Delphi: AES CBC encryption compatible with PHP mcrypt_encrypt - php

I'm trying to encrypt data in Delphi then decrypt it in PHP, but the Delphi output differs from what I get with PHP, so I am first testing whether both the PHP and Delphi output from encrypting a string is the same:
Delphi encryption, using DCPcrypt:
Uses DCPcrypt2, DCPblockciphers, DCPrijndael;
var Cipher : TDCP_rijndael;
Data, Key, IV : Ansistring;
begin
key := '12345678901234567890123456789012';
iv := '1234567890123456';
Data := 'thisis128bitstxt';
Cipher := TDCP_rijndael.Create(nil);
Cipher.Init(Key[1],128,#IV[1]);
Cipher.EncryptCBC(Data[1],Data[1],Length(Data));
Cipher.Free;
With TMemoryStream.Create do begin
Write(Data[1],Length(Data));
SaveToFile('z:\delphi');
Free;
end;
Now the code in PHP:
<?php
$source = "thisis128bitstxt"; //128-bits block
$key = "12345678901234567890123456789012"; // 32
$iv = "1234567890123456"; // 16
$source = mcrypt_encrypt(MCRYPT_RIJNDAEL_128,$key,$source,MCRYPT_MODE_CBC,$iv);
$out = fopen ('php', 'w');
fwrite ($out, $source);
fclose ($out);
?>
Results:
What's wrong?

Change:
$source = mcrypt_encrypt(MCRYPT_RIJNDAEL_128,$key,$source,MCRYPT_MODE_CBC,$iv);
to:
$source = mcrypt_cbc(MCRYPT_RIJNDAEL_128,$KEYkey$source,MCRYPT_ENCRYPT,$iv);

Related

Encrypt in PHP, decrypt in C

I'd like to encrypt a string in PHP and then decrypt it in C. I'm stuck on the decryption part.
(PHP) I first encrypt the string:
function encrypt($plaintext, $key) {
$iv = 'aaaaaaaaaaaaaaaa';
$ciphertext = openssl_encrypt($plaintext, "AES-256-CBC", $key, OPENSSL_RAW_DATA, $iv);
return $ciphertext;
}
echo encrypt('This is a test', 'test');
// output: 7q�7h_��8� ��L
(C) Then I want to decrypt it, I use tiny-AES-c library for the functions:
int test_decrypt_cbc(void) {
uint8_t key[] = "test";
uint8_t iv[] = "aaaaaaaaaaaaaaaa";
uint8_t str[] = "7q�7h_��8� ��L";
printf("%s", str);
printf("\n Decrypted buffer\n");
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx, key, iv);
AES_CBC_decrypt_buffer(&ctx, str, sizeof(str));
printf("%s", str);
printf("\n");
return 1;
}
This outputs:
7q�7h_��8� ��L
Decrypted buffer
?L??Ɵ??m??Dˍ?'?&??c?W
It should instead output "This is a test".
How can I fix this?
In the PHP code, AES-256 is used. tiny-AES-c only supports AES-128 by default. In order for AES-256 to be supported, the corresponding constant must be defined in aes.h, i.e. the line //#define AES256 1 must be commented in, here.
PHP uses PKCS7 padding by default. The padding should be removed in the C code.
PHP implicitly pads too short keys with zero values to the specified length. Since AES-256-CBC was specified in the PHP code, the key test is extended as follows:
test\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0
In the C code this extended key must be used (see also the comment of #r3mainer).
For the transfer of the ciphertext between the two codes a suitable encoding must be used, e.g. Base64 or hexadecimal (see also the comment of #Ôrel). For the latter, bin2hex can be applied to the ciphertext in the PHP code. An example of a hex decoding in C can be found here.
A possible C-implementation is:
// Pad the key with zero values
uint8_t key[] = "test\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
uint8_t iv[] = "aaaaaaaaaaaaaaaa";
uint8_t ciphertextHex[] = "3771e837685ff5d4173801900de6e14c";
// Hex decode (e.g. https://stackoverflow.com/a/3409211/9014097)
uint8_t ciphertext[sizeof(ciphertextHex) / 2], * pos = ciphertextHex;
for (size_t count = 0; count < sizeof ciphertext / sizeof * ciphertext; count++) {
sscanf((const char*)pos, "%2hhx", &ciphertext[count]);
pos += 2;
}
// Decrypt
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx, key, iv);
AES_CBC_decrypt_buffer(&ctx, ciphertext, sizeof(ciphertext));
// Remove the PKCS7 padding
uint8_t ciphertextLength = sizeof(ciphertext);
uint8_t numberOfPaddingBytes = ciphertext[ciphertextLength - 1];
ciphertext[ciphertextLength - numberOfPaddingBytes] = 0;
printf("%s", ciphertext);

Different results when encrypting with "same" method in Delphi and PHP

I am trying to exchange encrypted messages between Delphi and PHP.
From the Delphi side I downloaded DCPcrypt v2 Beta 3 from here:
http://www.cityinthesky.co.uk/opensource/dcpcrypt/
For encrypting I use this function:
function TForm1.Encrypt3DES(psData, psKey: string): string;
var
Cipher: TDCP_3des;
begin
Cipher:= TDCP_3des.Create(nil);
Cipher.InitStr(psKey,TDCP_sha256);
result:=Cipher.EncryptString(psData);
Cipher.Burn;
Cipher.Free;
end;
And I am testing it like this:
ShowMessage(Encrypt3DES('test','SecretKeySecretKeySecret'));
The result that I get is Z74E0Q== and I can successfully decrypt it with another similar delphi function:
function TForm1.Decrypt3DES(psData, psKey: string): string;
var
Cipher: TDCP_3des;
begin
Cipher:= TDCP_3des.Create(nil);
Cipher.InitStr(psKey, TDCP_sha256);
result:=Cipher.DecryptString(psData);
Cipher.Burn;
Cipher.Free;
end;
From PHP side I tried several function to encrypt the same string ('test') with the same key ('SecretKeySecretKeySecret') but the result is different from what I get in Delphi. Again I can successfully decrypt the messages in PHP with similar functions but I need to decrypt messages in Delphi.
This is what I do in PHP, I even tried to hash the key as I see Delphi function is using TDCP_sha256 but still results are diferent.
$key = "SecretKeySecretKeySecret";
echo base64_encode(mcrypt_encrypt(MCRYPT_3DES, $key, 'test', 'ecb')).'<BR><BR>';
echo openssl_encrypt('test', 'des-ede3', $key).'<BR><BR>';
$key = hash('sha256', $key);
echo openssl_encrypt('test', 'des-ede3', $key).'<BR><BR>';
This is the result:
Z05z5Bp4/vY=
L5qmk5nJOzs=
bm7yRdrMs5g=
What am I doing wrong? BTW I am using Delphi 7 and DCPcrypt is the only library for now that I managed to make it run.
I think that this will help you. TDCP_3des is blockcipher and EncryptString method uses EncryptCFB8bit method (Encrypt size bytes of data using the CFB (8 bit) method of encryption).
Two things are important:
use the same initialisation vector
hash the key in PHP part.
Delphi part:
function TForm1.Encrypt3DES(psData, psKey: string): string;
var
Cipher: TDCP_3des;
i: integer;
begin
Cipher := TDCP_3des.Create(nil);
try
Cipher.InitStr(psKey, TDCP_sha256);
Cipher.SetIV('00000000');
Result := Cipher.EncryptString(psData);
Cipher.Burn;
finally
Cipher.Free;
end{try};
end;
procedure TForm1.btnEncryptClick(Sender: TObject);
var
input, key: string;
begin
input := 'Some words in English';
key := 'SecretKeySecretKeySecret';
ShowMessage(Encrypt3DES(input, key));
end;
PHP part:
<?
$key = "SecretKeySecretKeySecret";
$key = hash('sha256', $key, true);
$key = substr($key, 0, 24);
$iv = '00000000';
$message = 'Some words in English';
$result = mcrypt_encrypt(MCRYPT_3DES, $key, $message, MCRYPT_MODE_CFB, $iv);
$result = base64_encode($result);
echo 'Input text: '.$message.'</br>';
echo 'Encrypted text: '.$result.'</br>';
?>
Output:
Input: Some words in English
Encrypted text: hTpdn+USolFTgv/4HnBEvo4scgmp
Input: This will test Delphi7 and PHP encryption.
Encrypted text: gik2Iw/m2rtMA9gdKqvFqDg3kuUSb4rnAieyZ8unIvt510Rbt1jLPO+/
Input: I hope this will work.
Encrypted text: n/JxW12zORaI7TSCAF4/6cBxqC3mZg==
Notes:
Tested with Delphi 7, DCPcrypt v2, PHP 5.2.10, mcrypt 2.5.7.
The length of your base64 ciphertext shows that DCPCrypt does not use ECB. With a minimal program I can reproduce your result and stepping through the code indeed shows that ECB is not used. The relevant parts are
function TDCP_blockcipher.EncryptString(const Str: string): string;
begin
SetLength(Result,Length(Str));
EncryptCFB8bit(Str[1],Result[1],Length(Str));
Result:= Base64EncodeStr(Result);
end;
function TDCP_blockcipher.DecryptString(const Str: string): string;
begin
Result:= Base64DecodeStr(Str);
DecryptCFB8bit(Result[1],Result[1],Length(Result));
end;

Aes|Rijndael-128 Hashed Text Decode in Delphi XE2

We have php code:
define('myaesKey', 'znwoq8fq0jf2qjve8laper9f'); // 192 bits and 25 ch.
function encode($CodeTo) {
$Type = 'rijndael-128';
$Mode = 'ecb';
$IV = "1234567890123450";
$Object = mcrypt_module_open($Type, '', $Mode, '');
mcrypt_generic_init($Object , myaesKey, $IV);
$Enc2Code = mcrypt_generic($Object , $CodeTo);
mcrypt_generic_deinit($Object);
mcrypt_module_close($Object);
return bin2hex($secEncCode);
}
Length of $CodeTo is 5, CodeTo is readable symbols of English Alphabet, function send somethind like this
1e49651ba23801907e1d67c5a7c18e06
aefdc02bbcb8ed8e8209a935aa62be53
I tried to decode by diff. ways, one of this :
const
KeySize = 24; // 32 bytes = 256 bits 24 - 192
BlockSize = 16; // 16 bytes = 128 bits
function Decrypt(AText:AnsiString):String;
var
Cipher : TDCP_rijndael; i:Integer;
Data, Key, IV,NewStr : ansistring;
begin
// Pad Key and IV with zeros as appropriate
Key := PadWithZeros(ansistring('znwoq8fq0jf2qjve8laper9f'),KeySize);
IV := PadWithZeros(ansistring('1234567890123450'),BlockSize);
// Decode the Base64 encoded string
NewStr:='';
for i:=1 to (Length(AText) div 2) do
NewStr:=NewStr+chr(byte(StrToInt('$'+Copy(AText,(i-1)*2+1,2))));
Data := NewStr;
// Create the cipher and initialise according to the key length
Cipher := TDCP_rijndael.Create(nil);
if Length(ansistring('znwoq8fq0jf2qjve8laper9f')) <= 16 then
Cipher.Init(Key[1],128,#IV[1])
else if Length(ansistring('znwoq8fq0jf2qjve8laper9f')) <= 24 then
Cipher.Init(Key[1],192,#IV[1])
else
Cipher.Init(Key[1],256,#IV[1]);
// Decrypt the data
// Cipher.DecryptCBC(Data[1],Data[1],Length(Data));
Cipher.DecryptECB(Data[1],Data[1]);
// Free the cipher and clear sensitive information
Cipher.Free;
FillChar(Key[1],Length(Key),0);
// Display the result
result:= Data;
end;
but the decoded text is wrong
6d309aab9887deed8da964cca8818eb4
µ€ц‰ъиTDHQ ЮB№еП
Why?
Can someone help? Easy to decode it by http://www.tools4noobs.com/online_tools/decrypt/ withot IV ...
Try to use this
function AESDecrypt(AData, AKey: String): string;
var
KeyByte,Data,Dest:TBytes;
KeyBlock:integer;
Cipher:TDCP_rijndael;
begin
KeyByte:=TEncoding.UTF8.GetBytes(AKey);
while (Length(KeyByte) mod 16 <> 0) do begin
SetLength(KeyByte,Length(KeyByte)+1);
KeyByte[Length(KeyByte)-1]:=0;
end;
SetLength(Data,Length(AData) div 2);
SetLEngth(Dest,Length(AData) div 2);
Data:=GetBytesFromHex(AData);
Cipher:= TDCP_rijndael.Create(nil);
KeyBlock:=192; //by PHP code comment
Cipher.Init(KeyByte[0],KeyBlock,nil); //for ECB method IV is optional
try
for i := 1 to (Length(AData) div 16) do
begin
Cipher.DecryptECB(Data[(i-1)*16],Dest[(i-1)*16]);
end;
finally
Cipher.Burn;
end;
AData:=TEncoding.UTF8.GetString(Dest);
Result:=AData;
end;

Ruby to PHP AES

Im trying to convert some ruby code that encrypts data with AES 265 in CBC mode to php but its not working, the converted php code returns a null string. Here is what i have:
Ruby:
require 'openssl'
module AESCrypt
def self.encrypt(message, password)
Base64.encode64(self.encrypt_data(message.to_s.strip, self.key_digest(password), nil, "AES-256-CBC"))
end
def self.decrypt(message, password)
base64_decoded = Base64.decode64(message.to_s.strip)
self.decrypt_data(base64_decoded, self.key_digest(password), nil, "AES-256-CBC")
end
def self.key_digest(password)
OpenSSL::Digest::SHA256.new(password).digest
end
def self.decrypt_data(encrypted_data, key, iv, cipher_type)
aes = OpenSSL::Cipher::Cipher.new(cipher_type)
aes.decrypt
aes.key = key
aes.iv = iv if iv != nil
aes.update(encrypted_data) + aes.final
end
def self.encrypt_data(data, key, iv, cipher_type)
aes = OpenSSL::Cipher::Cipher.new(cipher_type)
aes.encrypt
aes.key = key
aes.iv = iv if iv != nil
aes.update(data) + aes.final
end
end
And the php code:
echo base64_encode($encrypted_data = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, hash('sha256', 'p4ssw0rd'), 'hey', MCRYPT_MODE_CBC));
have a look at
https://github.com/nirnanaaa/xlix/blob/master/xlix/lib/Xlix/Bundle/Crypto/Aes/TwoLevel.php
I wrote this a while ago for my crypto functions based on a GIST I have found on the web

PHP to Delphi and back Encryption-Decryption using Rijndael

I have problems with decrypting strings sent from PHP to Delphi using the rijndael cipher.
I'm using mcrypt on the PHP side and DCP_rijndael on the Delphi side.
At the moment I have the below code.
PHP:
function encRJ($key, $iv, $data)
{
$r = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $data, MCRYPT_MODE_CBC, $iv);
$r = base64_encode($r);
return $r;
}
And in Delphi:
function decRJ(Data: string; Key: string; IV: string): string;
var ciph: TDCP_rijndael;
begin
Data := Base64DecodeStr(Data);
ciph:= TDCP_rijndael.Create(Self);
ciph.Init(Key[1], 256, #IV[1]);
ciph.DecryptCBC(Data[1], Data[1], Length(Data));
ciph.Free;
Result := Data;
end;
I have tried using several Units on the Internet implementing the cipher, and found out most people are saying about the DCP components. Even so, I haven't managed to make it correctly decrypt. I've tried using Byte arrays for the parameters, AnsiStrings, WideStrings, etc, but unfortunately no luck.
Excuse me if I'm missing something really obvious here, as my mind isn't in good shape atm, after hours of searching for the matter.
I seem to have spent too long on this but...
Your problem is the block size. TDCP_rijndael is equivalent to MCRYPT_RIJNDAEL_128 (not _256). The '256' value in ciph.Init(...) call is still correct though. Other than that it looks pretty much ok. That is, assuming you're using ansistrings for key/iv or you're using non-unicode Delphi.
For unicode Delphi versions I'd be inclined to use TBytes and key[0] / iv[0].
Padding may still be an issue. If so, then here's what I've mangled up based on the PHP manual pages and some trial and error.
PHP:
function Encrypt($src, $key, $iv)
{
$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, 'cbc');
//echo "Block size: " . $block . "\r\n";
$pad = $block - (strlen($src) % $block);
$src .= str_repeat(chr($pad), $pad);
$enc = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $src, MCRYPT_MODE_CBC, $iv);
$r = base64_encode($enc);
return $r;
}
function Decrypt($src, $key, $iv)
{
$enc = base64_decode($src);
$dec = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $enc, MCRYPT_MODE_CBC, $iv);
$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, 'cbc');
$pad = ord($dec[($len = strlen($dec)) - 1]);
return substr($dec, 0, strlen($dec) - $pad);
}
Delphi:
function DecryptData(Data: string; AKey: AnsiString; AIv: AnsiString): string;
var
key, iv, src, dest: TBytes;
cipher: TDCP_rijndael;
slen, pad: integer;
begin
//key := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AKey));
//iv := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AIv));
key := TEncoding.ASCII.GetBytes(AKey);
iv := TEncoding.ASCII.GetBytes(AIv);
src := Base64DecodeBytes(TEncoding.UTF8.GetBytes(Data));
cipher := TDCP_rijndael.Create(nil);
try
cipher.CipherMode := cmCBC;
slen := Length(src);
SetLength(dest, slen);
cipher.Init(key[0], 256, #iv[0]); // DCP uses key size in BITS not BYTES
cipher.Decrypt(src[0], dest[0], slen);
// Remove the padding. Get the numerical value of the last byte and remove
// that number of bytes
pad := dest[slen - 1];
SetLength(dest, slen - pad);
// Base64 encode it
result := TEncoding.Default.GetString(dest);
finally
cipher.Free;
end;
end;
function EncryptData(Data: string; AKey: AnsiString; AIv: AnsiString): string;
var
cipher: TDCP_rijndael;
key, iv, src, dest, b64: TBytes;
index, slen, bsize, pad: integer;
begin
//key := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AKey));
//iv := Base64DecodeBytes(TEncoding.UTF8.GetBytes(AIv));
key := TEncoding.ASCII.GetBytes(AKey);
iv := TEncoding.ASCII.GetBytes(AIv);
src := TEncoding.UTF8.GetBytes(Data);
cipher := TDCP_rijndael.Create(nil);
try
cipher.CipherMode := cmCBC;
// Add padding.
// Resize the Value array to make it a multiple of the block length.
// If it's already an exact multiple then add a full block of padding.
slen := Length(src);
bsize := (cipher.BlockSize div 8);
pad := bsize - (slen mod bsize);
Inc(slen, pad);
SetLength(src, slen);
for index := pad downto 1 do
begin
src[slen - index] := pad;
end;
SetLength(dest, slen);
cipher.Init(key[0], 256, #iv[0]); // DCP uses key size in BITS not BYTES
cipher.Encrypt(src[0], dest[0], slen);
b64 := Base64EncodeBytes(dest);
result := TEncoding.Default.GetString(b64);
finally
cipher.Free;
end;
end;
The PHP and Delphi functions now give me the same answer.
EDIT
Base64DecodeBytes was a bit of code I added to the DCP Base64 unit:
function Base64DecodeBytes(Input: TBytes): TBytes;
var
ilen, rlen: integer;
begin
ilen := Length(Input);
SetLength(result, (ilen div 4) * 3);
rlen := Base64Decode(#Input[0], #result[0], ilen);
// Adjust the length of the output buffer according to the number of valid
// b64 characters
SetLength(result, rlen);
end;
EDIT 2018 (Raising the dead...):
As requested, here is the encoding method, unchecked and pulled straight from an old source file I found.
DISCLAIMER: It is many years old and untested in recent memory and not used since Delphi 2010. There are probably many better alternatives now. Use at your own risk.
function Base64EncodeBytes(Input: TBytes): TBytes;
var
ilen: integer;
begin
ilen := Length(Input);
SetLength(result, ((ilen + 2) div 3) * 4);
Base64Encode(#Input[0], #result[0], ilen);
end;
Neither your PHP nor your Delphi methods appear to specify any padding. If the default paddings are different then you will get problems. Explicitly specify PKCS7 (or PKCS5) for both.
GregS' comment about the result of decoding Base64 is correct. You are supplying encrypted cyphertext to your decRJ() method. That will be random appearing bytes. Attempting to convert it to UTF-8 will mangle it enough that it cannot be decrypted. The incoming cyphertext must be converted from Base64 direct to a byte array. Cyphertext is not a character string, which is why it needs to be converted to Base64 to be transmitted as text. It will only be text again after it has been decrypted back to plaintext.

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