Starts work on https as well as some moving about

I now start the listener in the main.c file rather than proxy given that
I didn't feel proxy was the right place if a normal (non-proxied)
request came in. webserver.{c,h} and proxy.{c,h} had some changes
relating to this.

The config changed slightly - we now create a folder in ~/.config/
called yaip. This is where certificates and so on will be stored along
with the user configuration

I created a helper function to get files inside this directory (it
changes based on xdg_config_home) and updated relevant tests.

In ssl.{c,h} I have started work. If they don't exist, the tool now
creates and stores a key and certificate for the CA that this tool will
need to pretend to be. I still need to write tests for this.

.gitignore

@@ -3,3 +3,4 @@
 yaip
 mynotes.md
 *.sqlite
+/certs

Makefile

@@ -6,7 +6,7 @@ TESTFILES   = $(wildcard tests/*.c)
 TESTOUT = $(TESTFILES:.c=)
 OUT      = yaip
 CFLAGS   = -Wall -g
-LDLIBS   = -lsqlite3 -lm
+LDLIBS   = -lsqlite3 -lm -lssl -lcrypto
 CC = gcc
 
 

docs/certificate-authority.md

@@ -0,0 +1,6 @@
+# Certificate Authority
+
+At some point, it would be nice if yaip does this automatically, but for now,
+you need to create a certificate authority for yaip to sign requests with.
+
+;

src/config.c

@@ -34,35 +34,50 @@ char* resolveTilde(const char *path) {
 */
 Config* configDefaults(){
 	Config *conf = malloc( sizeof( Config ) );
-	conf->database = "proxy.sqlite";
+	conf->database = strdup("proxy.sqlite");
 	conf->port = 8080;
-	conf->localConfig = "proxy.conf";
-	conf->userConfig = getDefaultUserConfigLoc();
+	conf->localConfig = strdup("proxy.conf");
+	conf->userConfig = getUserConfigFile("proxy.conf");
+	conf->certfile = getUserConfigFile("cert.pem");
+	conf->keyfile = getUserConfigFile("key.pem");
 	
 	return conf;
 }
 
+void maybeMakeDir(const char *path){
+	if ( path_exists( path ) ) return;
+	mkdir( path, 0700 );
+}
+
 char* getConfigDir(){
 	char *xdg_config_home;
 	if ((xdg_config_home = getenv("XDG_CONFIG_HOME")) == NULL)
 		xdg_config_home = resolveTilde("~/.config");
 
-	return xdg_config_home;
+	char configDir[strlen(xdg_config_home) + 6];
+	memset(configDir, '\0', strlen(xdg_config_home) + 6);
+	
+	sprintf( configDir, "%s/yaip", xdg_config_home );
+	
+	return strdup(configDir);
 }
 
-char* getDefaultUserConfigLoc(){
+char* getUserConfigFile(char *filename){
+	//This doesn't end in a slash
 	char *configDir = getConfigDir();
-	char configFile[strlen(configDir) + 11];
+	//Make sure our filename doesn't start with a slash
+	while ( filename[0] == '/' ) filename++;
+	// Allocate space for both parts, a slash and a \0
+	char retFile[strlen(configDir) + strlen(filename) + 2];
 
-	memset(configFile, '\0', strlen(configDir) + 11);
+	memset(retFile, '\0', strlen(configDir) + strlen(filename) + 2);
 
-	strcpy( configFile, configDir );
+	sprintf(retFile, "%s/%s", configDir, filename);
 
-	strcat( configFile, "/proxy.conf" );
-
-	return strdup(configFile);
+	return strdup(retFile);
 }
 
+
 void setConfig(Config *config, char option[], char value[]){
 	if ( strcmp( option, "database" ) == 0 ){
 		config->database = value;

src/config.h

@@ -13,13 +13,16 @@ typedef struct {
 	char *localConfig; // Project Specific
 	char *userConfig; // User Specific
 	unsigned int port;
+	char *certfile;
+	char *keyfile;
 } Config;
 
 bool path_exists(const char *path);
 char* resolveTilde(const char *path);
 Config* configDefaults();
 char* getConfigDir();
-char* getDefaultUserConfigLoc();
+void maybeMakeDir(const char *path);
+char* getUserConfigFile();
 void setConfig(Config *config, char option[], char value[]);
 void printConfig(Config *config);
 

src/main.c

@@ -7,6 +7,7 @@
 #include "config.h"
 #include "request.h"
 #include "response.h"
+#include "ssl.h"
 
 #define PACKAGE_NAME "WICTP"
 #define DEFAULT_DATABASE "data.sqlite"
@@ -30,6 +31,40 @@ void printHelp(){
 	printf( "\t --print-config             Prints current config\n" );
 }
 
+int startListener(unsigned int port){
+	//we need to act as an http server
+	int server_fd;
+    struct sockaddr_in address;
+	memset( &address, 0, sizeof(address) );
+    int addrlen = sizeof(address);
+	Response *response;
+	char *responseStr;
+
+    // Creating socket file descriptor
+    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
+        perror("socket failed");
+		return -1;
+    }
+
+    address.sin_family = AF_INET;
+    address.sin_addr.s_addr = INADDR_ANY;
+    address.sin_port = htons( port );
+
+    // Forcefully attaching socket to the port 8080
+    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) != 0) {
+        perror("bind failed");
+		return -1;
+    }
+
+    if (listen(server_fd, 3) != 0) {
+        perror("listen");
+		return -1;
+    }
+
+	return server_fd;
+}
+
+
 int main(int argc, char**argv){
 	Config *config = configDefaults();
 	int listener;
@@ -67,7 +102,24 @@ int main(int argc, char**argv){
 		db_create(config->database);
 	}
 
-	listener = proxy_startListener(config->port);
+	maybeMakeDir( getConfigDir() );
+
+
+	if (!path_exists( config->keyfile ) ){
+		printf("Creating keyfile\n");
+		if ( !create_and_save_key(config->keyfile) ){
+			return 1;
+		}
+	}
+
+	if (!path_exists( config->certfile ) ){
+		printf("Creating cert\n");
+		if ( !create_and_save_cert(config->certfile, read_private_key( config->keyfile) ) ){
+			return 1;
+		}
+	}
+
+	listener = startListener(config->port);
 	
 	if ( listener < 0 ){
 		return 1;
@@ -78,8 +130,6 @@ int main(int argc, char**argv){
 		socklen_t addrlen = sizeof(addr);
 		int client = 0;
 		Request *request = NULL;
-		Response *response = NULL;
-		char *responseStr;
 		printf("Listening on port %i\n", config->port);
 
 		if ((client = accept(listener, (struct sockaddr *)&addr, 
@@ -94,61 +144,17 @@ int main(int argc, char**argv){
 
 		request = newRequestFromSocket(client);
 
-		// If the host is not defined, then it is not a proxy request
-		// Note that the host here is where the request should be sent, not
-		// necesarily the hosts header
 		if ( strcmp( request->host, "" ) == 0 ){
-			response = webserverGetResponse(request);
+			// If the host is not defined, then it is not a proxy request
+			// Note that the host here is where the request should be sent, not
+			// necesarily the hosts header
+			webserverRequest(request, client);
 		} else {
-			response = upstreamGetResponse(request);
+			proxyRequest(request, client);
 		}
 	
-		responseStr = responseToString( response );
-
-		// I'm also not convinced that strlen is the best function to use here
-		// When we get to dealing with binary requests / responses, they may
-		// well have null characters in them
-		send(client , responseStr, strlen(responseStr) , 0 );
-
-		printf( "\n1\n" );
 		close(client);
-		printf( "\n2\n" );
 		freeRequest( request );
-		printf( "\n3\n" );
-		freeResponse( response );
-		printf( "\n4\n" );
-		free(responseStr);
-		printf( "\n5\n" );
-
-		//If this is an https request - this is the first part
-		//if ( strcmp( request->method, "CONNECT" ) == 0 ){
-
-		//	// I am basically doing the same thing that mitmproxy does here
-		//	// We start by responding with 200 Connection Established which
-		//	// in a normal proxy would mean that we have established a
-		//	// connection with the remote host. However, we haven't because we
-		//	// are going to pretend to be the host to the client and pretend to
-		//	// be the client to the host
-
-		//	response = newResponse();
-		//	connectionEstablished(response);
-		//	responseStr = responseToString(response);
-		//	send(new_socket , responseStr, strlen(responseStr) , 0 );
-
-
-		//	char line[1024] = {'\0'};
-		//	//a length of 2 will indicate an empty line which will split the headers
-		//	//from the body (if there is a body)
-		//	int valread = read( new_socket, line, 1024);
-		//	while (valread > 0){
-		//		printf("%s", line);
-		//		//I believe at this point all the headers are done.
-		//		valread = read( new_socket , line, 1024);
-		//	}
-
-
-
-		//}
 
 	}
 

src/proxy.c

@@ -38,37 +38,50 @@ Response *upstreamGetResponse(Request *request){
 
 }
 
-int proxy_startListener(unsigned int port){
-	//we need to act as an http server
-	int server_fd;
-    struct sockaddr_in address;
-	memset( &address, 0, sizeof(address) );
-    int addrlen = sizeof(address);
-	Response *response;
-	char *responseStr;
+void proxyRequest(Request *request, int client){
 
-    // Creating socket file descriptor
-    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
-        perror("socket failed");
-		return -1;
-    }
+	if ( strcmp( request->method, "CONNECT" ) == 0 ){
+		// If it is a connect request, we are dealing with https
 
-    address.sin_family = AF_INET;
-    address.sin_addr.s_addr = INADDR_ANY;
-    address.sin_port = htons( port );
+		// I am basically doing the same thing that mitmproxy does here
+		// We start by responding with 200 Connection Established which
+		// in a normal proxy would mean that we have established a
+		// connection with the remote host. However, we haven't because we
+		// are going to pretend to be the host to the client and pretend to
+		// be the client to the host
 
-    // Forcefully attaching socket to the port 8080
-    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) != 0) {
-        perror("bind failed");
-		return -1;
-    }
-
-    if (listen(server_fd, 3) != 0) {
-        perror("listen");
-		return -1;
-    }
-
-	return server_fd;
+		Response *response = newResponse();
+		connectionEstablished(response);
+		char *responseStr = responseToString(response);
+		send(client , responseStr, strlen(responseStr) , 0 );
 
 
+
+
+
+		//SSL_CTX *ctx;
+		//SSL *ssl;
+		//char buf[1024] = {0};
+		//int bytes;
+
+		//SSL_library_init();
+		//ctx = InitServerCTX(config);
+		//ssl = SSL_new(ctx);
+		//SSL_set_fd( ssl, client );
+
+		//if ( SSL_accept(ssl) == -1 ){
+		//	ERR_print_errors_fp(stderr);
+		//} else {
+		//	bytes = SSL_read(ssl, buf, sizeof(buf));
+		//	buf[bytes] = '\0';
+		//	printf("%s", buf);
+		//}
+		
+	} else {
+		Response *response = upstreamGetResponse(request);
+		char *responseStr = responseToString( response );
+		send(client , responseStr, strlen(responseStr) , 0 );
+		free( responseStr );
+		freeResponse( response );
+	}
 }

src/proxy.h

@@ -12,9 +12,11 @@
 #include <stdbool.h>
 
 #include "request.h"
+#include "response.h"
 #include "webserver.h"
 
-int proxy_startListener( unsigned int port );
 Response *upstreamGetResponse(Request *request);
 
+void proxyRequest(Request *request, int client);
+
 #endif /* ifndef PROXY_H */

src/ssl.c

@@ -0,0 +1,180 @@
+#include "ssl.h"
+
+
+SSL_CTX* InitServerCTX(Config *config) {
+	const SSL_METHOD *method;
+	SSL_CTX *ctx;
+	OpenSSL_add_all_algorithms();  /* load & register all cryptos, etc. */
+	SSL_load_error_strings();   /* load all error messages */
+	method = TLS_server_method();  /* create new server-method instance */
+	ctx = SSL_CTX_new(method);   /* create new context from method */
+	if ( ctx == NULL ) {
+		ERR_print_errors_fp(stderr);
+		abort();
+	}
+
+	//set the local certificate from CertFile
+	if ( SSL_CTX_use_certificate_file(ctx, config->certfile, SSL_FILETYPE_PEM) <= 0 ){
+		ERR_print_errors_fp(stderr);
+		abort();
+	}
+	
+	//set the private key from KeyFile (may be the same as CertFile)
+	if ( SSL_CTX_use_PrivateKey_file(ctx, config->keyfile, SSL_FILETYPE_PEM) <= 0 ){
+		ERR_print_errors_fp(stderr);
+		abort();
+	}
+	//verify private key
+    if ( !SSL_CTX_check_private_key(ctx) )
+    {
+        fprintf(stderr, "Private key does not match the public certificate\n");
+        abort();
+    }
+
+	return ctx;
+}
+
+
+// Generates a 2048-bit RSA key.
+// Largely stolen from here: https://gist.github.com/nathan-osman/5041136
+EVP_PKEY* generate_ca_key() {
+	// Allocate memory for the EVP_PKEY structure.
+	EVP_PKEY *pkey = EVP_PKEY_new();
+	if(!pkey) {
+		perror("Unable to create EVP_PKEY structure.\n");
+		return NULL;
+	}
+
+	// Generate the RSA key and assign it to pkey.
+	RSA *rsa = RSA_new();
+	BIGNUM *bn = BN_new();
+	BN_set_word(bn, RSA_F4);
+	RSA_generate_key_ex(rsa, 2048, bn, NULL );
+	if(!EVP_PKEY_assign_RSA(pkey, rsa)) {
+		perror("Unable to generate 2048-bit RSA key.\n");
+		EVP_PKEY_free(pkey);
+		return NULL;
+	}
+
+    // The key has been generated, return it.
+    return pkey;
+}
+
+
+// Generates a self-signed x509 certificate.
+// Largely stolen from here: https://gist.github.com/nathan-osman/5041136
+X509* generate_ca_cert(EVP_PKEY * pkey) {
+	// Allocate memory for the X509 structure.
+	X509 *x509 = X509_new();
+	if(!x509) {
+		perror( "Unable to create X509 structure.\n");
+		return NULL;
+	}
+
+	// Set the serial number.
+	ASN1_INTEGER_set(X509_get_serialNumber(x509), 1);
+
+	// This certificate is valid from now until exactly one year from now.
+	X509_gmtime_adj(X509_get_notBefore(x509), 0);
+	X509_gmtime_adj(X509_get_notAfter(x509), 31536000L);
+
+	// Set the public key for our certificate.
+	X509_set_pubkey(x509, pkey);
+
+	// We want to copy the subject name to the issuer name.
+	X509_NAME *name = X509_get_subject_name(x509);
+
+	// Set the country code and common name.
+	X509_NAME_add_entry_by_txt(name, "C",  MBSTRING_ASC, (unsigned char *)"UK",        -1, -1, 0);
+	X509_NAME_add_entry_by_txt(name, "O",  MBSTRING_ASC, (unsigned char *)"Yet Another Intercepting Proxy", -1, -1, 0);
+	X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (unsigned char *)"jn.hn", -1, -1, 0);
+
+	// Now set the issuer name.
+	X509_set_issuer_name(x509, name);
+
+
+	// TODO: mitmproxy adds some extensions. I don' tknow if I need those
+	// https://github.com/mitmproxy/mitmproxy/blob/3cb89069b9f70c198cc89337bd5a9b1bbf3a69d0/mitmproxy/certs.py#L190-L204
+
+
+	// Actually sign the certificate with our key.
+	if(!X509_sign(x509, pkey, EVP_sha1()))
+	{
+		perror( "Error signing certificate.\n");
+		X509_free(x509);
+		return NULL;
+	}
+
+
+
+	return x509;
+}
+
+bool create_and_save_key(char keyfile[]) {
+	// Generate the key
+	EVP_PKEY *pkey = generate_ca_key();
+	if ( pkey == NULL ){
+		fprintf(stderr, "Unable to open generate key\n");
+		return false;
+	}
+
+	// Open the PEM file for writing the key to disk.
+	FILE * pkey_file = fopen(keyfile, "wb");
+	if(!pkey_file) {
+		fprintf(stderr, "Unable to open \"%s\" for writing.\n", keyfile);
+		return false;
+	}
+    // Write the key to disk.
+    bool ret = PEM_write_PrivateKey(pkey_file, pkey, NULL, NULL, 0, NULL, NULL);
+    fclose(pkey_file);
+
+    if(!ret) {
+        perror("Unable to write private key to disk.\n");
+        return false;
+    }
+	return true;
+}
+
+EVP_PKEY* read_private_key(char keyfile[]){
+
+	FILE *fp;
+	EVP_PKEY *pkey;
+
+	if (! (fp = fopen(keyfile, "r"))){
+		perror("Error cant open certificate private key file.\n");
+		return NULL;
+	}
+
+	pkey = PEM_read_PrivateKey( fp, NULL, NULL, NULL );
+
+	if ( pkey == NULL ){
+		perror("Error cant read certificate private key file.\n");
+	}
+
+	return pkey;
+}
+
+bool create_and_save_cert(char certfile[], EVP_PKEY *pkey) {
+    // Open the PEM file for writing the certificate to disk.
+    FILE * x509_file = fopen(certfile, "wb");
+    if(!x509_file) {
+		fprintf(stderr, "Unable to open \"%s\" for writing.\n", certfile);
+        return false;
+    }
+
+	X509 *x509 = generate_ca_cert(pkey);
+	if ( x509 == NULL ){
+		fprintf(stderr, "Unable to open generate cert\n");
+		return false;
+	}
+
+    // Write the certificate to disk.
+    int ret = PEM_write_X509(x509_file, x509);
+    fclose(x509_file);
+
+    if(!ret) {
+        perror("Unable to write certificate to disk.\n");
+        return false;
+    }
+	return true;
+}

src/ssl.h

@@ -0,0 +1,19 @@
+#ifndef SSL_H
+#define SSL_H
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/x509.h>
+#include <openssl/pem.h>
+
+#include "config.h"
+
+SSL_CTX* InitServerCTX(Config *config);
+
+EVP_PKEY* generate_ca_key();
+X509* generate_ca_cert(EVP_PKEY * pkey);
+bool create_and_save_key(char keyfile[]);
+bool create_and_save_cert(char keyfile[], EVP_PKEY *pkey);
+EVP_PKEY* read_private_key(char keyfile[]);
+
+#endif /* ifndef SSL_ */

src/webserver.c

@@ -6,3 +6,18 @@ Response* webserverGetResponse( Request *req ){
 	responseSetBody(rsp, "Test", 1);
 	return rsp;
 }
+
+void webserverRequest( Request *req, int client ){
+	Response *rsp = webserverGetResponse( req );
+	char *responseStr = responseToString( rsp );
+
+	// I'm also not convinced that strlen is the best function to use here
+	// When we get to dealing with binary requests / responses, they may
+	// well have null characters in them
+	send(client , responseStr, strlen(responseStr) , 0 );
+
+	free( responseStr );
+	freeResponse( rsp );
+
+}
+

src/webserver.h

@@ -8,6 +8,7 @@
 #include "response.h"
 
 Response* webserverGetResponse( Request *req );
+void webserverRequest( Request *req, int client);
 
 #endif /* ifndef WEBSERVER_H
 

tests/config.test.c

@@ -37,7 +37,7 @@ MunitResult checkConfigDirWithXdg(const MunitParameter params[],
 		void* user_data_or_fixture){
 	char directory[] =  "/testing/xdg/directory";
 	setenv( "XDG_CONFIG_HOME",directory, 1 );
-	munit_assert_string_equal( directory, getConfigDir() );
+	munit_assert_string_equal( "/testing/xdg/directory/yaip", getConfigDir() );
 	return MUNIT_OK;
 }
 
@@ -46,7 +46,7 @@ MunitResult checkConfigDirWithoutXdg(const MunitParameter params[],
 	unsetenv( "XDG_CONFIG_HOME" );
 	char dir[500] = {'\0'};
 	strcpy( dir, getenv("HOME") );
-	strcat( dir, "/.config" );
+	strcat( dir, "/.config/yaip" );
 	munit_assert_string_equal( dir, getConfigDir() );
 	return MUNIT_OK;
 }
@@ -55,14 +55,18 @@ MunitResult checkDefaults(const MunitParameter params[],
 		void* user_data_or_fixture){
 
 	char directory[] =  "/testing/xdg/directory";
-	char file[] =  "/testing/xdg/directory/proxy.conf";
+	char conffile[] =  "/testing/xdg/directory/yaip/proxy.conf";
+	char certfile[] =  "/testing/xdg/directory/yaip/cert.pem";
+	char keyfile[] =  "/testing/xdg/directory/yaip/key.pem";
 	setenv( "XDG_CONFIG_HOME",directory, 1 );
 	Config *conf = configDefaults();
 
 	munit_assert_string_equal(conf->database, "proxy.sqlite");
 	munit_assert_int(conf->port, ==, 8080);
 	munit_assert_string_equal(conf->localConfig, "proxy.conf");
-	munit_assert_string_equal(conf->userConfig, file);
+	munit_assert_string_equal(conf->userConfig, conffile);
+	munit_assert_string_equal(conf->certfile, certfile);
+	munit_assert_string_equal(conf->keyfile, keyfile);
 	return MUNIT_OK;
 }
 

tests/request.test.c

@@ -114,6 +114,7 @@ MunitResult testFirstLineVersions(const MunitParameter params[],
 		void* user_data_or_fixture){
 
 	Request *req;
+	printf("\nI get here\n");
 	requestTestFirstLine *line = getLineObj(params);
 	if ( line->fullLine == NULL ) return MUNIT_ERROR;
 	req = newRequest();