僅匹配域名中最左側的通配符 - Python

Question

我正在嘗試爲域名中最左側的通配符編寫正則表達式。到目前爲止，我有這樣的：

import re 
    o = urlparse(argv[1]) 
host_name = o.netloc 
context = SSL.Context(SSL.TLSv1_METHOD) # Use TLS Method 
context.set_options(SSL.OP_NO_SSLv2) # Don't accept SSLv2 
context.set_verify(SSL.VERIFY_PEER | SSL.VERIFY_FAIL_IF_NO_PEER_CERT, 
        callback) 
# context.load_verify_locations(ca_file, ca_path) 

sock = socket() 
ssl_sock = SSL.Connection(context, sock) 
ssl_sock.connect((host_name, 443)) 
ssl_sock.set_connect_state() 
ssl_sock.set_tlsext_host_name(host_name) 
ssl_sock.do_handshake() 

cert = ssl_sock.get_peer_certificate() 
common_name = cert.get_subject().commonName.decode() 
print "Common Name: ", common_name 
print "Cert number: ", cert.get_serial_number() 
regex = common_name.replace('.', r'\.').replace('*',r'.*') + '$' 
if re.match(regex, host_name): 
    print "matches" 
else: 
    print "invalid" 

# output: 
Common Name: *.example.com 
Cert number: 63694395280496902491340707875731768741 

然而，正則表達式不僅*.example.com，但*.*.*或www.*.com匹配。此外，https://wrong.host.example.com/不應該被允許匹配。我怎樣才能確保它只匹配最左邊的標籤？

Answer 1

你可以使用urlparse和split來代替正則表達式。

from urlparse import urlparse 
. 
. 
common_name = cert.get_subject().commonName.decode() 
domain = urlparse(common_name).netloc 
host = domain.split('.',1)[0] 

Answer 2

你可以試試這個正則表達式：

r'(?:^|\s)(\w+\.)?example\.com(?:$|\s)' 

完整的示例：

sock = socket() 
ssl_sock = SSL.Connection(context, sock) 
ssl_sock.connect((host_name, 443)) 
ssl_sock.set_connect_state() 
ssl_sock.set_tlsext_host_name(host_name) 
ssl_sock.do_handshake() 

cert = ssl_sock.get_peer_certificate() 
common_name = cert.get_subject().commonName.decode() 
print "Common Name: ", common_name 
print "Cert number: ", cert.get_serial_number() 

rxString = r'(?:^|\s)(\w+\.)?' + common_name.replace('.', '\.')[3:] + '(?:$|\s)' 
regex = re.compile(rxString) 

if regex.match(host_name): 
    print "matches" 
else: 
    print "invalid" 

輸入：

url     
------------------- 
www.example.com  
example.com   
hello.example.com 
foo.bar.example.com 
*.*.*    
www.*.com   

輸出：

url     | result 
------------------- | ----------- 
www.example.com  | matches 
example.com   | matches 
hello.example.com | matches 
foo.bar.example.com | invalid 
*.*.*    | invalid 
www.*.com   | invalid