intermediate commit for handshake

Working on negotiations between GO and C version of IPFS

crypto/key.c

@@ -187,6 +187,9 @@ exit:
  */
 int libp2p_crypto_public_key_to_peer_id(struct PublicKey* public_key, char** peer_id) {
 
+	/**
+	 * Converting to a peer id involves protobufing the struct PublicKey, SHA256 it, turn it into a MultiHash and base58 it
+	 */
 	size_t protobuf_len = libp2p_crypto_public_key_protobuf_encode_size(public_key);
 	unsigned char protobuf[protobuf_len];
 
@@ -198,6 +201,7 @@ int libp2p_crypto_public_key_to_peer_id(struct PublicKey* public_key, char** pee
 	size_t final_id_size = 100;
 	unsigned char final_id[final_id_size];
 	memset(final_id, 0, final_id_size);
+	// turn it into a multihash and base58 it
 	if (!PrettyID(final_id, &final_id_size, hashed, 32))
 		return 0;
 	*peer_id = (char*)malloc(final_id_size + 1);

include/libp2p/secio/propose.h

@@ -3,6 +3,7 @@
 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;

net/multistream.c

@@ -33,49 +33,46 @@ int libp2p_net_multistream_send(int socket_fd, const unsigned char* data, size_t
 	return num_bytes;
 }
 
-/***
- * Parse the incoming data, removing the size indicator at the front of the array
- * @param incoming the incoming data
- * @param incoming_size the size of the incoming data
- * @param outgoing the buffer to hold the outgoing data, allocated within this function
- * @param outgoing_size the outgoing size
- * @returns true(1) on success, otherwise false(0)
- */
-int libp2p_net_multistream_parse_results(char* incoming, size_t incoming_size, char** outgoing, size_t* outgoing_size) {
-	int retVal = 0;
-	if (incoming_size > 0) {
-		// TODO: handle this differently
-		// read the varint
-		// allocate memory
-		*outgoing = (char*)malloc(incoming_size - 1);
-		if (*outgoing == NULL)
-			return 0;
-		// copy in the data
-		memcpy(*outgoing, &incoming[1], incoming_size - 1);
-		*outgoing_size = incoming_size - 1;
-		retVal = 1;
-	}
-	return retVal;
-}
-
 /**
  * Read from a multistream socket
  * @param socket_fd the socket file descriptor
  * @param results where to put the results. NOTE: this memory is allocated
  * @param results_size the size of the results in bytes
- * @returns true(1) on success, otherwise false(0)
+ * @returns number of bytes received
  */
 int libp2p_net_multistream_receive(int socket_fd, char** results, size_t* results_size) {
 	int bytes = 0;
 	size_t buffer_size = 65535;
 	char buffer[buffer_size];
+	char* pos = buffer;
+	int num_bytes = 0;
+
+	// first read the varint
+	while(1) {
+		unsigned char c;
+		bytes = socket_read(socket_fd, (char*)&c, 1, 0);
+		pos[0] = c;
+		if (c >> 7 == 0) {
+			pos[1] = 0;
+			num_bytes = varint_decode((unsigned char*)buffer, strlen(buffer), NULL);
+			break;
+		}
+		pos++;
+	}
+	if (num_bytes <= 0)
+		return 0;
+
+	// now read the number of bytes we've found
+	bytes = socket_read(socket_fd, buffer, num_bytes, 0);
 
-	bytes = socket_read(socket_fd, buffer, buffer_size, 0);
 	if (bytes == 0)
 		return 0;
 
 	// parse the results, removing the leading size indicator
-	return libp2p_net_multistream_parse_results(buffer, bytes, results, results_size);
+	*results = malloc(bytes);
+	memcpy(*results, buffer, bytes);
+	*results_size = bytes;
+	return bytes;
 }
 
 

secio/propose.c

@@ -101,7 +101,7 @@ int libp2p_secio_propose_protobuf_encode(struct Propose* in, unsigned char* buff
  */
 int libp2p_secio_propose_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Propose** out) {
 	size_t pos = 0;
-	int retVal = 0;
+	int retVal = 0, got_something = 0;;
 
 	if ( (*out = libp2p_secio_propose_new()) == NULL)
 		goto exit;
@@ -113,37 +113,45 @@ int libp2p_secio_propose_protobuf_decode(unsigned char* buffer, size_t buffer_le
 		if (protobuf_decode_field_and_type(&buffer[pos], buffer_length, &field_no, &field_type, &bytes_read) == 0) {
 			goto exit;
 		}
+		if (field_no < 1 || field_no > 5) {
+			fprintf(stderr, "Invalid character in Propose protobuf at position %lu. Value: %02x\n", pos, buffer[pos]);
+		}
 		pos += bytes_read;
 		switch(field_no) {
 			case (1): // rand
 				if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*out)->rand), &((*out)->rand_size), &bytes_read) == 0)
 					goto exit;
 				pos += bytes_read;
+				got_something = 1;
 				break;
 			case (2): // public key
 				if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*out)->public_key), &((*out)->public_key_size), &bytes_read) == 0)
 					goto exit;
 				pos += bytes_read;
+				got_something = 1;
 				break;
 			case (3): // ciphers
 				if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*out)->ciphers), &((*out)->ciphers_size), &bytes_read) == 0)
 					goto exit;
 				pos += bytes_read;
+				got_something = 1;
 				break;
 			case (4): // exchanges
 				if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*out)->exchanges), &((*out)->exchanges_size), &bytes_read) == 0)
 					goto exit;
 				pos += bytes_read;
+				got_something = 1;
 				break;
 			case (5): // hashes
 				if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*out)->hashes), &((*out)->hashes_size), &bytes_read) == 0)
 					goto exit;
 				pos += bytes_read;
+				got_something = 1;
 				break;
 		}
 	}
 
-	retVal = 1;
+	retVal = got_something;
 
 exit:
 	if (retVal == 0) {

secio/secio.c

@@ -2,11 +2,14 @@
 #include <stdio.h> // for debugging, can remove
 #include <string.h>
 #include <stdint.h>
+#include <errno.h>
+#include <arpa/inet.h>
 
 #include "libp2p/secio/secio.h"
 #include "libp2p/secio/propose.h"
 #include "libp2p/secio/exchange.h"
 #include "libp2p/net/multistream.h"
+#include "libp2p/net/p2pnet.h"
 #include "libp2p/crypto/ephemeral.h"
 #include "libp2p/crypto/sha1.h"
 #include "libp2p/crypto/sha256.h"
@@ -196,7 +199,8 @@ int libp2p_secio_sign(struct PrivateKey* private_key, const char* in, size_t in_
 		rsa_key.der = (char*)private_key->data;
 		rsa_key.der_length = private_key->data_size;
 		// SHA2-256 signatures are 32 bytes
-		*signature = (unsigned char*)malloc(32);
+		*signature_size = 32;
+		*signature = (unsigned char*)malloc(*signature_size);
 		return libp2p_crypto_rsa_sign(&rsa_key, in, in_length, *signature);
 	}
 	// TODO: Implement this method for non-RSA
@@ -361,15 +365,104 @@ int libp2p_secio_make_mac_and_cipher(struct SecureSession* session) {
 	return 0;
 }
 
-int libp2p_secio_write(struct SecureSession* session, unsigned char* bytes, size_t length) {
+int libp2p_secio_write(struct SecureSession* session, unsigned char* bytes, size_t data_length) {
-	// TODO: Implement this method
+	int num_bytes = 0;
+
+	if (data_length > 0) { // only do this is if there is something to send
+		// first send the size
+		uint32_t size = htonl(data_length);
+		char* size_as_char = (char*)&size;
+		int left = 4;
+		int written = 0;
+		int written_this_time = 0;
+		do {
+			written_this_time = socket_write(session->socket_descriptor, &size_as_char[written], left, 0);
+			if (written_this_time < 0) {
+				written_this_time = 0;
+				if ( (errno == EAGAIN) || (errno == EWOULDBLOCK)) {
+					// TODO: use epoll or select to wait for socket to be writable
+				} else {
 					return 0;
 				}
-
+			}
-int libp2p_secio_read(struct SecureSession* session, unsigned char** bytes, size_t* bytes_read) {
+			left = left - written_this_time;
-	// TODO: Implement this method
+		} while (left > 0);
+		// then send the actual data
+		left = data_length;
+		written = 0;
+		do {
+			written_this_time = socket_write(session->socket_descriptor, (char*)&bytes[written], left, 0);
+			if (written_this_time < 0) {
+				written_this_time = 0;
+				if ( (errno == EAGAIN) || (errno == EWOULDBLOCK)) {
+					// TODO: use epoll or select to wait for socket to be writable
+				} else {
 					return 0;
 				}
+			}
+			left = left - written_this_time;
+			written += written_this_time;
+		} while (left > 0);
+		num_bytes = written;
+	} // there was something to send
+
+	return num_bytes;
+}
+
+int libp2p_secio_read(struct SecureSession* session, unsigned char** results, size_t* results_size) {
+	uint32_t buffer_size;
+
+	// first read the 4 byte integer
+	char* size = (char*)&buffer_size;
+	int left = 4;
+	int read = 0;
+	int read_this_time = 0;
+	do {
+		read_this_time = socket_read(session->socket_descriptor, &size[read], 1, 0);
+		if (read_this_time < 0) {
+			read_this_time = 0;
+			if ( (errno == EAGAIN) || (errno == EWOULDBLOCK)) {
+				// TODO: use epoll or select to wait for socket to be writable
+			} else {
+				return 0;
+			}
+		}
+		if (read == 0 && size[0] == 10) {
+			// a spurious \n
+			// write over this value by not adding it
+		} else {
+			left = left - read_this_time;
+			read += read_this_time;
+		}
+	} while (left > 0);
+	// now read the number of bytes we've found, minus the 4 that we just read
+	buffer_size = ntohl(buffer_size);
+	// JMJ
+	fprintf(stderr, "which switching bits results in %u.\n", buffer_size);
+	if (buffer_size == 0)
+		return 0;
+
+	left = buffer_size;
+	read = 0;
+	read_this_time = 0;
+	*results = malloc(left);
+	unsigned char* ptr = *results;
+	do {
+		read_this_time = socket_read(session->socket_descriptor, (char*)&ptr[read], left, 0);
+		if (read_this_time < 0) {
+			read_this_time = 0;
+			if ( (errno == EAGAIN) || (errno == EWOULDBLOCK)) {
+				// TODO: use epoll or select to wait for socket to be writable
+			} else {
+				return 0;
+			}
+		}
+		left = left - read_this_time;
+	} while (left > 0);
+
+	*results_size = buffer_size;
+	return buffer_size;
+}
 
 /***
  * performs initial communication over an insecure channel to share
@@ -406,41 +499,15 @@ int libp2p_secio_handshake(struct SecureSession* local_session, struct RsaPrivat
 	if (bytes_written <= 0)
 		goto exit;
 
-	// we should get back the protocol to signify it was accepted, as well as the protobuf of the Propose struct
+	// we should get back the secio confirmation
 	bytes_written = libp2p_net_multistream_receive(local_session->socket_descriptor, (char**)&results, &results_size);
 	if (bytes_written < 1 || strstr((char*)results, "secio") == NULL)
 		goto exit;
 
-	// skip to the protobuf section
-	propose_in_bytes = (unsigned char*)strchr((char*)results, '\n');
-	if (propose_in_bytes == NULL)
-		goto exit;
-	// are we at the end of the buffer?
-	if (propose_in_bytes - results + 1 >= results_size) {
-		free(results);
-		// read some more
-		bytes_written = libp2p_net_multistream_receive(local_session->socket_descriptor, (char**)&results, &results_size);
-		propose_in_bytes = results;
-	} else {
-		propose_in_bytes++;
-	}
-	propose_in_size  = results_size - (propose_in_bytes - results);
-
-	if (!libp2p_secio_propose_protobuf_decode(propose_in_bytes, propose_in_size, &propose_in))
-		goto exit;
-
-	// clear results
 	free(results);
 	results = NULL;
 	results_size = 0;
 
-	// get public key and put it in a struct PublicKey
-	if (!libp2p_crypto_public_key_protobuf_decode(propose_in->public_key, propose_in->public_key_size, &public_key))
-		goto exit;
-	// generate their peer id
-	char* remote_peer_id;
-	libp2p_crypto_public_key_to_peer_id(public_key, &remote_peer_id);
-
 	//TODO: make sure we're not talking to ourself
 
 	// generate 16 byte nonce
@@ -451,17 +518,54 @@ int libp2p_secio_handshake(struct SecureSession* local_session, struct RsaPrivat
 	propose_out = libp2p_secio_propose_new();
 	libp2p_secio_propose_set_property((void**)&propose_out->rand, &propose_out->rand_size, local_session->nonce, 16);
 
-	// we have their information, now we need to gather ours.
+	// public key - protobuf it and stick it in propose_out
-	// public key
+	struct PublicKey pub_key;
-	propose_out->public_key_size = public_key->data_size;
+	pub_key.type = KEYTYPE_RSA;
-	propose_out->public_key = (unsigned char*)malloc(public_key->data_size);
+	pub_key.data_size = private_key->public_key_length;
-	memcpy(propose_out->public_key, public_key->data, public_key->data_size);
+	pub_key.data = malloc(pub_key.data_size);
+	results_size = libp2p_crypto_public_key_protobuf_encode_size(&pub_key);
+	results = malloc(results_size);
+	if (libp2p_crypto_public_key_protobuf_encode(&pub_key, results, result_size, &results_size) == 0)
+		goto exit;
+	propose_out->public_key_size = results_size;
+	propose_out->public_key = malloc(results_size);
+	memcpy(propose_out->public_key, results, results_size);
+	free(results);
+	results = NULL;
+	results_size = 0;
 	// supported exchanges
 	libp2p_secio_propose_set_property((void**)&propose_out->exchanges, &propose_out->exchanges_size, SupportedExchanges, strlen(SupportedExchanges));
 	// supported ciphers
 	libp2p_secio_propose_set_property((void**)&propose_out->ciphers, &propose_out->ciphers_size, SupportedCiphers, strlen(SupportedCiphers));
 	// supported hashes
 	libp2p_secio_propose_set_property((void**)&propose_out->hashes, &propose_out->hashes_size, SupportedHashes, strlen(SupportedHashes));
+
+	// send proposal
+	propose_out_size = libp2p_secio_propose_protobuf_encode_size(propose_out);
+	propose_out_bytes = (unsigned char*)malloc(propose_out_size);
+	if (libp2p_secio_propose_protobuf_encode(propose_out, propose_out_bytes, propose_out_size, &propose_out_size) == 0)
+		goto exit;
+
+	bytes_written = libp2p_secio_write(local_session, propose_out_bytes, propose_out_size);
+	if (bytes_written < propose_out_size)
+		goto exit;
+
+	// try to get the propose object from the server
+	bytes_written = libp2p_secio_read(local_session, &propose_in_bytes, &propose_in_size);
+	if (bytes_written <= 0)
+			goto exit;
+
+	if (!libp2p_secio_propose_protobuf_decode(propose_in_bytes, propose_in_size, &propose_in))
+		goto exit;
+
+	// get public key and put it in a struct PublicKey
+	if (!libp2p_crypto_public_key_protobuf_decode(propose_in->public_key, propose_in->public_key_size, &public_key))
+		goto exit;
+	// generate their peer id
+	char* remote_peer_id;
+	libp2p_crypto_public_key_to_peer_id(public_key, &remote_peer_id);
+
+
 	// negotiate encryption parameters NOTE: SelectBest must match, otherwise this won't work
 	// first determine order
 	libp2p_secio_hash(propose_in, order_hash_in);
@@ -474,6 +578,7 @@ int libp2p_secio_handshake(struct SecureSession* local_session, struct RsaPrivat
 	// hash
 	libp2p_secio_select_best(order, propose_out->hashes, propose_out->hashes_size, propose_in->hashes, propose_in->hashes_size, &local_session->chosen_hash);
 
+
 	// prepare exchange of encryption parameters
 	struct SecureSession remote_session;
 	remote_session.chosen_cipher = local_session->chosen_cipher;
@@ -515,11 +620,11 @@ int libp2p_secio_handshake(struct SecureSession* local_session, struct RsaPrivat
 	if (exchange_out_protobuf == NULL)
 		goto exit;
 	libp2p_secio_exchange_protobuf_encode(exchange_out, exchange_out_protobuf, exchange_out_protobuf_size, &bytes_written);
-	bytes_written = libp2p_net_multistream_send(local_session->socket_descriptor, exchange_out_protobuf, exchange_out_protobuf_size);
+	bytes_written = libp2p_secio_write(local_session, exchange_out_protobuf, exchange_out_protobuf_size);
 	free(exchange_out_protobuf);
 
 	// receive Exchange packet
-	bytes_written = libp2p_net_multistream_receive(local_session->socket_descriptor, (char**)&results, &results_size);
+	bytes_written = libp2p_secio_read(local_session, &results, &results_size);
 	if (bytes_written == 0)
 		goto exit;
 	libp2p_secio_exchange_protobuf_decode(results, results_size, &exchange_in);
@@ -568,6 +673,13 @@ int libp2p_secio_handshake(struct SecureSession* local_session, struct RsaPrivat
 
 	exit:
 
+	if (propose_in_bytes != NULL)
+		free(propose_in_bytes);
+	if (propose_out_bytes != NULL)
+		free(propose_out_bytes);
+	if (results != NULL)
+		free(results);
+
 	libp2p_secio_propose_free(propose_out);
 	libp2p_secio_propose_free(propose_in);