1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
#!/usr/bin/python3
import argparse
import configparser
import datetime
import hashlib
import os
import pathlib
import secrets
import sys
import urllib.parse
CHRSET_NUM = "0123456789"
CHRSET_alpha = "abcdefghijklmnopqrstuvwxyz"
CHRSET_ALPHA = CHRSET_alpha.upper()
CHRSET_ALNUM = CHRSET_NUM + CHRSET_alpha + CHRSET_ALPHA
CHRSET_af = "abcdef"
CHRSET_AF = CHRSET_af.upper()
CHRSET_HEX = CHRSET_NUM + CHRSET_af + CHRSET_AF
class ConfigReader(object):
def __init__(self, path):
try:
self.__p = configparser.ConfigParser()
self.__p.read(path)
except configparser.Error as e:
raise Exception("Failed to parse config.")
def __get(self, section, option):
try:
return self.__p.get(section, option)
except configparser.Error as e:
raise Exception(f"Failed to parse config {section}/{option}.")
def __getlist(self, section, optionbase):
try:
return [ (int(v[0].split("_")[-1]), v[1])
for v in self.__p.items(section)
if v[0].startswith(optionbase + "_") ]
except (configparser.Error, ValueError, IndexError) as e:
raise Exception(f"Failed to parse config list {section}/{optionbase}_.")
def getUsers(self):
return self.__getlist("CREDENTIALS", "user")
def getPw(self, userIndex):
fields = self.__get("CREDENTIALS", f"pw_{userIndex}").split(":")
try:
if fields[2] != "pbkdf2hmac":
raise ValueError
return (bytes.fromhex(fields[0]), # password hash
bytes.fromhex(fields[1]), # salt
fields[3].strip().lower(), # kdf hash function
int(fields[4]) # kdf iterations
)
except (IndexError, ValueError) as e:
raise Exception(f"Failed to parse config CREDENTIALS/pw_{index}.")
def getDomains(self, userIndex):
return self.__getlist(f"DOMAINS_user_{userIndex}", "domain")
def getDomainByName(self, userIndex, domain):
for confDomainIndex, confDomain in self.getDomains(userIndex=userIndex):
if confDomain == domain:
return confDomainIndex
return None
def getInfofile(self, userIndex, domainIndex):
return self.__get(f"DOMAINS_user_{userIndex}",
f"infofile_domain_{domainIndex}")
def out(s=""):
print(s, "\r\n", file=sys.stdout, sep="", end="")
def error(msg):
out("Status: 500 Internal Server Error")
out() # End of headers.
out("Error.")
# out(msg)
raise Exception(msg)
def update(conf, userIndex, domainIndex, domain, ip4, ip6, ip6pfx):
infofile = conf.getInfofile(userIndex=userIndex,
domainIndex=domainIndex)
with open(infofile, "w") as f:
f.write(f"domain={domain}\n"
f"ip4={ip4}\n"
f"ip6={ip6}\n"
f"ip6pfx={ip6pfx}\n"
f"updated={datetime.datetime.now().isoformat()}\n")
out("Status: 200 Ok")
out() # End of headers.
out("Ok.")
return 0
def checkCredentials(conf, user, pw):
ok = False
foundUserIndex = None
for confUserIndex, confUserName in conf.getUsers():
if secrets.compare_digest(confUserName, user):
foundUserIndex = confUserIndex
if foundUserIndex is not None:
phashExp, salt, kdfHash, kdfIter = conf.getPw(userIndex=foundUserIndex)
phashAct = hashlib.pbkdf2_hmac(hash_name=kdfHash,
password=pw.encode("UTF-8"),
salt=salt,
iterations=kdfIter)
ok = secrets.compare_digest(phashAct, phashExp)
return ok, foundUserIndex
def runAdminCmds(conf, args):
if args.hash_pw is not None:
salt = secrets.token_bytes(args.salt_bytes)
phash = hashlib.pbkdf2_hmac(hash_name=args.kdf_hash.lower(),
password=args.hash_pw.encode("UTF-8"),
salt=salt,
iterations=args.kdf_iter)
print(f"{phash.hex()}:"
f"{salt.hex()}:"
f"pbkdf2hmac:"
f"{args.kdf_hash.lower()}:"
f"{args.kdf_iter}")
return 0
return 1
def main():
p = argparse.ArgumentParser()
p.add_argument("-c", "--config", type=pathlib.Path,
default=pathlib.Path("/etc/dyndns-update.conf"),
help="Path to configuration file.")
p.add_argument("-p", "--hash-pw", type=str,
help="Hash a password string, then exit.")
p.add_argument("-H", "--kdf-hash", type=str,
default="sha256",
help="Hash function for --hash-pw.")
p.add_argument("-I", "--kdf-iter", type=int,
default=1000,
help="Number of KDF iterations for --hash-pw.")
p.add_argument("-S", "--salt-bytes", type=int,
default=16,
help="Number of salt bytes for --hash-pw.")
args = p.parse_args()
conf = ConfigReader(args.config)
if args.hash_pw is not None:
return runAdminCmds(conf=conf, args=args)
out("Content-type: text/plain")
qs = os.environ.get("QUERY_STRING", "")
if not qs:
return error("No query string.")
forms = urllib.parse.parse_qs(qs)
def getform(key, default=""):
values = forms.get(key, None)
if values:
return values[-1]
return default
ok, userIndex = checkCredentials(conf=conf,
user=getform("user"),
pw=getform("pw"))
if not ok:
return error("Invalid credentials.")
domain = getform("domain")
ip4 = getform("ip4")
ip6 = getform("ip6")
ip6pfx = getform("ip6pfx")
if (not domain or
len(domain) > 128 or
not all(c in (CHRSET_ALNUM + ".-") for c in domain)):
return error("Invalid domain.")
if (len(ip4) > (4*3)+3 or
not all(c in (CHRSET_NUM + ".") for c in ip4)):
return error("Invalid ip4")
if (len(ip6) > (8*4)+7 or
not all(c in (CHRSET_HEX + ":") for c in ip6)):
return error("Invalid ip6")
if (len(ip6pfx) > (8*4)+7+1+3 or
not all(c in (CHRSET_HEX + ":/") for c in ip6pfx)):
return error("Invalid ip6pfx")
domainIndex = conf.getDomainByName(userIndex=userIndex,
domain=domain)
if domainIndex is None:
return error("Unknown domain.")
return update(conf=conf,
userIndex=userIndex,
domainIndex=domainIndex,
domain=domain,
ip4=ip4,
ip6=ip6,
ip6pfx=ip6pfx)
sys.exit(main())
|
