version22/c/rsa.h

/*
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  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
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*/

/**
 * @file rsa.h
 * @author Mike Scott and Kealan McCusker
 * @date 2nd June 2015
 * @brief RSA Header file for implementation of RSA protocol
 *
 * declares functions
 *
 */

#ifndef RSA_H
#define RSA_H

#include "amcl.h"

#define MAX_RSA_BYTES 512 // Maximum of 4096
#define HASH_TYPE_RSA SHA256 /**< Chosen Hash algorithm */
#define RFS MODBYTES*FFLEN /**< RSA Public Key Size in bytes */

/* RSA Auxiliary Functions */

/**	@brief RSA Key Pair Generator
 *
	@param R is a pointer to a cryptographically secure random number generator
	@param e the encryption exponent
	@param PRIV the output RSA private key
	@param PUB the output RSA public key
        @param P Input prime number. Used when R is equal to NULL for testing
        @param Q Inpuy prime number. Used when R is equal to NULL for testing
 */
extern void RSA_KEY_PAIR(csprng *R,sign32 e,rsa_private_key* PRIV,rsa_public_key* PUB,octet *P, octet* Q);
/**	@brief PKCS V1.5 padding of a message prior to RSA signature
 *
	@param h is the hash type
	@param M is the input message
	@param W is the output encoding, ready for RSA signature
	@return 1 if OK, else 0
 */
extern int PKCS15(int h,octet *M,octet *W);
/**	@brief OAEP padding of a message prior to RSA encryption
 *
	@param h is the hash type
	@param M is the input message
	@param R is a pointer to a cryptographically secure random number generator
	@param P are input encoding parameter string (could be NULL)
	@param F is the output encoding, ready for RSA encryption
	@return 1 if OK, else 0
 */
extern int	OAEP_ENCODE(int h,octet *M,csprng *R,octet *P,octet *F);
/**	@brief OAEP unpadding of a message after RSA decryption
 *
	Unpadding is done in-place
	@param h is the hash type
	@param P are input encoding parameter string (could be NULL)
	@param F is input padded message, unpadded on output
	@return 1 if OK, else 0
 */
extern int  OAEP_DECODE(int h,octet *P,octet *F);
/**	@brief RSA encryption of suitably padded plaintext
 *
	@param PUB the input RSA public key
	@param F is input padded message
	@param G is the output ciphertext
 */
extern void RSA_ENCRYPT(rsa_public_key* PUB,octet *F,octet *G);
/**	@brief RSA decryption of ciphertext
 *
	@param PRIV the input RSA private key
	@param G is the input ciphertext
	@param F is output plaintext (requires unpadding)

 */
extern void RSA_DECRYPT(rsa_private_key* PRIV,octet *G,octet *F);
/**	@brief Destroy an RSA private Key
 *
	@param PRIV the input RSA private key. Destroyed on output.
 */
extern void RSA_PRIVATE_KEY_KILL(rsa_private_key *PRIV);

#endif