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| 1 | +import http.server |
| 2 | +import sys |
| 3 | +import os |
| 4 | +import socket |
| 5 | +import ssl |
| 6 | +import random |
| 7 | +from datetime import datetime, timedelta, timezone |
| 8 | +from cryptography.hazmat.primitives import hashes, serialization |
| 9 | +from cryptography import utils, x509 |
| 10 | +from cryptography.hazmat.primitives.asymmetric import rsa, dsa |
| 11 | + |
| 12 | +import select |
| 13 | + |
| 14 | + |
| 15 | +def generateCA(ca_cert_file, ca_key_file): |
| 16 | + ca_key = dsa.generate_private_key(4096) |
| 17 | + name = x509.Name([ |
| 18 | + x509.NameAttribute(x509.NameOID.COUNTRY_NAME, "US"), |
| 19 | + x509.NameAttribute(x509.NameOID.ORGANIZATION_NAME, "GitHub"), |
| 20 | + x509.NameAttribute(x509.NameOID.COMMON_NAME, "GitHub CodeQL Proxy")]) |
| 21 | + ca_cert = x509.CertificateBuilder().subject_name(name).issuer_name(name) |
| 22 | + ca_cert = ca_cert.public_key(ca_key.public_key()) |
| 23 | + ca_cert = ca_cert.serial_number(random.randint(50000000, 100000000)) |
| 24 | + ca_cert = ca_cert.not_valid_before(datetime.now(timezone.utc)) |
| 25 | + ca_cert = ca_cert.not_valid_after( |
| 26 | + datetime.now(timezone.utc) + timedelta(days=3650)) |
| 27 | + ca_cert = ca_cert.add_extension(x509.BasicConstraints( |
| 28 | + ca=True, path_length=None), critical=True) |
| 29 | + ca_cert = ca_cert.add_extension( |
| 30 | + x509.SubjectKeyIdentifier.from_public_key(ca_key.public_key()), critical=False) |
| 31 | + ca_cert = ca_cert.sign(ca_key, hashes.SHA256()) |
| 32 | + with open(ca_cert_file, 'wb') as f: |
| 33 | + f.write(ca_cert.public_bytes(encoding=serialization.Encoding.PEM)) |
| 34 | + with open(ca_key_file, 'wb') as f: |
| 35 | + f.write(ca_key.private_bytes(encoding=serialization.Encoding.PEM, |
| 36 | + format=serialization.PrivateFormat.PKCS8, encryption_algorithm=serialization.NoEncryption())) |
| 37 | + |
| 38 | + |
| 39 | +def create_certificate(hostname): |
| 40 | + pkey = rsa.generate_private_key(public_exponent=65537, key_size=2048) |
| 41 | + subject = x509.Name( |
| 42 | + [x509.NameAttribute(x509.NameOID.COMMON_NAME, hostname)]) |
| 43 | + |
| 44 | + cert = x509.CertificateBuilder() |
| 45 | + cert = cert.subject_name(subject).issuer_name(ca_certificate.subject) |
| 46 | + cert = cert.public_key(pkey.public_key()) |
| 47 | + cert = cert.serial_number(random.randint(50000000, 100000000)) |
| 48 | + cert = cert.not_valid_before(datetime.now(timezone.utc)).not_valid_after( |
| 49 | + datetime.now(timezone.utc) + timedelta(days=3650)) |
| 50 | + cert = cert.add_extension(x509.BasicConstraints( |
| 51 | + ca=False, path_length=None), critical=True) |
| 52 | + cert = cert.add_extension( |
| 53 | + x509.SubjectAlternativeName([x509.DNSName(hostname), x509.DNSName(f"*.{hostname}")]), critical=False) |
| 54 | + |
| 55 | + cert = cert.sign(ca_key, hashes.SHA256()) |
| 56 | + |
| 57 | + return (cert, pkey) |
| 58 | + |
| 59 | + |
| 60 | +class Handler(http.server.SimpleHTTPRequestHandler): |
| 61 | + def check_auth(self): |
| 62 | + username = os.getenv('PROXY_USER') |
| 63 | + password = os.getenv('PROXY_PASSWORD') |
| 64 | + if username is None or password is None: |
| 65 | + return True |
| 66 | + |
| 67 | + authorization = self.headers.get( |
| 68 | + 'Proxy-Authorization', self.headers.get('Authorization', '')) |
| 69 | + authorization = authorization.split() |
| 70 | + if len(authorization) == 2: |
| 71 | + import base64 |
| 72 | + import binascii |
| 73 | + auth_type = authorization[0] |
| 74 | + if auth_type.lower() == "basic": |
| 75 | + try: |
| 76 | + authorization = authorization[1].encode('ascii') |
| 77 | + authorization = base64.decodebytes( |
| 78 | + authorization).decode('ascii') |
| 79 | + except (binascii.Error, UnicodeError): |
| 80 | + pass |
| 81 | + else: |
| 82 | + authorization = authorization.split(':') |
| 83 | + if len(authorization) == 2: |
| 84 | + return username == authorization[0] and password == authorization[1] |
| 85 | + return False |
| 86 | + |
| 87 | + def do_CONNECT(self): |
| 88 | + if not self.check_auth(): |
| 89 | + self.send_response( |
| 90 | + http.HTTPStatus.PROXY_AUTHENTICATION_REQUIRED) |
| 91 | + self.send_header('Proxy-Authenticate', 'Basic realm="Proxy"') |
| 92 | + self.end_headers() |
| 93 | + return |
| 94 | + # split self.path into host and port |
| 95 | + host, port = self.path.split(':') |
| 96 | + port = int(port) |
| 97 | + self.send_response(http.HTTPStatus.OK, 'Connection established') |
| 98 | + self.send_header('Connection', 'close') |
| 99 | + self.end_headers() |
| 100 | + self.mitm(host, port) |
| 101 | + |
| 102 | + # man in the middle SSL connection |
| 103 | + def mitm(self, host, port): |
| 104 | + ssl_client_context = ssl.create_default_context( |
| 105 | + purpose=ssl.Purpose.CLIENT_AUTH) |
| 106 | + if not os.path.exists("certs/" + host + '.pem'): |
| 107 | + cert, pkey = create_certificate(host) |
| 108 | + with open("certs/" + host + '.pem', 'wb') as f: |
| 109 | + f.write(pkey.private_bytes(encoding=serialization.Encoding.PEM, |
| 110 | + format=serialization.PrivateFormat.TraditionalOpenSSL, encryption_algorithm=serialization.NoEncryption())) |
| 111 | + f.write(cert.public_bytes(encoding=serialization.Encoding.PEM)) |
| 112 | + |
| 113 | + ssl_client_context.load_cert_chain("certs/" + host + '.pem') |
| 114 | + ssl_client_context.load_verify_locations(ca_certificate_path) |
| 115 | + # wrap self.connection in SSL |
| 116 | + client = ssl_client_context.wrap_socket( |
| 117 | + self.connection, server_side=True) |
| 118 | + |
| 119 | + # create socket to host:port |
| 120 | + remote = socket.create_connection( |
| 121 | + (host, port)) |
| 122 | + # wrap socket in SSL |
| 123 | + ssl_server_context = ssl.create_default_context( |
| 124 | + purpose=ssl.Purpose.SERVER_AUTH) |
| 125 | + remote = ssl_server_context.wrap_socket(remote, server_hostname=host) |
| 126 | + |
| 127 | + try: |
| 128 | + while True: |
| 129 | + ready, _, _ = select.select( |
| 130 | + [client, remote], [], [], 2.0) |
| 131 | + if not ready: |
| 132 | + break |
| 133 | + for src in ready: |
| 134 | + if src is client: |
| 135 | + dst = remote |
| 136 | + else: |
| 137 | + dst = client |
| 138 | + src.setblocking(False) |
| 139 | + dst.setblocking(True) |
| 140 | + pending = 8192 |
| 141 | + while pending: |
| 142 | + try: |
| 143 | + data = src.recv(pending) |
| 144 | + except ssl.SSLWantReadError: |
| 145 | + break |
| 146 | + if not data: |
| 147 | + return |
| 148 | + pending = src.pending() |
| 149 | + dst.sendall(data) |
| 150 | + finally: |
| 151 | + remote.close() |
| 152 | + client.close() |
| 153 | + |
| 154 | + def do_GET(self): |
| 155 | + raise NotImplementedError() |
| 156 | + |
| 157 | + |
| 158 | +if __name__ == '__main__': |
| 159 | + port = int(sys.argv[1]) |
| 160 | + ca_certificate = None |
| 161 | + ca_certificate_path = None |
| 162 | + ca_key = None |
| 163 | + if len(sys.argv) > 2: |
| 164 | + ca_certificate_path = sys.argv[2] |
| 165 | + with open(ca_certificate_path, 'rb') as f: |
| 166 | + ca_certificate = x509.load_pem_x509_certificate(f.read()) |
| 167 | + with open(sys.argv[3], 'rb') as f: |
| 168 | + ca_key = serialization.load_pem_private_key( |
| 169 | + f.read(), password=None) |
| 170 | + |
| 171 | + server_address = ('localhost', port) |
| 172 | + httpd = http.server.HTTPServer(server_address, Handler) |
| 173 | + httpd.serve_forever() |
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