Bug Summary

File:src/lib/libcrypto/bn/bn_print.c
Warning:line 228, column 2
Value stored to 'm' is never read

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 bn_print.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 -pic-is-pie -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 -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/bn/bn_print.c
1/* $OpenBSD: bn_print.c,v 1.32 2021/08/31 11:19:19 tb 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 <ctype.h>
60#include <limits.h>
61#include <stdio.h>
62
63#include <openssl/opensslconf.h>
64
65#include <openssl/bio.h>
66#include <openssl/buffer.h>
67#include <openssl/err.h>
68
69#include "bn_lcl.h"
70
71static const char Hex[]="0123456789ABCDEF";
72
73/* Must 'free' the returned data */
74char *
75BN_bn2hex(const BIGNUM *a)
76{
77 int i, j, v, z = 0;
78 char *buf;
79 char *p;
80
81 buf = malloc(BN_is_negative(a) + a->top * BN_BYTES8 * 2 + 2);
82 if (buf == NULL((void*)0)) {
83 BNerror(ERR_R_MALLOC_FAILURE)ERR_put_error(3,(0xfff),((1|64)),"/usr/src/lib/libcrypto/bn/bn_print.c"
,83)
;
84 goto err;
85 }
86 p = buf;
87 if (BN_is_negative(a))
88 *p++ = '-';
89 if (BN_is_zero(a))
90 *p++ = '0';
91 for (i = a->top - 1; i >=0; i--) {
92 for (j = BN_BITS264 - 8; j >= 0; j -= 8) {
93 /* strip leading zeros */
94 v = ((int)(a->d[i] >> (long)j)) & 0xff;
95 if (z || (v != 0)) {
96 *p++ = Hex[v >> 4];
97 *p++ = Hex[v & 0x0f];
98 z = 1;
99 }
100 }
101 }
102 *p = '\0';
103
104err:
105 return (buf);
106}
107
108/* Must 'free' the returned data */
109char *
110BN_bn2dec(const BIGNUM *a)
111{
112 int i = 0, num, bn_data_num, ok = 0;
113 char *buf = NULL((void*)0);
114 char *p;
115 BIGNUM *t = NULL((void*)0);
116 BN_ULONGunsigned long *bn_data = NULL((void*)0), *lp;
117
118 if (BN_is_zero(a)) {
119 buf = malloc(BN_is_negative(a) + 2);
120 if (buf == NULL((void*)0)) {
121 BNerror(ERR_R_MALLOC_FAILURE)ERR_put_error(3,(0xfff),((1|64)),"/usr/src/lib/libcrypto/bn/bn_print.c"
,121)
;
122 goto err;
123 }
124 p = buf;
125 if (BN_is_negative(a))
126 *p++ = '-';
127 *p++ = '0';
128 *p++ = '\0';
129 return (buf);
130 }
131
132 /* get an upper bound for the length of the decimal integer
133 * num <= (BN_num_bits(a) + 1) * log(2)
134 * <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1 (rounding error)
135 * <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1
136 */
137 i = BN_num_bits(a) * 3;
138 num = (i / 10 + i / 1000 + 1) + 1;
139 bn_data_num = num / BN_DEC_NUM19 + 1;
140 bn_data = reallocarray(NULL((void*)0), bn_data_num, sizeof(BN_ULONGunsigned long));
141 buf = malloc(num + 3);
142 if ((buf == NULL((void*)0)) || (bn_data == NULL((void*)0))) {
143 BNerror(ERR_R_MALLOC_FAILURE)ERR_put_error(3,(0xfff),((1|64)),"/usr/src/lib/libcrypto/bn/bn_print.c"
,143)
;
144 goto err;
145 }
146 if ((t = BN_dup(a)) == NULL((void*)0))
147 goto err;
148
149#define BUF_REMAIN(num+3 - (size_t)(p - buf)) (num+3 - (size_t)(p - buf))
150 p = buf;
151 lp = bn_data;
152 if (BN_is_negative(t))
153 *p++ = '-';
154
155 while (!BN_is_zero(t)) {
156 if (lp - bn_data >= bn_data_num)
157 goto err;
158 *lp = BN_div_word(t, BN_DEC_CONV(10000000000000000000UL));
159 if (*lp == (BN_ULONGunsigned long)-1)
160 goto err;
161 lp++;
162 }
163 lp--;
164 /* We now have a series of blocks, BN_DEC_NUM chars
165 * in length, where the last one needs truncation.
166 * The blocks need to be reversed in order. */
167 snprintf(p, BUF_REMAIN(num+3 - (size_t)(p - buf)), BN_DEC_FMT1"%lu", *lp);
168 while (*p)
169 p++;
170 while (lp != bn_data) {
171 lp--;
172 snprintf(p, BUF_REMAIN(num+3 - (size_t)(p - buf)), BN_DEC_FMT2"%019lu", *lp);
173 while (*p)
174 p++;
175 }
176 ok = 1;
177
178err:
179 free(bn_data);
180 BN_free(t);
181 if (!ok && buf) {
182 free(buf);
183 buf = NULL((void*)0);
184 }
185
186 return (buf);
187}
188
189int
190BN_hex2bn(BIGNUM **bn, const char *a)
191{
192 BIGNUM *ret = NULL((void*)0);
193 BN_ULONGunsigned long l = 0;
194 int neg = 0, h, m, i,j, k, c;
195 int num;
196
197 if ((a == NULL((void*)0)) || (*a == '\0'))
198 return (0);
199
200 if (*a == '-') {
201 neg = 1;
202 a++;
203 }
204
205 for (i = 0; i <= (INT_MAX2147483647 / 4) && isxdigit((unsigned char)a[i]); i++)
206 ;
207 if (i > INT_MAX2147483647 / 4)
208 goto err;
209
210 num = i + neg;
211 if (bn == NULL((void*)0))
212 return (num);
213
214 /* a is the start of the hex digits, and it is 'i' long */
215 if (*bn == NULL((void*)0)) {
216 if ((ret = BN_new()) == NULL((void*)0))
217 return (0);
218 } else {
219 ret = *bn;
220 BN_zero(ret)(BN_set_word((ret),0));
221 }
222
223 /* i is the number of hex digits */
224 if (bn_expand(ret, i * 4) == NULL((void*)0))
225 goto err;
226
227 j = i; /* least significant 'hex' */
228 m = 0;
Value stored to 'm' is never read
229 h = 0;
230 while (j > 0) {
231 m = ((BN_BYTES8 * 2) <= j) ? (BN_BYTES8 * 2) : j;
232 l = 0;
233 for (;;) {
234 c = a[j - m];
235 if ((c >= '0') && (c <= '9'))
236 k = c - '0';
237 else if ((c >= 'a') && (c <= 'f'))
238 k = c - 'a' + 10;
239 else if ((c >= 'A') && (c <= 'F'))
240 k = c - 'A' + 10;
241 else
242 k = 0; /* paranoia */
243 l = (l << 4) | k;
244
245 if (--m <= 0) {
246 ret->d[h++] = l;
247 break;
248 }
249 }
250 j -= (BN_BYTES8 * 2);
251 }
252 ret->top = h;
253 bn_correct_top(ret){ unsigned long *ftl; int tmp_top = (ret)->top; if (tmp_top
> 0) { for (ftl= &((ret)->d[tmp_top-1]); tmp_top >
0; tmp_top--) if (*(ftl--)) break; (ret)->top = tmp_top; }
; }
;
254 ret->neg = neg;
255
256 *bn = ret;
257 bn_check_top(ret);
258 return (num);
259
260err:
261 if (*bn == NULL((void*)0))
262 BN_free(ret);
263 return (0);
264}
265
266int
267BN_dec2bn(BIGNUM **bn, const char *a)
268{
269 BIGNUM *ret = NULL((void*)0);
270 BN_ULONGunsigned long l = 0;
271 int neg = 0, i, j;
272 int num;
273
274 if ((a == NULL((void*)0)) || (*a == '\0'))
275 return (0);
276 if (*a == '-') {
277 neg = 1;
278 a++;
279 }
280
281 for (i = 0; i <= (INT_MAX2147483647 / 4) && isdigit((unsigned char)a[i]); i++)
282 ;
283 if (i > INT_MAX2147483647 / 4)
284 goto err;
285
286 num = i + neg;
287 if (bn == NULL((void*)0))
288 return (num);
289
290 /* a is the start of the digits, and it is 'i' long.
291 * We chop it into BN_DEC_NUM digits at a time */
292 if (*bn == NULL((void*)0)) {
293 if ((ret = BN_new()) == NULL((void*)0))
294 return (0);
295 } else {
296 ret = *bn;
297 BN_zero(ret)(BN_set_word((ret),0));
298 }
299
300 /* i is the number of digits, a bit of an over expand */
301 if (bn_expand(ret, i * 4) == NULL((void*)0))
302 goto err;
303
304 j = BN_DEC_NUM19 - (i % BN_DEC_NUM19);
305 if (j == BN_DEC_NUM19)
306 j = 0;
307 l = 0;
308 while (*a) {
309 l *= 10;
310 l += *a - '0';
311 a++;
312 if (++j == BN_DEC_NUM19) {
313 BN_mul_word(ret, BN_DEC_CONV(10000000000000000000UL));
314 BN_add_word(ret, l);
315 l = 0;
316 j = 0;
317 }
318 }
319 ret->neg = neg;
320
321 bn_correct_top(ret){ unsigned long *ftl; int tmp_top = (ret)->top; if (tmp_top
> 0) { for (ftl= &((ret)->d[tmp_top-1]); tmp_top >
0; tmp_top--) if (*(ftl--)) break; (ret)->top = tmp_top; }
; }
;
322 *bn = ret;
323 bn_check_top(ret);
324 return (num);
325
326err:
327 if (*bn == NULL((void*)0))
328 BN_free(ret);
329 return (0);
330}
331
332int
333BN_asc2bn(BIGNUM **bn, const char *a)
334{
335 const char *p = a;
336 if (*p == '-')
337 p++;
338
339 if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {
340 if (!BN_hex2bn(bn, p + 2))
341 return 0;
342 } else {
343 if (!BN_dec2bn(bn, p))
344 return 0;
345 }
346 if (*a == '-')
347 (*bn)->neg = 1;
348 return 1;
349}
350
351#ifndef OPENSSL_NO_BIO
352int
353BN_print_fp(FILE *fp, const BIGNUM *a)
354{
355 BIO *b;
356 int ret;
357
358 if ((b = BIO_new(BIO_s_file())) == NULL((void*)0))
359 return (0);
360 BIO_set_fp(b, fp, BIO_NOCLOSE)BIO_ctrl(b,106,0x00,(char *)fp);
361 ret = BN_print(b, a);
362 BIO_free(b);
363 return (ret);
364}
365
366int
367BN_print(BIO *bp, const BIGNUM *a)
368{
369 int i, j, v, z = 0;
370 int ret = 0;
371
372 if ((a->neg) && (BIO_write(bp, "-", 1) != 1))
373 goto end;
374 if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1))
375 goto end;
376 for (i = a->top - 1; i >= 0; i--) {
377 for (j = BN_BITS264 - 4; j >= 0; j -= 4) {
378 /* strip leading zeros */
379 v = ((int)(a->d[i] >> (long)j)) & 0x0f;
380 if (z || (v != 0)) {
381 if (BIO_write(bp, &(Hex[v]), 1) != 1)
382 goto end;
383 z = 1;
384 }
385 }
386 }
387 ret = 1;
388
389end:
390 return (ret);
391}
392#endif
393
394char *
395BN_options(void)
396{
397 static int init = 0;
398 static char data[16];
399
400 if (!init) {
401 init++;
402#ifdef BN_LLONG
403 snprintf(data,sizeof data, "bn(%d,%d)",
404 (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONGunsigned long) * 8);
405#else
406 snprintf(data,sizeof data, "bn(%d,%d)",
407 (int)sizeof(BN_ULONGunsigned long) * 8, (int)sizeof(BN_ULONGunsigned long) * 8);
408#endif
409 }
410 return (data);
411}