Encryption result is different on Android and IOS

[CDNRahulSonpaliya]

Hello,

I am using this library in my android project and its counter part https://github.com/Gurpartap/aescrypt in ios project. I am encrypting same text with same encryption key, but it is giving me different results on ios and android.

I am using this key : 25c35734b1ef623ca2a7f730cf2fea8b790739ba

String to encrypt is : Password

Encrypted String IOS : W3LyAxKq2+QdDBfKUGVgTg==
Encrypted String Android : zdgSimKva1jblici7F8DGw==

[Rahulgupta-cdnsol]

Hi,

I am getting same issue with library as it is not generating same result as iOS.What needs to do to get similar result as iOS.

[ninjatrench]

Hi, I can look into it.
Can you post the IV used by you in Android as well as iOS as iOS directly doesn't take blank IV

[Rahulgupta-cdnsol]

in IOS I am using below function :

• (NSData *)doCipher:(NSData *)plainText key:(NSData *)aSymmetricKey
  context:(CCOperation)encryptOrDecrypt padding:(CCOptions *)pkcs7{
  CCCryptorStatus ccStatus = kCCSuccess;
  // Symmetric crypto reference.
  CCCryptorRef thisEncipher = NULL;
  // Cipher Text container.
  NSData * cipherOrPlainText = nil;
  // Pointer to output buffer.
  uint8_t * bufferPtr = NULL;
  // Total size of the buffer.
  size_t bufferPtrSize = 0;
  // Remaining bytes to be performed on.
  size_t remainingBytes = 0;
  // Number of bytes moved to buffer.
  size_t movedBytes = 0;
  // Length of plainText buffer.
  size_t plainTextBufferSize = 0;
  // Placeholder for total written.
  size_t totalBytesWritten = 0;
  // A friendly helper pointer.
  uint8_t * ptr;

  // Initialization vector; dummy in this case 0's.
  uint8_t iv[kChosenCipherBlockSize];
  memset((void *) iv, 0x0, (size_t) sizeof(iv));

  // //NSLog(@"doCipher: plaintext: %@", plainText);
  // //NSLog(@"doCipher: key length: %d", [aSymmetricKey length]);

  plainTextBufferSize = [plainText length];

  if(encryptOrDecrypt == kCCEncrypt) {
  if(*pkcs7 != kCCOptionECBMode) {
  if((plainTextBufferSize % kChosenCipherBlockSize) == 0) {
  *pkcs7 = 0x0000;
  } else {
  *pkcs7 = kCCOptionPKCS7Padding;
  }
  }
  } else if(encryptOrDecrypt != kCCDecrypt) {
  //NSLog(@"Invalid CCOperation parameter [%d] for cipher context.", *pkcs7 );
  }

  // Create and Initialize the crypto reference.
  ccStatus = CCCryptorCreate(encryptOrDecrypt,
  kCCAlgorithmAES128,
  *pkcs7,
  (const void *)[aSymmetricKey bytes],
  kChosenCipherKeySize,
  (const void *)iv,
  &thisEncipher
  );

  //LOGGING_FACILITY1( ccStatus == kCCSuccess, @"Problem creating the context, ccStatus == %d.", ccStatus );

  // Calculate byte block alignment for all calls through to and including final.
  bufferPtrSize = CCCryptorGetOutputLength(thisEncipher, plainTextBufferSize, true);

  // Allocate buffer.
  bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t) );

  // Zero out buffer.
  memset((void *)bufferPtr, 0x0, bufferPtrSize);

  // Initialize some necessary book keeping.

  ptr = bufferPtr;

  // Set up initial size.
  remainingBytes = bufferPtrSize;

  // Actually perform the encryption or decryption.
  ccStatus = CCCryptorUpdate(thisEncipher,
  (const void *) [plainText bytes],
  plainTextBufferSize,
  ptr,
  remainingBytes,
  &movedBytes
  );

  //LOGGING_FACILITY1( ccStatus == kCCSuccess, @"Problem with CCCryptorUpdate, ccStatus == %d.", ccStatus );

  // Handle book keeping.
  ptr += movedBytes;
  remainingBytes -= movedBytes;
  totalBytesWritten += movedBytes;

  /* From CommonCryptor.h:

  @enum CCCryptorStatus
  @abstract Return values from CommonCryptor operations.

  @constant kCCSuccess Operation completed normally.
  @constant kCCParamError Illegal parameter value.
  @constant kCCBufferTooSmall Insufficent buffer provided for specified operation.
  @constant kCCMemoryFailure Memory allocation failure.
  @constant kCCAlignmentError Input size was not aligned properly.
  @constant kCCDecodeError Input data did not decode or decrypt properly.
  @constant kCCUnimplemented Function not implemented for the current algorithm.

  enum {
  kCCSuccess = 0,
  kCCParamError = -4300,
  kCCBufferTooSmall = -4301,
  kCCMemoryFailure = -4302,
  kCCAlignmentError = -4303,
  kCCDecodeError = -4304,
  kCCUnimplemented = -4305
  };
  typedef int32_t CCCryptorStatus;
  */

  // Finalize everything to the output buffer.
  ccStatus = CCCryptorFinal(thisEncipher,
  ptr,
  remainingBytes,
  &movedBytes
  );

  totalBytesWritten += movedBytes;

  if(thisEncipher) {
  (void) CCCryptorRelease(thisEncipher);
  thisEncipher = NULL;
  }

  //LOGGING_FACILITY1( ccStatus == kCCSuccess, @"Problem with encipherment ccStatus == %d", ccStatus );

  if (ccStatus == kCCSuccess)
  cipherOrPlainText = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)totalBytesWritten];
  else
  cipherOrPlainText = nil;

  if(bufferPtr) free(bufferPtr);

  return cipherOrPlainText;

}
Android :- byte[] ivBytes = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};