1 /*-
2 * Copyright (c) 2012 Alistair Crooks <agc@NetBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <sys/mman.h>
28
29 #include <err.h>
30 #include <inttypes.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35
36 #include "digest.h"
37 #include "pgpsum.h"
38
39 #ifndef USE_ARG
40 #define USE_ARG(x) /*LINTED*/(void)&(x)
41 #endif
42
43 /* add the ascii armor line endings (except for last line) */
44 static size_t
don_armor(digest_t * hash,uint8_t * in,size_t insize,int doarmor)45 don_armor(digest_t *hash, uint8_t *in, size_t insize, int doarmor)
46 {
47 uint8_t *from;
48 uint8_t *newp;
49 uint8_t *p;
50 uint8_t dos_line_end[2];
51
52 dos_line_end[0] = '\r';
53 dos_line_end[1] = '\n';
54 for (from = in ; (p = memchr(from, '\n', insize - (size_t)(from - in))) != NULL ; from = p + 1) {
55 for (newp = p ; doarmor == 'w' && newp > from ; --newp) {
56 if (*(newp - 1) != ' ' && *(newp - 1) != '\t') {
57 break;
58 }
59 }
60 digest_update(hash, from, (size_t)(newp - from));
61 digest_update(hash, dos_line_end, sizeof(dos_line_end));
62 }
63 digest_update(hash, from, insize - (size_t)(from - in));
64 return 1;
65 }
66
67 #ifdef NETPGPV_DEBUG
68 /* just for giggles, write what we're about to checksum */
69 static int
writefile(uint8_t * mem,size_t insize)70 writefile(uint8_t *mem, size_t insize)
71 {
72 size_t cc;
73 size_t wc;
74 char template[256];
75 int fd;
76
77 snprintf(template, sizeof(template), "netpgpvmd.XXXXXX");
78 if ((fd = mkstemp(template)) < 0) {
79 fprintf(stderr, "can't mkstemp %s\n", template);
80 return 0;
81 }
82 for (cc = 0 ; cc < insize ; cc += wc) {
83 if ((wc = write(fd, &mem[cc], insize - cc)) <= 0) {
84 fprintf(stderr, "short write\n");
85 break;
86 }
87 }
88 close(fd);
89 return 1;
90 }
91 #endif
92
93 /* return non-zero if this is actually an armored piece already */
94 static int
already_armored(uint8_t * in,size_t insize)95 already_armored(uint8_t *in, size_t insize)
96 {
97 uint8_t *from;
98 uint8_t *p;
99
100 for (from = in ; (p = memchr(from, '\n', insize - (size_t)(from - in))) != NULL ; from = p + 1) {
101 if (*(p - 1) != '\r') {
102 return 0;
103 }
104 }
105 return 1;
106 }
107
108 /* calculate the checksum for the data we have */
109 static int
calcsum(uint8_t * out,size_t size,uint8_t * mem,size_t cc,const uint8_t * hashed,size_t hashsize,int doarmor)110 calcsum(uint8_t *out, size_t size, uint8_t *mem, size_t cc, const uint8_t *hashed, size_t hashsize, int doarmor)
111 {
112 digest_t hash;
113 uint32_t len32;
114 uint16_t len16;
115 uint8_t hashalg;
116 uint8_t trailer[6];
117
118 USE_ARG(size);
119 /* hashed data is non-null (previously checked) */
120 hashalg = hashed[3];
121 memcpy(&len16, &hashed[4], sizeof(len16));
122 len32 = ntohs(len16) + 6;
123 len32 = htonl(len32);
124 trailer[0] = 0x04;
125 trailer[1] = 0xff;
126 memcpy(&trailer[2], &len32, sizeof(len32));
127 #ifdef NETPGPV_DEBUG
128 writefile(mem, cc);
129 #endif
130 digest_init(&hash, (const unsigned)hashalg);
131 if (strchr("tw", doarmor) != NULL && !already_armored(mem, cc)) {
132 /* this took me ages to find - something causes gpg to truncate its input */
133 don_armor(&hash, mem, cc - 1, doarmor);
134 } else {
135 digest_update(&hash, mem, cc);
136 }
137 if (hashed) {
138 digest_update(&hash, hashed, hashsize);
139 }
140 digest_update(&hash, trailer, sizeof(trailer));
141 return digest_final(out, &hash);
142 }
143
144 /* open the file, mmap it, and then get the checksum on that */
145 int
pgpv_digest_file(uint8_t * data,size_t size,const char * name,const uint8_t * hashed,size_t hashsize,int doarmor)146 pgpv_digest_file(uint8_t *data, size_t size, const char *name, const uint8_t *hashed, size_t hashsize, int doarmor)
147 {
148 struct stat st;
149 uint8_t *mem;
150 size_t cc;
151 FILE *fp;
152 int ret;
153
154 if (hashed == NULL || data == NULL || name == NULL) {
155 fprintf(stderr, "no hashed data provided\n");
156 return 0;
157 }
158 ret = 0;
159 mem = NULL;
160 cc = 0;
161 if ((fp = fopen(name, "r")) == NULL) {
162 warn("%s - not found", name);
163 return 0;
164 }
165 if (fstat(fileno(fp), &st) < 0) {
166 warn("%s - can't stat", name);
167 goto done;
168 }
169 cc = (size_t)(st.st_size);
170 if ((mem = mmap(NULL, cc, PROT_READ, MAP_SHARED, fileno(fp), 0)) == MAP_FAILED) {
171 warn("%s - can't mmap", name);
172 goto done;
173 }
174 ret = calcsum(data, size, mem, cc, hashed, hashsize, doarmor);
175 done:
176 if (data) {
177 munmap(mem, cc);
178 }
179 fclose(fp);
180 return ret;
181 }
182
183 /* calculate the digest over memory too */
184 int
pgpv_digest_memory(uint8_t * data,size_t size,void * mem,size_t cc,const uint8_t * hashed,size_t hashsize,int doarmor)185 pgpv_digest_memory(uint8_t *data, size_t size, void *mem, size_t cc, const uint8_t *hashed, size_t hashsize, int doarmor)
186 {
187 if (hashed == NULL || data == NULL || mem == NULL) {
188 fprintf(stderr, "no hashed data provided\n");
189 return 0;
190 }
191 return calcsum(data, size, mem, cc, hashed, hashsize, doarmor);
192 }
193