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