Upload files to "crypto"

lw2.py

@@ -188,7 +188,9 @@ if __name__ == "__main__":
         287390,
         480837,
     }
-    print("#2:", *(f"gcd({m}, {n}) = {gcd(m,n)}" for m, n in cooked(E2)), sep="\n")
+    dih = [f"gcd({m}, {n}) = {gcd(m,n)}" for m, n in cooked(E2)]
+    print("#2:", *dih, sep="\n")
+    print(f"pairs = {len(dih)}")
     print("#3:")
     fahhh(856, 25, 7)
     print(f"{pow(856, 25, 7) = }")

lw3.py

@@ -0,0 +1,40 @@
+def e1():
+    s = "flow"
+
+    return int(bytes(s, encoding="ascii").hex(), 16)
+
+
+def dec_ascii(i: int):
+    b = bytes.fromhex(f"{i:x}")
+    return b.decode("ascii")
+
+
+def e2():
+    i = 14445
+    return dec_ascii(i)
+
+
+from proto_rsa import LdaRsahh
+
+
+def e3():
+    a = LdaRsahh(p=251, q=191, e=65537).enc(26729)
+
+    b = LdaRsahh(p=233, q=151, d=9473).dec(29600)
+
+    return a, b
+
+
+def e4():
+    C = 412589464
+    M = LdaRsahh(p=81401, q=27109, e=65537).dec(C)
+    return dec_ascii(M)
+
+
+if __name__ == "__main__":
+    print("#1:", e1())
+    print("#2:", e2())
+    C, M = e3()
+    print("#3:", f"{C = }, {M = }")
+    print("#4:", e4())
+

proto_rsa.py

@@ -0,0 +1,73 @@
+def inv(a, n):
+    return pow(a, -1, n)
+
+
+import math
+from functools import cached_property
+from typing import Callable
+import warnings
+
+
+class LdaRsahh:
+    def __init__(
+        self,
+        p,
+        q,
+        d: int | None = None,
+        e: int | None = None,
+        ln_ops: Callable[[int, int], int] | None = None,
+    ):
+        # operator.mul or math.lcm
+        self._lnops = ln_ops or math.lcm
+        self._p, self._q = p, q
+        if d is None and e is None:
+            raise ValueError("at least d or e needs to be math.gcd(e, phi)fed in")
+        ln = self.ln
+        if e is None:
+            e = inv(d, ln)
+        if not 1 < e < ln:
+            warnings.warn(
+                f"{e = }, {ln = }, 1 < e < ln not satisfied, e rebinds to e % ln",
+                UserWarning,
+            )
+            e %= ln
+        if not 1 < e < ln:
+            raise ValueError(f"{e = }, {ln = }, 1 < e < ln not satisfied")
+        if math.gcd(e, ln) != 1:
+            raise ValueError(
+                f"{e = }, {ln = }, gcd(e, ln) == 1 (coprime) not satisfied"
+            )
+        if d is None:
+            d = inv(e, ln)
+        self._d, self._e = d, e
+
+    @cached_property
+    def n(self):
+        return self.p * self.q
+
+    @cached_property
+    def ln(self):
+        return self._lnops((self.p - 1), (self.q - 1))
+
+    @property
+    def p(self):
+        return self._p
+
+    @property
+    def q(self):
+        return self._q
+
+    @property
+    def d(self):
+        return self._d
+
+    @property
+    def e(self):
+        return self._e
+
+    def enc(self, m: int):
+        return pow(m, self.e, self.n)
+
+    def dec(self, c: int):
+        return pow(c, self.d, self.n)
+