add gnutls certificate support

certificate.go

@@ -0,0 +1,184 @@
+package gnutls
+
+/*
+#include "_gnutls.h"
+*/
+import "C"
+import (
+	"fmt"
+	"log"
+	"strings"
+	"unsafe"
+)
+
+// Certificate x509 certificate
+type Certificate struct {
+	cert     *C.gnutls_pcert_st
+	privkey  C.gnutls_privkey_t
+	certSize C.int
+	names    []string
+}
+
+// Free free the certificate context
+func (c *Certificate) Free() {
+	if c.cert != nil {
+		C.free_cert_list(c.cert, c.certSize)
+	}
+	if c.privkey != nil {
+		C.gnutls_privkey_deinit(c.privkey)
+	}
+	c.cert = nil
+	c.privkey = nil
+	c.certSize = 0
+}
+
+func (c *Certificate) matchName(name string) bool {
+	for _, n := range c.names {
+		if n == name {
+			return true
+		}
+		if strings.HasPrefix(n, "*") {
+			n1 := strings.Replace(n, "*.", "", 1)
+			if strings.HasSuffix(name, n1) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (c *Certificate) buildNames() {
+	if c.names != nil {
+		return
+	}
+	c.names = []string{}
+	for i := 0; i < int(c.certSize); i++ {
+		cn := c.commonName(i)
+		if cn != "" {
+			c.names = append(c.names, cn)
+		}
+	}
+}
+
+// CommonName get CN field in subject
+// example: subject C=xx,ST=bbb,CN=abc will return abc
+func (c *Certificate) CommonName() string {
+	return c.commonName(0)
+}
+func (c *Certificate) commonName(index int) string {
+	dnMap := make(map[string]string)
+	dn := c.getDN(0)
+	if dn != "" {
+		dnFields := strings.Split(dn, ",")
+		for _, d := range dnFields {
+			dd := strings.Split(d, "=")
+			k := dd[0]
+			v := dd[1]
+			dnMap[k] = v
+		}
+	}
+
+	if cn, ok := dnMap["CN"]; ok {
+		return cn
+	}
+	return ""
+}
+
+// GetAltName get altname in certificate
+func (c *Certificate) GetAltName() string {
+	return c.getAltName(0, 0)
+}
+func (c *Certificate) getAltName(index int, nameindex int) string {
+	out := C.malloc(1024)
+	defer C.free(out)
+	size := C.get_pcert_alt_name(
+		c.cert, C.int(index), C.int(nameindex), (*C.char)(out))
+	if int(size) < 0 {
+		log.Println(C.GoString(C.gnutls_strerror(size)))
+		return ""
+	}
+
+	name := C.GoBytes(out, size)
+	return string(name)
+}
+
+//GetCertString get cert info string
+func (c *Certificate) GetCertString() string {
+	return c.getCertString(0, 1)
+}
+
+func (c *Certificate) getCertString(index int, flag int) string {
+	out := C.malloc(4096)
+	defer C.free(out)
+	size := C.get_cert_str(c.cert, C.int(index), C.int(flag), (*C.char)(out))
+	if int(size) < 0 {
+		log.Println(C.GoString(C.gnutls_strerror(size)))
+		return ""
+	}
+	s := C.GoBytes(out, size)
+	return string(s)
+}
+
+// GetDN get the subject like O=st,C=aa,CN=localhost
+func (c *Certificate) GetDN() string {
+	return c.getDN(0)
+}
+
+func (c *Certificate) getDN(index int) string {
+	cbuf := C.malloc(200)
+	defer C.free(cbuf)
+	size := C.get_cert_dn(c.cert, C.int(index), (*C.char)(cbuf))
+	if int(size) < 0 {
+		log.Println(C.GoString(C.gnutls_strerror(size)))
+		return ""
+	}
+	s := C.GoBytes(cbuf, size)
+	return string(s)
+}
+
+// GetIssuerDN get the issuer's subject like O=st,C=ac,CN=localhost
+func (c *Certificate) GetIssuerDN() string {
+	return c.getIssuerDN(0)
+}
+
+func (c *Certificate) getIssuerDN(index int) string {
+	cbuf := C.malloc(200)
+	defer C.free(cbuf)
+	size := C.get_cert_issuer_dn(c.cert, C.int(index), (*C.char)(cbuf))
+	if int(size) < 0 {
+		log.Println(C.GoString(C.gnutls_strerror(size)))
+		return ""
+	}
+	s := C.GoBytes(cbuf, size)
+	return string(s)
+}
+
+// LoadX509KeyPair load certificate pair,
+// the return Certifciate must be freed by call Free()
+func LoadX509KeyPair(certfile, keyfile string) (*Certificate, error) {
+	_certfile := C.CString(certfile)
+	_keyfile := C.CString(keyfile)
+
+	defer C.free(unsafe.Pointer(_certfile))
+	defer C.free(unsafe.Pointer(_keyfile))
+
+	certificate := &Certificate{}
+	var ret C.int
+	var certSize C.int
+	cert := C.load_cert_list(_certfile, (*C.int)(unsafe.Pointer(&certSize)),
+		(*C.int)(unsafe.Pointer(&ret)))
+	if int(ret) < 0 {
+		return nil, fmt.Errorf("load cert failed: %s",
+			C.GoString(C.gnutls_strerror(ret)))
+	}
+	privkey := C.load_privkey(_keyfile, (*C.int)(unsafe.Pointer(&ret)))
+	if int(ret) < 0 {
+		return nil, fmt.Errorf("load privkey: %s",
+			C.GoString(C.gnutls_strerror(ret)))
+	}
+	certificate.cert = cert
+	certificate.privkey = privkey
+	certificate.certSize = certSize
+	certificate.buildNames()
+	return certificate, nil
+}

certificate_test.go

@@ -0,0 +1,24 @@
+package gnutls
+
+import (
+	"log"
+	"testing"
+)
+
+func TestGetAltname(t *testing.T) {
+	cert, err := LoadX509KeyPair("testdata/server.crt", "testdata/server.key")
+	if err != nil {
+		t.Fatal(err)
+	}
+	log.Printf("%+v", cert)
+	log.Println(cert.GetAltName())
+	log.Println(cert.GetCertString())
+	log.Println(cert.GetDN())
+	log.Println(cert.GetIssuerDN())
+	log.Println("CN ", cert.CommonName())
+	//log.Println("flag 0: ", cert.getCertString(0, 0))
+	//log.Println("flag 1: ", cert.getCertString(0, 1))
+	//log.Println("flag 2: ", cert.getCertString(0, 2))
+	//log.Println("flag 3: ", cert.getCertString(0, 3))
+	cert.Free()
+}