server: implement working db transaction with users

server/api/auth.go

@@ -0,0 +1,13 @@
+package api
+
+import "golang.org/x/crypto/bcrypt"
+
+func hashPassword(password string) (string, error) {
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password),
+		bcrypt.DefaultCost)
+	return string(hashedPassword), err
+}
+
+func validatePassword(hashedPassword, password string) error {
+	return bcrypt.CompareHashAndPassword([]byte(hashedPassword), []byte(password))
+}