iv, v1)(v1 =((unsigned int)(*((iv)++))) , v1|=((unsigned int)(*((iv)
++)))<< 8L, v1|=((unsigned int)(*((iv)++)))<<16L,
v1|=((unsigned int)(*((iv)++)))<<24L)
;
98 ti[0] = v0;
99 ti[1] = v1;
100 while (l-- > 0) {
101 ti[0] = v0;
102 ti[1] = v1;
103 DES_encrypt1((DES_LONGunsigned int *)ti, schedule, DES_ENCRYPT1);
104 vv0 = ti[0];
105 vv1 = ti[1];
106 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)))); } }
;
107 in += n;
108 d0 = (d0 ^ vv0) & mask0;
109 d1 = (d1 ^ vv1) & mask1;
110 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); } }
;
111 out += n;
112
113 if (num == 32) {
114 v0 = v1;
115 v1 = vv0;
116 } else if (num == 64) {
117 v0 = vv0;
118 v1 = vv1;
119 } else if (num > 32) { /* && num != 64 */
120 v0 = ((v1 >> (num - 32))|(vv0 << (64 - num))) &
121 0xffffffffL;
122 v1 = ((vv0 >> (num - 32))|(vv1 << (64 - num))) &
123 0xffffffffL;
124 } else /* num < 32 */ {
125 v0 = ((v0 >> num)|(v1 << (32 - num))) & 0xffffffffL;
126 v1 = ((v1 >> num)|(vv0 << (32 - num))) & 0xffffffffL;
127 }
128 }
129 iv = &(*ivec)[0];
130 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))
;
131 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))
;
132 v0 = v1 = d0 = d1 = ti[0] = ti[1] = vv0 = vv1 = 0;
Although the value stored to 'v1' is used in the enclosing expression, the value is never actually read from 'v1'
133}