/*

* Copyright (c) 2006-2006 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members

* which accompanies this distribution, and is available

* at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: Crypto graphy utils api declaration

*

*/

#ifndef C_SEN_CRYPTO_UTILS_H

#define C_SEN_CRYPTO_UTILS_H

#include <hash.h>

/**

 * Set of static convenience methods to help in cryptography

 */

class SenCryptoUtils

    {

    public:

        /**

        * Algorithm taken from of TLS specification RFC 2246 - 5.HMAC and the pseudorandom function  

        *           

        *           P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +

        *                              HMAC_hash(secret, A(2) + seed) +

        *                              HMAC_hash(secret, A(3) + seed) + ...

        *

        *               Where + indicates concatenation.

        *

        *               A() is defined as:

        *                   A(0) = seed

        *                   A(i) = HMAC_hash(secret, A(i-1))

        *

        *       P_hash can be iterated as many times as is necessary to produce the

        *       required quantity of data. For example, if P_SHA-1 was being used to

        *       create 64 bytes of data, it would have to be iterated 4 times

        *       (through A(4)), creating 80 bytes of output data; the last 16 bytes

        *       of the final iteration would then be discarded, leaving 64 bytes of

        *       output data.

        * @param aSecret - secret

        * @param aSeed - seed

        * @param aLength - length of new secret

        * @since Series60 4.0

        */

        IMPORT_C static HBufC8* GetPSHA1HashL( const TDesC8& aSecret, 

                                               const TDesC8& aSeed, 

                                               const TInt aLength );

        /*

        * Encode data into Base64 format

        * @param aData - source data

        * @return encoded data, if some problem occurs, NULL is returned

        * @since Series60 4.0

        */

        IMPORT_C static HBufC8* EncodeBase64L(const TDesC8& aData);

        /*

        * Decode data from Base64 format

        * @param aData - source data

        * @return decoded data, if some problem occurs, NULL is returned

        * @since Series60 4.0

        */

        IMPORT_C static HBufC8* DecodeBase64L(const TDesC8& aData);

        /*

        * Randomize some data and hash it using MD5 digest algorithm.

        * @return hashed randomized data (constant length of hash according to MD5 specification)

        * @since Series60 4.0

        */

        IMPORT_C static HBufC8* RandomAndHashMd5LC();

        /*

        * Create <BinarySecret> tag from security token.

        * @param aSecret security context token.

        * @param aValueType Indicates what the security token is

        * @return <BinarySecret> tag with encoded (base64) token.

        */

        IMPORT_C static HBufC8* CreateEncodedBinarySecretL( const TDesC8& aSecret, 

                                                            const TDesC8& aValueType );

        /*

        * Timestamp as number of seconds since 1 january 1970 

        *   Calculated for present phone time.

        * @return timestamp value

        * @since Series60 5.0

        */

        IMPORT_C static HBufC8* GetTimestampL();

        /*

        * Timestamp as number of seconds since 1 january 1970.

        *   Calculated for provided time.

        * @param aTime base for generated timestamp

        * @return timestamp value

        * @since Series60 5.0

        */

        IMPORT_C static HBufC8* GetTimestampL(TTime aTime);

        /*

        * Randomize some data (based on time) and hash it using MD5 digest algorithm, 

        * convert each byte to hex nember representation

        * @return hashed randomized data (constant length of hash according to MD5 specification

        * doubled during hex conversion)

        * @since Series60 5.0

        */

        IMPORT_C static HBufC8* GetRandomNonceL();

    private:

        /**

        * Hide default C++ constructor.

        */

        SenCryptoUtils();

    };

#endif // C_SEN_CRYPTO_UTILS_H