Merge branch 'addexamples' into 'master'

Add examples

See merge request ProtonMail/go-pm-crypto!20

README.md

@@ -44,7 +44,71 @@ If you use build.sh, you may need to modify the paths in it.
 
 ### Encrypt and decrypt
 
+Encryption and decryption will use the AES256 algorithm by default.
+
+#### Encrypt / Decrypt with password
+```
+var pmCrypto = PmCrypto{}
+
+const password = "my secret password"
+
+// Encrypt data with password
+armor, err := pmCrypto.EncryptMessageWithPassword("my message", password)
+
+// Decrypt data with password
+message, err := pmCrypto.DecryptMessageWithPassword(armor, password)
+```
+
+#### Encrypt / Decrypt with PGP keys
+```
+// put keys in backtick (``) to avoid errors caused by spaces or tabs
+const pubkey = `-----BEGIN PGP PUBLIC KEY BLOCK-----
+...
+-----END PGP PUBLIC KEY BLOCK-----`
+
+const privkey = `-----BEGIN PGP PRIVATE KEY BLOCK-----
+...
+-----END PGP PRIVATE KEY BLOCK-----` // encrypted private key
+
+const passphrase = `the passphrase of the private key` // what the privKey is encrypted with
+
+privateKeyRing, err := crypto.ReadArmoredKeyRing(strings.NewReader(privkey))
+publicKeyRing, err := crypto.ReadArmoredKeyRing(strings.NewReader(pubkey))
+
+// encrypt message using public key and can be optionally signed using private key and passphrase
+armor, err := pmCrypto.EncryptMessage("plain text", publicKeyRing, privateKeyRing, passphrase, false)
+// OR
+privateKeyRing.Unlock([]byte(passphrase)) // if private key is locked with passphrase
+armor, err := publicKeyRing.EncryptString("plain text", privateKeyRing)
+
+// decrypt armored encrypted message using the private key and the passphrase of the private key
+plainText, err := pmCrypto.DecryptMessage(armor, privateKeyRing, passphrase)
+// OR
+signedText, err := privateKeyRing.DecryptString(armor)
+plainText = signedText.String
+
+```
+
 ### Generate key
+Keys are generated with the `GenerateKey` function, that returns the armored key as a string and a potential error.  
+The library supports RSA with different key lengths or Curve25519 keys.
+```
+var pmCrypto = PmCrypto{}
+
+var (
+  localPart = "name.surname"
+  domain = "example.com"
+  passphrase = "LongSecret"
+  rsaBits = 2048
+  ecBits = 256
+)
+
+// RSA
+rsaKey, err := pmCrypto.GenerateKey(localPart, domain, passphrase, "rsa", rsaBits)
+
+// Curve 25519
+ecKey, err := pmCrypto.GenerateKey(localPart, domain, passphrase, "x25519", ecBits)
+```
 
 ### Sign
 

crypto/message.go

@@ -55,7 +55,6 @@ func (pm *PmCrypto) DecryptMessage(encryptedText string, privateKey *KeyRing, pa
 		return "", err
 	}
 
-	println(4)
 	return string(b), nil
 }
 

crypto/message_test.go

@@ -0,0 +1,49 @@
+package crypto
+
+import (
+	"github.com/stretchr/testify/assert"
+	"strings"
+	"testing"
+)
+
+func TestMessageEncryptionWithPassword(t *testing.T) {
+	var pmCrypto = PmCrypto{}
+
+	const password = "my secret password"
+
+	// Encrypt data with password
+	armor, err := pmCrypto.EncryptMessageWithPassword("my message", password)
+	if err != nil {
+		t.Fatal("Expected no error when encrypting, got:", err)
+	}
+	// Decrypt data with wrong password
+	text, err := pmCrypto.DecryptMessageWithPassword(armor, "wrong password")
+	assert.NotNil(t, err)
+	// Decrypt data with the good password
+	text, err = pmCrypto.DecryptMessageWithPassword(armor, password)
+	if err != nil {
+		t.Fatal("Expected no error when decrypting, got:", err)
+	}
+	assert.Exactly(t, "my message", text)
+}
+
+func TestMessageEncryption(t *testing.T) {
+	var pmCrypto = PmCrypto{}
+	var (
+		message = "plain text"
+	)
+
+	testPrivateKeyRing, err = ReadArmoredKeyRing(strings.NewReader(readTestFile("keyring_privateKey")))
+	testPrivateKeyRing.Unlock([]byte(testMailboxPassword))
+	testPublicKeyRing, err = ReadArmoredKeyRing(strings.NewReader(readTestFile("keyring_publicKey")))
+
+	armor, err := pmCrypto.EncryptMessage(message, testPublicKeyRing, testPrivateKeyRing, testMailboxPassword, false)
+	if err != nil {
+		t.Fatal("Expected no error when encrypting, got:", err)
+	}
+	plainText, err := pmCrypto.DecryptMessage(armor, testPrivateKeyRing, testMailboxPassword)
+	if err != nil {
+		t.Fatal("Expected no error when decrypting, got:", err)
+	}
+	assert.Exactly(t, message, plainText)
+}