QuickHash Library

Type Library

HMAC_UpdateStr

int HMAC_UpdateStr( [ in,out ]HMAC_Context* pContext, [ in , string ] unsigned char* pSrc );

Return value

Nonzero if update is successful, otherwise 0. In particular, this function returns 0 when the context was improperly initialized.

Parameters

pContext

    [in/out] A memory buffer that is used as the context.

     Note. All predefined types are specified in the Predefined Types List.

 pSrc

    [in] A null-terminated string with which to update the context.

Remarks

Updates the context specified by pContext with the null-terminated string specified by pSrc. Call this function for each null-terminated string for which the HMAC is calculated. To retrieve the HMAC after using HMAC_UpdateStr, call HMAC_Final or HMAC_FinalHex.

Note. Before the first call to HMAC_Update, HMAC_UpdateStr, HMAC_Final or HMAC_FinalHex functions, the context must be initialized with HMAC_Init or HMAC_InitKeyStr.

VB Example

Private Sub MyButton_Click()   

    Dim Context As HMAC_Context

    Dim Hmac As HMAC_Digest

    Dim MyStrData As String

    MyStrData = "Hello World!"

    Dim MyStrKey As String

    MyStrKey = "password"

    'Initialize the context for MD5-HMAC calculations

    HMAC_InitKeyStr Context, MD5_ALGID, MyStrKey

    'Update the context 

    HMAC_UpdateStr Context, MyStrData

    'Get the MD5-HMAC

    HMAC_Final Context, Hmac 

    'Show the hexadecimal representation of the MD5-HMAC

    MsgBox QHASH_ConvertToHex(Hmac.Value(0), MD5_DIGESTSIZE, True)

End Sub

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See Also    HMAC_Update, HMAC_Final, HMAC_FinalHex, HMAC_Init, HMAC_InitKeyStr, QHASH_ConvertToHex