added login api

config/config.go

@@ -0,0 +1,15 @@
+package config
+
+const MIN_USERNAME_LENGTH = 4
+
+const MAX_USERNAME_LENGTH = 20
+
+const MIN_PASSWORD_LENGTH = 8
+
+const MAX_PASSWORD_LENGTH = 128
+
+const PASSWORD_REGEX = `^[A-Za-z0-9!@#$%^&*(),.?":{}|<>]+$`
+
+const USERNAME_REGEX = `^[a-zA-Z0-9_]+$`
+
+const BCRYPT_COST = 16