I need to encrypt a string on the iPhone and send it to a .Net for decryption using Triple DES. I am able to encrypt/decrypt on the iPhone and with .Net, but I get different results in both platforms.
I use the very same code as the encryption/decryption with AES between .Net and iPhone in here
The only thing that I changed .net is the encryption algorithm, so where it says AesCryptoServiceProvider, I put TripleDesServiceProvider
As in .net the only thing that I changed is the encryption algorithm, so where it says kCCAlgorithmAES128, I put kCCAlgorithm3DES
What am I missing?
[UPDATE]
Thanks for your responses.
If I stay in the same platform I can encrypt/decrypt without a problem, but if I encrypt in iPhone and decrypt in .net there is a problem because in each platform has different results with the same inputs.
As Overslacked said I think the problem has to do with salt, but I couldn't find any sha or md5 documentation that the algorithm is using in each platform, or any parameter to customize this.
Here is the code that I am actually using in iPhone:
int main(int argc, char *argv[]){
NSString * _secret = @"hello";
NSString * _key = @"1234567890";
_out = [self doCipher:_secret key:_key context:kCCEncrypt];
NSLog(@"encrypted data in str: %@", _out);
_outDecrypted = [StringEncryption doCipher:_out key:_key context:kCCDecrypt];
NSLog(@"decrypted data in str: %@", _outDecrypted);
}
+ (NSString *)doCipher:(NSString *)sTextIn key:(NSString *)sKey
context:(CCOperation)encryptOrDecrypt {
NSMutableData * dTextIn;
if (encryptOrDecrypt == kCCDecrypt) {
dTextIn = [[[NSData alloc] base64DecodeString:sTextIn ]mutableCopy];
}
else{
dTextIn = [[sTextIn dataUsingEncoding: NSASCIIStringEncoding]mutableCopy];
}
NSMutableData * dKey = [[sKey dataUsingEncoding:NSASCIIStringEncoding]mutableCopy];
[dKey setLength:24];
uint8_t *bufferPtr1 = NULL;
size_t bufferPtrSize1 = 0;
size_t movedBytes1 = 0;
uint8_t iv[kCCBlockSize3DES];
memset((void *) iv, 0x0, (size_t) sizeof(iv));
bufferPtrSize1 = ([sTextIn length] + kCCBlockSize3DES) & ~(kCCBlockSize3DES -1);
bufferPtr1 = malloc(bufferPtrSize1 * sizeof(uint8_t));
memset((void *)bufferPtr1, 0x00, bufferPtrSize1);
ccStatus = CCCrypt(encryptOrDecrypt, // CCOperation op
kCCAlgorithm3DES, // CCAlgorithm alg
kCCOptionPKCS7Padding, // CCOptions options
[dKey bytes], // const void *key
[dKey length], // size_t keyLength
iv, // const void *iv
[dTextIn bytes], // const void *dataIn
[dTextIn length], // size_t dataInLength
(void *)bufferPtr1, // void *dataOut
bufferPtrSize1, // size_t dataOutAvailable
&movedBytes1); // size_t *dataOutMoved
NSString * sResult;
if (encryptOrDecrypt == kCCDecrypt){
sResult = [[[ NSString alloc] initWithData:[NSData dataWithBytes:bufferPtr1
length:movedBytes1] encoding:NSASCIIStringEncoding] autorelease];
}
else {
NSData *dResult = [NSData dataWithBytes:bufferPtr1 length:movedBytes1];
sResult = [dResult base64EncodeData:dResult];
}
return sResult;
}
Here is the code that I am using for .net
class Program
{
static void Main(string[] args)
{
string key = "1234567890";
string secret = "hello";
string crypto = EncryptedString.EncryptString(secret, key);
Console.WriteLine(crypto);
secret = EncryptedString.DecryptString(crypto, key);
Console.WriteLine(secret);
Main(null);
}
}
public class EncryptedString
{
public static string EncryptString(string plainSourceStringToEncrypt, string passPhrase)
{
//Set up the encryption objects
using (TripleDESCryptoServiceProvider acsp = GetProvider(Encoding.ASCII.GetBytes(passPhrase)))
{
byte[] sourceBytes = Encoding.ASCII.GetBytes(plainSourceStringToEncrypt);
ICryptoTransform ictE = acsp.CreateEncryptor();
//Set up stream to contain the encryption
MemoryStream msS = new MemoryStream();
//Perform the encrpytion, storing output into the stream
CryptoStream csS = new CryptoStream(msS, ictE, CryptoStreamMode.Write);
csS.Write(sourceBytes, 0, sourceBytes.Length);
csS.FlushFinalBlock();
//sourceBytes are now encrypted as an array of secure bytes
byte[] encryptedBytes = msS.ToArray(); //.ToArray() is important, don't mess with the buffer
String b64 = System.Text.ASCIIEncoding.ASCII.GetString(encryptedBytes);
return Convert.ToBase64String(encryptedBytes);
}
}
public static string DecryptString(string base64StringToDecrypt, string passphrase)
{
//Set up the encryption objects
using (TripleDESCryptoServiceProvider acsp = GetProvider(Encoding.Default.GetBytes(passphrase)))
{
byte[] RawBytes = Convert.FromBase64String(base64StringToDecrypt);
ICryptoTransform ictD = acsp.CreateDecryptor();
MemoryStream msD = new MemoryStream(RawBytes, 0, RawBytes.Length);
CryptoStream csD = new CryptoStream(msD, ictD, CryptoStreamMode.Read);
return (new StreamReader(csD)).ReadToEnd();
}
}
private static TripleDESCryptoServiceProvider GetProvider(byte[] key)
{
TripleDESCryptoServiceProvider result = new TripleDESCryptoServiceProvider();
result.Mode = CipherMode.CBC;
result.Padding = PaddingMode.PKCS7;
result.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0 };
result.Key = key;
return result;
}
}
