http: initial windows schannel http support

vlib/http/backend_nix.v

@@ -0,0 +1,96 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module http
+
+import strings 
+
+#flag windows -I @VROOT/thirdparty/openssl/include 
+#flag darwin -I @VROOT/thirdparty/openssl/include 
+#flag -l ssl -l crypto
+// MacPorts
+#flag darwin -L/opt/local/lib
+// Brew
+#flag darwin -L/usr/local/opt/openssl/lib
+
+#include <openssl/ssl.h>
+
+struct C.SSL {
+ 
+} 
+
+fn init_module() {
+	$if mac { 
+		C.SSL_library_init() 
+	} 
+	$if linux { 
+		C.SSL_library_init() 
+	} 
+	//C.SSL_load_error_strings() 
+	//C.OPENSSL_config(0) 
+}
+
+fn ssl_do(method, host_name, path string) string { 
+	//ssl_method := C.SSLv23_method() 
+	ssl_method := C.TLSv1_2_method() 
+	if isnil(method) { 
+	} 
+	ctx := C.SSL_CTX_new(ssl_method) 
+	if isnil(ctx) { 
+	} 
+	C.SSL_CTX_set_verify_depth(ctx, 4) 
+	flags := C.SSL_OP_NO_SSLv2 | C.SSL_OP_NO_SSLv3 | C.SSL_OP_NO_COMPRESSION 
+	C.SSL_CTX_set_options(ctx, flags) 
+	mut res := C.SSL_CTX_load_verify_locations(ctx, 'random-org-chain.pem', 0) 
+	if res != 1 {
+	} 
+	web := C.BIO_new_ssl_connect(ctx) 
+	if isnil(ctx) { 
+	} 
+	addr := host_name + ':443' 
+	res = C.BIO_set_conn_hostname(web, addr.str) 
+	if res != 1 {
+	} 
+	ssl := &C.SSL{!} 
+	C.BIO_get_ssl(web, &ssl) 
+	if isnil(ssl) { 
+	} 
+	preferred_ciphers := 'HIGH:!aNULL:!kRSA:!PSK:!SRP:!MD5:!RC4' 
+	res = C.SSL_set_cipher_list(ssl, preferred_ciphers.str) 
+	if res != 1 {
+	} 
+	res = C.SSL_set_tlsext_host_name(ssl, host_name.str) 
+	out := C.BIO_new_fp(stdout, C.BIO_NOCLOSE) 
+	res = C.BIO_do_connect(web) 
+	res = C.BIO_do_handshake(web) 
+	cert := C.SSL_get_peer_certificate(ssl) 
+	res = C.SSL_get_verify_result(ssl) 
+	/////// 
+	s := '$method $path HTTP/1.1\r\n' + 
+	     'Host: $host_name\r\n' + 
+	     'Connection: close\r\n\r\n' 
+	C.BIO_puts(web, s.str) 
+	C.BIO_puts(out, '\n') 
+	mut sb := strings.new_builder(100) 
+	for {
+		buff := [1536]byte 
+		len := int(C.BIO_read(web, buff, 1536) ) 
+		if len > 0 { 
+			sb.write(tos(buff, len)) 
+		} 
+		else {
+			break 
+		} 
+	} 
+	if !isnil(out) { 
+		C.BIO_free(out) 
+	} 
+	if !isnil(web) { 
+		C.BIO_free_all(web)
+	} 
+	if !isnil(ctx) { 
+		C.SSL_CTX_free(ctx) 
+	} 
+	return sb.str() 
+}