//
// Decrypt.cc
//
-// Copyright 1996 Derek B. Noonburg
+// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================
-#ifdef __GNUC__
+#include <aconf.h>
+
+#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif
// Decrypt
//------------------------------------------------------------------------
-Decrypt::Decrypt(Guchar *fileKey, int objNum, int objGen) {
+Decrypt::Decrypt(Guchar *fileKey, int keyLength, int objNum, int objGen) {
+ int i;
+
// construct object key
- objKey[0] = fileKey[0];
- objKey[1] = fileKey[1];
- objKey[2] = fileKey[2];
- objKey[3] = fileKey[3];
- objKey[4] = fileKey[4];
- objKey[5] = objNum & 0xff;
- objKey[6] = (objNum >> 8) & 0xff;
- objKey[7] = (objNum >> 16) & 0xff;
- objKey[8] = objGen & 0xff;
- objKey[9] = (objGen >> 8) & 0xff;
- md5(objKey, 10, objKey);
+ for (i = 0; i < keyLength; ++i) {
+ objKey[i] = fileKey[i];
+ }
+ objKey[keyLength] = objNum & 0xff;
+ objKey[keyLength + 1] = (objNum >> 8) & 0xff;
+ objKey[keyLength + 2] = (objNum >> 16) & 0xff;
+ objKey[keyLength + 3] = objGen & 0xff;
+ objKey[keyLength + 4] = (objGen >> 8) & 0xff;
+ md5(objKey, keyLength + 5, objKey);
// set up for decryption
x = y = 0;
- rc4InitKey(objKey, 10, state);
+ if ((objKeyLength = keyLength + 5) > 16) {
+ objKeyLength = 16;
+ }
+ rc4InitKey(objKey, objKeyLength, state);
}
void Decrypt::reset() {
x = y = 0;
- rc4InitKey(objKey, 10, state);
+ rc4InitKey(objKey, objKeyLength, state);
}
Guchar Decrypt::decryptByte(Guchar c) {
return rc4DecryptByte(state, &x, &y, c);
}
-GBool Decrypt::makeFileKey(GString *ownerKey, GString *userKey,
+GBool Decrypt::makeFileKey(int encVersion, int encRevision, int keyLength,
+ GString *ownerKey, GString *userKey,
int permissions, GString *fileID,
- GString *userPassword, Guchar *fileKey) {
+ GString *ownerPassword, GString *userPassword,
+ Guchar *fileKey, GBool *ownerPasswordOk) {
+ Guchar test[32], test2[32];
+ GString *userPassword2;
+ Guchar fState[256];
+ Guchar tmpKey[16];
+ Guchar fx, fy;
+ int len, i, j;
+
+ // try using the supplied owner password to generate the user password
+ *ownerPasswordOk = gFalse;
+ if (ownerPassword) {
+ len = ownerPassword->getLength();
+ if (len < 32) {
+ memcpy(test, ownerPassword->getCString(), len);
+ memcpy(test + len, passwordPad, 32 - len);
+ } else {
+ memcpy(test, ownerPassword->getCString(), 32);
+ }
+ md5(test, 32, test);
+ if (encRevision == 3) {
+ for (i = 0; i < 50; ++i) {
+ md5(test, 16, test);
+ }
+ }
+ if (encRevision == 2) {
+ rc4InitKey(test, keyLength, fState);
+ fx = fy = 0;
+ for (i = 0; i < 32; ++i) {
+ test2[i] = rc4DecryptByte(fState, &fx, &fy, ownerKey->getChar(i));
+ }
+ } else {
+ memcpy(test2, ownerKey->getCString(), 32);
+ for (i = 19; i >= 0; --i) {
+ for (j = 0; j < keyLength; ++j) {
+ tmpKey[j] = test[j] ^ i;
+ }
+ rc4InitKey(tmpKey, keyLength, fState);
+ fx = fy = 0;
+ for (j = 0; j < 32; ++j) {
+ test2[j] = rc4DecryptByte(fState, &fx, &fy, test2[j]);
+ }
+ }
+ }
+ userPassword2 = new GString((char *)test2, 32);
+ if (makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey,
+ permissions, fileID, userPassword2, fileKey)) {
+ *ownerPasswordOk = gTrue;
+ delete userPassword2;
+ return gTrue;
+ }
+ delete userPassword2;
+ }
+
+ // try using the supplied user password
+ return makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey,
+ permissions, fileID, userPassword, fileKey);
+}
+
+GBool Decrypt::makeFileKey2(int encVersion, int encRevision, int keyLength,
+ GString *ownerKey, GString *userKey,
+ int permissions, GString *fileID,
+ GString *userPassword, Guchar *fileKey) {
Guchar *buf;
- Guchar userTest[32];
+ Guchar test[32];
Guchar fState[256];
+ Guchar tmpKey[16];
Guchar fx, fy;
- int len, i;
+ int len, i, j;
GBool ok;
// generate file key
buf[67] = (permissions >> 24) & 0xff;
memcpy(buf + 68, fileID->getCString(), fileID->getLength());
md5(buf, 68 + fileID->getLength(), fileKey);
+ if (encRevision == 3) {
+ for (i = 0; i < 50; ++i) {
+ md5(fileKey, keyLength, fileKey);
+ }
+ }
- // test user key
- fx = fy = 0;
- rc4InitKey(fileKey, 5, fState);
- for (i = 0; i < 32; ++i) {
- userTest[i] = rc4DecryptByte(fState, &fx, &fy, userKey->getChar(i));
+ // test user password
+ if (encRevision == 2) {
+ rc4InitKey(fileKey, keyLength, fState);
+ fx = fy = 0;
+ for (i = 0; i < 32; ++i) {
+ test[i] = rc4DecryptByte(fState, &fx, &fy, userKey->getChar(i));
+ }
+ ok = memcmp(test, passwordPad, 32) == 0;
+ } else if (encRevision == 3) {
+ memcpy(test, userKey->getCString(), 32);
+ for (i = 19; i >= 0; --i) {
+ for (j = 0; j < keyLength; ++j) {
+ tmpKey[j] = fileKey[j] ^ i;
+ }
+ rc4InitKey(tmpKey, keyLength, fState);
+ fx = fy = 0;
+ for (j = 0; j < 32; ++j) {
+ test[j] = rc4DecryptByte(fState, &fx, &fy, test[j]);
+ }
+ }
+ memcpy(buf, passwordPad, 32);
+ memcpy(buf + 32, fileID->getCString(), fileID->getLength());
+ md5(buf, 32 + fileID->getLength(), buf);
+ ok = memcmp(test, buf, 16) == 0;
+ } else {
+ ok = gFalse;
}
- ok = memcmp(userTest, passwordPad, 32) == 0;
- gfree(buf);
+ gfree(buf);
return ok;
}
// MD5 message digest
//------------------------------------------------------------------------
+// this works around a bug in older Sun compilers
static inline Gulong rotateLeft(Gulong x, int r) {
x &= 0xffffffff;
return ((x << r) | (x >> (32 - r))) & 0xffffffff;
}
// break digest into bytes
- digest[0] = a & 0xff;
- digest[1] = (a >>= 8) & 0xff;
- digest[2] = (a >>= 8) & 0xff;
- digest[3] = (a >>= 8) & 0xff;
- digest[4] = b & 0xff;
- digest[5] = (b >>= 8) & 0xff;
- digest[6] = (b >>= 8) & 0xff;
- digest[7] = (b >>= 8) & 0xff;
- digest[8] = c & 0xff;
- digest[9] = (c >>= 8) & 0xff;
- digest[10] = (c >>= 8) & 0xff;
- digest[11] = (c >>= 8) & 0xff;
- digest[12] = d & 0xff;
- digest[13] = (d >>= 8) & 0xff;
- digest[14] = (d >>= 8) & 0xff;
- digest[15] = (d >>= 8) & 0xff;
+ digest[0] = (Guchar)(a & 0xff);
+ digest[1] = (Guchar)((a >>= 8) & 0xff);
+ digest[2] = (Guchar)((a >>= 8) & 0xff);
+ digest[3] = (Guchar)((a >>= 8) & 0xff);
+ digest[4] = (Guchar)(b & 0xff);
+ digest[5] = (Guchar)((b >>= 8) & 0xff);
+ digest[6] = (Guchar)((b >>= 8) & 0xff);
+ digest[7] = (Guchar)((b >>= 8) & 0xff);
+ digest[8] = (Guchar)(c & 0xff);
+ digest[9] = (Guchar)((c >>= 8) & 0xff);
+ digest[10] = (Guchar)((c >>= 8) & 0xff);
+ digest[11] = (Guchar)((c >>= 8) & 0xff);
+ digest[12] = (Guchar)(d & 0xff);
+ digest[13] = (Guchar)((d >>= 8) & 0xff);
+ digest[14] = (Guchar)((d >>= 8) & 0xff);
+ digest[15] = (Guchar)((d >>= 8) & 0xff);
}
git.asbjorn.biz / swftools.git / blobdiff