9acadc2b |
1 | #include <stdio.h> |
2 | #include <errno.h> |
3 | #include <string.h> |
6b7a3adf |
4 | #include <stdlib.h> |
9acadc2b |
5 | |
6 | #define isbase64(c) ( ((c) >= 'A' && (c) <= 'Z') || \ |
7 | ((c) >= 'a' && (c) <= 'z') || \ |
8 | ((c) >= '0' && (c) <= '9') || \ |
9 | (c) == '+' || (c) == '/' || (c) == '=' \ |
10 | ) |
11 | |
12 | int base64_decode_atom(char *atom, unsigned char *out) { |
13 | int vals[4]; |
14 | int i, v, len; |
15 | unsigned word; |
16 | char c; |
17 | |
18 | for (i = 0; i < 4; i++) { |
19 | c = atom[i]; |
20 | if (c >= 'A' && c <= 'Z') |
21 | v = c - 'A'; |
22 | else if (c >= 'a' && c <= 'z') |
23 | v = c - 'a' + 26; |
24 | else if (c >= '0' && c <= '9') |
25 | v = c - '0' + 52; |
26 | else if (c == '+') |
27 | v = 62; |
28 | else if (c == '/') |
29 | v = 63; |
30 | else if (c == '=') |
31 | v = -1; |
32 | else |
33 | return 0; /* invalid atom */ |
34 | vals[i] = v; |
35 | } |
36 | |
37 | if (vals[0] == -1 || vals[1] == -1) |
38 | return 0; |
39 | if (vals[2] == -1 && vals[3] != -1) |
40 | return 0; |
41 | |
42 | if (vals[3] != -1) |
43 | len = 3; |
44 | else if (vals[2] != -1) |
45 | len = 2; |
46 | else |
47 | len = 1; |
48 | |
49 | word = ((vals[0] << 18) | |
50 | (vals[1] << 12) | |
51 | ((vals[2] & 0x3F) << 6) | |
52 | (vals[3] & 0x3F)); |
53 | out[0] = (word >> 16) & 0xFF; |
54 | if (len > 1) |
55 | out[1] = (word >> 8) & 0xFF; |
56 | if (len > 2) |
57 | out[2] = word & 0xFF; |
58 | return len; |
59 | } |
60 | |
61 | void base64_encode_atom(unsigned char *data, int n, char *out) { |
62 | static const char base64_chars[] = |
63 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
64 | |
65 | unsigned word; |
66 | |
67 | word = data[0] << 16; |
68 | if (n > 1) |
69 | word |= data[1] << 8; |
70 | if (n > 2) |
71 | word |= data[2]; |
72 | out[0] = base64_chars[(word >> 18) & 0x3F]; |
73 | out[1] = base64_chars[(word >> 12) & 0x3F]; |
74 | if (n > 1) |
75 | out[2] = base64_chars[(word >> 6) & 0x3F]; |
76 | else |
77 | out[2] = '='; |
78 | if (n > 2) |
79 | out[3] = base64_chars[word & 0x3F]; |
80 | else |
81 | out[3] = '='; |
82 | } |
83 | |
84 | const char usagemsg[] = |
85 | "usage: base64 [-d] [filename] decode from a file or from stdin\n" |
86 | " or: base64 -e [-cNNN] [filename] encode from a file or from stdin\n" |
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87 | "where: -d decode mode (default)\n" |
88 | " -e encode mode\n" |
89 | " -cNNN set number of chars per line for encoded output\n" |
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90 | " also: base64 --version report version number\n" |
91 | " base64 --help display this help text\n" |
92 | " base64 --licence display the (MIT) licence text\n" |
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93 | ; |
94 | |
95 | void usage(void) { |
96 | fputs(usagemsg, stdout); |
97 | } |
98 | |
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99 | const char licencemsg[] = |
100 | "base64 is copyright 2001,2004 Simon Tatham.\n" |
101 | "\n" |
102 | "Permission is hereby granted, free of charge, to any person\n" |
103 | "obtaining a copy of this software and associated documentation files\n" |
104 | "(the \"Software\"), to deal in the Software without restriction,\n" |
105 | "including without limitation the rights to use, copy, modify, merge,\n" |
106 | "publish, distribute, sublicense, and/or sell copies of the Software,\n" |
107 | "and to permit persons to whom the Software is furnished to do so,\n" |
108 | "subject to the following conditions:\n" |
109 | "\n" |
110 | "The above copyright notice and this permission notice shall be\n" |
111 | "included in all copies or substantial portions of the Software.\n" |
112 | "\n" |
113 | "THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND,\n" |
114 | "EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\n" |
115 | "MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\n" |
116 | "NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS\n" |
117 | "BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN\n" |
118 | "ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\n" |
119 | "CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n" |
120 | "SOFTWARE.\n" |
121 | ; |
122 | |
123 | void licence(void) { |
124 | fputs(licencemsg, stdout); |
125 | } |
126 | |
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127 | void version(void) { |
128 | #define SVN_REV "$Revision$" |
129 | char rev[sizeof(SVN_REV)]; |
130 | char *p, *q; |
131 | |
132 | strcpy(rev, SVN_REV); |
133 | |
134 | for (p = rev; *p && *p != ':'; p++); |
135 | if (*p) { |
136 | p++; |
137 | while (*p && isspace(*p)) p++; |
138 | for (q = p; *q && *q != '$'; q++); |
139 | if (*q) *q = '\0'; |
140 | printf("base64 revision %s\n", p); |
141 | } else { |
142 | printf("base64: unknown version\n"); |
143 | } |
144 | } |
145 | |
146 | int main(int ac, char **av) { |
147 | int encoding = 0; |
148 | int cpl = 64; |
149 | FILE *fp; |
150 | char *fname; |
151 | char *eptr; |
152 | |
153 | fname = NULL; |
154 | |
155 | while (--ac) { |
156 | char *v, *p = *++av; |
157 | if (*p == '-') { |
158 | while (*p) { |
159 | char c = *++p; |
160 | switch (c) { |
161 | case '-': |
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162 | p++; |
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163 | if (!strcmp(p, "version")) { |
164 | version(); |
165 | exit(0); |
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166 | } else if (!strcmp(p, "help")) { |
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167 | usage(); |
168 | exit(0); |
da0f8522 |
169 | } else if (!strcmp(p, "licence") || |
170 | !strcmp(p, "license")) { |
171 | licence(); |
172 | exit(0); |
173 | } else { |
174 | fprintf(stderr, "base64: unknown long option '--%s'\n", |
175 | p); |
176 | exit(1); |
177 | } |
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178 | break; |
179 | case 'v': |
180 | case 'V': |
181 | version(); |
182 | exit(0); |
183 | break; |
184 | case 'h': |
185 | case 'H': |
186 | usage(); |
187 | exit(0); |
188 | break; |
189 | case 'd': |
190 | encoding = 0; |
191 | break; |
192 | case 'e': |
193 | encoding = 1; |
194 | break; |
195 | case 'c': |
196 | /* |
197 | * Options requiring values. |
198 | */ |
199 | v = p+1; |
200 | if (!*v && ac > 1) { |
201 | --ac; |
202 | v = *++av; |
203 | } |
204 | if (!*v) { |
205 | fprintf(stderr, "base64: option '-%c' expects" |
206 | " an argument\n", c); |
207 | exit(1); |
208 | } |
209 | switch (c) { |
210 | case 'c': |
211 | cpl = strtol(v, &eptr, 10); |
212 | if (eptr && *eptr) { |
213 | fprintf(stderr, "base64: option -c expects" |
214 | " a numeric argument\n"); |
215 | exit(1); |
216 | } |
217 | if (cpl % 4) { |
218 | fprintf(stderr, "base64: chars per line should be" |
219 | " divisible by 4\n"); |
220 | exit(1); |
221 | } |
222 | break; |
223 | } |
224 | p = ""; |
225 | break; |
226 | } |
227 | } |
228 | } else { |
229 | if (!fname) |
230 | fname = p; |
231 | else { |
232 | fprintf(stderr, "base64: expected only one filename\n"); |
233 | exit(0); |
234 | } |
235 | } |
236 | } |
237 | |
238 | if (fname) { |
239 | fp = fopen(fname, encoding ? "rb" : "r"); |
240 | if (!fp) { |
241 | fprintf(stderr, "base64: unable to open '%s': %s\n", fname, |
242 | strerror(errno)); |
243 | exit(1); |
244 | } |
245 | } else |
246 | fp = stdin; |
247 | |
248 | if (encoding) { |
249 | unsigned char in[3]; |
250 | char out[4]; |
251 | int column; |
252 | int n; |
253 | |
254 | column = 0; |
255 | while (1) { |
256 | if (cpl && column >= cpl) { |
257 | putchar('\n'); |
258 | column = 0; |
259 | } |
260 | n = fread(in, 1, 3, fp); |
261 | if (n == 0) break; |
262 | base64_encode_atom(in, n, out); |
263 | fwrite(out, 1, 4, stdout); |
264 | column += 4; |
265 | } |
266 | |
267 | putchar('\n'); |
268 | } else { |
269 | char in[4]; |
270 | unsigned char out[3]; |
271 | int c, i, n, eof; |
272 | |
273 | eof = 0; |
274 | do { |
275 | for (i = 0; i < 4; i++) { |
276 | do { |
277 | c = fgetc(fp); |
278 | } while (c != EOF && !isbase64(c)); |
279 | if (c == EOF) { |
280 | eof = 1; |
281 | break; |
282 | } |
283 | in[i] = c; |
284 | } |
285 | if (i > 0) { |
286 | if (i < 4) { |
287 | fprintf(stderr, "base64: warning: number of base64" |
288 | " characters was not a multiple of 4\n"); |
289 | while (i < 4) in[i++] = '='; |
290 | } |
291 | n = base64_decode_atom(in, out); |
292 | fwrite(out, 1, n, stdout); |
293 | } |
294 | } while (!eof); |
295 | } |
296 | |
297 | if (fname) |
298 | fclose(fp); |
299 | |
300 | return 0; |
301 | } |