2 * lib/ext2fs/digest_encode.c
4 * A function to encode a digest using 64 characters that are valid in a
5 * filename per ext2fs rules.
7 * Written by Uday Savagaonkar, 2014.
9 * Copyright 2014 Google Inc. All Rights Reserved.
12 * This file may be redistributed under the terms of the GNU Library
13 * General Public License, version 2.
19 #include <sys/types.h>
23 static const char *lookup_table =
24 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
27 * ext2fs_digest_encode() -
29 * Encodes the input digest using characters from the set [a-zA-Z0-9_+].
30 * The encoded string is roughly 4/3 times the size of the input string.
32 int ext2fs_digest_encode(const char *src, int len, char *dst)
34 int i = 0, bits = 0, ac = 0;
38 ac += (((unsigned char) src[i]) << bits);
41 *cp++ = lookup_table[ac & 0x3f];
48 *cp++ = lookup_table[ac & 0x3f];
52 int ext2fs_digest_decode(const char *src, int len, char *dst)
54 int i = 0, bits = 0, ac = 0;
59 p = strchr(lookup_table, src[i]);
60 if (p == NULL || src[i] == 0)
62 ac += (p - lookup_table) << bits;
83 { { 0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
84 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
85 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
86 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55 }, 32,
87 "jDLxChJ,cQhm7TPyZ+WukcirBROZbOJTkWZmbgnU4WF"
89 { { 0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea,
90 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
91 0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c,
92 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad }, 32,
93 "6inF,+YAPreQBBk3d5qIjA7AhNqlXoHn0Cx,hJPAV0K"
95 { { 0x24, 0x8d, 0x6a, 0x61, 0xd2, 0x06, 0x38, 0xb8,
96 0xe5, 0xc0, 0x26, 0x93, 0x0c, 0x3e, 0x60, 0x39,
97 0xa3, 0x3c, 0xe4, 0x59, 0x64, 0xff, 0x21, 0x67,
98 0xf6, 0xec, 0xed, 0xd4, 0x19, 0xdb, 0x06, 0xc1 }, 32,
99 "k0oahJtB4gb5AbykM4DY5MKPknFZ,HyZ2ze7Unx2GEM"
110 { { 0x01, 0x02, 0x03 }, 3,
113 { { 0x01, 0x02, 0x03, 0x04 }, 4,
116 { { 0x01, 0x02, 0x03, 0x04, 0xff }, 5,
119 { { 0x01, 0x02, 0x03, 0x04, 0xff, 0xfe }, 6,
122 { { 0x01, 0x02, 0x03, 0x04, 0xff, 0xfe, 0xfd }, 7,
127 int main(int argc, char **argv)
131 char tmp[1024], tmp2[1024];
133 if (argc == 3 && !strcmp(argv[1], "encode")) {
134 memset(tmp, 0, sizeof(tmp));
135 ext2fs_digest_encode(argv[2], strlen(argv[2]), tmp);
139 if (argc == 3 && !strcmp(argv[1], "decode")) {
140 memset(tmp, 0, sizeof(tmp));
141 ret = ext2fs_digest_decode(argv[2], strlen(argv[2]), tmp);
143 fprintf(stderr, "returned %d\n", ret);
146 for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
147 memset(tmp, 0, sizeof(tmp));
148 ret = ext2fs_digest_encode((const char *) tests[i].d,
151 printf("Test Digest %d (returned %d): ", i, ret);
153 printf("FAILED returned %d, string length was %d\n",
157 } else if (strcmp(tmp, tests[i].ed) != 0) {
158 printf("FAILED: got %s, expected %s\n", tmp,
163 ret = ext2fs_digest_decode(tmp, len, tmp2);
164 if (ret != tests[i].len) {
165 printf("FAILED decode returned %d, expected %d\n",
170 if (memcmp(tmp2, tests[i].d, ret) != 0) {
171 puts("FAILED: decode mismatched");
177 for (i = 1; i < argc; i++) {
178 memset(tmp, 0, sizeof(tmp));
179 ret = ext2fs_digest_encode(argv[i], strlen(argv[i]), tmp);
181 printf("Digest of '%s' is '%s' (returned %d, length %d)\n",
182 argv[i], tmp, ret, len);
187 #endif /* UNITTEST */