make sure backup dir exists

[lets-encrypt-tiny.git] / letsencrypt-tiny

diff --git a/letsencrypt-tiny b/letsencrypt-tiny
index 0d8c985d800aa616a7b2a9e24feed5cf9d20075d..2e8ea149061986de112c5d0ff7bed2c7f9c690e9 100755 (executable)
--- a/letsencrypt-tiny
+++ b/letsencrypt-tiny
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 #!/usr/bin/env python3

-## Call with "--help" for documentation.
+## See <https://www.ralfj.de/blog/2017/12/26/lets-encrypt.html> for documentation.

 
 

-import argparse, configparser, itertools, os, os.path, sys, subprocess, datetime
+import argparse, configparser, itertools, stat, os, os.path, sys, subprocess, datetime

 
 ## Helper functions
 def readConfig(fname, defSection = 'DEFAULT'):
 
 ## Helper functions
 def readConfig(fname, defSection = 'DEFAULT'):


@@ -11,20 +11,17 @@ def readConfig(fname, defSection = 'DEFAULT'):
         config.read_file(stream)
     return config
 
         config.read_file(stream)
     return config
 

-def certfile(name, suff = None):
+def certfile(name):

     global config
     global config

-    return os.path.join(config['dirs']['certs'], name + ".crt" + ('' if suff is None else '+'+suff) )
+    return os.path.join(config['dirs']['certs'], name + ".crt" )

 
 def keyfile(name):
     global config
     return os.path.join(config['dirs']['keys'], name + ".key")
 
 
 def keyfile(name):
     global config
     return os.path.join(config['dirs']['keys'], name + ".key")
 

-def csrfile(name):
-    global config
-    return os.path.join(config['dirs']['csrs'], name + ".csr")
-

 def make_backup(fname):
     if os.path.exists(fname):
 def make_backup(fname):
     if os.path.exists(fname):

+        os.makedirs(config['dirs']['backups'])

         backupname = os.path.basename(fname) + "." + str(datetime.date.today())
         i = 0
         while True:
         backupname = os.path.basename(fname) + "." + str(datetime.date.today())
         i = 0
         while True:


@@ -39,46 +36,115 @@ def make_backup(fname):
 
 def trigger_hook(hook):
     global config
 
 def trigger_hook(hook):
     global config

-    exe = config['hooks'][hook]
+    exe = config['hooks'].get(hook)

     if exe is not None:
         subprocess.check_call([exe])
 
     if exe is not None:
         subprocess.check_call([exe])
 

+def key_mtime(name):
+    return datetime.datetime.fromtimestamp(os.stat(keyfile(name)).st_mtime)
+
+def cert_expiry(name):
+    from certcheck import cert_expiry_date
+    return cert_expiry_date(certfile(name))
+
+## Work functions, operating on file names
+

 ## The interesting work
 ## The interesting work

-def gencsr(name, domains):
-    # This is done by a shell script
+def acme(keyfilename, certfilename, domains):
+    global config
+    accountkey = config['acme']['account-key']
+    csrfilename = certfilename + '.csr.tmp'
+    assert os.path.exists(keyfilename)
+    assert accountkey
+    # Generating the CSR is done by a shell script

     exe = os.path.join(os.path.dirname(__file__), 'gencsr')
     exe = os.path.join(os.path.dirname(__file__), 'gencsr')

-    csr = subprocess.check_output([exe, keyfile(name)] + domains)
-    with open(csrfile(name), 'wb') as file:
+    csr = subprocess.check_output([exe, keyfilename] + domains)
+    assert not os.path.exists(csrfilename), "The temporary CSR file {} still exists. It seems something went wrong on a previous request. You may want to remove the file manually.".format(csrfilename)
+    with open(csrfilename, 'wb') as file:

         file.write(csr)
         file.write(csr)

+    try:
+        # call acme-tiny as a script
+        acme_tiny = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'acme-tiny', 'acme_tiny.py')
+        signed_crt = subprocess.check_output(["python3", acme_tiny, "--quiet", "--account-key", accountkey, "--csr", csrfilename, "--acme-dir", config['acme']['challenge-dir']])
+        # save new certificate
+        make_backup(certfilename)
+        with open(certfilename, 'wb') as f:
+            f.write(signed_crt)
+    finally:
+        # clean up
+        os.remove(csrfilename)

 
 

-def acme(name, domains):
-    global config
-    print("Obtaining certificate {} for domains {}".format(name, ' '.join(domains)))
-    gencsr(name, domains)
-    # call acme-tiny as a script
-    acme_tiny = os.path.join(config['acme']['acme-tiny'], 'acme_tiny.py')
-    signed_crt = subprocess.check_output([acme_tiny, "--quiet", "--account-key", config['acme']['account-key'], "--csr", csrfile(name), "--acme-dir", config['acme']['challenge-dir']])
-    # save new certificate
-    make_backup(certfile(name))
-    with open(certfile(name), 'wb') as file:
-        file.write(signed_crt)
-    # append DH params
-    dhfile = config['DEFAULT']['dh-params']
-    if dhfile is not None:
-        with open(dhfile, 'rb') as file:
-            dh = file.read()
-        make_backup(certfile(name, 'dh'))
-        with open(certfile(name, 'dh'), 'wb') as file:
-            file.write(signed_crt)
-            file.write(dh)
-
-def getcert(name):
+def openssl_genrsa(keyfilename):
+    with subprocess.Popen(["openssl", "genrsa", str(int(config['DEFAULT']['key-length']))], stdout=subprocess.PIPE, stderr=subprocess.PIPE) as f:
+        (stdout, stderr) = f.communicate()
+        if f.returncode:
+            sys.stderr.write(stderr)
+            raise Exception("Error while generating private key")
+    # Now we have a key, save it. This should never overwrite anything.
+    assert not os.path.exists(keyfilename)
+    with open(keyfilename, 'wb') as f:
+        f.write(stdout)
+
+## High-level functions, operating on nice key names
+def request_cert(name):

     global config
     if not os.path.exists(keyfile(name)):
         raise Exception("No such key: {}".format(name))
     domains = config['DEFAULT']['domains'].split()
     global config
     if not os.path.exists(keyfile(name)):
         raise Exception("No such key: {}".format(name))
     domains = config['DEFAULT']['domains'].split()

-    acme(name, domains)
-    trigger_hook('post-cert')
+    print("Obtaining certificate '{}' for domains: {}".format(name, ' '.join(domains)))
+    acme(keyfile(name), certfile(name), domains)
+
+def generate_key(name):
+    assert not os.path.exists(certfile(name)), "Don't make create a new key for an old cert"
+    print("Generating new private key '{}'".format(name))
+    openssl_genrsa(keyfile(name))
+
+def check_staging(live, staging):
+    '''Returns 0 if nothing was done, 1 if a stage key is present but has to be kept, 2 is a stage key was unstaged.'''
+    if not os.path.exists(keyfile(staging)):
+        return 0
+    
+    staging_time = datetime.timedelta(hours = int(config['timing'].get('staging-hours', 0)))
+    key_age = datetime.datetime.now() - key_mtime(staging)
+    if key_age < staging_time:
+        return 1
+    print("Unstaging '{}' to '{}'".format(staging, live))
+    # unstage the key!
+    make_backup(keyfile(live))
+    os.rename(keyfile(staging), keyfile(live))
+    make_backup(certfile(live))
+    os.rename(certfile(staging), certfile(live))
+    return 2
+
+def auto_renewal(live, staging):
+    '''Returns 0 if nothing was done, 1 if only certs were changed, 2 if certs and keys were changed.'''
+    max_key_age = datetime.timedelta(days = int(config['timing']['max-key-age-days']))
+    renew_cert_time = datetime.timedelta(days = int(config['timing']['renew-cert-before-expiry-days']))
+    
+    # determine what to do
+    now = datetime.datetime.now()
+    key_age = now - key_mtime(live)
+    need_new_key = key_age >= max_key_age
+    if os.path.exists(certfile(live)):
+        cert_validity = cert_expiry(live) - now
+        need_new_cert = cert_validity <= renew_cert_time
+    else:
+        need_new_cert = True
+    if need_new_cert and key_age + renew_cert_time >= max_key_age:
+        # We are about to request a new certificate, and within <renew_cert_time>, we need a new key: Get the new key now
+        need_new_key = True
+    
+    # Do it
+    if need_new_key:
+        generate_key(staging)
+        request_cert(staging)
+        check_staging(live, staging) # we may want to immediately enable the new key & cert
+        return 2
+    elif need_new_cert:
+        request_cert(live)
+        return 1
+    else:
+        return 0

 
 ## Main
 if __name__ == "__main__":
 
 ## Main
 if __name__ == "__main__":


@@ -87,22 +153,66 @@ if __name__ == "__main__":
     parser.add_argument("-c", "--config",
                         dest="config",
                         help="The configuration file")
     parser.add_argument("-c", "--config",
                         dest="config",
                         help="The configuration file")

-    parser.add_argument
+    parser.add_argument("-k", "--hooks",
+                        dest="hooks", action="store_true",
+                        help="Trigger hooks.")

     parser.add_argument("action", metavar='ACTION', nargs=1,
     parser.add_argument("action", metavar='ACTION', nargs=1,

-                        help="The action to perform. Possible values: renew, cron")
+                        help="The action to perform. Possible values: init, renew, cron")

     args = parser.parse_args()
     
     args = parser.parse_args()
     

-    # read config
+    # read config, sanity check

     if not os.path.isfile(args.config):
         raise Exception("The config file does not exist: "+args.config)
     global config
     config = readConfig(args.config)
     
     if not os.path.isfile(args.config):
         raise Exception("The config file does not exist: "+args.config)
     global config
     config = readConfig(args.config)
     

+    live = config['files']['live']
+    staging = config['files']['staging']

     if args.action[0] == 'renew':
     if args.action[0] == 'renew':

-        getcert(config['files']['live'])
-        # We may also have to renew the staging
-        staging = config['files']['staging']
-        if staging is not None and os.path.exists(keyfile(staging)):
-            getcert(staging)
+        request_cert(live)
+        if os.path.exists(keyfile(staging)) and os.path.exists(certfile(staging)):
+            request_cert(staging)
+        # trigger the "new cert" hook
+        if args.hooks:
+            trigger_hook('post-certchange')
+    elif args.action[0] == 'cron':
+        # First, check if we need to unstage a staging key
+        unstaged = check_staging(live, staging)
+        if unstaged >= 1:
+            # A staging key is present, do *not* check for renewal
+            if unstaged >= 2 and args.hooks:
+                # trigger all the hooks
+                trigger_hook('post-certchange')
+                trigger_hook('post-keychange')
+        else:
+            # Check if we need to renew anything
+            renewed = auto_renewal(live, staging)
+            if args.hooks:
+                if renewed >= 1:
+                    trigger_hook('post-certchange')
+                if renewed >= 2:
+                    trigger_hook('post-keychange')
+    elif args.action[0] == 'init':
+        # create directories with appropriate permissions
+        try:
+            os.makedirs(config['dirs']['certs'], mode = 0o755, exist_ok = True)
+            os.makedirs(config['dirs']['keys'], mode = 0o710, exist_ok = True)
+            os.makedirs(config['dirs']['backups'], mode = 0o700, exist_ok = True)
+        except OSError:
+            pass
+        # if necessary, generate ACME account key
+        accountkey = config['acme']['account-key']
+        if not os.path.exists(accountkey):
+            print("Generating new ACME key")
+            openssl_genrsa(accountkey)
+        # if necessary, generate key + certificate
+        live = config['files']['live']
+        if not os.path.exists(keyfile(live)):
+            generate_key(live)
+        if not os.path.exists(certfile(live)):
+            request_cert(live)
+            if args.hooks:
+                trigger_hook('post-certchange')
+                trigger_hook('post-keychange')

     else:
         raise Exception("Unknown action {}".format(args.action))
     else:
         raise Exception("Unknown action {}".format(args.action))