1258945Sroberto/* 2258945Sroberto * Copyright (C) 2008, 2009 Internet Systems Consortium, Inc. ("ISC") 3258945Sroberto * 4258945Sroberto * Permission to use, copy, modify, and/or distribute this software for any 5258945Sroberto * purpose with or without fee is hereby granted, provided that the above 6258945Sroberto * copyright notice and this permission notice appear in all copies. 7258945Sroberto * 8258945Sroberto * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 9258945Sroberto * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 10258945Sroberto * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 11258945Sroberto * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 12258945Sroberto * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 13258945Sroberto * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 14258945Sroberto * PERFORMANCE OF THIS SOFTWARE. 15258945Sroberto */ 16258945Sroberto 17280849Scy/* $Id: base32.c,v 1.6 2009/10/21 01:22:29 each Exp $ */ 18258945Sroberto 19258945Sroberto/*! \file */ 20258945Sroberto 21258945Sroberto#include <config.h> 22258945Sroberto 23258945Sroberto#include <isc/base32.h> 24258945Sroberto#include <isc/buffer.h> 25258945Sroberto#include <isc/lex.h> 26258945Sroberto#include <isc/region.h> 27258945Sroberto#include <isc/string.h> 28258945Sroberto#include <isc/util.h> 29258945Sroberto 30258945Sroberto#define RETERR(x) do { \ 31258945Sroberto isc_result_t _r = (x); \ 32258945Sroberto if (_r != ISC_R_SUCCESS) \ 33258945Sroberto return (_r); \ 34258945Sroberto } while (0) 35258945Sroberto 36258945Sroberto 37258945Sroberto/*@{*/ 38258945Sroberto/*! 39258945Sroberto * These static functions are also present in lib/dns/rdata.c. I'm not 40258945Sroberto * sure where they should go. -- bwelling 41258945Sroberto */ 42258945Srobertostatic isc_result_t 43258945Srobertostr_totext(const char *source, isc_buffer_t *target); 44258945Sroberto 45258945Srobertostatic isc_result_t 46258945Srobertomem_tobuffer(isc_buffer_t *target, void *base, unsigned int length); 47258945Sroberto 48258945Sroberto/*@}*/ 49258945Sroberto 50258945Srobertostatic const char base32[] = 51258945Sroberto "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=abcdefghijklmnopqrstuvwxyz234567"; 52258945Srobertostatic const char base32hex[] = 53258945Sroberto "0123456789ABCDEFGHIJKLMNOPQRSTUV=0123456789abcdefghijklmnopqrstuv"; 54258945Sroberto 55258945Srobertostatic isc_result_t 56258945Srobertobase32_totext(isc_region_t *source, int wordlength, const char *wordbreak, 57258945Sroberto isc_buffer_t *target, const char base[]) 58258945Sroberto{ 59258945Sroberto char buf[9]; 60258945Sroberto unsigned int loops = 0; 61258945Sroberto 62258945Sroberto if (wordlength >= 0 && wordlength < 8) 63258945Sroberto wordlength = 8; 64258945Sroberto 65258945Sroberto memset(buf, 0, sizeof(buf)); 66258945Sroberto while (source->length > 0) { 67258945Sroberto buf[0] = base[((source->base[0]>>3)&0x1f)]; /* 5 + */ 68258945Sroberto if (source->length == 1) { 69258945Sroberto buf[1] = base[(source->base[0]<<2)&0x1c]; 70258945Sroberto buf[2] = buf[3] = buf[4] = '='; 71258945Sroberto buf[5] = buf[6] = buf[7] = '='; 72258945Sroberto RETERR(str_totext(buf, target)); 73258945Sroberto break; 74258945Sroberto } 75258945Sroberto buf[1] = base[((source->base[0]<<2)&0x1c)| /* 3 = 8 */ 76258945Sroberto ((source->base[1]>>6)&0x03)]; /* 2 + */ 77258945Sroberto buf[2] = base[((source->base[1]>>1)&0x1f)]; /* 5 + */ 78258945Sroberto if (source->length == 2) { 79258945Sroberto buf[3] = base[(source->base[1]<<4)&0x10]; 80258945Sroberto buf[4] = buf[5] = buf[6] = buf[7] = '='; 81258945Sroberto RETERR(str_totext(buf, target)); 82258945Sroberto break; 83258945Sroberto } 84258945Sroberto buf[3] = base[((source->base[1]<<4)&0x10)| /* 1 = 8 */ 85258945Sroberto ((source->base[2]>>4)&0x0f)]; /* 4 + */ 86258945Sroberto if (source->length == 3) { 87258945Sroberto buf[4] = base[(source->base[2]<<1)&0x1e]; 88258945Sroberto buf[5] = buf[6] = buf[7] = '='; 89258945Sroberto RETERR(str_totext(buf, target)); 90258945Sroberto break; 91258945Sroberto } 92258945Sroberto buf[4] = base[((source->base[2]<<1)&0x1e)| /* 4 = 8 */ 93258945Sroberto ((source->base[3]>>7)&0x01)]; /* 1 + */ 94258945Sroberto buf[5] = base[((source->base[3]>>2)&0x1f)]; /* 5 + */ 95258945Sroberto if (source->length == 4) { 96258945Sroberto buf[6] = base[(source->base[3]<<3)&0x18]; 97258945Sroberto buf[7] = '='; 98258945Sroberto RETERR(str_totext(buf, target)); 99258945Sroberto break; 100258945Sroberto } 101258945Sroberto buf[6] = base[((source->base[3]<<3)&0x18)| /* 2 = 8 */ 102258945Sroberto ((source->base[4]>>5)&0x07)]; /* 3 + */ 103258945Sroberto buf[7] = base[source->base[4]&0x1f]; /* 5 = 8 */ 104258945Sroberto RETERR(str_totext(buf, target)); 105258945Sroberto isc_region_consume(source, 5); 106258945Sroberto 107258945Sroberto loops++; 108258945Sroberto if (source->length != 0 && wordlength >= 0 && 109258945Sroberto (int)((loops + 1) * 8) >= wordlength) 110258945Sroberto { 111258945Sroberto loops = 0; 112258945Sroberto RETERR(str_totext(wordbreak, target)); 113258945Sroberto } 114258945Sroberto } 115280849Scy if (source->length > 0) 116280849Scy isc_region_consume(source, source->length); 117258945Sroberto return (ISC_R_SUCCESS); 118258945Sroberto} 119258945Sroberto 120258945Srobertoisc_result_t 121258945Srobertoisc_base32_totext(isc_region_t *source, int wordlength, 122258945Sroberto const char *wordbreak, isc_buffer_t *target) 123258945Sroberto{ 124258945Sroberto return (base32_totext(source, wordlength, wordbreak, target, base32)); 125258945Sroberto} 126258945Sroberto 127258945Srobertoisc_result_t 128258945Srobertoisc_base32hex_totext(isc_region_t *source, int wordlength, 129258945Sroberto const char *wordbreak, isc_buffer_t *target) 130258945Sroberto{ 131258945Sroberto return (base32_totext(source, wordlength, wordbreak, target, 132258945Sroberto base32hex)); 133258945Sroberto} 134258945Sroberto 135258945Sroberto/*% 136258945Sroberto * State of a base32 decoding process in progress. 137258945Sroberto */ 138258945Srobertotypedef struct { 139258945Sroberto int length; /*%< Desired length of binary data or -1 */ 140258945Sroberto isc_buffer_t *target; /*%< Buffer for resulting binary data */ 141258945Sroberto int digits; /*%< Number of buffered base32 digits */ 142258945Sroberto isc_boolean_t seen_end; /*%< True if "=" end marker seen */ 143258945Sroberto int val[8]; 144258945Sroberto const char *base; /*%< Which encoding we are using */ 145258945Sroberto int seen_32; /*%< Number of significant bytes if non zero */ 146258945Sroberto} base32_decode_ctx_t; 147258945Sroberto 148258945Srobertostatic inline void 149258945Srobertobase32_decode_init(base32_decode_ctx_t *ctx, int length, 150258945Sroberto const char base[], isc_buffer_t *target) 151258945Sroberto{ 152258945Sroberto ctx->digits = 0; 153258945Sroberto ctx->seen_end = ISC_FALSE; 154258945Sroberto ctx->seen_32 = 0; 155258945Sroberto ctx->length = length; 156258945Sroberto ctx->target = target; 157258945Sroberto ctx->base = base; 158258945Sroberto} 159258945Sroberto 160258945Srobertostatic inline isc_result_t 161258945Srobertobase32_decode_char(base32_decode_ctx_t *ctx, int c) { 162258945Sroberto char *s; 163258945Sroberto unsigned int last; 164258945Sroberto 165258945Sroberto if (ctx->seen_end) 166258945Sroberto return (ISC_R_BADBASE32); 167258945Sroberto if ((s = strchr(ctx->base, c)) == NULL) 168258945Sroberto return (ISC_R_BADBASE32); 169258945Sroberto last = s - ctx->base; 170258945Sroberto /* 171258945Sroberto * Handle lower case. 172258945Sroberto */ 173258945Sroberto if (last > 32) 174258945Sroberto last -= 33; 175258945Sroberto /* 176258945Sroberto * Check that padding is contiguous. 177258945Sroberto */ 178258945Sroberto if (last != 32 && ctx->seen_32 != 0) 179258945Sroberto return (ISC_R_BADBASE32); 180258945Sroberto /* 181258945Sroberto * Check that padding starts at the right place and that 182258945Sroberto * bits that should be zero are. 183258945Sroberto * Record how many significant bytes in answer (seen_32). 184258945Sroberto */ 185258945Sroberto if (last == 32 && ctx->seen_32 == 0) 186258945Sroberto switch (ctx->digits) { 187258945Sroberto case 0: 188258945Sroberto case 1: 189258945Sroberto return (ISC_R_BADBASE32); 190258945Sroberto case 2: 191258945Sroberto if ((ctx->val[1]&0x03) != 0) 192258945Sroberto return (ISC_R_BADBASE32); 193258945Sroberto ctx->seen_32 = 1; 194258945Sroberto break; 195258945Sroberto case 3: 196258945Sroberto return (ISC_R_BADBASE32); 197258945Sroberto case 4: 198258945Sroberto if ((ctx->val[3]&0x0f) != 0) 199258945Sroberto return (ISC_R_BADBASE32); 200258945Sroberto ctx->seen_32 = 3; 201258945Sroberto break; 202258945Sroberto case 5: 203258945Sroberto if ((ctx->val[4]&0x01) != 0) 204258945Sroberto return (ISC_R_BADBASE32); 205258945Sroberto ctx->seen_32 = 3; 206258945Sroberto break; 207258945Sroberto case 6: 208258945Sroberto return (ISC_R_BADBASE32); 209258945Sroberto case 7: 210258945Sroberto if ((ctx->val[6]&0x07) != 0) 211258945Sroberto return (ISC_R_BADBASE32); 212258945Sroberto ctx->seen_32 = 4; 213258945Sroberto break; 214258945Sroberto } 215258945Sroberto /* 216258945Sroberto * Zero fill pad values. 217258945Sroberto */ 218258945Sroberto ctx->val[ctx->digits++] = (last == 32) ? 0 : last; 219258945Sroberto 220258945Sroberto if (ctx->digits == 8) { 221258945Sroberto int n = 5; 222258945Sroberto unsigned char buf[5]; 223258945Sroberto 224258945Sroberto if (ctx->seen_32 != 0) { 225258945Sroberto ctx->seen_end = ISC_TRUE; 226258945Sroberto n = ctx->seen_32; 227258945Sroberto } 228258945Sroberto buf[0] = (ctx->val[0]<<3)|(ctx->val[1]>>2); 229258945Sroberto buf[1] = (ctx->val[1]<<6)|(ctx->val[2]<<1)|(ctx->val[3]>>4); 230258945Sroberto buf[2] = (ctx->val[3]<<4)|(ctx->val[4]>>1); 231258945Sroberto buf[3] = (ctx->val[4]<<7)|(ctx->val[5]<<2)|(ctx->val[6]>>3); 232258945Sroberto buf[4] = (ctx->val[6]<<5)|(ctx->val[7]); 233258945Sroberto RETERR(mem_tobuffer(ctx->target, buf, n)); 234258945Sroberto if (ctx->length >= 0) { 235258945Sroberto if (n > ctx->length) 236258945Sroberto return (ISC_R_BADBASE32); 237258945Sroberto else 238258945Sroberto ctx->length -= n; 239258945Sroberto } 240258945Sroberto ctx->digits = 0; 241258945Sroberto } 242258945Sroberto return (ISC_R_SUCCESS); 243258945Sroberto} 244258945Sroberto 245258945Srobertostatic inline isc_result_t 246258945Srobertobase32_decode_finish(base32_decode_ctx_t *ctx) { 247258945Sroberto if (ctx->length > 0) 248258945Sroberto return (ISC_R_UNEXPECTEDEND); 249258945Sroberto if (ctx->digits != 0) 250258945Sroberto return (ISC_R_BADBASE32); 251258945Sroberto return (ISC_R_SUCCESS); 252258945Sroberto} 253258945Sroberto 254258945Srobertostatic isc_result_t 255258945Srobertobase32_tobuffer(isc_lex_t *lexer, const char base[], isc_buffer_t *target, 256258945Sroberto int length) 257258945Sroberto{ 258258945Sroberto base32_decode_ctx_t ctx; 259258945Sroberto isc_textregion_t *tr; 260258945Sroberto isc_token_t token; 261258945Sroberto isc_boolean_t eol; 262258945Sroberto 263258945Sroberto base32_decode_init(&ctx, length, base, target); 264258945Sroberto 265258945Sroberto while (!ctx.seen_end && (ctx.length != 0)) { 266258945Sroberto unsigned int i; 267258945Sroberto 268258945Sroberto if (length > 0) 269258945Sroberto eol = ISC_FALSE; 270258945Sroberto else 271258945Sroberto eol = ISC_TRUE; 272258945Sroberto RETERR(isc_lex_getmastertoken(lexer, &token, 273258945Sroberto isc_tokentype_string, eol)); 274258945Sroberto if (token.type != isc_tokentype_string) 275258945Sroberto break; 276258945Sroberto tr = &token.value.as_textregion; 277258945Sroberto for (i = 0; i < tr->length; i++) 278258945Sroberto RETERR(base32_decode_char(&ctx, tr->base[i])); 279258945Sroberto } 280258945Sroberto if (ctx.length < 0 && !ctx.seen_end) 281258945Sroberto isc_lex_ungettoken(lexer, &token); 282258945Sroberto RETERR(base32_decode_finish(&ctx)); 283258945Sroberto return (ISC_R_SUCCESS); 284258945Sroberto} 285258945Sroberto 286258945Srobertoisc_result_t 287258945Srobertoisc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) { 288258945Sroberto return (base32_tobuffer(lexer, base32, target, length)); 289258945Sroberto} 290258945Sroberto 291258945Srobertoisc_result_t 292258945Srobertoisc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) { 293258945Sroberto return (base32_tobuffer(lexer, base32hex, target, length)); 294258945Sroberto} 295258945Sroberto 296258945Srobertostatic isc_result_t 297258945Srobertobase32_decodestring(const char *cstr, const char base[], isc_buffer_t *target) { 298258945Sroberto base32_decode_ctx_t ctx; 299258945Sroberto 300258945Sroberto base32_decode_init(&ctx, -1, base, target); 301258945Sroberto for (;;) { 302258945Sroberto int c = *cstr++; 303258945Sroberto if (c == '\0') 304258945Sroberto break; 305258945Sroberto if (c == ' ' || c == '\t' || c == '\n' || c== '\r') 306258945Sroberto continue; 307258945Sroberto RETERR(base32_decode_char(&ctx, c)); 308258945Sroberto } 309258945Sroberto RETERR(base32_decode_finish(&ctx)); 310258945Sroberto return (ISC_R_SUCCESS); 311258945Sroberto} 312258945Sroberto 313258945Srobertoisc_result_t 314258945Srobertoisc_base32_decodestring(const char *cstr, isc_buffer_t *target) { 315258945Sroberto return (base32_decodestring(cstr, base32, target)); 316258945Sroberto} 317258945Sroberto 318258945Srobertoisc_result_t 319258945Srobertoisc_base32hex_decodestring(const char *cstr, isc_buffer_t *target) { 320258945Sroberto return (base32_decodestring(cstr, base32hex, target)); 321258945Sroberto} 322258945Sroberto 323258945Srobertostatic isc_result_t 324258945Srobertobase32_decoderegion(isc_region_t *source, const char base[], isc_buffer_t *target) { 325258945Sroberto base32_decode_ctx_t ctx; 326258945Sroberto 327258945Sroberto base32_decode_init(&ctx, -1, base, target); 328258945Sroberto while (source->length != 0) { 329258945Sroberto int c = *source->base; 330258945Sroberto RETERR(base32_decode_char(&ctx, c)); 331258945Sroberto isc_region_consume(source, 1); 332258945Sroberto } 333258945Sroberto RETERR(base32_decode_finish(&ctx)); 334258945Sroberto return (ISC_R_SUCCESS); 335258945Sroberto} 336258945Sroberto 337258945Srobertoisc_result_t 338258945Srobertoisc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target) { 339258945Sroberto return (base32_decoderegion(source, base32, target)); 340258945Sroberto} 341258945Sroberto 342258945Srobertoisc_result_t 343258945Srobertoisc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target) { 344258945Sroberto return (base32_decoderegion(source, base32hex, target)); 345258945Sroberto} 346258945Sroberto 347258945Srobertostatic isc_result_t 348258945Srobertostr_totext(const char *source, isc_buffer_t *target) { 349258945Sroberto unsigned int l; 350258945Sroberto isc_region_t region; 351258945Sroberto 352258945Sroberto isc_buffer_availableregion(target, ®ion); 353258945Sroberto l = strlen(source); 354258945Sroberto 355258945Sroberto if (l > region.length) 356258945Sroberto return (ISC_R_NOSPACE); 357258945Sroberto 358258945Sroberto memcpy(region.base, source, l); 359258945Sroberto isc_buffer_add(target, l); 360258945Sroberto return (ISC_R_SUCCESS); 361258945Sroberto} 362258945Sroberto 363258945Srobertostatic isc_result_t 364258945Srobertomem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) { 365258945Sroberto isc_region_t tr; 366258945Sroberto 367258945Sroberto isc_buffer_availableregion(target, &tr); 368258945Sroberto if (length > tr.length) 369258945Sroberto return (ISC_R_NOSPACE); 370258945Sroberto memcpy(tr.base, base, length); 371258945Sroberto isc_buffer_add(target, length); 372258945Sroberto return (ISC_R_SUCCESS); 373258945Sroberto} 374