inital working commit

crypt/keys.go

@@ -0,0 +1,130 @@
+package crypt
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha512"
+	"crypto/x509"
+	"encoding/pem"
+	"os"
+)
+
+func (f *EncryptedFile) encryptSymmetricKey() error {
+	hash := sha512.New()
+	ciphertext, err := rsa.EncryptOAEP(hash, rand.Reader, f.PublicKey, f.symmetricKey, nil)
+	if err != nil {
+		return err
+	}
+
+	f.symmetricKeyEnc = ciphertext
+
+	return nil
+}
+
+func (f *EncryptedFile) decryptSymmetricKey() error {
+	hash := sha512.New()
+	plaintext, err := rsa.DecryptOAEP(hash, rand.Reader, f.privateKey, f.symmetricKeyEnc, nil)
+	if err != nil {
+		return err
+	}
+
+	f.symmetricKey = plaintext
+
+	return nil
+}
+
+func (f *EncryptedFile) OsReadPublicKey(path string) error {
+	pemKey, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	f.PublicPem = pemKey
+	err = f.ParsePublicPem()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (f *EncryptedFile) OsReadPrivateKey(path string) error {
+	pemKey, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	f.privatePem = pemKey
+
+	err = f.ParsePrivatePem()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (f *EncryptedFile) GenerateSymmetricKey() error {
+	symKey := make([]byte, 32)
+	_, err := rand.Read(symKey)
+	if err != nil {
+		return err
+	}
+
+	f.symmetricKey = symKey
+
+	err = f.encryptSymmetricKey()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (f *EncryptedFile) ParsePublicPem() error {
+	pemKeyBin, _ := pem.Decode(f.PublicPem)
+
+	if bytes.Contains(f.PublicPem, []byte("-----BEGIN PUBLIC KEY-----")) {
+		key, err := x509.ParsePKIXPublicKey(pemKeyBin.Bytes)
+		if err != nil {
+			return err
+		}
+
+		f.PublicKey = key.(*rsa.PublicKey)
+		return nil
+	}
+
+	pubKey, err := x509.ParsePKCS1PublicKey(pemKeyBin.Bytes)
+
+	if err != nil {
+		return err
+	}
+
+	f.PublicKey = pubKey
+
+	return nil
+}
+
+func (f *EncryptedFile) ParsePrivatePem() error {
+	pemKeyBin, _ := pem.Decode(f.privatePem)
+
+	if bytes.Contains(f.privatePem, []byte("-----BEGIN PRIVATE KEY-----")) {
+		key, err := x509.ParsePKCS8PrivateKey(pemKeyBin.Bytes)
+		if err != nil {
+			return err
+		}
+
+		f.privateKey = key.(*rsa.PrivateKey)
+		return nil
+	}
+
+	privKey, err := x509.ParsePKCS1PrivateKey(pemKeyBin.Bytes)
+	if err != nil {
+		return err
+	}
+
+	f.privateKey = privKey
+
+	return nil
+}