1 /* 2 * The copyright in this software is being made available under the 2-clauses 3 * BSD License, included below. This software may be subject to other third 4 * party and contributor rights, including patent rights, and no such rights 5 * are granted under this license. 6 * 7 * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium 8 * Copyright (c) 2002-2014, Professor Benoit Macq 9 * Copyright (c) 2001-2003, David Janssens 10 * Copyright (c) 2002-2003, Yannick Verschueren 11 * Copyright (c) 2003-2007, Francois-Olivier Devaux 12 * Copyright (c) 2003-2014, Antonin Descampe 13 * Copyright (c) 2005, Herve Drolon, FreeImage Team 14 * All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS' 26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include "opj_includes.h" 39 40 /** @defgroup BIO BIO - Individual bit input-output stream */ 41 /*@{*/ 42 43 /** @name Local static functions */ 44 /*@{*/ 45 46 /** 47 Write a bit 48 @param bio BIO handle 49 @param b Bit to write (0 or 1) 50 */ 51 static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b); 52 /** 53 Read a bit 54 @param bio BIO handle 55 @return Returns the read bit 56 */ 57 static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio); 58 /** 59 Write a byte 60 @param bio BIO handle 61 @return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise 62 */ 63 static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio); 64 /** 65 Read a byte 66 @param bio BIO handle 67 @return Returns OPJ_TRUE if successful, returns OPJ_FALSE otherwise 68 */ 69 static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio); 70 71 /*@}*/ 72 73 /*@}*/ 74 75 /* 76 ========================================================== 77 local functions 78 ========================================================== 79 */ 80 81 static OPJ_BOOL opj_bio_byteout(opj_bio_t *bio) 82 { 83 bio->buf = (bio->buf << 8) & 0xffff; 84 bio->ct = bio->buf == 0xff00 ? 7 : 8; 85 if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) { 86 return OPJ_FALSE; 87 } 88 *bio->bp++ = (OPJ_BYTE)(bio->buf >> 8); 89 return OPJ_TRUE; 90 } 91 92 static OPJ_BOOL opj_bio_bytein(opj_bio_t *bio) 93 { 94 bio->buf = (bio->buf << 8) & 0xffff; 95 bio->ct = bio->buf == 0xff00 ? 7 : 8; 96 if ((OPJ_SIZE_T)bio->bp >= (OPJ_SIZE_T)bio->end) { 97 return OPJ_FALSE; 98 } 99 bio->buf |= *bio->bp++; 100 return OPJ_TRUE; 101 } 102 103 static void opj_bio_putbit(opj_bio_t *bio, OPJ_UINT32 b) 104 { 105 if (bio->ct == 0) { 106 opj_bio_byteout( 107 bio); /* MSD: why not check the return value of this function ? */ 108 } 109 bio->ct--; 110 bio->buf |= b << bio->ct; 111 } 112 113 static OPJ_UINT32 opj_bio_getbit(opj_bio_t *bio) 114 { 115 if (bio->ct == 0) { 116 opj_bio_bytein( 117 bio); /* MSD: why not check the return value of this function ? */ 118 } 119 bio->ct--; 120 return (bio->buf >> bio->ct) & 1; 121 } 122 123 /* 124 ========================================================== 125 Bit Input/Output interface 126 ========================================================== 127 */ 128 129 opj_bio_t* opj_bio_create(void) 130 { 131 opj_bio_t *bio = (opj_bio_t*)opj_malloc(sizeof(opj_bio_t)); 132 return bio; 133 } 134 135 void opj_bio_destroy(opj_bio_t *bio) 136 { 137 if (bio) { 138 opj_free(bio); 139 } 140 } 141 142 ptrdiff_t opj_bio_numbytes(opj_bio_t *bio) 143 { 144 return (bio->bp - bio->start); 145 } 146 147 void opj_bio_init_enc(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len) 148 { 149 bio->start = bp; 150 bio->end = bp + len; 151 bio->bp = bp; 152 bio->buf = 0; 153 bio->ct = 8; 154 } 155 156 void opj_bio_init_dec(opj_bio_t *bio, OPJ_BYTE *bp, OPJ_UINT32 len) 157 { 158 bio->start = bp; 159 bio->end = bp + len; 160 bio->bp = bp; 161 bio->buf = 0; 162 bio->ct = 0; 163 } 164 165 void opj_bio_write(opj_bio_t *bio, OPJ_UINT32 v, OPJ_UINT32 n) 166 { 167 OPJ_INT32 i; 168 169 assert((n > 0U) && (n <= 32U)); 170 for (i = (OPJ_INT32)n - 1; i >= 0; i--) { 171 opj_bio_putbit(bio, (v >> i) & 1); 172 } 173 } 174 175 OPJ_UINT32 opj_bio_read(opj_bio_t *bio, OPJ_UINT32 n) 176 { 177 OPJ_INT32 i; 178 OPJ_UINT32 v; 179 180 assert((n > 0U) /* && (n <= 32U)*/); 181 #ifdef OPJ_UBSAN_BUILD 182 /* This assert fails for some corrupted images which are gracefully rejected */ 183 /* Add this assert only for ubsan build. */ 184 /* This is the condition for overflow not to occur below which is needed because of OPJ_NOSANITIZE */ 185 assert(n <= 32U); 186 #endif 187 v = 0U; 188 for (i = (OPJ_INT32)n - 1; i >= 0; i--) { 189 v |= opj_bio_getbit(bio) << 190 i; /* can't overflow, opj_bio_getbit returns 0 or 1 */ 191 } 192 return v; 193 } 194 195 OPJ_BOOL opj_bio_flush(opj_bio_t *bio) 196 { 197 if (! opj_bio_byteout(bio)) { 198 return OPJ_FALSE; 199 } 200 if (bio->ct == 7) { 201 if (! opj_bio_byteout(bio)) { 202 return OPJ_FALSE; 203 } 204 } 205 return OPJ_TRUE; 206 } 207 208 OPJ_BOOL opj_bio_inalign(opj_bio_t *bio) 209 { 210 if ((bio->buf & 0xff) == 0xff) { 211 if (! opj_bio_bytein(bio)) { 212 return OPJ_FALSE; 213 } 214 } 215 bio->ct = 0; 216 return OPJ_TRUE; 217 } 218