#ifndef XMSS_H
#define XMSS_H

#include <stdint.h>

/**
 * Generates a XMSS key pair for a given parameter set.
 * Format sk: [oid || (32bit) idx || SK_SEED || SK_PRF || PUB_SEED || root]
 * Format pk: [oid || root || PUB_SEED]
 */
int xmss_keypair(unsigned char *pk, unsigned char *sk, const uint32_t oid);

/**
 * Signs a message.
 * Returns
 * 1. an array containing the signature followed by the message AND
 * 2. an updated secret key!
 */
int xmss_sign(unsigned char *sk,
              unsigned char *sm, unsigned long long *smlen,
              const unsigned char *m, unsigned long long mlen);

/**
 * Verifies a given message signature pair under a given public key.
 *
 * Note: msg and msglen are pure outputs which carry the message in case verification succeeds. The (input) message is assumed to be within sig_msg which has the form (sig||msg).
 */
int xmss_sign_open(unsigned char *m, unsigned long long *mlen,
                   const unsigned char *sm, unsigned long long smlen,
                   const unsigned char *pk);

/*
 * Generates a XMSSMT key pair for a given parameter set.
 * Format sk: [oid || (ceil(h/8) bit) idx || SK_SEED || SK_PRF || PUB_SEED || root]
 * Format pk: [oid || root || PUB_SEED]
 */
int xmssmt_keypair(unsigned char *pk, unsigned char *sk, const uint32_t oid);

/**
 * Signs a message.
 * Returns
 * 1. an array containing the signature followed by the message AND
 * 2. an updated secret key!
 */
int xmssmt_sign(unsigned char *sk,
                unsigned char *sm, unsigned long long *smlen,
                const unsigned char *m, unsigned long long mlen);

/**
 * Verifies a given message signature pair under a given public key.
 */
int xmssmt_sign_open(unsigned char *m, unsigned long long *mlen,
                     const unsigned char *sm, unsigned long long smlen,
                     const unsigned char *pk);
#endif