Hi,
i am generating the key and encryting the data using 3DES algorithm,
My code work for only particular string "this is some secret labs" or "this is some secret test".
If i change the string it does not work throught the exception "'Problem with encipherment ccStatus == -4301'"
my code is here please anyone tell me what is the problem and it is catching exception in ccStatus = CCCryptorFinal(thisEncipher,
ptr,
remainingBytes,
&movedBytes
);
please help me following is my code
- (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: %@", [[NSString alloc]initWithData
lainText encoding:NSASCIIStringEncoding]);
NSLog(@"doCipher: key length: %d", [aSymmetricKey length]);
LOGGING_FACILITY(plainText != nil, @"PlainText object cannot be nil." );
LOGGING_FACILITY(aSymmetricKey != nil, @"Symmetric key object cannot be nil." );
LOGGING_FACILITY(pkcs7 != NULL, @"CCOptions * pkcs7 cannot be NULL." );
// LOGGING_FACILITY([aSymmetricKey length] == kChosenCipherKeySize, @"Disjoint choices for key size." );// prathibha since error was coming
plainTextBufferSize = [plainText length];
LOGGING_FACILITY(plainTextBufferSize > 0, @"Empty plaintext passed in." );
NSLog(@"pkcs7: %d", *pkcs7);
// We don't want to toss padding on if we don't need to
if(encryptOrDecrypt == kCCEncrypt) {
if(*pkcs7 != kCCOptionECBMode) {
if((plainTextBufferSize % kChosenCipherBlockSize) == 0) {
*pkcs7 = 0x0000;
} else {
*pkcs7 = kCCAlgorithm3DES;
}
}
} else if(encryptOrDecrypt != kCCDecrypt) {
LOGGING_FACILITY1( 0, @"Invalid CCOperation parameter [%d] for cipher context.", *pkcs7 );
}
// Create and Initialize the crypto reference.
ccStatus = CCCryptorCreate(encryptOrDecrypt,
kCCAlgorithm3DES,
*pkcs7,
(const void *)[aSymmetricKey bytes],
kChosenCipherKeySize * 3,
(const void * )iv,
&thisEncipher
);
NSLog(@"1111 %d",ccStatus);
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);
// bufferPtrSize = ([plainText length] + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
NSLog(@"size is %ld",bufferPtrSize);
// 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;
NSLog(@"value of ptr is %lu",ptr);
NSLog(@"value of remaining byte is %lu",remainingBytes);
NSLog(@"value of movedbyte is %lu",movedBytes);
// Actually perform the encryption or decryption.
ccStatus = CCCryptorUpdate(thisEncipher,
(const void *) [plainText bytes],
plainTextBufferSize,
ptr,
remainingBytes,
&movedBytes
);
NSLog(@"2222 %d",ccStatus);
NSLog(@"value of movedbyte is %lu",movedBytes);
LOGGING_FACILITY1( ccStatus == kCCSuccess, @"Problem with CCCryptorUpdate, ccStatus == %d.", ccStatus );
// Handle book keeping.
ptr += movedBytes;//16 = MovedBytes
NSLog(@"value of ptr is %lu",ptr);
NSLog(@"value of movedbytes 1111 is %lu",movedBytes);
remainingBytes -= movedBytes;
NSLog(@"value of remaining byte is %lu",remainingBytes);
NSLog(@"value of movedbytes 2222 is %lu",movedBytes);
totalBytesWritten += movedBytes;
NSLog(@"value of totoalbytes is %lu",totalBytesWritten);
NSLog(@"value of movedbytes 333 is %lu",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
);
NSLog(@"3333 %d",ccStatus);
// totalBytesWritten += movedBytes;
NSLog(@"11111111111 %lu",totalBytesWritten);
NSLog(@"222222 %lu",movedBytes);
if(thisEncipher) {
(void) CCCryptorRelease(thisEncipher);
thisEncipher = NULL;
}
LOGGING_FACILITY1( ccStatus == kCCSuccess, @"Problem with encipherment ccStatus == %d", ccStatus );//here crashing
if (ccStatus == kCCSuccess)
cipherOrPlainText = [NSData dataWithBytes
const void *)bufferPtr length
NSUInteger)totalBytesWritten];
else
cipherOrPlainText = nil;
if(bufferPtr) free(bufferPtr);
return cipherOrPlainText;
/*
Or the corresponding one-shot call:
ccStatus = CCCrypt( encryptOrDecrypt,
kCCAlgorithmAES128,
typeOfSymmetricOpts,
(const void *)[self getSymmetricKeyBytes],
kChosenCipherKeySize,
iv,
(const void *) [plainText bytes],
plainTextBufferSize,
(void *)bufferPtr,
bufferPtrSize,
&movedBytes
);
*/
}
symmetric key algorithm
Linear Mode
