1 files changed, 49 insertions, 0 deletions
diff --git a/api/src/util/utility/passwordStrength.ts b/api/src/util/utility/passwordStrength.ts
new file mode 100644
index 00000000..047df008
--- /dev/null
+++ b/api/src/util/utility/passwordStrength.ts
@@ -0,0 +1,49 @@
+import { Config } from "@fosscord/util";
+import "missing-native-js-functions";
+
+const reNUMBER = /[0-9]/g;
+const reUPPERCASELETTER = /[A-Z]/g;
+const reSYMBOLS = /[A-Z,a-z,0-9]/g;
+
+const blocklist: string[] = []; // TODO: update ones passwordblocklist is stored in db
+/*
+ * https://en.wikipedia.org/wiki/Password_policy
+ * password must meet following criteria, to be perfect:
+ *  - min <n> chars
+ *  - min <n> numbers
+ *  - min <n> symbols
+ *  - min <n> uppercase chars
+ *
+ * Returns: 0 > pw > 1
+ */
+export function checkPassword(password: string): number {
+	const { minLength, minNumbers, minUpperCase, minSymbols } = Config.get().register.password;
+	var strength = 0;
+
+	// checks for total password len
+	if (password.length >= minLength - 1) {
+		strength += 0.25;
+	}
+
+	// checks for amount of Numbers
+	if (password.count(reNUMBER) >= minNumbers - 1) {
+		strength += 0.25;
+	}
+
+	// checks for amount of Uppercase Letters
+	if (password.count(reUPPERCASELETTER) >= minUpperCase - 1) {
+		strength += 0.25;
+	}
+
+	// checks for amount of symbols
+	if (password.replace(reSYMBOLS, "").length >= minSymbols - 1) {
+		strength += 0.25;
+	}
+
+	// checks if password only consists of numbers or only consists of chars
+	if (password.length == password.count(reNUMBER) || password.length === password.count(reUPPERCASELETTER)) {
+		strength = 0;
+	}
+
+	return strength;
+}