1 files changed, 641 insertions, 0 deletions

diff --git a/noncore/unsupported/qpdf/xpdf/XRef.cc b/noncore/unsupported/qpdf/xpdf/XRef.cc
new file mode 100644
index 0000000..5d526e9
--- a/dev/null
+++ b/noncore/unsupported/qpdf/xpdf/XRef.cc
@@ -0,0 +1,641 @@
+//========================================================================
+//
+// XRef.cc
+//
+// Copyright 1996 Derek B. Noonburg
+//
+//========================================================================
+
+#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 "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;
+  int i;
+
+  ok = gTrue;
+  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())) {
+      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].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())) {
+        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;
+    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() {
+  Parser *parser;
+  Object obj;
+  char buf[xrefSearchSize+1];
+  int n, pos, pos1;
+  char *p;
+  int c;
+  int i;
+
+  // read last xrefSearchSize bytes
+  str->setPos(-xrefSearchSize);
+  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);
+
+  // 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);
+    for (i = 0; i < 35; ++i) {
+      if ((c = str->getChar()) == EOF)
+        return 0;
+      buf[i] = c;
+    }
+    if (!strncmp(buf, "trailer", 7))
+      break;
+    p = buf;
+    while (isspace(*p)) ++p;
+    while ('0' <= *p && *p <= '9') ++p;
+    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->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();
+    } else {
+      pos = 0;
+    }
+    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) {
+  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)) ;
+  s[0] = (char)c;
+  s[1] = (char)str->getChar();
+  s[2] = (char)str->getChar();
+  s[3] = (char)str->getChar();
+  if (!(s[0] == 'x' && s[1] == 'r' && s[2] == 'e' && s[3] == 'f')) {
+    goto err2;
+  }
+
+  // read xref
+  while (1) {
+    while ((c = str->lookChar()) != EOF && isspace(c)) {
+      str->getChar();
+    }
+    if (c == 't') {
+      break;
+    }
+    for (i = 0; (c = str->getChar()) != EOF && isdigit(c) && i < 20; ++i) {
+      s[i] = (char)c;
+    }
+    if (i == 0) {
+      goto err2;
+    }
+    s[i] = '\0';
+    first = atoi(s);
+    while ((c = str->lookChar()) != EOF && isspace(c)) {
+      str->getChar();
+    }
+    for (i = 0; (c = str->getChar()) != EOF && isdigit(c) && i < 20; ++i) {
+      s[i] = (char)c;
+    }
+    if (i == 0) {
+      goto err2;
+    }
+    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].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) {
+        s[10] = '\0';
+        entries[i].offset = atoi(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;
+        }
+      }
+    }
+  }
+
+  // read prev pointer from trailer dictionary
+  obj.initNull();
+  parser = new Parser(NULL, new Lexer(NULL, str->makeSubStream(str->getPos(),
+                                                               -1, &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();
+    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;
+  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)));
+      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 {
+        pos = 0;
+      }
+      delete parser;
+
+    // look for object
+    } else if (isdigit(*p)) {
+      num = atoi(p);
+      do {
+        ++p;
+      } while (*p && isdigit(*p));
+      if (isspace(*p)) {
+        do {
+          ++p;
+        } while (*p && isspace(*p));
+        if (isdigit(*p)) {
+          gen = atoi(p);
+          do {
+            ++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].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[streamEndsLen++] = pos;
+    }
+  }
+
+  if (gotRoot)
+    return gTrue;
+
+  error(-1, "Couldn't find trailer dictionary");
+  return gFalse;
+}
+
+#ifndef NO_DECRYPTION
+GBool XRef::checkEncrypted(GString *ownerPassword, GString *userPassword) {
+  Object encrypt, filterObj, versionObj, revisionObj, lengthObj;
+  Object ownerKey, userKey, permissions, fileID, fileID1;
+  GBool encrypted1;
+  GBool ret;
+
+  ret = gFalse;
+
+  permFlags = defPermFlags;
+  trailerDict.dictLookup("Encrypt", &encrypt);
+  if ((encrypted1 = encrypt.isDict())) {
+    ret = gTrue;
+    encrypt.dictLookup("Filter", &filterObj);
+    if (filterObj.isName("Standard")) {
+      encrypt.dictLookup("V", &versionObj);
+      encrypt.dictLookup("R", &revisionObj);
+      encrypt.dictLookup("Length", &lengthObj);
+      encrypt.dictLookup("O", &ownerKey);
+      encrypt.dictLookup("U", &userKey);
+      encrypt.dictLookup("P", &permissions);
+      trailerDict.dictLookup("ID", &fileID);
+      if (versionObj.isInt() &&
+          revisionObj.isInt() &&
+          ownerKey.isString() && ownerKey.getString()->getLength() == 32 &&
+          userKey.isString() && userKey.getString()->getLength() == 32 &&
+          permissions.isInt() &&
+          fileID.isArray()) {
+        encVersion = versionObj.getInt();
+        encRevision = revisionObj.getInt();
+        if (lengthObj.isInt()) {
+          keyLength = lengthObj.getInt() / 8;
+        } else {
+          keyLength = 5;
+        }
+        permFlags = permissions.getInt();
+        if (encVersion >= 1 && encVersion <= 2 &&
+            encRevision >= 2 && encRevision <= 3) {
+          fileID.arrayGet(0, &fileID1);
+          if (fileID1.isString()) {
+            if (Decrypt::makeFileKey(encVersion, encRevision, keyLength,
+                                     ownerKey.getString(), userKey.getString(),
+                                     permFlags, fileID1.getString(),
+                                     ownerPassword, userPassword, fileKey,
+                                     &ownerPasswordOk)) {
+              if (ownerPassword && !ownerPasswordOk) {
+                error(-1, "Incorrect owner password");
+              }
+              ret = gFalse;
+            } else {
+              error(-1, "Incorrect password");
+            }
+          } else {
+            error(-1, "Weird encryption info");
+          }
+          fileID1.free();
+        } else {
+          error(-1, "Unsupported version/revision (%d/%d) of Standard security handler",
+                encVersion, encRevision);
+        }
+      } else {
+        error(-1, "Weird encryption info");
+      }
+      fileID.free();
+      permissions.free();
+      userKey.free();
+      ownerKey.free();
+      lengthObj.free();
+      revisionObj.free();
+      versionObj.free();
+    } else {
+      error(-1, "Unknown security handler '%s'",
+            filterObj.isName() ? filterObj.getName() : "???");
+    }
+    filterObj.free();
+  }
+  encrypt.free();
+
+  // this flag has to be set *after* we read the O/U/P strings
+  encrypted = encrypted1;
+
+  return ret;
+}
+#else
+GBool XRef::checkEncrypted(GString *ownerPassword, GString *userPassword) {
+  Object obj;
+  GBool encrypted;
+
+  trailerDict.dictLookup("Encrypt", &obj);
+  if ((encrypted = !obj.isNull())) {
+    error(-1, "PDF file is encrypted and this version of the Xpdf tools");
+    error(-1, "was built without decryption support.");
+  }
+  obj.free();
+  return encrypted;
+}
+#endif
+
+GBool XRef::okToPrint(GBool ignoreOwnerPW) {
+#ifndef NO_DECRYPTION
+  if ((ignoreOwnerPW || !ownerPasswordOk) && !(permFlags & permPrint)) {
+    return gFalse;
+  }
+#endif
+  return gTrue;
+}
+
+GBool XRef::okToChange(GBool ignoreOwnerPW) {
+#ifndef NO_DECRYPTION
+  if ((ignoreOwnerPW || !ownerPasswordOk) && !(permFlags & permChange)) {
+    return gFalse;
+  }
+#endif
+  return gTrue;
+}
+
+GBool XRef::okToCopy(GBool ignoreOwnerPW) {
+#ifndef NO_DECRYPTION
+  if ((ignoreOwnerPW || !ownerPasswordOk) && !(permFlags & permCopy)) {
+    return gFalse;
+  }
+#endif
+  return gTrue;
+}
+
+GBool XRef::okToAddNotes(GBool ignoreOwnerPW) {
+#ifndef NO_DECRYPTION
+  if ((ignoreOwnerPW || !ownerPasswordOk) && !(permFlags & permNotes)) {
+    return gFalse;
+  }
+#endif
+  return gTrue;
+}
+
+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) {
+    obj1.initNull();
+    parser = new Parser(this, new Lexer(this,
+                   str->makeSubStream(start + e->offset, -1, &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
+    } else {
+      obj->initNull();
+    }
+    obj1.free();
+    obj2.free();
+    obj3.free();
+    delete parser;
+  } else {
+    obj->initNull();
+  }
+  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) {
+  int a, b, m;
+
+  if (streamEndsLen == 0 ||
+      streamStart > streamEnds[streamEndsLen - 1]) {
+    return -1;
+  }
+
+  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];
+}