Go API for GmSSL

go/mac.go

@@ -0,0 +1,76 @@
+/* +build cgo */
+
+package gmssl
+
+/*
+#include <openssl/hmac.h>
+#include <openssl/cmac.h>
+*/
+import "C"
+
+import (
+	"errors"
+	"fmt"
+	"runtime"
+	"unsafe"
+)
+
+func GetMacs(aliases bool) []string {
+	return []string{"hello", "world"}
+}
+
+func GetMacKeyLength(name string) (int, error) {
+	return 0, nil
+}
+
+func GetMacLength(name string) (int, error) {
+	return 0, nil
+}
+
+type MACContext struct {
+	hctx *C.HMAC_CTX
+}
+
+func NewMACContext(name string, args map[string]string, key []byte) (*MACContext, error) {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	md := C.EVP_get_digestbyname(cname)
+	if md == nil {
+		return nil, fmt.Errorf("shit")
+	}
+
+	ctx := C.HMAC_CTX_new()
+	if ctx == nil {
+		return nil, fmt.Errorf("shit")
+	}
+
+	ret := &MACContext{ctx}
+	runtime.SetFinalizer(ret, func(ret *MACContext) {
+		C.HMAC_CTX_free(ret.hctx)
+	})
+
+	if 1 != C.HMAC_Init_ex(ctx, unsafe.Pointer(&key[0]), C.int(len(key)), md, nil) {
+		return nil, fmt.Errorf("shit")
+	}
+
+	return ret, nil
+}
+
+func (ctx *MACContext) Update(data []byte) error {
+	if len(data) == 0 {
+		return nil
+	}
+	if 1 != C.HMAC_Update(ctx.hctx, (*C.uchar)(unsafe.Pointer(&data[0])), C.size_t(len(data))) {
+		return errors.New("hello")
+	}
+	return nil
+}
+
+func (ctx *MACContext) Final() ([]byte, error) {
+	outbuf := make([]byte, 64)
+	outlen := C.uint(len(outbuf))
+	if 1 != C.HMAC_Final(ctx.hctx, (*C.uchar)(unsafe.Pointer(&outbuf[0])), &outlen) {
+		return nil, errors.New("error")
+	}
+	return outbuf[:outlen], nil
+}