Click here to Skip to main content
Rate this: bad
good
Please Sign up or sign in to vote.
I have tried to generate an encrypted text using AES algorithm In both ( Android and IPhone ) platforms but the problem is even I use the same encryption decryption algorithm (AES-128) and I use the same fixed variables ( Key , IV ,mode) but I get two deferent result for them.

I appreciate any help .

The below code presents the used encryption and decryption methods ,
Code version for Android:
- Key = “123456789abcdefg” ;
 - IV   = “1111111111111111” ;
 - Plain text = “HelloThere”;
 - Mode = “AES/CBC/NoPadding” ;

Code :
public class Crypto {
    public static String encrypt(String seed, String cleartext) throws Exception {
            byte[] rawKey = getRawKey(seed.getBytes());
            byte[] result = encrypt(rawKey, cleartext.getBytes());
            return toHex(result);
    }
    public static String decrypt(String seed, String encrypted) throws Exception {
            byte[] rawKey = getRawKey(seed.getBytes());
            byte[] enc = toByte(encrypted);
            byte[] result = decrypt(rawKey, enc);
            return new String(result);
    }
    private static byte[] getRawKey(byte[] seed) throws Exception {
            KeyGenerator kgen = KeyGenerator.getInstance(“CBC”);
            SecureRandom sr = SecureRandom.getInstance(“SHA1PRNG”);
            sr.setSeed(seed);
        kgen.init(128, sr); // 192 and 256 bits may not be available
        SecretKey skey = kgen.generateKey();
        byte[] raw = skey.getEncoded();
        return raw;
    }
    private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, “AES”);
            Cipher cipher = Cipher.getInstance(“AES”);
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal(clear);
            return encrypted;
    }
    private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, “AES”);
            Cipher cipher = Cipher.getInstance(“AES”);
        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
        byte[] decrypted = cipher.doFinal(encrypted);
            return decrypted;
    }
    public static String toHex(String txt) {
            return toHex(txt.getBytes());
    }
    public static String fromHex(String hex) {
            return new String(toByte(hex));
    }
    public static byte[] toByte(String hexString) {
            int len = hexString.length()/2;
            byte[] result = new byte[len];
            for (int i = 0; i < len; i++)
                    result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();
            return result;
    }
    public static String toHex(byte[] buf) {
            if (buf == null)
                    return “”;
            StringBuffer result = new StringBuffer(2*buf.length);
            for (int i = 0; i < buf.length; i++) {
                    appendHex(result, buf[i]);
            }
            return result.toString();
    }
    private final static String HEX = “0123456789ABCDEF”;
    private static void appendHex(StringBuffer sb, byte b) {
            sb.append(HEX.charAt((b»4)&0x0f)).append(HEX.charAt(b&0x0f));
    }
}
Code version for IPhone:
 
- (NSData *) transform:(CCOperation) encryptOrDecrypt data:(NSData *) inputData {
 
    NSData* secretKey = [Cipher md5:cipherKey];
    
    CCCryptorRef cryptor = NULL;
    CCCryptorStatus status = kCCSuccess;
    
    uint8_t iv[kCCBlockSizeAES128];
    memset((void *) iv, 0x0, (size_t) sizeof(iv));
    
    status = CCCryptorCreate(encryptOrDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                             [secretKey bytes], kCCKeySizeAES128, iv, &cryptor);
    
    if (status != kCCSuccess) {
        return nil;
    }
    
    size_t bufsize = CCCryptorGetOutputLength(cryptor, (size_t)[inputData length], true);
    
    void * buf = malloc(bufsize * sizeof(uint8_t));
    memset(buf, 0x0, bufsize);
    
    size_t bufused = 0;
    size_t bytesTotal = 0;
    
    status = CCCryptorUpdate(cryptor, [inputData bytes], (size_t)[inputData length],
                             buf, bufsize, &bufused);
    
    if (status != kCCSuccess) {
        free(buf);
        CCCryptorRelease(cryptor);
        return nil;
    }
    
    bytesTotal += bufused;
    
    status = CCCryptorFinal(cryptor, buf + bufused, bufsize - bufused, &bufused);
    
    if (status != kCCSuccess) {
        free(buf);
        CCCryptorRelease(cryptor);
        return nil;
    }
    
    bytesTotal += bufused;
    
    CCCryptorRelease(cryptor);
    
    return [NSData dataWithBytesNoCopy:buf length:bytesTotal];
}
 
+ (NSData *) md5:(NSString *) stringToHash {
    
    const char *src = [stringToHash UTF8String];
    
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    
    CC_MD5(src, strlen(src), result);
    
    return [NSData dataWithBytes:result length:CC_MD5_DIGEST_LENGTH];
}

Some of my references :

- http://automagical.rationalmind.net/2009/02/12/aes-interoperability-between-net-and-iphone/[^]
- http://stackoverflow.com/questions/538435/aes-interoperability-between-net-and-iphone/[^]
- http://stackoverflow.com/questions/538435/aes-interoperability-between-net-and-iphone[^]
- http://www.example-code.com/objc/rsa_encryptKey.asp[^]
- http://stackoverflow.com/questions/10031137/cccrypt-encryption-result-issue[^]
- http://stackoverflow.com/questions/10631076/how-to-encrypt-the-nsstring-value-using-des-in-iphone[^]
- http://www.code2learn.com/2011/06/encryption-and-decryption-of-data-using.html[^]
- http://code.google.com/p/aes-encryption-samples/wiki/HowToEncryptWithJava[^]
Posted 3-Nov-12 22:56pm
Edited 3-Nov-12 23:21pm
(no name)498.5K
v2
Comments
Sergey Alexandrovich Kryukov at 4-Nov-12 12:46pm
   
My 5 just for accurate formulation of the problem. These days, this is extremely rare case in CodeProject Questions & Answers, unfortunately.
--SA
MZ-Zyadat at 6-Nov-12 4:39am
   
I have posted this question after a lot of searches regarding this issue hoping i can find the proper answer here.
 
Thank you for your feedback

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)



Advertise | Privacy | Mobile
Web02 | 2.8.1411022.1 | Last Updated 6 Nov 2012
Copyright © CodeProject, 1999-2014
All Rights Reserved. Terms of Service
Layout: fixed | fluid

CodeProject, 503-250 Ferrand Drive Toronto Ontario, M3C 3G8 Canada +1 416-849-8900 x 100