I'm trying do some encrypt something using 3des on the iphone that must match the results from java and .NET.
the code i have is:
+ (NSString*) doCipher:(NSString*)plainText:(CCOperation)encryptOrDecrypt {
const void *vplainText;
size_t plainTextBufferSize;
if (encryptOrDecrypt == kCCDecrypt)
{
NSData *EncryptData = [NSData dataWithBase64EncodedString:plainText];
plainTextBufferSize = [EncryptData length];
vplainText = [EncryptData bytes];
}
else
{
NSData *tempData = [plainText dataUsingEncoding:NSASCIIStringEncoding];
plainTextBufferSize = [tempData length];
vplainText = [tempData bytes];
}
CCCryptorStatus ccStatus;
uint8_t *bufferPtr = NULL;
size_t bufferPtrSize = 0;
size_t movedBytes = 0;
// uint8_t ivkCCBlockSize3DES;
bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
memset((void *)bufferPtr, 0x0, bufferPtrSize);
NSString *key = [NSString MD5:@"HSDNIFFU"];
NSData *_keyData = [key dataUsingEncoding:NSASCIIStringEncoding];
NSLog(@"key byte is %s", [_keyData bytes]);
// Initialization vector; dummy in this case 0's.
uint8_t iv[kCCBlockSize3DES];
memset((void *) iv, 0x0, (size_t) sizeof(iv));
ccStatus = CCCrypt(encryptOrDecrypt,
kCCAlgorithm3DES,
kCCOptionPKCS7Padding,
(const void *)[_keyData bytes], //"123456789012345678901234", //key
kCCKeySize3DES,
iv, //iv,
vplainText, //plainText,
plainTextBufferSize,
(void *)bufferPtr,
bufferPtrSize,
&movedBytes);
//if (ccStatus == kCCSuccess) NSLog(@"SUCCESS");
/*else*/ if (ccStatus == kCCParamError) return @"PARAM ERROR";
else if (ccStatus == kCCBufferTooSmall) return @"BUFFER TOO SMALL";
else if (ccStatus == kCCMemoryFailure) return @"MEMORY FAILURE";
else if (ccStatus == kCCAlignmentError) return @"ALIGNMENT";
else if (ccStatus == kCCDecodeError) return @"DECODE ERROR";
else if (ccStatus == kCCUnimplemented) return @"UNIMPLEMENTED";
NSString *result;
if (encryptOrDecrypt == kCCDecrypt)
{
// result = [[NSString alloc] initWithData: [NSData dataWithBytes:(const void *)bufferPtr length:[(NSUInteger)movedBytes] encoding:NSASCIIStringEncoding]];
result = [[[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes] encoding:NSASCIIStringEncoding] autorelease];
}
else
{
NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];
NSLog(@"data is: %@", myData);
result = [myData base64Encoding];
}
return result;
}
This code successfully encrypts and decrypts a string. As you can see, it uses md5 on the key. However, it does not match the results from .NET and java.
The java code from the java developer looks like:
public static byte[] encryptTripleDES(String message) throws Exception {
final MessageDigest md = MessageDigest.getInstance("md5");
final byte[] digestOfPassword = md.digest("--KEY--".getBytes("utf-8"));
final SecretKey key = new SecretKeySpec(digestOfPassword, "DESede");
final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
final Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, iv);
return cipher.doFinal(message.getBytes("utf-8"));
}
Unfortunately I'm not too familiar with java encryption. I did notice that after using md5 on the KEY it creates a SecretKey with the method SecretKeySpec. My Java developer told me that he needed to create a secretkey using the byte array of the key so that it could match the .NET key.
Can anyone explain this better to me and help me with a solution to match the results of the .NET and java counterparts?