c-libp2p/include/libp2p/secio/propose.h

#pragma once

#include "libp2p/crypto/rsa.h"

struct Propose {
	unsigned char* rand;
	size_t rand_size;
	// a protobuf'd struct PublicKey (defined in crypto/key.h)
	unsigned char* public_key;
	size_t public_key_size;
	char* exchanges;
	size_t exchanges_size;
	char* ciphers;
	size_t ciphers_size;
	char* hashes;
	size_t hashes_size;
};

struct Propose* libp2p_secio_propose_new();
void libp2p_secio_propose_free(struct Propose* in);
/**
 * Helper to set the property to a value
 * @param to the property
 * @param to_size the size that matches the property
 * @param from the value to be set in the property
 * @param from_size the size of from
 * @returns true(1) on success, otherwise false(0)
 */
int libp2p_secio_propose_set_property(void** to, size_t* to_size, const void* from, size_t from_size);

/**
 * retrieves the approximate size of an encoded version of the passed in struct
 * @param in the struct to look at
 * @reutrns the size of buffer needed
 */
size_t libp2p_secio_propose_protobuf_encode_size(struct Propose* in);

/**
 * Encode the struct Propose in protobuf format
 * @param in the struct to be encoded
 * @param buffer where to put the results
 * @param max_buffer_length the max to write
 * @param bytes_written how many bytes were written to the buffer
 * @returns true(1) on success, otherwise false(0)
 */
int libp2p_secio_propose_protobuf_encode(struct Propose* in, unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written);

/**
 * Turns a protobuf array into a Propose struct
 * @param buffer the protobuf array
 * @param max_buffer_length the length of the buffer
 * @param out a pointer to the new struct Propose NOTE: this method allocates memory
 * @returns true(1) on success, otherwise false(0)
 */
int libp2p_secio_propose_protobuf_decode(const unsigned char* buffer, size_t max_buffer_length, struct Propose** out);

/***
 * Build a propose structure for sending to the remote client
 * @param nonce a 16 byte nonce, previously defined
 * @param rsa_key the local RSA key
 * @param supportedExchanges a comma separated list of supported exchange protocols
 * @param supportedCiphers a comma separated list of supported ciphers
 * @param supportedHashes a comma separated list of supported hashes
 * @returns an initialized Propose struct, or NULL
 */
struct Propose* libp2p_secio_propose_build(unsigned char nonce[16], struct RsaPrivateKey* rsa_key,
		const char* supportedExchanges, const char* supportedCiphers, const char* supportedHashes);