diff options
Diffstat (limited to 'src/lib/tlslite/utils/Python_RC4.py')
-rwxr-xr-x | src/lib/tlslite/utils/Python_RC4.py | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/lib/tlslite/utils/Python_RC4.py b/src/lib/tlslite/utils/Python_RC4.py new file mode 100755 index 000000000..56ce5fb2f --- /dev/null +++ b/src/lib/tlslite/utils/Python_RC4.py @@ -0,0 +1,39 @@ +"""Pure-Python RC4 implementation.""" + +from RC4 import RC4 +from cryptomath import * + +def new(key): + return Python_RC4(key) + +class Python_RC4(RC4): + def __init__(self, key): + RC4.__init__(self, key, "python") + keyBytes = stringToBytes(key) + S = [i for i in range(256)] + j = 0 + for i in range(256): + j = (j + S[i] + keyBytes[i % len(keyBytes)]) % 256 + S[i], S[j] = S[j], S[i] + + self.S = S + self.i = 0 + self.j = 0 + + def encrypt(self, plaintext): + plaintextBytes = stringToBytes(plaintext) + S = self.S + i = self.i + j = self.j + for x in range(len(plaintextBytes)): + i = (i + 1) % 256 + j = (j + S[i]) % 256 + S[i], S[j] = S[j], S[i] + t = (S[i] + S[j]) % 256 + plaintextBytes[x] ^= S[t] + self.i = i + self.j = j + return bytesToString(plaintextBytes) + + def decrypt(self, ciphertext): + return self.encrypt(ciphertext) |