9b30c444d5c7b85bfcc231bfd91455d0b1edf674
[utils.git] / acmecert
1 #!/usr/bin/python3
2
3 import sys, os, getopt, binascii, json, pprint, signal, time
4 import urllib.request
5 import Crypto.PublicKey.RSA, Crypto.Random, Crypto.Hash.SHA256, Crypto.Signature.PKCS1_v1_5
6
7 service = "https://acme-v02.api.letsencrypt.org/directory"
8 _directory = None
9 def directory():
10     global _directory
11     if _directory is None:
12         with req(service) as resp:
13             _directory = json.loads(resp.read().decode("utf-8"))
14     return _directory
15
16 def base64url(dat):
17     return binascii.b2a_base64(dat).decode("us-ascii").translate({43: 45, 47: 95, 61: None}).strip()
18
19 def ebignum(num):
20     h = "%x" % num
21     if len(h) % 2 == 1: h = "0" + h
22     return base64url(binascii.a2b_hex(h))
23
24 def getnonce():
25     with urllib.request.urlopen(directory()["newNonce"]) as resp:
26         resp.read()
27         return resp.headers["Replay-Nonce"]
28
29 def req(url, data=None, ctype=None, headers={}, method=None, **kws):
30     if data is not None and not isinstance(data, bytes):
31         data = json.dumps(data).encode("utf-8")
32         ctype = "application/jose+json"
33     req = urllib.request.Request(url, data=data, method=method)
34     for hnam, hval in headers.items():
35         req.add_header(hnam, hval)
36     if ctype is not None:
37         req.add_header("Content-Type", ctype)
38     return urllib.request.urlopen(req)
39
40 def jreq(url, data, auth):
41     authdata = {"alg": "RS256", "url": url, "nonce": getnonce()}
42     authdata.update(auth.authdata())
43     authdata = base64url(json.dumps(authdata).encode("us-ascii"))
44     if data is None:
45         data = ""
46     else:
47         data = base64url(json.dumps(data).encode("us-ascii"))
48     seal = base64url(auth.sign(("%s.%s" % (authdata, data)).encode("us-ascii")))
49     enc = {"protected": authdata, "payload": data, "signature": seal}
50     with req(url, data=enc) as resp:
51         return json.loads(resp.read().decode("utf-8")), resp.headers
52
53 class certificate(object):
54     @property
55     def enddate(self):
56         # No X509 parser for Python?
57         import subprocess, re, calendar
58         with subprocess.Popen(["openssl", "x509", "-noout", "-enddate"], stdin=subprocess.PIPE, stdout=subprocess.PIPE) as openssl:
59             openssl.stdin.write(self.data.encode("us-ascii"))
60             openssl.stdin.close()
61             resp = openssl.stdout.read().decode("utf-8")
62             if openssl.wait() != 0:
63                 raise Exception("openssl error")
64         m = re.search(r"notAfter=(.*)$", resp)
65         if m is None: raise Exception("unexpected openssl reply: %r" % (resp,))
66         return calendar.timegm(time.strptime(m.group(1), "%b %d %H:%M:%S %Y GMT"))
67
68     def expiring(self, timespec):
69         if timespec.endswith("y"):
70             timespec = int(timespec[:-1]) * 365 * 86400
71         elif timespec.endswith("m"):
72             timespec = int(timespec[:-1]) * 30 * 86400
73         elif timespec.endswith("w"):
74             timespec = int(timespec[:-1]) * 7 * 86400
75         elif timespec.endswith("d"):
76             timespec = int(timespec[:-1]) * 86400
77         elif timespec.endswith("h"):
78             timespec = int(timespec[:-1]) * 3600
79         else:
80             timespec = int(timespec)
81         return (self.enddate - time.time()) < timespec
82
83     @classmethod
84     def read(cls, fp):
85         self = cls()
86         self.data = fp.read()
87         return self
88
89 class signreq(object):
90     def domains(self):
91         # No PCKS10 parser for Python?
92         import subprocess, re
93         with subprocess.Popen(["openssl", "req", "-noout", "-text"], stdin=subprocess.PIPE, stdout=subprocess.PIPE) as openssl:
94             openssl.stdin.write(self.data.encode("us-ascii"))
95             openssl.stdin.close()
96             resp = openssl.stdout.read().decode("utf-8")
97             if openssl.wait() != 0:
98                 raise Exception("openssl error")
99         m = re.search(r"X509v3 Subject Alternative Name:[^\n]*\n\s*((\w+:\S+,\s*)*\w+:\S+)\s*\n", resp)
100         if m is None:
101             return []
102         ret = []
103         for nm in m.group(1).split(","):
104             nm = nm.strip()
105             typ, nm = nm.split(":", 1)
106             if typ == "DNS":
107                 ret.append(nm)
108         return ret
109
110     def der(self):
111         import subprocess
112         with subprocess.Popen(["openssl", "req", "-outform", "der"], stdin=subprocess.PIPE, stdout=subprocess.PIPE) as openssl:
113             openssl.stdin.write(self.data.encode("us-ascii"))
114             openssl.stdin.close()
115             resp = openssl.stdout.read()
116             if openssl.wait() != 0:
117                 raise Exception("openssl error")
118         return resp
119
120     @classmethod
121     def read(cls, fp):
122         self = cls()
123         self.data = fp.read()
124         return self
125
126 class jwkauth(object):
127     def __init__(self, key):
128         self.key = key
129
130     def authdata(self):
131         return {"jwk": {"kty": "RSA", "e": ebignum(self.key.e), "n": ebignum(self.key.n)}}
132
133     def sign(self, data):
134         dig = Crypto.Hash.SHA256.new()
135         dig.update(data)
136         return Crypto.Signature.PKCS1_v1_5.new(self.key).sign(dig)
137
138 class account(object):
139     def __init__(self, uri, key):
140         self.uri = uri
141         self.key = key
142
143     def authdata(self):
144         return {"kid": self.uri}
145
146     def sign(self, data):
147         dig = Crypto.Hash.SHA256.new()
148         dig.update(data)
149         return Crypto.Signature.PKCS1_v1_5.new(self.key).sign(dig)
150
151     def getinfo(self):
152         data, headers = jreq(self.uri, None, self)
153         return data
154
155     def validate(self):
156         data = self.getinfo()
157         if data.get("status", "") != "valid":
158             raise Exception("account is not valid: %s" % (data.get("status", "\"\"")))
159
160     def write(self, out):
161         out.write("%s\n" % (self.uri,))
162         out.write("%s\n" % (self.key.exportKey().decode("us-ascii"),))
163
164     @classmethod
165     def read(cls, fp):
166         uri = fp.readline()
167         if uri == "":
168             raise Exception("missing account URI")
169         uri = uri.strip()
170         key = Crypto.PublicKey.RSA.importKey(fp.read())
171         return cls(uri, key)
172
173 class htconfig(object):
174     def __init__(self):
175         self.roots = {}
176
177     @classmethod
178     def read(cls, fp):
179         self = cls()
180         for ln in fp:
181             words = ln.split()
182             if len(words) < 1 or ln[0] == '#':
183                 continue
184             if words[0] == "root":
185                 self.roots[words[1]] = words[2]
186             else:
187                 sys.stderr.write("acmecert: warning: unknown htconfig directive: %s\n" % (words[0]))
188         return self
189
190 def register(keysize=4096):
191     key = Crypto.PublicKey.RSA.generate(keysize, Crypto.Random.new().read)
192     # jwk = {"kty": "RSA", "e": ebignum(key.e), "n": ebignum(key.n)}
193     # cjwk = json.dumps(jwk, separators=(',', ':'), sort_keys=True)
194     data, headers = jreq(directory()["newAccount"], {"termsOfServiceAgreed": True}, jwkauth(key))
195     return account(headers["Location"], key)
196     
197 def mkorder(acct, csr):
198     data, headers = jreq(directory()["newOrder"], {"identifiers": [{"type": "dns", "value": dn} for dn in csr.domains()]}, acct)
199     data["acmecert.location"] = headers["Location"]
200     return data
201
202 def httptoken(acct, ch):
203     jwk = {"kty": "RSA", "e": ebignum(acct.key.e), "n": ebignum(acct.key.n)}
204     dig = Crypto.Hash.SHA256.new()
205     dig.update(json.dumps(jwk, separators=(',', ':'), sort_keys=True).encode("us-ascii"))
206     khash = base64url(dig.digest())
207     return ch["token"], ("%s.%s" % (ch["token"], khash))
208
209 def authorder(acct, htconf, orderid):
210     order, headers = jreq(orderid, None, acct)
211     valid = False
212     tries = 0
213     while not valid:
214         valid = True
215         tries += 1
216         if tries > 5:
217             raise Exception("challenges refuse to become valid even after 5 retries")
218         for authuri in order["authorizations"]:
219             auth, headers = jreq(authuri, None, acct)
220             if auth["status"] == "valid":
221                 continue
222             elif auth["status"] == "pending":
223                 pass
224             else:
225                 raise Exception("unknown authorization status: %s" % (auth["status"],))
226             valid = False
227             if auth["identifier"]["type"] != "dns":
228                 raise Exception("unknown authorization type: %s" % (auth["identifier"]["type"],))
229             dn = auth["identifier"]["value"]
230             if dn not in htconf.roots:
231                 raise Exception("no configured ht-root for domain name %s" % (dn,))
232             for ch in auth["challenges"]:
233                 if ch["type"] == "http-01":
234                     break
235             else:
236                 raise Exception("no http-01 challenge for %s" % (dn,))
237             root = htconf.roots[dn]
238             tokid, tokval = httptoken(acct, ch)
239             tokpath = os.path.join(root, tokid);
240             fp = open(tokpath, "w")
241             try:
242                 with fp:
243                     fp.write(tokval)
244                 with req("http://%s/.well-known/acme-challenge/%s" % (dn, tokid)) as resp:
245                     if resp.read().decode("utf-8") != tokval:
246                         raise Exception("challenge from %s does not match written value" % (dn,))
247                 for n in range(30):
248                     resp, headers = jreq(ch["url"], {}, acct)
249                     if resp["status"] == "processing":
250                         time.sleep(2)
251                     elif resp["status"] == "valid":
252                         break
253                     else:
254                         raise Exception("unexpected challenge status for %s when validating: %s" % (dn, resp["status"]))
255                 else:
256                     raise Exception("challenge processing timed out for %s" % (dn,))
257             finally:
258                 os.unlink(tokpath)
259
260 def finalize(acct, csr, orderid):
261     order, headers = jreq(orderid, None, acct)
262     if order["status"] == "valid":
263         pass
264     elif order["status"] == "ready":
265         jreq(order["finalize"], {"csr": base64url(csr.der())}, acct)
266         for n in range(30):
267             resp, headers = jreq(orderid, None, acct)
268             if resp["status"] == "processing":
269                 time.sleep(2)
270             elif resp["status"] == "valid":
271                 order = resp
272                 break
273             else:
274                 raise Exception("unexpected order status when finalizing: %s" % resp["status"])
275         else:
276             raise Exception("order finalization timed out")
277     else:
278         raise Exception("unexpected order state when finalizing: %s" % (order["status"],))
279     with req(order["certificate"]) as resp:
280         return resp.read().decode("us-ascii")
281
282 def usage(out):
283     out.write("usage: acmecert [-h] [-D SERVICE]\n")
284
285 def main(argv):
286     global service
287     opts, args = getopt.getopt(argv[1:], "hD:")
288     for o, a in opts:
289         if o == "-h":
290             usage(sys.stdout)
291             sys.exit(0)
292         elif o == "-D":
293             service = a
294     if len(args) < 1:
295         usage(sys.stderr)
296         sys.exit(1)
297     if args[0] == "reg":
298         register().write(sys.stdout)
299     elif args[0] == "validate-acct":
300         with open(args[1], "r") as fp:
301             account.read(fp).validate()
302     elif args[0] == "acctinfo":
303         with open(args[1], "r") as fp:
304             pprint.pprint(account.read(fp).getinfo())
305     elif args[0] == "order":
306         with open(args[1], "r") as fp:
307             acct = account.read(fp)
308         with open(args[2], "r") as fp:
309             csr = signreq.read(fp)
310         order = mkorder(acct, csr)
311         with open(args[3], "w") as fp:
312             fp.write("%s\n" % (order["acmecert.location"]))
313     elif args[0] == "http-auth":
314         with open(args[1], "r") as fp:
315             acct = account.read(fp)
316         with open(args[2], "r") as fp:
317             htconf = htconfig.read(fp)
318         with open(args[3], "r") as fp:
319             orderid = fp.readline().strip()
320         authorder(acct, htconf, orderid)
321     elif args[0] == "get":
322         with open(args[1], "r") as fp:
323             acct = account.read(fp)
324         with open(args[2], "r") as fp:
325             csr = signreq.read(fp)
326         with open(args[3], "r") as fp:
327             orderid = fp.readline().strip()
328         sys.stdout.write(finalize(acct, csr, orderid))
329     elif args[0] == "http-order":
330         with open(args[1], "r") as fp:
331             acct = account.read(fp)
332         with open(args[2], "r") as fp:
333             csr = signreq.read(fp)
334         with open(args[3], "r") as fp:
335             htconf = htconfig.read(fp)
336         orderid = mkorder(acct, csr)["acmecert.location"]
337         authorder(acct, htconf, orderid)
338         sys.stdout.write(finalize(acct, csr, orderid))
339     elif args[0] == "check-cert":
340         with open(args[1], "r") as fp:
341             crt = certificate.read(fp)
342         sys.exit(1 if crt.expiring(args[2]) else 0)
343     elif args[0] == "directory":
344         pprint.pprint(directory())
345     else:
346         sys.stderr.write("acmecert: unknown command: %s\n" % (args[0],))
347         usage(sys.stderr)
348         sys.exit(1)
349
350 if __name__ == "__main__":
351     try:
352         main(sys.argv)
353     except KeyboardInterrupt:
354         signal.signal(signal.SIGINT, signal.SIG_DFL)
355         os.kill(os.getpid(), signal.SIGINT)