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@0xbb
Last active October 17, 2015 23:35
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Sends a TLS 1.2 Client Hello and extracts the resulting random bytes from the Server Hello
#!/usr/bin/env python3
# Usage: ./tlsrand server port
import socket
import sys
hello = bytearray([3, 3]) # Version: TLS 1.2
hello += bytearray([0]*32) # Random
hello += bytearray([
0, # Session ID Length
0, 6, # Cipher Suites Length
0xc0, 0x2f, # TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
0, 0x2f, # TLS_RSA_WITH_AES_128_CBC_SHA
0, 0x39, # TLS_DHE_RSA_WITH_AES_256_CBC_SHA
1, # Compression Methods Length: 1
0, # Compression Method: null
0, 0 # Extensions Length
])
msg = bytearray([1]) # Handshake Type: Client Hello
msg += bytearray([0, 0, len(hello)]) + hello
record = bytearray([
0x16, # Content Type: Handshake
3, 3 # Version TLS 1.2
])
record += bytearray([0, len(msg)]) + msg
s = socket.socket()
s.connect((sys.argv[1], int(sys.argv[2])))
s.sendall(record)
buf = s.recv(4096)
s.close()
if buf[0] == 0x16 and buf[5] == 2: # Response is: Handshake + Server Hello
sys.stdout.buffer.write(buf[15:15+28])
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