refactor: prepare backend refactor

backend-legacy/utils.py

@@ -0,0 +1,64 @@
+import hashlib
+import random
+import uuid
+import time
+import math
+import re
+
+USERNAME_PATTERN: re.Pattern = re.compile("^[0-9A-Za-z]+$")
+PASSWORD_PATTERN: re.Pattern = re.compile("^[!-~]+$")
+
+
+def IsValidUsername(strl: str) -> bool:
+    return USERNAME_PATTERN.match(strl) is not None
+
+
+def IsValidPassword(strl: str) -> bool:
+    return PASSWORD_PATTERN.match(strl) is not None
+
+
+def ComputePasswordHash(password: str) -> str:
+    s = hashlib.sha256()
+    s.update(password.encode("utf-8"))
+    return s.hexdigest()
+
+
+def GenerateUUID() -> str:
+    return str(uuid.uuid1())
+
+
+def GenerateToken(username: str) -> str:
+    s = hashlib.sha256()
+    s.update(username.encode("utf-8"))
+    s.update(GenerateUUID().encode("utf-8"))
+    return s.hexdigest()
+
+
+def GenerateSalt() -> int:
+    return random.randint(0, 6172748)
+
+
+def ComputePasswordHashWithSalt(passwordHashed: str, salt: int) -> str:
+    s = hashlib.sha256()
+    s.update((passwordHashed + str(salt)).encode("utf-8"))
+    return s.hexdigest()
+
+
+def GetCurrentTimestamp() -> int:
+    return int(time.time())
+
+
+def GetTokenExpireOn() -> int:
+    return GetCurrentTimestamp() + 60 * 60 * 24 * 2  # add 2 day from now
+
+
+def Str2Bool(strl: str) -> bool:
+    return strl.lower() == "true"
+
+
+def GCD(a: int, b: int) -> int:
+    return math.gcd(a, b)
+
+
+def LCM(a: int, b: int) -> int:
+    return (a * b) // GCD(a, b)