/*

 * 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 "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.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