EXC_BAD_ACCESS 2 code on CCCrypt

Question

I am trying to use encryption DESto encrypt passwords (do not ask why DES, I know that it is less secure). This is my first time doing this on iOS, so I had to rely on another post on how to do this.

When I run the encryption, it returns null, the same with decrypting the already encrypted string (I used the online encryption tool). When I set a breakpoint to see what was happening, she stopped at CCCrypt, pointing EXC_BAD_ACCESS (Code 2).

I tried to use different CCOptions, but it always returns the same. Any hint what is going wrong? Is iv string required?

I used the following NSString category to encrypt or decrypt strings -

#import "NSString+DES.h"

@implementation NSString(DES)

- (NSString*) encryptDES: (NSString *) key
{
    const void *vplainText;
    size_t plainTextBufferSize;

    plainTextBufferSize = [self length];
    vplainText = (const void *) [self UTF8String];

    CCCryptorStatus ccStatus;
    uint8_t *bufferPtr = NULL;
    size_t bufferPtrSize = 0;
    size_t *movedBytes;

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
    memset((void *)bufferPtr, 0x0, bufferPtrSize);
    // memset((void *) iv, 0x0, (size_t) sizeof(iv));


    //NSString *initVec = @"init Vec";
    const void *vkey = (const void *) [key UTF8String];
    //const void *vinitVec = (const void *) [initVec UTF8String];

    ccStatus = CCCrypt(kCCEncrypt,
                       kCCAlgorithmDES,
                       kCCOptionPKCS7Padding | kCCOptionECBMode,
                       vkey,
                       kCCKeySizeDES,
                       NULL,
                       vplainText,
                       plainTextBufferSize,
                       (void *)bufferPtr,
                       bufferPtrSize,
                       movedBytes);

    NSString *result;
    NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];
    result = [myData base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    return result;
}

- (NSString *) decryptDES: (NSString *) key
{
    const void *vplainText;
    size_t plainTextBufferSize;

    plainTextBufferSize = [self length];
    vplainText = (const void *) [self UTF8String];

    CCCryptorStatus ccStatus;
    uint8_t *bufferPtr = NULL;
    size_t bufferPtrSize = 0;
    size_t *movedBytes;

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
    memset((void *)bufferPtr, 0x0, bufferPtrSize);
    // memset((void *) iv, 0x0, (size_t) sizeof(iv));


    //NSString *initVec = @"init Vec";
    const void *vkey = (const void *) [key UTF8String];
    //const void *vinitVec = (const void *) [initVec UTF8String];

    ccStatus = CCCrypt(kCCDecrypt,
                       kCCAlgorithmDES,
                       kCCOptionPKCS7Padding | kCCOptionECBMode,
                       vkey, //"123456789012345678901234", //key
                       kCCKeySizeDES,
                       NULL,// vinitVec, //"init Vec", //iv,
                       vplainText, //"Your Name", //plainText,
                       plainTextBufferSize,
                       (void *)bufferPtr,
                       bufferPtrSize,
                       movedBytes);

    NSString *result;
    NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];
    result = [myData base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    return result;
}

@end

Update:

, , .

, YourName 12345 , Fu2sK61e7l5rkXRhAKjPWA== , +54qWCYTB5LkdARDZjAow==, YourName.

:

#import "NSString+DES.h"

@implementation NSString(DES)

- (NSString*) encryptDES: (NSString *) key
{
    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
    NSData *stringData = [self dataUsingEncoding:NSUTF8StringEncoding];
    size_t numBytesEncrypted = 0;
    size_t bufferSize = stringData.length + kCCBlockSizeDES;
    void *buffer = malloc(bufferSize);

    CCCryptorStatus result = CCCrypt( kCCEncrypt, kCCAlgorithmDES, kCCOptionPKCS7Padding,
                                     keyData.bytes, kCCKeySizeDES,
                                     NULL,
                                     stringData.bytes, stringData.length,
                                     buffer, bufferSize,
                                     &numBytesEncrypted);
    NSData *output = [NSData dataWithBytes:buffer length:numBytesEncrypted];
    free(buffer);
    if( result == kCCSuccess )
    {
        NSString *resultStr = [output base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
        return resultStr;
    } else {
        NSLog(@"Failed DES encrypt...");
        return nil;
    }

}

- (NSString *) decryptDES: (NSString *) key
{
    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
    NSData *stringData = [[NSData alloc] initWithBase64EncodedString:self options:0];

    size_t numBytesEncrypted = 0;
    size_t bufferSize = stringData.length + kCCBlockSizeDES;
    void *buffer = malloc(bufferSize);

    CCCryptorStatus result = CCCrypt( kCCDecrypt, kCCAlgorithmDES, kCCOptionPKCS7Padding,
                                     keyData.bytes, kCCKeySizeDES,
                                     NULL,
                                     stringData.bytes, stringData.length,
                                     buffer, bufferSize,
                                     &numBytesEncrypted);
    NSData *output = [NSData dataWithBytes:buffer length:numBytesEncrypted];
    free(buffer);
    if( result == kCCSuccess )
    {
        NSString *resultStr = [output base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
        return resultStr;
    } else {
        NSLog(@"Failed DES decrypt...");
        return nil;
    }
}

@end

Answer 1

, DES 3DES, , - 3DES (24 ). 8 . kCCBlockSizeDES, , .

:

- (NSString *) decryptDES: (NSString *) key

, movedBytes , . :

size_t movedBytes;

movedBytes CCCrypt &movedBytes.

:

: " "
key: "12345678"

moveBytes: 16
myData: 136142f6 6cd98e01 af1eef46 28d36499
: E2FC9mzZjgGvHu9GKNNkmQ ==

:

ECB iv.

8 DES, undefined. 5 , 8- (kCCKeySizeDES), , keyData.

ECB, CBC. kCCOptionECBMode.

Base64, NSString:

NSString * resultStr = [[NSString alloc] initWithData:output encoding:NSUTF8StringEncoding];  

-, php mcrypt, , mcrypt PKCS # 7, .