QuickHash Library

C++ Interface

CHMAC::Calculate

static void Calculate( unsigned char* pDest, const unsigned char* pSrc, unsigned int nSrcLength, const unsigned char* pKey, unsigned int nKeyLength = DEFAULTKEYLEN );

static void Calculate( unsigned char* pDest, const char* pSrc, const char* pKey );

Parameters

 pDest

    [out] Pointer to the memory buffer that will receive the HMAC.

  pSrc

    [in]

    In the first case - pointer to the continuous memory block for which to calculate the HMAC.

    In the second case - pointer to the null-terminated string for which to calculate the HMAC.

 nSrcLength

    [in] Length in bytes of the memory block.

 pKey

    [in]

    In the first case - pointer to the continuous memory block used as the key.

    In the second case - pointer to the null-terminated string used as the key.

 nKeyLength

    [in] Length in bytes of the key.

Remarks

• static void Calculate( unsigned char* pDest, const unsigned char* pSrc, unsigned int nSrcLength, const unsigned char* pKey, unsigned int nKeyLength = DEFAULTKEYLEN );

Calculates the HMAC for the memory block pointed by pSrc using the key using the key which is a memory block pointed by pKey.

• static void Calculate( unsigned char* pDest, const char* pSrc, const char* pKey );

Calculates the HMAC for the null-terminated string pointed by pSrc using the key which is a null-terminated string pointed by pKey.

The HMAC is retrieved in the memory buffer pointed by pDest. The size of the memory buffer pointed by pDest must be at least CHMAC<T>::DIGESTSIZE bytes. For example, the size of the memory buffer pointed by pDest must be at least CHMAC<CMD5>::DIGESTSIZE bytes, if the HMAC is calculated using the MD5 hash algorithm.

Example

#include <string.h>
#include <QuickHash.h>
using namespace QuickHash;

int main()
{
    char mydata[] = "Test String";
    char key[] = "Test Password";

    unsigned char hmac[ CHMAC<CMD5>::DIGESTSIZE ]; 

    //Calculate the HMAC using MD5 algorithm

    CHMAC<CMD5>::Calculate( hmac, (const unsigned char*)mydata, strlen( mydata ), 
                                  (const unsigned char*)key, strlen( key ) );

    //Use the HMAC
    //...

    return 0;
}

Note.

In the above example mydata and key are null-terminated strings. Therefore, the call

    CHMAC<CMD5>::Calculate( hmac, (const unsigned char*)mydata, strlen( mydata ), (const unsigned char*)key, strlen( key ) );

can be replaced by

    CHMAC<CMD5>::Calculate( hmac, mydata, key );

CHMAC Overview   |   Class Members   |   Useful Links   |   HashCalc

See Also    CHMAC::CalculateHex