1 /* $NetBSD: base32.c,v 1.1.1.1 2009/12/13 16:54:19 kardel Exp $ */ 2 3 /* 4 * Copyright (C) 2008, 2009 Internet Systems Consortium, Inc. ("ISC") 5 * 6 * Permission to use, copy, modify, and/or distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 11 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 12 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 13 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 14 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 15 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 16 * PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /* Id: base32.c,v 1.3.116.2 2009/01/18 23:47:41 tbox Exp */ 20 21 /*! \file */ 22 23 #include <config.h> 24 25 #include <isc/base32.h> 26 #include <isc/buffer.h> 27 #include <isc/lex.h> 28 #include <isc/region.h> 29 #include <isc/string.h> 30 #include <isc/util.h> 31 32 #define RETERR(x) do { \ 33 isc_result_t _r = (x); \ 34 if (_r != ISC_R_SUCCESS) \ 35 return (_r); \ 36 } while (0) 37 38 39 /*@{*/ 40 /*! 41 * These static functions are also present in lib/dns/rdata.c. I'm not 42 * sure where they should go. -- bwelling 43 */ 44 static isc_result_t 45 str_totext(const char *source, isc_buffer_t *target); 46 47 static isc_result_t 48 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length); 49 50 /*@}*/ 51 52 static const char base32[] = 53 "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=abcdefghijklmnopqrstuvwxyz234567"; 54 static const char base32hex[] = 55 "0123456789ABCDEFGHIJKLMNOPQRSTUV=0123456789abcdefghijklmnopqrstuv"; 56 57 static isc_result_t 58 base32_totext(isc_region_t *source, int wordlength, const char *wordbreak, 59 isc_buffer_t *target, const char base[]) 60 { 61 char buf[9]; 62 unsigned int loops = 0; 63 64 if (wordlength >= 0 && wordlength < 8) 65 wordlength = 8; 66 67 memset(buf, 0, sizeof(buf)); 68 while (source->length > 0) { 69 buf[0] = base[((source->base[0]>>3)&0x1f)]; /* 5 + */ 70 if (source->length == 1) { 71 buf[1] = base[(source->base[0]<<2)&0x1c]; 72 buf[2] = buf[3] = buf[4] = '='; 73 buf[5] = buf[6] = buf[7] = '='; 74 RETERR(str_totext(buf, target)); 75 break; 76 } 77 buf[1] = base[((source->base[0]<<2)&0x1c)| /* 3 = 8 */ 78 ((source->base[1]>>6)&0x03)]; /* 2 + */ 79 buf[2] = base[((source->base[1]>>1)&0x1f)]; /* 5 + */ 80 if (source->length == 2) { 81 buf[3] = base[(source->base[1]<<4)&0x10]; 82 buf[4] = buf[5] = buf[6] = buf[7] = '='; 83 RETERR(str_totext(buf, target)); 84 break; 85 } 86 buf[3] = base[((source->base[1]<<4)&0x10)| /* 1 = 8 */ 87 ((source->base[2]>>4)&0x0f)]; /* 4 + */ 88 if (source->length == 3) { 89 buf[4] = base[(source->base[2]<<1)&0x1e]; 90 buf[5] = buf[6] = buf[7] = '='; 91 RETERR(str_totext(buf, target)); 92 break; 93 } 94 buf[4] = base[((source->base[2]<<1)&0x1e)| /* 4 = 8 */ 95 ((source->base[3]>>7)&0x01)]; /* 1 + */ 96 buf[5] = base[((source->base[3]>>2)&0x1f)]; /* 5 + */ 97 if (source->length == 4) { 98 buf[6] = base[(source->base[3]<<3)&0x18]; 99 buf[7] = '='; 100 RETERR(str_totext(buf, target)); 101 break; 102 } 103 buf[6] = base[((source->base[3]<<3)&0x18)| /* 2 = 8 */ 104 ((source->base[4]>>5)&0x07)]; /* 3 + */ 105 buf[7] = base[source->base[4]&0x1f]; /* 5 = 8 */ 106 RETERR(str_totext(buf, target)); 107 isc_region_consume(source, 5); 108 109 loops++; 110 if (source->length != 0 && wordlength >= 0 && 111 (int)((loops + 1) * 8) >= wordlength) 112 { 113 loops = 0; 114 RETERR(str_totext(wordbreak, target)); 115 } 116 } 117 return (ISC_R_SUCCESS); 118 } 119 120 isc_result_t 121 isc_base32_totext(isc_region_t *source, int wordlength, 122 const char *wordbreak, isc_buffer_t *target) 123 { 124 return (base32_totext(source, wordlength, wordbreak, target, base32)); 125 } 126 127 isc_result_t 128 isc_base32hex_totext(isc_region_t *source, int wordlength, 129 const char *wordbreak, isc_buffer_t *target) 130 { 131 return (base32_totext(source, wordlength, wordbreak, target, 132 base32hex)); 133 } 134 135 /*% 136 * State of a base32 decoding process in progress. 137 */ 138 typedef struct { 139 int length; /*%< Desired length of binary data or -1 */ 140 isc_buffer_t *target; /*%< Buffer for resulting binary data */ 141 int digits; /*%< Number of buffered base32 digits */ 142 isc_boolean_t seen_end; /*%< True if "=" end marker seen */ 143 int val[8]; 144 const char *base; /*%< Which encoding we are using */ 145 int seen_32; /*%< Number of significant bytes if non zero */ 146 } base32_decode_ctx_t; 147 148 static inline void 149 base32_decode_init(base32_decode_ctx_t *ctx, int length, 150 const char base[], isc_buffer_t *target) 151 { 152 ctx->digits = 0; 153 ctx->seen_end = ISC_FALSE; 154 ctx->seen_32 = 0; 155 ctx->length = length; 156 ctx->target = target; 157 ctx->base = base; 158 } 159 160 static inline isc_result_t 161 base32_decode_char(base32_decode_ctx_t *ctx, int c) { 162 char *s; 163 unsigned int last; 164 165 if (ctx->seen_end) 166 return (ISC_R_BADBASE32); 167 if ((s = strchr(ctx->base, c)) == NULL) 168 return (ISC_R_BADBASE32); 169 last = s - ctx->base; 170 /* 171 * Handle lower case. 172 */ 173 if (last > 32) 174 last -= 33; 175 /* 176 * Check that padding is contiguous. 177 */ 178 if (last != 32 && ctx->seen_32 != 0) 179 return (ISC_R_BADBASE32); 180 /* 181 * Check that padding starts at the right place and that 182 * bits that should be zero are. 183 * Record how many significant bytes in answer (seen_32). 184 */ 185 if (last == 32 && ctx->seen_32 == 0) 186 switch (ctx->digits) { 187 case 0: 188 case 1: 189 return (ISC_R_BADBASE32); 190 case 2: 191 if ((ctx->val[1]&0x03) != 0) 192 return (ISC_R_BADBASE32); 193 ctx->seen_32 = 1; 194 break; 195 case 3: 196 return (ISC_R_BADBASE32); 197 case 4: 198 if ((ctx->val[3]&0x0f) != 0) 199 return (ISC_R_BADBASE32); 200 ctx->seen_32 = 3; 201 break; 202 case 5: 203 if ((ctx->val[4]&0x01) != 0) 204 return (ISC_R_BADBASE32); 205 ctx->seen_32 = 3; 206 break; 207 case 6: 208 return (ISC_R_BADBASE32); 209 case 7: 210 if ((ctx->val[6]&0x07) != 0) 211 return (ISC_R_BADBASE32); 212 ctx->seen_32 = 4; 213 break; 214 } 215 /* 216 * Zero fill pad values. 217 */ 218 ctx->val[ctx->digits++] = (last == 32) ? 0 : last; 219 220 if (ctx->digits == 8) { 221 int n = 5; 222 unsigned char buf[5]; 223 224 if (ctx->seen_32 != 0) { 225 ctx->seen_end = ISC_TRUE; 226 n = ctx->seen_32; 227 } 228 buf[0] = (ctx->val[0]<<3)|(ctx->val[1]>>2); 229 buf[1] = (ctx->val[1]<<6)|(ctx->val[2]<<1)|(ctx->val[3]>>4); 230 buf[2] = (ctx->val[3]<<4)|(ctx->val[4]>>1); 231 buf[3] = (ctx->val[4]<<7)|(ctx->val[5]<<2)|(ctx->val[6]>>3); 232 buf[4] = (ctx->val[6]<<5)|(ctx->val[7]); 233 RETERR(mem_tobuffer(ctx->target, buf, n)); 234 if (ctx->length >= 0) { 235 if (n > ctx->length) 236 return (ISC_R_BADBASE32); 237 else 238 ctx->length -= n; 239 } 240 ctx->digits = 0; 241 } 242 return (ISC_R_SUCCESS); 243 } 244 245 static inline isc_result_t 246 base32_decode_finish(base32_decode_ctx_t *ctx) { 247 if (ctx->length > 0) 248 return (ISC_R_UNEXPECTEDEND); 249 if (ctx->digits != 0) 250 return (ISC_R_BADBASE32); 251 return (ISC_R_SUCCESS); 252 } 253 254 static isc_result_t 255 base32_tobuffer(isc_lex_t *lexer, const char base[], isc_buffer_t *target, 256 int length) 257 { 258 base32_decode_ctx_t ctx; 259 isc_textregion_t *tr; 260 isc_token_t token; 261 isc_boolean_t eol; 262 263 base32_decode_init(&ctx, length, base, target); 264 265 while (!ctx.seen_end && (ctx.length != 0)) { 266 unsigned int i; 267 268 if (length > 0) 269 eol = ISC_FALSE; 270 else 271 eol = ISC_TRUE; 272 RETERR(isc_lex_getmastertoken(lexer, &token, 273 isc_tokentype_string, eol)); 274 if (token.type != isc_tokentype_string) 275 break; 276 tr = &token.value.as_textregion; 277 for (i = 0; i < tr->length; i++) 278 RETERR(base32_decode_char(&ctx, tr->base[i])); 279 } 280 if (ctx.length < 0 && !ctx.seen_end) 281 isc_lex_ungettoken(lexer, &token); 282 RETERR(base32_decode_finish(&ctx)); 283 return (ISC_R_SUCCESS); 284 } 285 286 isc_result_t 287 isc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) { 288 return (base32_tobuffer(lexer, base32, target, length)); 289 } 290 291 isc_result_t 292 isc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) { 293 return (base32_tobuffer(lexer, base32hex, target, length)); 294 } 295 296 static isc_result_t 297 base32_decodestring(const char *cstr, const char base[], isc_buffer_t *target) { 298 base32_decode_ctx_t ctx; 299 300 base32_decode_init(&ctx, -1, base, target); 301 for (;;) { 302 int c = *cstr++; 303 if (c == '\0') 304 break; 305 if (c == ' ' || c == '\t' || c == '\n' || c== '\r') 306 continue; 307 RETERR(base32_decode_char(&ctx, c)); 308 } 309 RETERR(base32_decode_finish(&ctx)); 310 return (ISC_R_SUCCESS); 311 } 312 313 isc_result_t 314 isc_base32_decodestring(const char *cstr, isc_buffer_t *target) { 315 return (base32_decodestring(cstr, base32, target)); 316 } 317 318 isc_result_t 319 isc_base32hex_decodestring(const char *cstr, isc_buffer_t *target) { 320 return (base32_decodestring(cstr, base32hex, target)); 321 } 322 323 static isc_result_t 324 base32_decoderegion(isc_region_t *source, const char base[], isc_buffer_t *target) { 325 base32_decode_ctx_t ctx; 326 327 base32_decode_init(&ctx, -1, base, target); 328 while (source->length != 0) { 329 int c = *source->base; 330 RETERR(base32_decode_char(&ctx, c)); 331 isc_region_consume(source, 1); 332 } 333 RETERR(base32_decode_finish(&ctx)); 334 return (ISC_R_SUCCESS); 335 } 336 337 isc_result_t 338 isc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target) { 339 return (base32_decoderegion(source, base32, target)); 340 } 341 342 isc_result_t 343 isc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target) { 344 return (base32_decoderegion(source, base32hex, target)); 345 } 346 347 static isc_result_t 348 str_totext(const char *source, isc_buffer_t *target) { 349 unsigned int l; 350 isc_region_t region; 351 352 isc_buffer_availableregion(target, ®ion); 353 l = strlen(source); 354 355 if (l > region.length) 356 return (ISC_R_NOSPACE); 357 358 memcpy(region.base, source, l); 359 isc_buffer_add(target, l); 360 return (ISC_R_SUCCESS); 361 } 362 363 static isc_result_t 364 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) { 365 isc_region_t tr; 366 367 isc_buffer_availableregion(target, &tr); 368 if (length > tr.length) 369 return (ISC_R_NOSPACE); 370 memcpy(tr.base, base, length); 371 isc_buffer_add(target, length); 372 return (ISC_R_SUCCESS); 373 } 374