jagadeesh karri jagadeesh karri - 25 days ago 14
iOS Question

AES/cbc/pkcs5padding encription IOS

I have used AES algorithm for encryption in android.
The following code we have used for encryption.

String seed = "somekey";
Key key = null;
// 128 bit key
byte[] byteKey = seed.substring(0, 16).getBytes("UTF-8");
key = new SecretKeySpec(byteKey, "AES");

Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(
new byte[16]));
byte[] encValue = cipher.doFinal(pValue.getBytes());
encryptedText = new BASE64Encoder().encode(encValue);


Can any one please provide the above logic for IOS.

Thanking in Advance.

Answer

You can use the following snippet as start point:

+ (NSData*)encryptData:(NSData*)data key:(NSData*)key iv:(NSData*)iv;
{
    NSData* result = nil;

    // setup key
    unsigned char cKey[FBENCRYPT_KEY_SIZE];
    bzero(cKey, sizeof(cKey));
    [key getBytes:cKey length:FBENCRYPT_KEY_SIZE];

    // setup iv
    char cIv[FBENCRYPT_BLOCK_SIZE];
    bzero(cIv, FBENCRYPT_BLOCK_SIZE);
    if (iv) {
        [iv getBytes:cIv length:FBENCRYPT_BLOCK_SIZE];
    }

    // setup output buffer
    size_t bufferSize = [data length] + FBENCRYPT_BLOCK_SIZE;
    void *buffer = malloc(bufferSize);

    // do encrypt
    size_t encryptedSize = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          FBENCRYPT_ALGORITHM,
                                          kCCOptionPKCS7Padding,
                                          cKey,
                                          FBENCRYPT_KEY_SIZE,
                                          cIv,
                                          [data bytes],
                                          [data length],
                                          buffer,
                                          bufferSize,
                                          &encryptedSize);
    if (cryptStatus == kCCSuccess) {
        result = [NSData dataWithBytesNoCopy:buffer length:encryptedSize];
    } else {
        free(buffer);
        NSLog(@"[ERROR] failed to encrypt|CCCryptoStatus: %d", cryptStatus);
    }

    return result;
}

+ (NSData*)decryptData:(NSData*)data key:(NSData*)key iv:(NSData*)iv;
{
    NSData* result = nil;

    // setup key
    unsigned char cKey[FBENCRYPT_KEY_SIZE];
    bzero(cKey, sizeof(cKey));
    [key getBytes:cKey length:FBENCRYPT_KEY_SIZE];

    // setup iv
    char cIv[FBENCRYPT_BLOCK_SIZE];
    bzero(cIv, FBENCRYPT_BLOCK_SIZE);
    if (iv) {
        [iv getBytes:cIv length:FBENCRYPT_BLOCK_SIZE];
    }

    // setup output buffer
    size_t bufferSize = [data length] + FBENCRYPT_BLOCK_SIZE;
    void *buffer = malloc(bufferSize);

    // do decrypt
    size_t decryptedSize = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          FBENCRYPT_ALGORITHM,
                                          kCCOptionPKCS7Padding,
                                          cKey,
                                          FBENCRYPT_KEY_SIZE,
                                          cIv,
                                          [data bytes],
                                          [data length],
                                          buffer,
                                          bufferSize,
                                          &decryptedSize);

    if (cryptStatus == kCCSuccess) {
        result = [NSData dataWithBytesNoCopy:buffer length:decryptedSize];
    } else {
        free(buffer);
        NSLog(@"[ERROR] failed to decrypt| CCCryptoStatus: %d", cryptStatus);
    }

    return result;
}

Constants

#define FBENCRYPT_ALGORITHM     kCCAlgorithmAES128
#define FBENCRYPT_BLOCK_SIZE    kCCBlockSizeAES128
#define FBENCRYPT_KEY_SIZE      kCCKeySizeAES256

For more information, see FBEncryptor

Hope this helps.

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