inital working commit

commands/generate-keypair.go

@@ -0,0 +1,71 @@
+package commands
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"github.com/siteworxpro/rsa-file-encryption/printer"
+	"os"
+)
+
+func GenerateKeypair(bitSize uint, path string, overwrite bool) error {
+	if bitSize == 0 {
+		bitSize = 4096
+	}
+
+	if bitSize < 2048 {
+		return fmt.Errorf("key to weak. size must be greater than 2048")
+	}
+
+	if bitSize > 16384 {
+		return fmt.Errorf("key to large. size must be less than 16384")
+	}
+
+	if _, err := os.Stat(path); err == nil && !overwrite {
+		return fmt.Errorf("key file already exists - use another filename or -force (-F) to overwrite")
+	}
+
+	p := printer.NewPrinter()
+	c := make(chan bool)
+
+	go p.LogSpinner("Generating RSA key...", c)
+	key, err := rsa.GenerateKey(rand.Reader, int(bitSize))
+	c <- true
+
+	if err != nil {
+		return err
+	}
+
+	pub := key.Public()
+
+	keyPEM := pem.EncodeToMemory(
+		&pem.Block{
+			Type:  "RSA PRIVATE KEY",
+			Bytes: x509.MarshalPKCS1PrivateKey(key),
+		},
+	)
+
+	pubPEM := pem.EncodeToMemory(
+		&pem.Block{
+			Type:  "RSA PUBLIC KEY",
+			Bytes: x509.MarshalPKCS1PublicKey(pub.(*rsa.PublicKey)),
+		},
+	)
+
+	p.LogInfo("Writing private key...")
+	err = os.WriteFile(path, keyPEM, 0600)
+	if err != nil {
+		return err
+	}
+
+	p.LogInfo("Writing public key...")
+	err = os.WriteFile(path+".pub", pubPEM, 0644)
+	if err != nil {
+		return err
+	}
+
+	p.LogSuccess("Done!")
+	return nil
+}