(15 . 6)(15 . 27)
 */
static const int KEY_LENGTH_OCTETS = 512;

/*
 * This is the maximum length of a plain-text message (in octets) that can be 
 * oeap+rsa encrypted in a single block. Its value is defined in smg_oaep.ads
 */
extern int max_len_msg;

/*
 * ada-exported oaep encrypt
 */
extern void oaep_encrypt_c( char* msg, int msglen,
                            char* entropy, int entlen,
                            char* encr, int encrlen,
                            int* success);

/*
 * ada-exported oaep decrypt
 */
extern void oaep_decrypt_c( char* encr, int encrlen,
                            char* decr, int* decrlen,
                            int* success);

typedef struct {
    MPI n;	    /* modulus */
    MPI e;	    /* public exponent */
(163 . 6)(184 . 34)
 */
void secret_rsa( MPI output, MPI input, RSA_secret_key *sk );

/*********
 * @param output - an MPI with KEY_LENGTH_OCTETS octets allocated space;
                   it will hold the result: (rsa(oaep(input), pk))
   @param input  - the plain-text message to be encrypted; maximum length is 
                   245 octets (1960 bits)
   @param pk     - public key with which to encrypt
   NB: this method does NOT allocate memory for output!
   preconditions:
     - output IS different from input!
     - output has at least KEY_LENGTH_OCTETS octets allocated space
     - input is AT MOST max_len_msg octets long (ct defined in smg_oaep.ads)
 */
void rsa_oaep_encrypt( MPI output, MPI input, RSA_public_key *pk);

/*
 * Opposite operation to rsa_oaep_encrypt.
 * Attempts oaep_decrypt(rsa_decrypt(input))
 * @param output - an MPI to hold the result; allocated >= max_len_msg octets
 * @param input  - an MPI previously obtained with rsa_oaep_encrypt
 * @param sk     - the secret key with which to decrypt
 * @param success - this will be set to -1 if there is an error
 *
 * preconditions:
 *   - output IS different from input!
 *   - output has at least KEY_LENGTH_OCTETS octets allocated space
 *   - input is precisely KEY_LENGTH_OCTETS
 */
void rsa_oaep_decrypt( MPI output, MPI input, RSA_secret_key *sk, int *success);

#endif /*SMG_RSA*/