feat: add rsa key generator command

internal/cmd/key/key.go

@@ -16,6 +16,10 @@ func Key() *cobra.Command {
 		Example: "jwt key rsa|hmac|ecdsa",
 	}
 
+	c.AddCommand(
+		rsaCommand(),
+	)
+
 	return c
 }
 
@@ -36,7 +40,7 @@ func key(_ *cobra.Command, _ []string) {
 
 	switch config.SigningMethod(selected) {
 	case config.RSA:
-
+		rsa(nil, nil)
 	case config.HMAC:
 
 	case config.ECDSA:

internal/cmd/key/rsa.go

@@ -0,0 +1,66 @@
+package key
+
+import (
+	"log"
+	"os"
+	"strconv"
+
+	"github.com/AlecAivazis/survey/v2"
+	keyGenerator "github.com/mehditeymorian/jwt/internal/key"
+	"github.com/spf13/cobra"
+)
+
+func rsaCommand() *cobra.Command {
+	c := &cobra.Command{
+		Use:     "rsa",
+		Short:   "generate rsa key",
+		Example: "jwt key rsa",
+		Run:     rsa,
+	}
+
+	return c
+}
+
+func rsa(_ *cobra.Command, _ []string) {
+
+	prompt := &survey.Select{
+		Message: "select number of bits",
+		Options: []string{
+			"512",
+			"1024",
+			"2048",
+			"4096",
+		},
+	}
+
+	var bitsStr string
+
+	survey.AskOne(prompt, &bitsStr)
+
+	bits, _ := strconv.ParseInt(bitsStr, 10, 64)
+
+	publicKey, privateKey := keyGenerator.GenerateRsaKeys(int(bits))
+
+	dir, _ := os.Getwd()
+
+	publicPem, err := os.Create(dir + "/public.pem")
+	if err != nil {
+		log.Fatalf("failed to create public pem file: %v\n", err)
+	}
+	defer publicPem.Close()
+
+	publicPem.WriteString(publicKey)
+
+	privatePem, err := os.Create(dir + "/private.pem")
+	if err != nil {
+		log.Fatalf("failed to create private pem file: %v\n", err)
+	}
+	defer privatePem.Close()
+
+	privatePem.WriteString(privateKey)
+
+	log.Printf(`
+	Publickey: %s/public.pem
+	PrivateKey: %s/private.pem
+`, dir, dir)
+}

internal/key/rsa.go

@@ -3,13 +3,20 @@ package key
 import (
 	"crypto/rand"
 	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
 )
 
-func GenerateRsaKeys() (*rsa.PublicKey, *rsa.PrivateKey) {
-	privateKey, err := rsa.GenerateKey(rand.Reader, 1024)
+func GenerateRsaKeys(bits int) (string, string) {
+	privateKey, err := rsa.GenerateKey(rand.Reader, bits)
 	if err != nil {
-		return nil, nil
+		return "", ""
 	}
 
-	return &privateKey.PublicKey, privateKey
+	publicKey := &privateKey.PublicKey
+	pemEncodedPub := pem.EncodeToMemory(&pem.Block{Type: "PUBLIC KEY", Bytes: x509.MarshalPKCS1PublicKey(publicKey)})
+
+	pemEncoded := pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)})
+
+	return string(pemEncodedPub), string(pemEncoded)
 }