[PD1] cryptoUtils start and protocol tweaks

Projs/PD1/internal/utils/cryptoUtils/cryptoUtils.go

@@ -1,7 +1,49 @@
 package cryptoUtils
 
-import "fmt"
+import (
+	"PD1/internal/client"
+	"PD1/internal/protocol"
+	"crypto/rsa"
+	"crypto/x509"
+	"fmt"
+	"log"
+	"os"
+
+	"software.sslmate.com/src/go-pkcs12"
+)
+
+func Print() {
+	fmt.Println("crypto package")
+}
+
+func getUserInfo(certFilename string) (
+	rsa.PrivateKey,
+	*x509.Certificate,
+	[]*x509.Certificate,
+	error) {
+	var privKey rsa.PrivateKey
+
+	certFile, err := os.ReadFile(certFilename)
+	if err != nil {
+		log.Panicln("Provided certificate %v couldn't be opened", certFilename)
+		return rsa.PrivateKey{}, nil, nil, err
+	}
+
+	password := client.AskUserPassword()
+	privKeyInterface, cert, caCerts, err := pkcs12.DecodeChain(certFile, password)
+	privKey = privKeyInterface.(rsa.PrivateKey)
+	if err != nil {
+		log.Panicln("PKCS12 key store couldn't be decoded")
+		return rsa.PrivateKey{}, nil, nil, err
+	}
+	if err := privKey.Validate(); err != nil {
+		log.Panicln("Private key is not valid")
+		return rsa.PrivateKey{}, nil, nil, err
+	}
+	return privKey, cert, caCerts, nil
+}
+
+func encryptMessageContent(privKey rsa.PrivateKey, peerPubKey rsa.PublicKey, content []byte) []byte {
+	// Digital envolope
 
-func Print(){
-    fmt.Println("crypto package")
 }