1: /*
2: * Copyright (C) 2008, 2009 Internet Systems Consortium, Inc. ("ISC")
3: *
4: * Permission to use, copy, modify, and/or distribute this software for any
5: * purpose with or without fee is hereby granted, provided that the above
6: * copyright notice and this permission notice appear in all copies.
7: *
8: * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9: * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10: * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11: * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12: * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13: * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14: * PERFORMANCE OF THIS SOFTWARE.
15: */
16:
17: /* $Id: base32.c,v 1.1.1.1 2012/05/29 12:08:38 misho Exp $ */
18:
19: /*! \file */
20:
21: #include <config.h>
22:
23: #include <isc/base32.h>
24: #include <isc/buffer.h>
25: #include <isc/lex.h>
26: #include <isc/region.h>
27: #include <isc/string.h>
28: #include <isc/util.h>
29:
30: #define RETERR(x) do { \
31: isc_result_t _r = (x); \
32: if (_r != ISC_R_SUCCESS) \
33: return (_r); \
34: } while (0)
35:
36:
37: /*@{*/
38: /*!
39: * These static functions are also present in lib/dns/rdata.c. I'm not
40: * sure where they should go. -- bwelling
41: */
42: static isc_result_t
43: str_totext(const char *source, isc_buffer_t *target);
44:
45: static isc_result_t
46: mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length);
47:
48: /*@}*/
49:
50: static const char base32[] =
51: "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=abcdefghijklmnopqrstuvwxyz234567";
52: static const char base32hex[] =
53: "0123456789ABCDEFGHIJKLMNOPQRSTUV=0123456789abcdefghijklmnopqrstuv";
54:
55: static isc_result_t
56: base32_totext(isc_region_t *source, int wordlength, const char *wordbreak,
57: isc_buffer_t *target, const char base[])
58: {
59: char buf[9];
60: unsigned int loops = 0;
61:
62: if (wordlength >= 0 && wordlength < 8)
63: wordlength = 8;
64:
65: memset(buf, 0, sizeof(buf));
66: while (source->length > 0) {
67: buf[0] = base[((source->base[0]>>3)&0x1f)]; /* 5 + */
68: if (source->length == 1) {
69: buf[1] = base[(source->base[0]<<2)&0x1c];
70: buf[2] = buf[3] = buf[4] = '=';
71: buf[5] = buf[6] = buf[7] = '=';
72: RETERR(str_totext(buf, target));
73: break;
74: }
75: buf[1] = base[((source->base[0]<<2)&0x1c)| /* 3 = 8 */
76: ((source->base[1]>>6)&0x03)]; /* 2 + */
77: buf[2] = base[((source->base[1]>>1)&0x1f)]; /* 5 + */
78: if (source->length == 2) {
79: buf[3] = base[(source->base[1]<<4)&0x10];
80: buf[4] = buf[5] = buf[6] = buf[7] = '=';
81: RETERR(str_totext(buf, target));
82: break;
83: }
84: buf[3] = base[((source->base[1]<<4)&0x10)| /* 1 = 8 */
85: ((source->base[2]>>4)&0x0f)]; /* 4 + */
86: if (source->length == 3) {
87: buf[4] = base[(source->base[2]<<1)&0x1e];
88: buf[5] = buf[6] = buf[7] = '=';
89: RETERR(str_totext(buf, target));
90: break;
91: }
92: buf[4] = base[((source->base[2]<<1)&0x1e)| /* 4 = 8 */
93: ((source->base[3]>>7)&0x01)]; /* 1 + */
94: buf[5] = base[((source->base[3]>>2)&0x1f)]; /* 5 + */
95: if (source->length == 4) {
96: buf[6] = base[(source->base[3]<<3)&0x18];
97: buf[7] = '=';
98: RETERR(str_totext(buf, target));
99: break;
100: }
101: buf[6] = base[((source->base[3]<<3)&0x18)| /* 2 = 8 */
102: ((source->base[4]>>5)&0x07)]; /* 3 + */
103: buf[7] = base[source->base[4]&0x1f]; /* 5 = 8 */
104: RETERR(str_totext(buf, target));
105: isc_region_consume(source, 5);
106:
107: loops++;
108: if (source->length != 0 && wordlength >= 0 &&
109: (int)((loops + 1) * 8) >= wordlength)
110: {
111: loops = 0;
112: RETERR(str_totext(wordbreak, target));
113: }
114: }
115: return (ISC_R_SUCCESS);
116: }
117:
118: isc_result_t
119: isc_base32_totext(isc_region_t *source, int wordlength,
120: const char *wordbreak, isc_buffer_t *target)
121: {
122: return (base32_totext(source, wordlength, wordbreak, target, base32));
123: }
124:
125: isc_result_t
126: isc_base32hex_totext(isc_region_t *source, int wordlength,
127: const char *wordbreak, isc_buffer_t *target)
128: {
129: return (base32_totext(source, wordlength, wordbreak, target,
130: base32hex));
131: }
132:
133: /*%
134: * State of a base32 decoding process in progress.
135: */
136: typedef struct {
137: int length; /*%< Desired length of binary data or -1 */
138: isc_buffer_t *target; /*%< Buffer for resulting binary data */
139: int digits; /*%< Number of buffered base32 digits */
140: isc_boolean_t seen_end; /*%< True if "=" end marker seen */
141: int val[8];
142: const char *base; /*%< Which encoding we are using */
143: int seen_32; /*%< Number of significant bytes if non zero */
144: } base32_decode_ctx_t;
145:
146: static inline void
147: base32_decode_init(base32_decode_ctx_t *ctx, int length,
148: const char base[], isc_buffer_t *target)
149: {
150: ctx->digits = 0;
151: ctx->seen_end = ISC_FALSE;
152: ctx->seen_32 = 0;
153: ctx->length = length;
154: ctx->target = target;
155: ctx->base = base;
156: }
157:
158: static inline isc_result_t
159: base32_decode_char(base32_decode_ctx_t *ctx, int c) {
160: char *s;
161: unsigned int last;
162:
163: if (ctx->seen_end)
164: return (ISC_R_BADBASE32);
165: if ((s = strchr(ctx->base, c)) == NULL)
166: return (ISC_R_BADBASE32);
167: last = s - ctx->base;
168: /*
169: * Handle lower case.
170: */
171: if (last > 32)
172: last -= 33;
173: /*
174: * Check that padding is contiguous.
175: */
176: if (last != 32 && ctx->seen_32 != 0)
177: return (ISC_R_BADBASE32);
178: /*
179: * Check that padding starts at the right place and that
180: * bits that should be zero are.
181: * Record how many significant bytes in answer (seen_32).
182: */
183: if (last == 32 && ctx->seen_32 == 0)
184: switch (ctx->digits) {
185: case 0:
186: case 1:
187: return (ISC_R_BADBASE32);
188: case 2:
189: if ((ctx->val[1]&0x03) != 0)
190: return (ISC_R_BADBASE32);
191: ctx->seen_32 = 1;
192: break;
193: case 3:
194: return (ISC_R_BADBASE32);
195: case 4:
196: if ((ctx->val[3]&0x0f) != 0)
197: return (ISC_R_BADBASE32);
198: ctx->seen_32 = 3;
199: break;
200: case 5:
201: if ((ctx->val[4]&0x01) != 0)
202: return (ISC_R_BADBASE32);
203: ctx->seen_32 = 3;
204: break;
205: case 6:
206: return (ISC_R_BADBASE32);
207: case 7:
208: if ((ctx->val[6]&0x07) != 0)
209: return (ISC_R_BADBASE32);
210: ctx->seen_32 = 4;
211: break;
212: }
213: /*
214: * Zero fill pad values.
215: */
216: ctx->val[ctx->digits++] = (last == 32) ? 0 : last;
217:
218: if (ctx->digits == 8) {
219: int n = 5;
220: unsigned char buf[5];
221:
222: if (ctx->seen_32 != 0) {
223: ctx->seen_end = ISC_TRUE;
224: n = ctx->seen_32;
225: }
226: buf[0] = (ctx->val[0]<<3)|(ctx->val[1]>>2);
227: buf[1] = (ctx->val[1]<<6)|(ctx->val[2]<<1)|(ctx->val[3]>>4);
228: buf[2] = (ctx->val[3]<<4)|(ctx->val[4]>>1);
229: buf[3] = (ctx->val[4]<<7)|(ctx->val[5]<<2)|(ctx->val[6]>>3);
230: buf[4] = (ctx->val[6]<<5)|(ctx->val[7]);
231: RETERR(mem_tobuffer(ctx->target, buf, n));
232: if (ctx->length >= 0) {
233: if (n > ctx->length)
234: return (ISC_R_BADBASE32);
235: else
236: ctx->length -= n;
237: }
238: ctx->digits = 0;
239: }
240: return (ISC_R_SUCCESS);
241: }
242:
243: static inline isc_result_t
244: base32_decode_finish(base32_decode_ctx_t *ctx) {
245: if (ctx->length > 0)
246: return (ISC_R_UNEXPECTEDEND);
247: if (ctx->digits != 0)
248: return (ISC_R_BADBASE32);
249: return (ISC_R_SUCCESS);
250: }
251:
252: static isc_result_t
253: base32_tobuffer(isc_lex_t *lexer, const char base[], isc_buffer_t *target,
254: int length)
255: {
256: base32_decode_ctx_t ctx;
257: isc_textregion_t *tr;
258: isc_token_t token;
259: isc_boolean_t eol;
260:
261: base32_decode_init(&ctx, length, base, target);
262:
263: while (!ctx.seen_end && (ctx.length != 0)) {
264: unsigned int i;
265:
266: if (length > 0)
267: eol = ISC_FALSE;
268: else
269: eol = ISC_TRUE;
270: RETERR(isc_lex_getmastertoken(lexer, &token,
271: isc_tokentype_string, eol));
272: if (token.type != isc_tokentype_string)
273: break;
274: tr = &token.value.as_textregion;
275: for (i = 0; i < tr->length; i++)
276: RETERR(base32_decode_char(&ctx, tr->base[i]));
277: }
278: if (ctx.length < 0 && !ctx.seen_end)
279: isc_lex_ungettoken(lexer, &token);
280: RETERR(base32_decode_finish(&ctx));
281: return (ISC_R_SUCCESS);
282: }
283:
284: isc_result_t
285: isc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
286: return (base32_tobuffer(lexer, base32, target, length));
287: }
288:
289: isc_result_t
290: isc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
291: return (base32_tobuffer(lexer, base32hex, target, length));
292: }
293:
294: static isc_result_t
295: base32_decodestring(const char *cstr, const char base[], isc_buffer_t *target) {
296: base32_decode_ctx_t ctx;
297:
298: base32_decode_init(&ctx, -1, base, target);
299: for (;;) {
300: int c = *cstr++;
301: if (c == '\0')
302: break;
303: if (c == ' ' || c == '\t' || c == '\n' || c== '\r')
304: continue;
305: RETERR(base32_decode_char(&ctx, c));
306: }
307: RETERR(base32_decode_finish(&ctx));
308: return (ISC_R_SUCCESS);
309: }
310:
311: isc_result_t
312: isc_base32_decodestring(const char *cstr, isc_buffer_t *target) {
313: return (base32_decodestring(cstr, base32, target));
314: }
315:
316: isc_result_t
317: isc_base32hex_decodestring(const char *cstr, isc_buffer_t *target) {
318: return (base32_decodestring(cstr, base32hex, target));
319: }
320:
321: static isc_result_t
322: base32_decoderegion(isc_region_t *source, const char base[], isc_buffer_t *target) {
323: base32_decode_ctx_t ctx;
324:
325: base32_decode_init(&ctx, -1, base, target);
326: while (source->length != 0) {
327: int c = *source->base;
328: RETERR(base32_decode_char(&ctx, c));
329: isc_region_consume(source, 1);
330: }
331: RETERR(base32_decode_finish(&ctx));
332: return (ISC_R_SUCCESS);
333: }
334:
335: isc_result_t
336: isc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target) {
337: return (base32_decoderegion(source, base32, target));
338: }
339:
340: isc_result_t
341: isc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target) {
342: return (base32_decoderegion(source, base32hex, target));
343: }
344:
345: static isc_result_t
346: str_totext(const char *source, isc_buffer_t *target) {
347: unsigned int l;
348: isc_region_t region;
349:
350: isc_buffer_availableregion(target, ®ion);
351: l = strlen(source);
352:
353: if (l > region.length)
354: return (ISC_R_NOSPACE);
355:
356: memcpy(region.base, source, l);
357: isc_buffer_add(target, l);
358: return (ISC_R_SUCCESS);
359: }
360:
361: static isc_result_t
362: mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
363: isc_region_t tr;
364:
365: isc_buffer_availableregion(target, &tr);
366: if (length > tr.length)
367: return (ISC_R_NOSPACE);
368: memcpy(tr.base, base, length);
369: isc_buffer_add(target, length);
370: return (ISC_R_SUCCESS);
371: }
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