--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/go/crypto.go	Sun Sep 30 17:27:04 2018 +0900
@@ -0,0 +1,77 @@
+/*
+ crypto.go  : crypto-program.
+ Version    : 0.0
+ Last Change: 2018-09-30 Sun 16:47:45.
+
+ install to: rsearcher_root/
+             server_root/
+*/
+package main
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"flag"
+	"os"
+)
+
+func main() {
+	salt := flag.String( "s", "#!@-", "salt." )
+	enca := flag.String( "a", "", "encrypt plaintext." )
+	encb := flag.String( "b", "", "encrypt csv-file." )
+	coll := flag.String( "c", "", "collate user/password." )
+
+	decr := flag.String( "d", "", "deecrypt hhs." )
+	encr := flag.String( "e", "", "encrypt hhs." )
+	chdb := flag.String( "f", "", "collate hhs." )
+	chhs := flag.String( "g", "", "collate hhs." )
+
+	flag.Parse()
+
+	if *enca != "" {
+		buf := *salt + enc_sha256( *enca ) + *salt
+		fmt.Println( enc_sha256( buf ) )
+		os.Exit( 0 )	// done.
+	}
+
+	if *encb != "" {
+		r := csv.NewReader(strings.NewReader(in))
+		for {
+			record, err := r.Read()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				log.Fatal( err )
+			}
+			buf := *salt + enc_sha256( record[1] ) + *salt
+			fmt.Println( record[0], ",", enc_sha256( buf ) )
+		}
+	}
+
+	if *coll != "" {
+	}
+
+	if *decr != "" {
+	}
+
+	if *encr != "" {
+	}
+
+	if *chdb != "" && *chhs != "" {
+	}
+
+	fmt.Fprintf( os.Stderr, "bad argument\n" )
+	os.Exit( 1 )
+}
+
+func enc_sha256( text string ) string {
+	h := sha256.New()
+	h.Write( []byte( text ) )
+	return fmt.Sprintf( "%x", h.Sum( nil ) )
+}
+
+func encrypt( text string ) []byte {
+	return nil
+}
+