Encrypt passwords in DB (#1187)

* Encode/Encrypt passwords in DB

* Only decrypts passwords if it is necessary

* Add tests for encryption functions

utils/encrypt_test.go

@@ -0,0 +1,38 @@
+package utils
+
+import (
+	"context"
+	"crypto/sha256"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("encrypt", func() {
+	It("decrypts correctly when using the same encryption key", func() {
+		sum := sha256.Sum256([]byte("password"))
+		encKey := sum[0:]
+		data := "Can you keep a secret?"
+
+		encrypted, err := Encrypt(context.Background(), encKey, data)
+		Expect(err).ToNot(HaveOccurred())
+		decrypted, err := Decrypt(context.Background(), encKey, encrypted)
+		Expect(err).ToNot(HaveOccurred())
+
+		Expect(decrypted).To(Equal(data))
+	})
+
+	It("fails to decrypt if not using the same encryption key", func() {
+		sum := sha256.Sum256([]byte("password"))
+		encKey := sum[0:]
+		data := "Can you keep a secret?"
+
+		encrypted, err := Encrypt(context.Background(), encKey, data)
+		Expect(err).ToNot(HaveOccurred())
+
+		sum = sha256.Sum256([]byte("different password"))
+		encKey = sum[0:]
+		_, err = Decrypt(context.Background(), encKey, encrypted)
+		Expect(err).To(MatchError("cipher: message authentication failed"))
+	})
+})