def test_ofb_symmetric(self):
for _ in range(100):
pt = urandom(randint(0, 16 * 2))
iv = urandom(8 * 2)
ciph = GOST3412Magma(urandom(32))
ct = ofb(ciph.encrypt, 8, pt, iv)
self.assertSequenceEqual(ofb(ciph.encrypt, 8, ct, iv), pt)
def test_ofb_vectors(self):
iv = self.iv[:16]
ciphtext = ""
ciphtext += "db37e0e266903c83"
ciphtext += "0d46644c1f9a089c"
ciphtext += "a0f83062430e327e"
ciphtext += "c824efb8bd4fdb05"
self.assertSequenceEqual(
hexenc(ofb(self.ciph.encrypt, 8, hexdec(self.plaintext), iv)),
ciphtext,
)
self.assertSequenceEqual(
hexenc(ofb(self.ciph.encrypt, 8, hexdec(ciphtext), iv)),
self.plaintext,
)
def test_ofb_vectors(self):
ciphtext = ""
ciphtext += "81800a59b1842b24ff1f795e897abd95"
ciphtext += "ed5b47a7048cfab48fb521369d9326bf"
ciphtext += "66a257ac3ca0b8b1c80fe7fc10288a13"
ciphtext += "203ebbc066138660a0292243f6903150"
self.assertSequenceEqual(
hexenc(ofb(self.ciph.encrypt, 16, hexdec(self.plaintext),
self.iv)),
ciphtext,
)
self.assertSequenceEqual(
hexenc(ofb(self.ciph.encrypt, 16, hexdec(ciphtext), self.iv)),
self.plaintext,
)
def test_ofb_manual(self):
iv = [urandom(16) for _ in range(randint(2, 10))]
pt = [urandom(16) for _ in range(len(iv), len(iv) + randint(1, 10))]
ciph = GOST3412Kuznechik(urandom(32))
r = [ciph.encrypt(i) for i in iv]
for i in range(len(pt) - len(iv)):
r.append(ciph.encrypt(r[i]))
ct = [strxor(g, r) for g, r in zip(pt, r)]
self.assertSequenceEqual(
ofb(ciph.encrypt, 16, b"".join(pt), b"".join(iv)),
b"".join(ct),
)
def decrypt(self, ctxt):
res = gost3413.ofb(self.enc, self.blen, ctxt, self.iv)
return res
def encrypt(self, text):
res = gost3413.ofb(self.enc, self.blen, text, self.iv)
return res