168349Sobrien/* 2133359Sobrien * Copyright (c) Ian F. Darwin 1986-1995. 3133359Sobrien * Software written by Ian F. Darwin and others; 4133359Sobrien * maintained 1995-present by Christos Zoulas and others. 5191736Sobrien * 6133359Sobrien * Redistribution and use in source and binary forms, with or without 7133359Sobrien * modification, are permitted provided that the following conditions 8133359Sobrien * are met: 9133359Sobrien * 1. Redistributions of source code must retain the above copyright 10133359Sobrien * notice immediately at the beginning of the file, without modification, 11133359Sobrien * this list of conditions, and the following disclaimer. 12133359Sobrien * 2. Redistributions in binary form must reproduce the above copyright 13133359Sobrien * notice, this list of conditions and the following disclaimer in the 14133359Sobrien * documentation and/or other materials provided with the distribution. 15191736Sobrien * 16133359Sobrien * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17133359Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18133359Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19133359Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20133359Sobrien * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21133359Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22133359Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23133359Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24133359Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25133359Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26133359Sobrien * SUCH DAMAGE. 27133359Sobrien */ 28133359Sobrien/* 29226048Sobrien * ASCII magic -- try to detect text encoding. 3068349Sobrien * 3168349Sobrien * Extensively modified by Eric Fischer <enf@pobox.com> in July, 2000, 3268349Sobrien * to handle character codes other than ASCII on a unified basis. 3368349Sobrien */ 3468349Sobrien 3568349Sobrien#include "file.h" 36191736Sobrien 37191736Sobrien#ifndef lint 38330569SgordonFILE_RCSID("@(#)$File: ascmagic.c,v 1.97 2016/06/27 20:56:25 christos Exp $") 39191736Sobrien#endif /* lint */ 40191736Sobrien 41133359Sobrien#include "magic.h" 4268349Sobrien#include <string.h> 4368349Sobrien#include <memory.h> 4468349Sobrien#include <ctype.h> 4568349Sobrien#include <stdlib.h> 4668349Sobrien#ifdef HAVE_UNISTD_H 4768349Sobrien#include <unistd.h> 4868349Sobrien#endif 4968349Sobrien 5068349Sobrien#define MAXLINELEN 300 /* longest sane line length */ 5168349Sobrien#define ISSPC(x) ((x) == ' ' || (x) == '\t' || (x) == '\r' || (x) == '\n' \ 5268349Sobrien || (x) == 0x85 || (x) == '\f') 5368349Sobrien 54186690Sobrienprivate unsigned char *encode_utf8(unsigned char *, size_t, unichar *, size_t); 55191736Sobrienprivate size_t trim_nuls(const unsigned char *, size_t); 5668349Sobrien 57191736Sobrien/* 58191736Sobrien * Undo the NUL-termination kindly provided by process() 59191736Sobrien * but leave at least one byte to look at 60191736Sobrien */ 61191736Sobrienprivate size_t 62191736Sobrientrim_nuls(const unsigned char *buf, size_t nbytes) 63191736Sobrien{ 64191736Sobrien while (nbytes > 1 && buf[nbytes - 1] == '\0') 65191736Sobrien nbytes--; 66133359Sobrien 67191736Sobrien return nbytes; 68191736Sobrien} 69191736Sobrien 70133359Sobrienprotected int 71234250Sobrienfile_ascmagic(struct magic_set *ms, const unsigned char *buf, size_t nbytes, 72234250Sobrien int text) 7368349Sobrien{ 74191736Sobrien unichar *ubuf = NULL; 75267843Sdelphij size_t ulen = 0; 76191736Sobrien int rv = 1; 77191736Sobrien 78191736Sobrien const char *code = NULL; 79191736Sobrien const char *code_mime = NULL; 80191736Sobrien const char *type = NULL; 81191736Sobrien 82191736Sobrien nbytes = trim_nuls(buf, nbytes); 83191736Sobrien 84191736Sobrien /* If file doesn't look like any sort of text, give up. */ 85191736Sobrien if (file_encoding(ms, buf, nbytes, &ubuf, &ulen, &code, &code_mime, 86234250Sobrien &type) == 0) 87191736Sobrien rv = 0; 88234250Sobrien else 89234250Sobrien rv = file_ascmagic_with_encoding(ms, buf, nbytes, ubuf, ulen, code, 90234250Sobrien type, text); 91191736Sobrien 92234250Sobrien free(ubuf); 93191736Sobrien 94191736Sobrien return rv; 95191736Sobrien} 96191736Sobrien 97191736Sobrienprotected int 98191736Sobrienfile_ascmagic_with_encoding(struct magic_set *ms, const unsigned char *buf, 99191736Sobrien size_t nbytes, unichar *ubuf, size_t ulen, const char *code, 100234250Sobrien const char *type, int text) 101191736Sobrien{ 102191736Sobrien unsigned char *utf8_buf = NULL, *utf8_end; 103191736Sobrien size_t mlen, i; 104159764Sobrien int rv = -1; 105175296Sobrien int mime = ms->flags & MAGIC_MIME; 10668349Sobrien 107133359Sobrien const char *subtype = NULL; 108133359Sobrien const char *subtype_mime = NULL; 10968349Sobrien 11068349Sobrien int has_escapes = 0; 11168349Sobrien int has_backspace = 0; 112159764Sobrien int seen_cr = 0; 11368349Sobrien 11468349Sobrien int n_crlf = 0; 11568349Sobrien int n_lf = 0; 11668349Sobrien int n_cr = 0; 11768349Sobrien int n_nel = 0; 118234250Sobrien int executable = 0; 11968349Sobrien 120169962Sobrien size_t last_line_end = (size_t)-1; 12168349Sobrien int has_long_lines = 0; 12268349Sobrien 123191736Sobrien nbytes = trim_nuls(buf, nbytes); 124133359Sobrien 125191736Sobrien /* If we have fewer than 2 bytes, give up. */ 126159764Sobrien if (nbytes <= 1) { 127159764Sobrien rv = 0; 128159764Sobrien goto done; 129159764Sobrien } 130159764Sobrien 131267843Sdelphij if (ulen > 0 && (ms->flags & MAGIC_NO_CHECK_SOFT) == 0) { 132226048Sobrien /* Convert ubuf to UTF-8 and try text soft magic */ 133226048Sobrien /* malloc size is a conservative overestimate; could be 134226048Sobrien improved, or at least realloced after conversion. */ 135226048Sobrien mlen = ulen * 6; 136226048Sobrien if ((utf8_buf = CAST(unsigned char *, malloc(mlen))) == NULL) { 137226048Sobrien file_oomem(ms, mlen); 138226048Sobrien goto done; 139226048Sobrien } 140226048Sobrien if ((utf8_end = encode_utf8(utf8_buf, mlen, ubuf, ulen)) 141226048Sobrien == NULL) 142226048Sobrien goto done; 143226048Sobrien if ((rv = file_softmagic(ms, utf8_buf, 144330569Sgordon (size_t)(utf8_end - utf8_buf), NULL, NULL, 145276415Sdelphij TEXTTEST, text)) == 0) 146226048Sobrien rv = -1; 147330569Sgordon if ((ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION))) { 148330569Sgordon rv = rv == -1 ? 0 : 1; 149330569Sgordon goto done; 150330569Sgordon } 15168349Sobrien } 152330569Sgordon if ((ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION))) 153330569Sgordon return 0; 15468349Sobrien 155186690Sobrien /* Now try to discover other details about the file. */ 15668349Sobrien for (i = 0; i < ulen; i++) { 157159764Sobrien if (ubuf[i] == '\n') { 158159764Sobrien if (seen_cr) 159159764Sobrien n_crlf++; 160159764Sobrien else 161159764Sobrien n_lf++; 162159764Sobrien last_line_end = i; 163159764Sobrien } else if (seen_cr) 164159764Sobrien n_cr++; 165159764Sobrien 166159764Sobrien seen_cr = (ubuf[i] == '\r'); 167159764Sobrien if (seen_cr) 168159764Sobrien last_line_end = i; 169159764Sobrien 170159764Sobrien if (ubuf[i] == 0x85) { /* X3.64/ECMA-43 "next line" character */ 171159764Sobrien n_nel++; 172159764Sobrien last_line_end = i; 173159764Sobrien } 174159764Sobrien 175159764Sobrien /* If this line is _longer_ than MAXLINELEN, remember it. */ 17668349Sobrien if (i > last_line_end + MAXLINELEN) 17768349Sobrien has_long_lines = 1; 17868349Sobrien 17968349Sobrien if (ubuf[i] == '\033') 18068349Sobrien has_escapes = 1; 18168349Sobrien if (ubuf[i] == '\b') 18268349Sobrien has_backspace = 1; 18368349Sobrien } 18468349Sobrien 185159764Sobrien /* Beware, if the data has been truncated, the final CR could have 186330569Sgordon been followed by a LF. If we have ms->bytes_max bytes, it indicates 187159764Sobrien that the data might have been truncated, probably even before 188159764Sobrien this function was called. */ 189330569Sgordon if (seen_cr && nbytes < ms->bytes_max) 190159764Sobrien n_cr++; 191159764Sobrien 192191736Sobrien if (strcmp(type, "binary") == 0) { 193191736Sobrien rv = 0; 194191736Sobrien goto done; 195191736Sobrien } 196175296Sobrien if (mime) { 197226048Sobrien if (!file_printedlen(ms) && (mime & MAGIC_MIME_TYPE) != 0) { 198175296Sobrien if (subtype_mime) { 199191736Sobrien if (file_printf(ms, "%s", subtype_mime) == -1) 200175296Sobrien goto done; 201175296Sobrien } else { 202175296Sobrien if (file_printf(ms, "text/plain") == -1) 203175296Sobrien goto done; 204175296Sobrien } 205133359Sobrien } 20668349Sobrien } else { 207226048Sobrien if (file_printedlen(ms)) { 208226048Sobrien switch (file_replace(ms, " text$", ", ")) { 209226048Sobrien case 0: 210226048Sobrien switch (file_replace(ms, " text executable$", 211226048Sobrien ", ")) { 212226048Sobrien case 0: 213226048Sobrien if (file_printf(ms, ", ") == -1) 214226048Sobrien goto done; 215267843Sdelphij break; 216226048Sobrien case -1: 217226048Sobrien goto done; 218226048Sobrien default: 219226048Sobrien executable = 1; 220226048Sobrien break; 221226048Sobrien } 222226048Sobrien break; 223226048Sobrien case -1: 224226048Sobrien goto done; 225226048Sobrien default: 226226048Sobrien break; 227226048Sobrien } 228226048Sobrien } 229226048Sobrien 230191736Sobrien if (file_printf(ms, "%s", code) == -1) 231159764Sobrien goto done; 23268349Sobrien 23368349Sobrien if (subtype) { 234191736Sobrien if (file_printf(ms, " %s", subtype) == -1) 235159764Sobrien goto done; 23668349Sobrien } 23768349Sobrien 238191736Sobrien if (file_printf(ms, " %s", type) == -1) 239159764Sobrien goto done; 24068349Sobrien 241226048Sobrien if (executable) 242226048Sobrien if (file_printf(ms, " executable") == -1) 243226048Sobrien goto done; 244226048Sobrien 24568349Sobrien if (has_long_lines) 246133359Sobrien if (file_printf(ms, ", with very long lines") == -1) 247159764Sobrien goto done; 24868349Sobrien 24968349Sobrien /* 25068349Sobrien * Only report line terminators if we find one other than LF, 25168349Sobrien * or if we find none at all. 25268349Sobrien */ 25368349Sobrien if ((n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0) || 25468349Sobrien (n_crlf != 0 || n_cr != 0 || n_nel != 0)) { 255133359Sobrien if (file_printf(ms, ", with") == -1) 256159764Sobrien goto done; 25768349Sobrien 258191736Sobrien if (n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0) { 259133359Sobrien if (file_printf(ms, " no") == -1) 260159764Sobrien goto done; 261133359Sobrien } else { 26268349Sobrien if (n_crlf) { 263133359Sobrien if (file_printf(ms, " CRLF") == -1) 264159764Sobrien goto done; 26568349Sobrien if (n_cr || n_lf || n_nel) 266133359Sobrien if (file_printf(ms, ",") == -1) 267159764Sobrien goto done; 26868349Sobrien } 26968349Sobrien if (n_cr) { 270133359Sobrien if (file_printf(ms, " CR") == -1) 271159764Sobrien goto done; 27268349Sobrien if (n_lf || n_nel) 273133359Sobrien if (file_printf(ms, ",") == -1) 274159764Sobrien goto done; 27568349Sobrien } 27668349Sobrien if (n_lf) { 277133359Sobrien if (file_printf(ms, " LF") == -1) 278159764Sobrien goto done; 27968349Sobrien if (n_nel) 280133359Sobrien if (file_printf(ms, ",") == -1) 281159764Sobrien goto done; 28268349Sobrien } 28368349Sobrien if (n_nel) 284133359Sobrien if (file_printf(ms, " NEL") == -1) 285159764Sobrien goto done; 28668349Sobrien } 28768349Sobrien 288133359Sobrien if (file_printf(ms, " line terminators") == -1) 289159764Sobrien goto done; 29068349Sobrien } 29168349Sobrien 29268349Sobrien if (has_escapes) 293133359Sobrien if (file_printf(ms, ", with escape sequences") == -1) 294159764Sobrien goto done; 29568349Sobrien if (has_backspace) 296133359Sobrien if (file_printf(ms, ", with overstriking") == -1) 297159764Sobrien goto done; 29868349Sobrien } 299159764Sobrien rv = 1; 300159764Sobriendone: 301234250Sobrien free(utf8_buf); 30268349Sobrien 303159764Sobrien return rv; 30468349Sobrien} 30568349Sobrien 30668349Sobrien/* 307186690Sobrien * Encode Unicode string as UTF-8, returning pointer to character 308186690Sobrien * after end of string, or NULL if an invalid character is found. 309186690Sobrien */ 310186690Sobrienprivate unsigned char * 311186690Sobrienencode_utf8(unsigned char *buf, size_t len, unichar *ubuf, size_t ulen) 31268349Sobrien{ 313169962Sobrien size_t i; 314186690Sobrien unsigned char *end = buf + len; 315186690Sobrien 316186690Sobrien for (i = 0; i < ulen; i++) { 317186690Sobrien if (ubuf[i] <= 0x7f) { 318186690Sobrien if (end - buf < 1) 319186690Sobrien return NULL; 320186690Sobrien *buf++ = (unsigned char)ubuf[i]; 321186690Sobrien } else if (ubuf[i] <= 0x7ff) { 322186690Sobrien if (end - buf < 2) 323186690Sobrien return NULL; 324186690Sobrien *buf++ = (unsigned char)((ubuf[i] >> 6) + 0xc0); 325186690Sobrien *buf++ = (unsigned char)((ubuf[i] & 0x3f) + 0x80); 326186690Sobrien } else if (ubuf[i] <= 0xffff) { 327186690Sobrien if (end - buf < 3) 328186690Sobrien return NULL; 329186690Sobrien *buf++ = (unsigned char)((ubuf[i] >> 12) + 0xe0); 330186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 6) & 0x3f) + 0x80); 331186690Sobrien *buf++ = (unsigned char)((ubuf[i] & 0x3f) + 0x80); 332186690Sobrien } else if (ubuf[i] <= 0x1fffff) { 333186690Sobrien if (end - buf < 4) 334186690Sobrien return NULL; 335186690Sobrien *buf++ = (unsigned char)((ubuf[i] >> 18) + 0xf0); 336186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 12) & 0x3f) + 0x80); 337186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 6) & 0x3f) + 0x80); 338186690Sobrien *buf++ = (unsigned char)((ubuf[i] & 0x3f) + 0x80); 339186690Sobrien } else if (ubuf[i] <= 0x3ffffff) { 340186690Sobrien if (end - buf < 5) 341186690Sobrien return NULL; 342186690Sobrien *buf++ = (unsigned char)((ubuf[i] >> 24) + 0xf8); 343186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 18) & 0x3f) + 0x80); 344186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 12) & 0x3f) + 0x80); 345186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 6) & 0x3f) + 0x80); 346186690Sobrien *buf++ = (unsigned char)((ubuf[i] & 0x3f) + 0x80); 347186690Sobrien } else if (ubuf[i] <= 0x7fffffff) { 348186690Sobrien if (end - buf < 6) 349186690Sobrien return NULL; 350186690Sobrien *buf++ = (unsigned char)((ubuf[i] >> 30) + 0xfc); 351186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 24) & 0x3f) + 0x80); 352186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 18) & 0x3f) + 0x80); 353186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 12) & 0x3f) + 0x80); 354186690Sobrien *buf++ = (unsigned char)(((ubuf[i] >> 6) & 0x3f) + 0x80); 355186690Sobrien *buf++ = (unsigned char)((ubuf[i] & 0x3f) + 0x80); 356186690Sobrien } else /* Invalid character */ 357186690Sobrien return NULL; 358186690Sobrien } 359186690Sobrien 360186690Sobrien return buf; 361186690Sobrien} 362