Diffstat (limited to 'noncore/unsupported/qpdf/xpdf/XRef.cc') (more/less context) (ignore whitespace changes)
-rw-r--r-- | noncore/unsupported/qpdf/xpdf/XRef.cc | 80 |
1 files changed, 52 insertions, 28 deletions
diff --git a/noncore/unsupported/qpdf/xpdf/XRef.cc b/noncore/unsupported/qpdf/xpdf/XRef.cc index 5d526e9..0e1bbc9 100644 --- a/noncore/unsupported/qpdf/xpdf/XRef.cc +++ b/noncore/unsupported/qpdf/xpdf/XRef.cc @@ -1,156 +1,162 @@ //======================================================================== // // XRef.cc // -// Copyright 1996 Derek B. Noonburg +// Copyright 1996-2002 Glyph & Cog, LLC // //======================================================================== #ifdef __GNUC__ #pragma implementation #endif #include <aconf.h> #include <stdlib.h> #include <stddef.h> #include <string.h> #include <ctype.h> #include "gmem.h" #include "Object.h" #include "Stream.h" #include "Lexer.h" #include "Parser.h" #include "Dict.h" #ifndef NO_DECRYPTION #include "Decrypt.h" #endif #include "Error.h" +#include "ErrorCodes.h" #include "XRef.h" //------------------------------------------------------------------------ #define xrefSearchSize 1024 // read this many bytes at end of file // to look for 'startxref' #ifndef NO_DECRYPTION //------------------------------------------------------------------------ // Permission bits //------------------------------------------------------------------------ #define permPrint (1<<2) #define permChange (1<<3) #define permCopy (1<<4) #define permNotes (1<<5) #define defPermFlags 0xfffc #endif //------------------------------------------------------------------------ // XRef //------------------------------------------------------------------------ XRef::XRef(BaseStream *strA, GString *ownerPassword, GString *userPassword) { - int pos; + Guint pos; int i; ok = gTrue; + errCode = errNone; size = 0; entries = NULL; streamEnds = NULL; streamEndsLen = 0; // read the trailer str = strA; start = str->getStart(); pos = readTrailer(); // if there was a problem with the trailer, // try to reconstruct the xref table if (pos == 0) { if (!(ok = constructXRef())) { + errCode = errDamaged; return; } // trailer is ok - read the xref table } else { entries = (XRefEntry *)gmalloc(size * sizeof(XRefEntry)); for (i = 0; i < size; ++i) { - entries[i].offset = -1; + entries[i].offset = 0xffffffff; entries[i].used = gFalse; } while (readXRef(&pos)) ; // if there was a problem with the xref table, // try to reconstruct it if (!ok) { gfree(entries); size = 0; entries = NULL; if (!(ok = constructXRef())) { + errCode = errDamaged; return; } } } // now set the trailer dictionary's xref pointer so we can fetch // indirect objects from it trailerDict.getDict()->setXRef(this); // check for encryption #ifndef NO_DECRYPTION encrypted = gFalse; #endif if (checkEncrypted(ownerPassword, userPassword)) { ok = gFalse; + errCode = errEncrypted; return; } } XRef::~XRef() { gfree(entries); trailerDict.free(); if (streamEnds) { gfree(streamEnds); } } // Read startxref position, xref table size, and root. Returns // first xref position. -int XRef::readTrailer() { +Guint XRef::readTrailer() { Parser *parser; Object obj; char buf[xrefSearchSize+1]; - int n, pos, pos1; + int n; + Guint pos, pos1; char *p; int c; int i; // read last xrefSearchSize bytes - str->setPos(-xrefSearchSize); + str->setPos(xrefSearchSize, -1); for (n = 0; n < xrefSearchSize; ++n) { if ((c = str->getChar()) == EOF) break; buf[n] = c; } buf[n] = '\0'; // find startxref for (i = n - 9; i >= 0; --i) { if (!strncmp(&buf[i], "startxref", 9)) break; } if (i < 0) return 0; for (p = &buf[i+9]; isspace(*p); ++p) ; - pos = lastXRefPos = atoi(p); + pos = lastXRefPos = strToUnsigned(p); // find trailer dict by looking after first xref table // (NB: we can't just use the trailer dict at the end of the file -- // this won't work for linearized files.) str->setPos(start + pos); for (i = 0; i < 4; ++i) buf[i] = str->getChar(); if (strncmp(buf, "xref", 4)) return 0; pos1 = pos + 4; while (1) { str->setPos(start + pos1); @@ -167,26 +173,27 @@ int XRef::readTrailer() { while (isspace(*p)) ++p; n = atoi(p); while ('0' <= *p && *p <= '9') ++p; while (isspace(*p)) ++p; if (p == buf) return 0; pos1 += (p - buf) + n * 20; } pos1 += 7; // read trailer dict obj.initNull(); - parser = new Parser(NULL, new Lexer(NULL, str->makeSubStream(start + pos1, - -1, &obj))); + parser = new Parser(NULL, + new Lexer(NULL, + str->makeSubStream(start + pos1, gFalse, 0, &obj))); parser->getObj(&trailerDict); if (trailerDict.isDict()) { trailerDict.dictLookupNF("Size", &obj); if (obj.isInt()) size = obj.getInt(); else pos = 0; obj.free(); trailerDict.dictLookupNF("Root", &obj); if (obj.isRef()) { rootNum = obj.getRefNum(); rootGen = obj.getRefGen(); @@ -195,25 +202,25 @@ int XRef::readTrailer() { } obj.free(); } else { pos = 0; } delete parser; // return first xref position return pos; } // Read an xref table and the prev pointer from the trailer. -GBool XRef::readXRef(int *pos) { +GBool XRef::readXRef(Guint *pos) { Parser *parser; Object obj, obj2; char s[20]; GBool more; int first, newSize, n, i, j; int c; // seek to xref in stream str->setPos(start + *pos); // make sure it's an xref table while ((c = str->getChar()) != EOF && isspace(c)) ; @@ -252,125 +259,127 @@ GBool XRef::readXRef(int *pos) { } s[i] = '\0'; n = atoi(s); while ((c = str->lookChar()) != EOF && isspace(c)) { str->getChar(); } // check for buggy PDF files with an incorrect (too small) xref // table size if (first + n > size) { newSize = size + 256; entries = (XRefEntry *)grealloc(entries, newSize * sizeof(XRefEntry)); for (i = size; i < newSize; ++i) { - entries[i].offset = -1; + entries[i].offset = 0xffffffff; entries[i].used = gFalse; } size = newSize; } for (i = first; i < first + n; ++i) { for (j = 0; j < 20; ++j) { if ((c = str->getChar()) == EOF) { goto err2; } s[j] = (char)c; } - if (entries[i].offset < 0) { + if (entries[i].offset == 0xffffffff) { s[10] = '\0'; - entries[i].offset = atoi(s); + entries[i].offset = strToUnsigned(s); s[16] = '\0'; entries[i].gen = atoi(&s[11]); if (s[17] == 'n') { entries[i].used = gTrue; } else if (s[17] == 'f') { entries[i].used = gFalse; } else { goto err2; } // PDF files of patents from the IBM Intellectual Property // Network have a bug: the xref table claims to start at 1 // instead of 0. if (i == 1 && first == 1 && entries[1].offset == 0 && entries[1].gen == 65535 && !entries[1].used) { i = first = 0; entries[0] = entries[1]; - entries[1].offset = -1; + entries[1].offset = 0xffffffff; } } } } // read prev pointer from trailer dictionary obj.initNull(); - parser = new Parser(NULL, new Lexer(NULL, str->makeSubStream(str->getPos(), - -1, &obj))); + parser = new Parser(NULL, + new Lexer(NULL, + str->makeSubStream(str->getPos(), gFalse, 0, &obj))); parser->getObj(&obj); if (!obj.isCmd("trailer")) { goto err1; } obj.free(); parser->getObj(&obj); if (!obj.isDict()) { goto err1; } obj.getDict()->lookupNF("Prev", &obj2); if (obj2.isInt()) { - *pos = obj2.getInt(); + *pos = (Guint)obj2.getInt(); more = gTrue; } else { more = gFalse; } obj.free(); obj2.free(); delete parser; return more; err1: obj.free(); err2: ok = gFalse; return gFalse; } // Attempt to construct an xref table for a damaged file. GBool XRef::constructXRef() { Parser *parser; Object obj; char buf[256]; - int pos; + Guint pos; int num, gen; int newSize; int streamEndsSize; char *p; int i; GBool gotRoot; error(0, "PDF file is damaged - attempting to reconstruct xref table..."); gotRoot = gFalse; streamEndsLen = streamEndsSize = 0; str->reset(); while (1) { pos = str->getPos(); if (!str->getLine(buf, 256)) { break; } p = buf; // got trailer dictionary if (!strncmp(p, "trailer", 7)) { obj.initNull(); - parser = new Parser(NULL, new Lexer(NULL, - str->makeSubStream(start + pos + 7, -1, &obj))); + parser = new Parser(NULL, + new Lexer(NULL, + str->makeSubStream(start + pos + 7, gFalse, 0, &obj))); if (!trailerDict.isNone()) trailerDict.free(); parser->getObj(&trailerDict); if (trailerDict.isDict()) { trailerDict.dictLookupNF("Root", &obj); if (obj.isRef()) { rootNum = obj.getRefNum(); rootGen = obj.getRefGen(); gotRoot = gTrue; } obj.free(); } else { @@ -394,43 +403,44 @@ GBool XRef::constructXRef() { ++p; } while (*p && isdigit(*p)); if (isspace(*p)) { do { ++p; } while (*p && isspace(*p)); if (!strncmp(p, "obj", 3)) { if (num >= size) { newSize = (num + 1 + 255) & ~255; entries = (XRefEntry *) grealloc(entries, newSize * sizeof(XRefEntry)); for (i = size; i < newSize; ++i) { - entries[i].offset = -1; + entries[i].offset = 0xffffffff; entries[i].used = gFalse; } size = newSize; } if (!entries[num].used || gen >= entries[num].gen) { entries[num].offset = pos - start; entries[num].gen = gen; entries[num].used = gTrue; } } } } } } else if (!strncmp(p, "endstream", 9)) { if (streamEndsLen == streamEndsSize) { streamEndsSize += 64; - streamEnds = (int *)grealloc(streamEnds, streamEndsSize * sizeof(int)); + streamEnds = (Guint *)grealloc(streamEnds, + streamEndsSize * sizeof(int)); } streamEnds[streamEndsLen++] = pos; } } if (gotRoot) return gTrue; error(-1, "Couldn't find trailer dictionary"); return gFalse; } @@ -571,28 +581,29 @@ GBool XRef::okToAddNotes(GBool ignoreOwnerPW) { Object *XRef::fetch(int num, int gen, Object *obj) { XRefEntry *e; Parser *parser; Object obj1, obj2, obj3; // check for bogus ref - this can happen in corrupted PDF files if (num < 0 || num >= size) { obj->initNull(); return obj; } e = &entries[num]; - if (e->gen == gen && e->offset >= 0) { + if (e->gen == gen && e->offset != 0xffffffff) { obj1.initNull(); - parser = new Parser(this, new Lexer(this, - str->makeSubStream(start + e->offset, -1, &obj1))); + parser = new Parser(this, + new Lexer(this, + str->makeSubStream(start + e->offset, gFalse, 0, &obj1))); parser->getObj(&obj1); parser->getObj(&obj2); parser->getObj(&obj3); if (obj1.isInt() && obj1.getInt() == num && obj2.isInt() && obj2.getInt() == gen && obj3.isCmd("obj")) { #ifndef NO_DECRYPTION parser->getObj(obj, encrypted ? fileKey : (Guchar *)NULL, keyLength, num, gen); #else parser->getObj(obj); #endif @@ -609,33 +620,46 @@ Object *XRef::fetch(int num, int gen, Object *obj) { return obj; } Object *XRef::getDocInfo(Object *obj) { return trailerDict.dictLookup("Info", obj); } // Added for the pdftex project. Object *XRef::getDocInfoNF(Object *obj) { return trailerDict.dictLookupNF("Info", obj); } -int XRef::getStreamEnd(int streamStart) { +GBool XRef::getStreamEnd(Guint streamStart, Guint *streamEnd) { int a, b, m; if (streamEndsLen == 0 || streamStart > streamEnds[streamEndsLen - 1]) { - return -1; + return gFalse; } a = -1; b = streamEndsLen - 1; // invariant: streamEnds[a] < streamStart <= streamEnds[b] while (b - a > 1) { m = (a + b) / 2; if (streamStart <= streamEnds[m]) { b = m; } else { a = m; } } - return streamEnds[b]; + *streamEnd = streamEnds[b]; + return gTrue; +} + +Guint XRef::strToUnsigned(char *s) { + Guint x; + char *p; + int i; + + x = 0; + for (p = s, i = 0; *p && isdigit(*p) && i < 10; ++p, ++i) { + x = 10 * x + (*p - '0'); + } + return x; } |