mostly working ACMEv2, except for letsencrypt/boulder#3367

acme_tiny.py

@@ -5,67 +5,86 @@
 except ImportError:
     from urllib2 import urlopen # Python 2
 
-#DEFAULT_CA = "https://acme-staging.api.letsencrypt.org"
-DEFAULT_CA = "https://acme-v01.api.letsencrypt.org"
+#DEFAULT_CA = "https://acme-staging-v02.api.letsencrypt.org"
+DEFAULT_CA = "https://acme-v02.api.letsencrypt.org"
 
 LOGGER = logging.getLogger(__name__)
 LOGGER.addHandler(logging.StreamHandler())
 LOGGER.setLevel(logging.INFO)
 
-def get_crt(account_key, csr, acme_dir, log=LOGGER, CA=DEFAULT_CA):
-    # helper function base64 encode for jose spec
+def get_crt(account_key, csr, acme_dir, log=LOGGER, CA=DEFAULT_CA, disable_check=False):
+    directory, acct_headers, alg, jwk = None, None, None, None # global variables
+
+    # helper functions - base64 encode for jose spec
     def _b64(b):
         return base64.urlsafe_b64encode(b).decode('utf8').replace("=", "")
 
+    # helper function - run external commands
+    def _cmd(cmd_list, cmd_input=None):
+        stdin = subprocess.PIPE if cmd_input is not None else None
+        proc = subprocess.Popen(cmd_list, stdin=stdin, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        out, err = proc.communicate(cmd_input)
+        return proc, out, err
+
+    # helper function - make request and automatically parse json response
+    def _do_request(url, data=None, err_msg="Error"):
+        try:
+            resp = urlopen(url, data)
+            resp_data, code, headers = resp.read().decode("utf8"), resp.getcode(), resp.headers
+            resp_data = json.loads(resp_data) # try to parse json results
+        except ValueError:
+            pass # ignore json parsing errors
+        except IOError as e:
+            resp_data = e.read().decode("utf8") if hasattr(e, "read") else str(e)
+            code, headers = getattr(e, "code", None), {}
+        if code not in [200, 201, 204]:
+            raise ValueError("{0}:\nUrl: {1}\nData: {2}\nResponse Code: {3}\nResponse: {4}".format(err_msg, url, data, code, resp_data))
+        return resp_data, code, headers
+
+    # helper function - make signed requests
+    def _send_signed_request(url, payload, err_msg):
+        payload64 = _b64(json.dumps(payload).encode('utf8'))
+        new_nonce = _do_request(directory['newNonce'])[2]['Replay-Nonce']
+        protected = {"url": url, "alg": alg, "nonce": new_nonce}
+        protected.update({"jwk": jwk} if acct_headers is None else {"kid": acct_headers['Location']})
+        protected64 = _b64(json.dumps(protected).encode('utf8'))
+        protected_input = "{0}.{1}".format(protected64, payload64).encode('utf8')
+        proc, out, err = _cmd(["openssl", "dgst", "-sha256", "-sign", account_key], cmd_input=protected_input)
+        if proc.returncode != 0:
+            raise IOError("OpenSSL Error: {0}".format(err))
+        data = json.dumps({"protected": protected64, "payload": payload64, "signature": _b64(out)})
+        return _do_request(url, data=data.encode('utf8'), err_msg=err_msg)
+
+    # helper function - poll until complete
+    def _poll_until_not(url, pending_statuses, err_msg):
+        while True:
+            result, _, _ = _do_request(url, err_msg=err_msg)
+            if result['status'] in pending_statuses:
+                time.sleep(2)
+                continue
+            return result
+
     # parse account key to get public key
     log.info("Parsing account key...")
-    proc = subprocess.Popen(["openssl", "rsa", "-in", account_key, "-noout", "-text"],
-        stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    out, err = proc.communicate()
+    proc, out, err = _cmd(["openssl", "rsa", "-in", account_key, "-noout", "-text"])
     if proc.returncode != 0:
         raise IOError("OpenSSL Error: {0}".format(err))
-    pub_hex, pub_exp = re.search(
-        r"modulus:\n\s+00:([a-f0-9\:\s]+?)\npublicExponent: ([0-9]+)",
-        out.decode('utf8'), re.MULTILINE|re.DOTALL).groups()
+    pub_pattern = r"modulus:\n\s+00:([a-f0-9\:\s]+?)\npublicExponent: ([0-9]+)"
+    pub_hex, pub_exp = re.search(pub_pattern, out.decode('utf8'), re.MULTILINE|re.DOTALL).groups()
     pub_exp = "{0:x}".format(int(pub_exp))
     pub_exp = "0{0}".format(pub_exp) if len(pub_exp) % 2 else pub_exp
-    header = {
-        "alg": "RS256",
-        "jwk": {
-            "e": _b64(binascii.unhexlify(pub_exp.encode("utf-8"))),
-            "kty": "RSA",
-            "n": _b64(binascii.unhexlify(re.sub(r"(\s|:)", "", pub_hex).encode("utf-8"))),
-        },
+    alg = "RS256"
+    jwk = {
+        "e": _b64(binascii.unhexlify(pub_exp.encode("utf-8"))),
+        "kty": "RSA",
+        "n": _b64(binascii.unhexlify(re.sub(r"(\s|:)", "", pub_hex).encode("utf-8"))),
     }
-    accountkey_json = json.dumps(header['jwk'], sort_keys=True, separators=(',', ':'))
+    accountkey_json = json.dumps(jwk, sort_keys=True, separators=(',', ':'))
     thumbprint = _b64(hashlib.sha256(accountkey_json.encode('utf8')).digest())
 
-    # helper function make signed requests
-    def _send_signed_request(url, payload):
-        payload64 = _b64(json.dumps(payload).encode('utf8'))
-        protected = copy.deepcopy(header)
-        protected["nonce"] = urlopen(CA + "/directory").headers['Replay-Nonce']
-        protected64 = _b64(json.dumps(protected).encode('utf8'))
-        proc = subprocess.Popen(["openssl", "dgst", "-sha256", "-sign", account_key],
-            stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-        out, err = proc.communicate("{0}.{1}".format(protected64, payload64).encode('utf8'))
-        if proc.returncode != 0:
-            raise IOError("OpenSSL Error: {0}".format(err))
-        data = json.dumps({
-            "header": header, "protected": protected64,
-            "payload": payload64, "signature": _b64(out),
-        })
-        try:
-            resp = urlopen(url, data.encode('utf8'))
-            return resp.getcode(), resp.read()
-        except IOError as e:
-            return getattr(e, "code", None), getattr(e, "read", e.__str__)()
-
     # find domains
     log.info("Parsing CSR...")
-    proc = subprocess.Popen(["openssl", "req", "-in", csr, "-noout", "-text"],
-        stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    out, err = proc.communicate()
+    proc, out, err = _cmd(["openssl", "req", "-in", csr, "-noout", "-text"])
     if proc.returncode != 0:
         raise IOError("Error loading {0}: {1}".format(csr, err))
     domains = set([])
@@ -77,93 +96,69 @@ def _send_signed_request(url, payload):
         for san in subject_alt_names.group(1).split(", "):
             if san.startswith("DNS:"):
                 domains.add(san[4:])
+    log.info("Found domains: {}".format(", ".join(domains)))
+
+    # get the ACME directory of urls
+    log.info("Getting directory...")
+    directory, _, _ = _do_request(CA + "/directory", err_msg="Error getting directory")
+    log.info("Directory found!")
 
-    # get the certificate domains and expiration
+    # create account and set the global key identifier
     log.info("Registering account...")
-    code, result = _send_signed_request(CA + "/acme/new-reg", {
-        "resource": "new-reg",
-        "agreement": json.loads(urlopen(CA + "/directory").read().decode('utf8'))['meta']['terms-of-service'],
-    })
-    if code == 201:
-        log.info("Registered!")
-    elif code == 409:
-        log.info("Already registered!")
-    else:
-        raise ValueError("Error registering: {0} {1}".format(code, result))
-
-    # verify each domain
-    for domain in domains:
+    reg_payload = {"termsOfServiceAgreed": True}
+    account, code, acct_headers = _send_signed_request(directory['newAccount'], reg_payload, "Error registering")
+    log.info("Registered!" if code == 201 else "Already registered!")
+
+    # create a new order
+    log.info("Creating new order...")
+    order_payload = {"identifiers": [{"type": "dns", "value": d} for d in domains]}
+    order, _, order_headers = _send_signed_request(directory['newOrder'], order_payload, "Error creating new order")
+    log.info("Order created!")
+
+    # get the authorizations that need to be completed
+    for auth_url in order['authorizations']:
+        authorization, _, _ = _do_request(auth_url, err_msg="Error getting challenges")
+        domain = authorization['identifier']['value']
         log.info("Verifying {0}...".format(domain))
 
-        # get new challenge
-        code, result = _send_signed_request(CA + "/acme/new-authz", {
-            "resource": "new-authz",
-            "identifier": {"type": "dns", "value": domain},
-        })
-        if code != 201:
-            raise ValueError("Error requesting challenges: {0} {1}".format(code, result))
-
-        # make the challenge file
-        challenge = [c for c in json.loads(result.decode('utf8'))['challenges'] if c['type'] == "http-01"][0]
+        # find the http-01 challenge and write the challenge file
+        challenge = [c for c in authorization['challenges'] if c['type'] == "http-01"][0]
         token = re.sub(r"[^A-Za-z0-9_\-]", "_", challenge['token'])
         keyauthorization = "{0}.{1}".format(token, thumbprint)
         wellknown_path = os.path.join(acme_dir, token)
         with open(wellknown_path, "w") as wellknown_file:
             wellknown_file.write(keyauthorization)
 
         # check that the file is in place
-        wellknown_url = "http://{0}/.well-known/acme-challenge/{1}".format(domain, token)
         try:
-            resp = urlopen(wellknown_url)
-            resp_data = resp.read().decode('utf8').strip()
-            assert resp_data == keyauthorization
-        except (IOError, AssertionError):
+            wellknown_url = "http://{0}/.well-known/acme-challenge/{1}".format(domain, token)
+            assert(disable_check or _do_request(wellknown_url)[0] == keyauthorization)
+        except (AssertionError, ValueError) as e:
             os.remove(wellknown_path)
-            raise ValueError("Wrote file to {0}, but couldn't download {1}".format(
-                wellknown_path, wellknown_url))
-
-        # notify challenge are met
-        code, result = _send_signed_request(challenge['uri'], {
-            "resource": "challenge",
-            "keyAuthorization": keyauthorization,
-        })
-        if code != 202:
-            raise ValueError("Error triggering challenge: {0} {1}".format(code, result))
-
-        # wait for challenge to be verified
-        while True:
-            try:
-                resp = urlopen(challenge['uri'])
-                challenge_status = json.loads(resp.read().decode('utf8'))
-            except IOError as e:
-                raise ValueError("Error checking challenge: {0} {1}".format(
-                    e.code, json.loads(e.read().decode('utf8'))))
-            if challenge_status['status'] == "pending":
-                time.sleep(2)
-            elif challenge_status['status'] == "valid":
-                log.info("{0} verified!".format(domain))
-                os.remove(wellknown_path)
-                break
-            else:
-                raise ValueError("{0} challenge did not pass: {1}".format(
-                    domain, challenge_status))
-
-    # get the new certificate
+            raise ValueError("Wrote file to {0}, but couldn't download {1}: {2}".format(wellknown_path, wellknown_url, e))
+
+        # say the challenge is done
+        challenge_payload = {"keyAuthorization": keyauthorization}
+        _send_signed_request(challenge['url'], challenge_payload, "Error submitting challenges: {0}".format(domain))
+        authorization = _poll_until_not(auth_url, ["pending"], "Error checking challenge status for {0}".format(domain))
+        if authorization['status'] != "valid":
+            raise ValueError("Challenge did not pass for {0}: {1}".format(domain, authorization))
+        log.info("{0} verified!".format(domain))
+
+    # finalize the order with the csr
     log.info("Signing certificate...")
-    proc = subprocess.Popen(["openssl", "req", "-in", csr, "-outform", "DER"],
-        stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    csr_der, err = proc.communicate()
-    code, result = _send_signed_request(CA + "/acme/new-cert", {
-        "resource": "new-cert",
-        "csr": _b64(csr_der),
-    })
-    if code != 201:
-        raise ValueError("Error signing certificate: {0} {1}".format(code, result))
-
-    # return signed certificate!
+    proc, csr_der, err = _cmd(["openssl", "req", "-in", csr, "-outform", "DER"])
+    _send_signed_request(order['finalize'], {"csr": _b64(csr_der)}, "Error finalizing order")
+
+    # poll the order to monitor when it's done
+    order = _poll_until_not(order_headers['Location'], ["pending", "processing"], "Error checking order status")
+    if order['status'] != "valid":
+        raise ValueError("Order failed: {0}".format(order))
+
+    # download the certificate
+    certificate_pem, _, _ = _do_request(order['certificate'], err_msg="Certificate download failed")
     log.info("Certificate signed!")
-    return """-----BEGIN CERTIFICATE-----\n{0}\n-----END CERTIFICATE-----\n""".format(
-        "\n".join(textwrap.wrap(base64.b64encode(result).decode('utf8'), 64)))
+    return certificate_pem
 
 def main(argv):
     parser = argparse.ArgumentParser(
@@ -188,10 +183,11 @@ def main(argv):
     parser.add_argument("--acme-dir", required=True, help="path to the .well-known/acme-challenge/ directory")
     parser.add_argument("--quiet", action="store_const", const=logging.ERROR, help="suppress output except for errors")
     parser.add_argument("--ca", default=DEFAULT_CA, help="certificate authority, default is Let's Encrypt")
+    parser.add_argument("--disable-check", default=False, action="store_true", help="disable checking if the challenge file is hosted correctly before telling the CA")
 
     args = parser.parse_args(argv)
     LOGGER.setLevel(args.quiet or LOGGER.level)
-    signed_crt = get_crt(args.account_key, args.csr, args.acme_dir, log=LOGGER, CA=args.ca)
+    signed_crt = get_crt(args.account_key, args.csr, args.acme_dir, log=LOGGER, CA=args.ca, disable_check=args.disable_check)
     sys.stdout.write(signed_crt)
 
 if __name__ == "__main__": # pragma: no cover

tests/test_module.py

@@ -14,7 +14,7 @@ class TestModule(unittest.TestCase):
     "Tests for acme_tiny.get_crt()"
 
     def setUp(self):
-        self.CA = "https://acme-staging.api.letsencrypt.org"
+        self.CA = "https://acme-staging-v02.api.letsencrypt.org"
         self.tempdir = tempfile.mkdtemp()
         self.fuse_proc = Popen(["python", "tests/monkey.py", self.tempdir])