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Decrypt.cc
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//========================================================================
//
// Decrypt.cc
//
// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================
//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2008 Julien Rebetez <[email protected]>
// Copyright (C) 2008, 2010, 2016-2021 Albert Astals Cid <[email protected]>
// Copyright (C) 2009 Matthias Franz <[email protected]>
// Copyright (C) 2009 David Benjamin <[email protected]>
// Copyright (C) 2012 Fabio D'Urso <[email protected]>
// Copyright (C) 2013, 2017 Adrian Johnson <[email protected]>
// Copyright (C) 2016 Alok Anand <[email protected]>
// Copyright (C) 2016 Thomas Freitag <[email protected]>
// Copyright (C) 2018 Adam Reichold <[email protected]>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================
#include <config.h>
#include <cstdint>
#include <cstring>
#include "goo/gmem.h"
#include "goo/grandom.h"
#include "Decrypt.h"
#include "Error.h"
static void rc4InitKey(const unsigned char *key, int keyLen, unsigned char *state);
static unsigned char rc4DecryptByte(unsigned char *state, unsigned char *x, unsigned char *y, unsigned char c);
static bool aesReadBlock(Stream *str, unsigned char *in, bool addPadding);
static void aesKeyExpansion(DecryptAESState *s, const unsigned char *objKey, int objKeyLen, bool decrypt);
static void aesEncryptBlock(DecryptAESState *s, const unsigned char *in);
static void aesDecryptBlock(DecryptAESState *s, const unsigned char *in, bool last);
static void aes256KeyExpansion(DecryptAES256State *s, const unsigned char *objKey, int objKeyLen, bool decrypt);
static void aes256EncryptBlock(DecryptAES256State *s, const unsigned char *in);
static void aes256DecryptBlock(DecryptAES256State *s, const unsigned char *in, bool last);
static void sha256(unsigned char *msg, int msgLen, unsigned char *hash);
static void sha384(unsigned char *msg, int msgLen, unsigned char *hash);
static void sha512(unsigned char *msg, int msgLen, unsigned char *hash);
static void revision6Hash(const GooString *inputPassword, unsigned char *K, const char *userKey);
static const unsigned char passwordPad[32] = { 0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41, 0x64, 0x00, 0x4e, 0x56, 0xff, 0xfa, 0x01, 0x08, 0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68, 0x3e, 0x80, 0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a };
//------------------------------------------------------------------------
// Decrypt
//------------------------------------------------------------------------
bool Decrypt::makeFileKey(int encVersion, int encRevision, int keyLength, const GooString *ownerKey, const GooString *userKey, const GooString *ownerEnc, const GooString *userEnc, int permissions, const GooString *fileID,
const GooString *ownerPassword, const GooString *userPassword, unsigned char *fileKey, bool encryptMetadata, bool *ownerPasswordOk)
{
DecryptAES256State state;
unsigned char test[127 + 56], test2[32];
GooString *userPassword2;
unsigned char fState[256];
unsigned char tmpKey[16];
unsigned char fx, fy;
int len, i, j;
*ownerPasswordOk = false;
if (encRevision == 5 || encRevision == 6) {
// check the owner password
if (ownerPassword) {
//~ this is supposed to convert the password to UTF-8 using "SASLprep"
len = ownerPassword->getLength();
if (len > 127) {
len = 127;
}
memcpy(test, ownerPassword->c_str(), len);
memcpy(test + len, ownerKey->c_str() + 32, 8);
memcpy(test + len + 8, userKey->c_str(), 48);
sha256(test, len + 56, test);
if (encRevision == 6) {
// test contains the initial SHA-256 hash as input K.
revision6Hash(ownerPassword, test, userKey->c_str());
}
if (!memcmp(test, ownerKey->c_str(), 32)) {
// compute the file key from the owner password
memcpy(test, ownerPassword->c_str(), len);
memcpy(test + len, ownerKey->c_str() + 40, 8);
memcpy(test + len + 8, userKey->c_str(), 48);
sha256(test, len + 56, test);
if (encRevision == 6) {
// test contains the initial SHA-256 hash input K.
revision6Hash(ownerPassword, test, userKey->c_str());
}
aes256KeyExpansion(&state, test, 32, true);
for (i = 0; i < 16; ++i) {
state.cbc[i] = 0;
}
aes256DecryptBlock(&state, (unsigned char *)ownerEnc->c_str(), false);
memcpy(fileKey, state.buf, 16);
aes256DecryptBlock(&state, (unsigned char *)ownerEnc->c_str() + 16, false);
memcpy(fileKey + 16, state.buf, 16);
*ownerPasswordOk = true;
return true;
}
}
// check the user password
if (userPassword) {
//~ this is supposed to convert the password to UTF-8 using "SASLprep"
len = userPassword->getLength();
if (len > 127) {
len = 127;
}
memcpy(test, userPassword->c_str(), len);
memcpy(test + len, userKey->c_str() + 32, 8);
sha256(test, len + 8, test);
if (encRevision == 6) {
// test contains the initial SHA-256 hash input K.
// user key is not used in checking user password.
revision6Hash(userPassword, test, nullptr);
}
if (!memcmp(test, userKey->c_str(), 32)) {
// compute the file key from the user password
memcpy(test, userPassword->c_str(), len);
memcpy(test + len, userKey->c_str() + 40, 8);
sha256(test, len + 8, test);
if (encRevision == 6) {
// test contains the initial SHA-256 hash input K.
// user key is not used in computing intermediate user key.
revision6Hash(userPassword, test, nullptr);
}
aes256KeyExpansion(&state, test, 32, true);
for (i = 0; i < 16; ++i) {
state.cbc[i] = 0;
}
aes256DecryptBlock(&state, (unsigned char *)userEnc->c_str(), false);
memcpy(fileKey, state.buf, 16);
aes256DecryptBlock(&state, (unsigned char *)userEnc->c_str() + 16, false);
memcpy(fileKey + 16, state.buf, 16);
return true;
}
}
return false;
} else {
// try using the supplied owner password to generate the user password
if (ownerPassword) {
len = ownerPassword->getLength();
if (len < 32) {
memcpy(test, ownerPassword->c_str(), len);
memcpy(test + len, passwordPad, 32 - len);
} else {
memcpy(test, ownerPassword->c_str(), 32);
}
md5(test, 32, test);
if (encRevision == 3) {
for (i = 0; i < 50; ++i) {
md5(test, keyLength, 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->c_str(), 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 GooString((char *)test2, 32);
if (makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey, permissions, fileID, userPassword2, fileKey, encryptMetadata)) {
*ownerPasswordOk = true;
delete userPassword2;
return true;
}
delete userPassword2;
}
// try using the supplied user password
return makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey, permissions, fileID, userPassword, fileKey, encryptMetadata);
}
}
bool Decrypt::makeFileKey2(int encVersion, int encRevision, int keyLength, const GooString *ownerKey, const GooString *userKey, int permissions, const GooString *fileID, const GooString *userPassword, unsigned char *fileKey,
bool encryptMetadata)
{
unsigned char *buf;
unsigned char test[32];
unsigned char fState[256];
unsigned char tmpKey[16];
unsigned char fx, fy;
int len, i, j;
bool ok;
// generate file key
buf = (unsigned char *)gmalloc(72 + fileID->getLength());
if (userPassword) {
len = userPassword->getLength();
if (len < 32) {
memcpy(buf, userPassword->c_str(), len);
memcpy(buf + len, passwordPad, 32 - len);
} else {
memcpy(buf, userPassword->c_str(), 32);
}
} else {
memcpy(buf, passwordPad, 32);
}
memcpy(buf + 32, ownerKey->c_str(), 32);
buf[64] = permissions & 0xff;
buf[65] = (permissions >> 8) & 0xff;
buf[66] = (permissions >> 16) & 0xff;
buf[67] = (permissions >> 24) & 0xff;
memcpy(buf + 68, fileID->c_str(), fileID->getLength());
len = 68 + fileID->getLength();
if (!encryptMetadata) {
buf[len++] = 0xff;
buf[len++] = 0xff;
buf[len++] = 0xff;
buf[len++] = 0xff;
}
md5(buf, len, fileKey);
if (encRevision == 3) {
for (i = 0; i < 50; ++i) {
md5(fileKey, keyLength, fileKey);
}
}
// 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->c_str(), 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->c_str(), fileID->getLength());
md5(buf, 32 + fileID->getLength(), buf);
ok = memcmp(test, buf, 16) == 0;
} else {
ok = false;
}
gfree(buf);
return ok;
}
//------------------------------------------------------------------------
// BaseCryptStream
//------------------------------------------------------------------------
BaseCryptStream::BaseCryptStream(Stream *strA, const unsigned char *fileKey, CryptAlgorithm algoA, int keyLength, Ref refA) : FilterStream(strA)
{
algo = algoA;
// construct object key
for (int i = 0; i < keyLength; ++i) {
objKey[i] = fileKey[i];
}
for (std::size_t i = keyLength; i < sizeof(objKey); ++i) {
objKey[i] = 0;
}
switch (algo) {
case cryptRC4:
if (likely(keyLength < static_cast<int>(sizeof(objKey) - 4))) {
objKey[keyLength] = refA.num & 0xff;
objKey[keyLength + 1] = (refA.num >> 8) & 0xff;
objKey[keyLength + 2] = (refA.num >> 16) & 0xff;
objKey[keyLength + 3] = refA.gen & 0xff;
objKey[keyLength + 4] = (refA.gen >> 8) & 0xff;
md5(objKey, keyLength + 5, objKey);
}
if ((objKeyLength = keyLength + 5) > 16) {
objKeyLength = 16;
}
break;
case cryptAES:
objKey[keyLength] = refA.num & 0xff;
objKey[keyLength + 1] = (refA.num >> 8) & 0xff;
objKey[keyLength + 2] = (refA.num >> 16) & 0xff;
objKey[keyLength + 3] = refA.gen & 0xff;
objKey[keyLength + 4] = (refA.gen >> 8) & 0xff;
objKey[keyLength + 5] = 0x73; // 's'
objKey[keyLength + 6] = 0x41; // 'A'
objKey[keyLength + 7] = 0x6c; // 'l'
objKey[keyLength + 8] = 0x54; // 'T'
md5(objKey, keyLength + 9, objKey);
if ((objKeyLength = keyLength + 5) > 16) {
objKeyLength = 16;
}
break;
case cryptAES256:
objKeyLength = keyLength;
break;
case cryptNone:
break;
}
charactersRead = 0;
nextCharBuff = EOF;
autoDelete = true;
}
BaseCryptStream::~BaseCryptStream()
{
if (autoDelete) {
delete str;
}
}
void BaseCryptStream::reset()
{
charactersRead = 0;
nextCharBuff = EOF;
str->reset();
}
Goffset BaseCryptStream::getPos()
{
return charactersRead;
}
int BaseCryptStream::getChar()
{
// Read next character and empty the buffer, so that a new character will be read next time
int c = lookChar();
nextCharBuff = EOF;
if (c != EOF) {
charactersRead++;
}
return c;
}
bool BaseCryptStream::isBinary(bool last) const
{
return str->isBinary(last);
}
void BaseCryptStream::setAutoDelete(bool val)
{
autoDelete = val;
}
//------------------------------------------------------------------------
// EncryptStream
//------------------------------------------------------------------------
EncryptStream::EncryptStream(Stream *strA, const unsigned char *fileKey, CryptAlgorithm algoA, int keyLength, Ref refA) : BaseCryptStream(strA, fileKey, algoA, keyLength, refA)
{
// Fill the CBC initialization vector for AES and AES-256
switch (algo) {
case cryptAES:
grandom_fill(state.aes.cbc, 16);
break;
case cryptAES256:
grandom_fill(state.aes256.cbc, 16);
break;
default:
break;
}
}
EncryptStream::~EncryptStream() { }
void EncryptStream::reset()
{
BaseCryptStream::reset();
switch (algo) {
case cryptRC4:
state.rc4.x = state.rc4.y = 0;
rc4InitKey(objKey, objKeyLength, state.rc4.state);
break;
case cryptAES:
aesKeyExpansion(&state.aes, objKey, objKeyLength, false);
memcpy(state.aes.buf, state.aes.cbc, 16); // Copy CBC IV to buf
state.aes.bufIdx = 0;
state.aes.paddingReached = false;
break;
case cryptAES256:
aes256KeyExpansion(&state.aes256, objKey, objKeyLength, false);
memcpy(state.aes256.buf, state.aes256.cbc, 16); // Copy CBC IV to buf
state.aes256.bufIdx = 0;
state.aes256.paddingReached = false;
break;
case cryptNone:
break;
}
}
int EncryptStream::lookChar()
{
unsigned char in[16];
int c;
if (nextCharBuff != EOF) {
return nextCharBuff;
}
c = EOF; // make gcc happy
switch (algo) {
case cryptRC4:
if ((c = str->getChar()) != EOF) {
// RC4 is XOR-based: the decryption algorithm works for encryption too
c = rc4DecryptByte(state.rc4.state, &state.rc4.x, &state.rc4.y, (unsigned char)c);
}
break;
case cryptAES:
if (state.aes.bufIdx == 16 && !state.aes.paddingReached) {
state.aes.paddingReached = !aesReadBlock(str, in, true);
aesEncryptBlock(&state.aes, in);
}
if (state.aes.bufIdx == 16) {
c = EOF;
} else {
c = state.aes.buf[state.aes.bufIdx++];
}
break;
case cryptAES256:
if (state.aes256.bufIdx == 16 && !state.aes256.paddingReached) {
state.aes256.paddingReached = !aesReadBlock(str, in, true);
aes256EncryptBlock(&state.aes256, in);
}
if (state.aes256.bufIdx == 16) {
c = EOF;
} else {
c = state.aes256.buf[state.aes256.bufIdx++];
}
break;
case cryptNone:
break;
}
return (nextCharBuff = c);
}
//------------------------------------------------------------------------
// DecryptStream
//------------------------------------------------------------------------
DecryptStream::DecryptStream(Stream *strA, const unsigned char *fileKey, CryptAlgorithm algoA, int keyLength, Ref refA) : BaseCryptStream(strA, fileKey, algoA, keyLength, refA) { }
DecryptStream::~DecryptStream() { }
void DecryptStream::reset()
{
int i;
BaseCryptStream::reset();
switch (algo) {
case cryptRC4:
state.rc4.x = state.rc4.y = 0;
rc4InitKey(objKey, objKeyLength, state.rc4.state);
break;
case cryptAES:
aesKeyExpansion(&state.aes, objKey, objKeyLength, true);
for (i = 0; i < 16; ++i) {
state.aes.cbc[i] = str->getChar();
}
state.aes.bufIdx = 16;
break;
case cryptAES256:
aes256KeyExpansion(&state.aes256, objKey, objKeyLength, true);
for (i = 0; i < 16; ++i) {
state.aes256.cbc[i] = str->getChar();
}
state.aes256.bufIdx = 16;
break;
case cryptNone:
break;
}
}
int DecryptStream::lookChar()
{
unsigned char in[16];
int c;
if (nextCharBuff != EOF) {
return nextCharBuff;
}
c = EOF; // make gcc happy
switch (algo) {
case cryptRC4:
if ((c = str->getChar()) != EOF) {
c = rc4DecryptByte(state.rc4.state, &state.rc4.x, &state.rc4.y, (unsigned char)c);
}
break;
case cryptAES:
if (state.aes.bufIdx == 16) {
if (aesReadBlock(str, in, false)) {
aesDecryptBlock(&state.aes, in, str->lookChar() == EOF);
}
}
if (state.aes.bufIdx == 16) {
c = EOF;
} else {
c = state.aes.buf[state.aes.bufIdx++];
}
break;
case cryptAES256:
if (state.aes256.bufIdx == 16) {
if (aesReadBlock(str, in, false)) {
aes256DecryptBlock(&state.aes256, in, str->lookChar() == EOF);
}
}
if (state.aes256.bufIdx == 16) {
c = EOF;
} else {
c = state.aes256.buf[state.aes256.bufIdx++];
}
break;
case cryptNone:
break;
}
return (nextCharBuff = c);
}
//------------------------------------------------------------------------
// RC4-compatible decryption
//------------------------------------------------------------------------
static void rc4InitKey(const unsigned char *key, int keyLen, unsigned char *state)
{
unsigned char index1, index2;
unsigned char t;
int i;
for (i = 0; i < 256; ++i) {
state[i] = i;
}
if (unlikely(keyLen == 0)) {
return;
}
index1 = index2 = 0;
for (i = 0; i < 256; ++i) {
index2 = (key[index1] + state[i] + index2) % 256;
t = state[i];
state[i] = state[index2];
state[index2] = t;
index1 = (index1 + 1) % keyLen;
}
}
static unsigned char rc4DecryptByte(unsigned char *state, unsigned char *x, unsigned char *y, unsigned char c)
{
unsigned char x1, y1, tx, ty;
x1 = *x = (*x + 1) % 256;
y1 = *y = (state[*x] + *y) % 256;
tx = state[x1];
ty = state[y1];
state[x1] = ty;
state[y1] = tx;
return c ^ state[(tx + ty) % 256];
}
//------------------------------------------------------------------------
// AES decryption
//------------------------------------------------------------------------
// Returns false if EOF was reached, true otherwise
static bool aesReadBlock(Stream *str, unsigned char *in, bool addPadding)
{
int c, i;
for (i = 0; i < 16; ++i) {
if ((c = str->getChar()) != EOF) {
in[i] = (unsigned char)c;
} else {
break;
}
}
if (i == 16) {
return true;
} else {
if (addPadding) {
c = 16 - i;
while (i < 16) {
in[i++] = (unsigned char)c;
}
}
return false;
}
}
static const unsigned char sbox[256] = { 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
static const unsigned char invSbox[256] = { 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };
static const unsigned int rcon[11] = { 0x00000000, // unused
0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000, 0x20000000, 0x40000000, 0x80000000, 0x1b000000, 0x36000000 };
static inline unsigned int subWord(unsigned int x)
{
return (sbox[x >> 24] << 24) | (sbox[(x >> 16) & 0xff] << 16) | (sbox[(x >> 8) & 0xff] << 8) | sbox[x & 0xff];
}
static inline unsigned int rotWord(unsigned int x)
{
return ((x << 8) & 0xffffffff) | (x >> 24);
}
static inline void subBytes(unsigned char *state)
{
int i;
for (i = 0; i < 16; ++i) {
state[i] = sbox[state[i]];
}
}
static inline void invSubBytes(unsigned char *state)
{
int i;
for (i = 0; i < 16; ++i) {
state[i] = invSbox[state[i]];
}
}
static inline void shiftRows(unsigned char *state)
{
unsigned char t;
t = state[4];
state[4] = state[5];
state[5] = state[6];
state[6] = state[7];
state[7] = t;
t = state[8];
state[8] = state[10];
state[10] = t;
t = state[9];
state[9] = state[11];
state[11] = t;
t = state[15];
state[15] = state[14];
state[14] = state[13];
state[13] = state[12];
state[12] = t;
}
static inline void invShiftRows(unsigned char *state)
{
unsigned char t;
t = state[7];
state[7] = state[6];
state[6] = state[5];
state[5] = state[4];
state[4] = t;
t = state[8];
state[8] = state[10];
state[10] = t;
t = state[9];
state[9] = state[11];
state[11] = t;
t = state[12];
state[12] = state[13];
state[13] = state[14];
state[14] = state[15];
state[15] = t;
}
// {02} \cdot s
struct Mul02Table
{
constexpr Mul02Table() : values()
{
for (int s = 0; s < 256; s++) {
values[s] = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
}
}
constexpr unsigned char operator()(uint8_t i) const { return values[i]; }
unsigned char values[256];
};
static constexpr Mul02Table mul02;
// {03} \cdot s
struct Mul03Table
{
constexpr Mul03Table() : values()
{
for (int s = 0; s < 256; s++) {
const unsigned char s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
values[s] = s ^ s2;
}
}
constexpr unsigned char operator()(uint8_t i) const { return values[i]; }
unsigned char values[256];
};
static constexpr Mul03Table mul03;
// {09} \cdot s
struct Mul09Table
{
constexpr Mul09Table() : values()
{
for (int s = 0; s < 256; s++) {
const unsigned char s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
const unsigned char s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
const unsigned char s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
values[s] = s ^ s8;
}
}
constexpr unsigned char operator()(uint8_t i) const { return values[i]; }
unsigned char values[256];
};
static constexpr Mul09Table mul09;
// {0b} \cdot s
struct Mul0bTable
{
constexpr Mul0bTable() : values()
{
for (int s = 0; s < 256; s++) {
const unsigned char s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
const unsigned char s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
const unsigned char s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
values[s] = s ^ s2 ^ s8;
}
}
constexpr unsigned char operator()(uint8_t i) const { return values[i]; }
unsigned char values[256];
};
static constexpr Mul0bTable mul0b;
// {0d} \cdot s
struct Mul0dTable
{
constexpr Mul0dTable() : values()
{
for (int s = 0; s < 256; s++) {
const unsigned char s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
const unsigned char s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
const unsigned char s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
values[s] = s ^ s4 ^ s8;
}
}
constexpr unsigned char operator()(uint8_t i) const { return values[i]; }
unsigned char values[256];
};
static constexpr Mul0dTable mul0d;
// {0e} \cdot s
struct Mul0eTable
{
constexpr Mul0eTable() : values()
{
for (int s = 0; s < 256; s++) {
const unsigned char s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
const unsigned char s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
const unsigned char s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
values[s] = s2 ^ s4 ^ s8;
}
}
constexpr unsigned char operator()(uint8_t i) const { return values[i]; }
unsigned char values[256];
};
static constexpr Mul0eTable mul0e;
static inline void mixColumns(unsigned char *state)
{
int c;
unsigned char s0, s1, s2, s3;
for (c = 0; c < 4; ++c) {
s0 = state[c];
s1 = state[4 + c];
s2 = state[8 + c];
s3 = state[12 + c];
state[c] = mul02(s0) ^ mul03(s1) ^ s2 ^ s3;
state[4 + c] = s0 ^ mul02(s1) ^ mul03(s2) ^ s3;
state[8 + c] = s0 ^ s1 ^ mul02(s2) ^ mul03(s3);
state[12 + c] = mul03(s0) ^ s1 ^ s2 ^ mul02(s3);
}
}
static inline void invMixColumns(unsigned char *state)
{
int c;
unsigned char s0, s1, s2, s3;
for (c = 0; c < 4; ++c) {
s0 = state[c];
s1 = state[4 + c];
s2 = state[8 + c];
s3 = state[12 + c];
state[c] = mul0e(s0) ^ mul0b(s1) ^ mul0d(s2) ^ mul09(s3);
state[4 + c] = mul09(s0) ^ mul0e(s1) ^ mul0b(s2) ^ mul0d(s3);
state[8 + c] = mul0d(s0) ^ mul09(s1) ^ mul0e(s2) ^ mul0b(s3);
state[12 + c] = mul0b(s0) ^ mul0d(s1) ^ mul09(s2) ^ mul0e(s3);
}
}
static inline void invMixColumnsW(unsigned int *w)
{
int c;
unsigned char s0, s1, s2, s3;
for (c = 0; c < 4; ++c) {
s0 = w[c] >> 24;
s1 = w[c] >> 16;
s2 = w[c] >> 8;
s3 = w[c];
w[c] = ((mul0e(s0) ^ mul0b(s1) ^ mul0d(s2) ^ mul09(s3)) << 24) | ((mul09(s0) ^ mul0e(s1) ^ mul0b(s2) ^ mul0d(s3)) << 16) | ((mul0d(s0) ^ mul09(s1) ^ mul0e(s2) ^ mul0b(s3)) << 8) | (mul0b(s0) ^ mul0d(s1) ^ mul09(s2) ^ mul0e(s3));
}
}
static inline void addRoundKey(unsigned char *state, const unsigned int *w)
{
int c;
for (c = 0; c < 4; ++c) {
state[c] ^= w[c] >> 24;
state[4 + c] ^= w[c] >> 16;
state[8 + c] ^= w[c] >> 8;
state[12 + c] ^= w[c];
}
}
static void aesKeyExpansion(DecryptAESState *s, const unsigned char *objKey, int /*objKeyLen*/, bool decrypt)
{
unsigned int temp;
int i, round;
//~ this assumes objKeyLen == 16
for (i = 0; i < 4; ++i) {
s->w[i] = (objKey[4 * i] << 24) + (objKey[4 * i + 1] << 16) + (objKey[4 * i + 2] << 8) + objKey[4 * i + 3];
}
for (i = 4; i < 44; ++i) {
temp = s->w[i - 1];
if (!(i & 3)) {
temp = subWord(rotWord(temp)) ^ rcon[i / 4];
}
s->w[i] = s->w[i - 4] ^ temp;
}
/* In case of decryption, adjust the key schedule for the equivalent inverse cipher */
if (decrypt) {
for (round = 1; round <= 9; ++round) {
invMixColumnsW(&s->w[round * 4]);
}
}
}
static void aesEncryptBlock(DecryptAESState *s, const unsigned char *in)
{
int c, round;
// initial state (input is xor'd with previous output because of CBC)
for (c = 0; c < 4; ++c) {
s->state[c] = in[4 * c] ^ s->buf[4 * c];
s->state[4 + c] = in[4 * c + 1] ^ s->buf[4 * c + 1];
s->state[8 + c] = in[4 * c + 2] ^ s->buf[4 * c + 2];
s->state[12 + c] = in[4 * c + 3] ^ s->buf[4 * c + 3];
}
// round 0
addRoundKey(s->state, &s->w[0]);
// rounds 1-9
for (round = 1; round <= 9; ++round) {
subBytes(s->state);
shiftRows(s->state);
mixColumns(s->state);
addRoundKey(s->state, &s->w[round * 4]);
}
// round 10
subBytes(s->state);
shiftRows(s->state);
addRoundKey(s->state, &s->w[10 * 4]);
for (c = 0; c < 4; ++c) {
s->buf[4 * c] = s->state[c];
s->buf[4 * c + 1] = s->state[4 + c];
s->buf[4 * c + 2] = s->state[8 + c];
s->buf[4 * c + 3] = s->state[12 + c];
}
s->bufIdx = 0;
}
static void aesDecryptBlock(DecryptAESState *s, const unsigned char *in, bool last)
{
int c, round, n, i;
// initial state
for (c = 0; c < 4; ++c) {
s->state[c] = in[4 * c];
s->state[4 + c] = in[4 * c + 1];
s->state[8 + c] = in[4 * c + 2];
s->state[12 + c] = in[4 * c + 3];
}
// round 0
addRoundKey(s->state, &s->w[10 * 4]);
// rounds 1-9
for (round = 9; round >= 1; --round) {
invSubBytes(s->state);
invShiftRows(s->state);
invMixColumns(s->state);
addRoundKey(s->state, &s->w[round * 4]);
}
// round 10
invSubBytes(s->state);
invShiftRows(s->state);
addRoundKey(s->state, &s->w[0]);
// CBC
for (c = 0; c < 4; ++c) {
s->buf[4 * c] = s->state[c] ^ s->cbc[4 * c];
s->buf[4 * c + 1] = s->state[4 + c] ^ s->cbc[4 * c + 1];
s->buf[4 * c + 2] = s->state[8 + c] ^ s->cbc[4 * c + 2];
s->buf[4 * c + 3] = s->state[12 + c] ^ s->cbc[4 * c + 3];
}