Command: Add wg for wireguard key generation (#2794)

* Command: Add `wg` for wireguard key generation

* Command: Merge `x25519` and `wg`

main/commands/all/curve25519.go

@@ -0,0 +1,57 @@
+package all
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+
+	"golang.org/x/crypto/curve25519"
+)
+
+func Curve25519Genkey(StdEncoding bool, input_base64 string) {
+	var output string
+	var err error
+	var privateKey, publicKey []byte
+	var encoding *base64.Encoding
+	if *input_stdEncoding || StdEncoding {
+		encoding = base64.StdEncoding
+	} else {
+		encoding = base64.RawURLEncoding
+	}
+
+	if len(input_base64) > 0 {
+		privateKey, err = encoding.DecodeString(input_base64)
+		if err != nil {
+			output = err.Error()
+			goto out
+		}
+		if len(privateKey) != curve25519.ScalarSize {
+			output = "Invalid length of private key."
+			goto out
+		}
+	}
+
+	if privateKey == nil {
+		privateKey = make([]byte, curve25519.ScalarSize)
+		if _, err = rand.Read(privateKey); err != nil {
+			output = err.Error()
+			goto out
+		}
+	}
+
+	// Modify random bytes using algorithm described at:
+	// https://cr.yp.to/ecdh.html.
+	privateKey[0] &= 248
+	privateKey[31] &= 127 | 64
+
+	if publicKey, err = curve25519.X25519(privateKey, curve25519.Basepoint); err != nil {
+		output = err.Error()
+		goto out
+	}
+
+	output = fmt.Sprintf("Private key: %v\nPublic key: %v",
+		encoding.EncodeToString(privateKey),
+		encoding.EncodeToString(publicKey))
+out:
+	fmt.Println(output)
+}