diff --git a/setup.py b/setup.py
index 4573e2f..c08d67b 100755
--- a/setup.py
+++ b/setup.py
@@ -24,12 +24,12 @@ import sys
 import setuptools
 
 deps = [
-    'certauth==1.1.6',
     'warctools>=4.10.0',
     'urlcanon>=0.3.0',
     'doublethink @ git+https://github.com/internetarchive/doublethink.git@Py311',
     'urllib3>=1.23',
     'requests>=2.0.1',
+    'pyopenssl',
     'PySocks>=1.6.8',
     'cryptography>=2.3,<40',
     'idna',
diff --git a/tests/test_certauth.py b/tests/test_certauth.py
new file mode 100644
index 0000000..61cf191
--- /dev/null
+++ b/tests/test_certauth.py
@@ -0,0 +1,89 @@
+import os
+import shutil
+
+from warcprox.certauth import main, CertificateAuthority
+import tempfile
+from OpenSSL import crypto
+import datetime
+import time
+
+def setup_module():
+    global TEST_CA_DIR
+    TEST_CA_DIR = tempfile.mkdtemp()
+
+    global TEST_CA_ROOT
+    TEST_CA_ROOT = os.path.join(TEST_CA_DIR, 'certauth_test_ca.pem')
+
+def teardown_module():
+    shutil.rmtree(TEST_CA_DIR)
+    assert not os.path.isdir(TEST_CA_DIR)
+    assert not os.path.isfile(TEST_CA_ROOT)
+
+def test_create_root():
+    ret = main([TEST_CA_ROOT, '-c', 'Test Root Cert'])
+    assert ret == 0
+
+def test_create_host_cert():
+    ret = main([TEST_CA_ROOT, '-d', TEST_CA_DIR, '-n', 'example.com'])
+    assert ret == 0
+    certfile = os.path.join(TEST_CA_DIR, 'example.com.pem')
+    assert os.path.isfile(certfile)
+
+def test_create_wildcard_host_cert_force_overwrite():
+    ret = main([TEST_CA_ROOT, '-d', TEST_CA_DIR, '--hostname', 'example.com', '-w', '-f'])
+    assert ret == 0
+    certfile = os.path.join(TEST_CA_DIR, 'example.com.pem')
+    assert os.path.isfile(certfile)
+
+def test_explicit_wildcard():
+    ca = CertificateAuthority(TEST_CA_ROOT, TEST_CA_DIR, 'Test CA')
+    filename = ca.get_wildcard_cert('test.example.proxy')
+    certfile = os.path.join(TEST_CA_DIR, 'example.proxy.pem')
+    assert filename == certfile
+    assert os.path.isfile(certfile)
+    os.remove(certfile)
+
+def test_create_already_exists():
+    ret = main([TEST_CA_ROOT, '-d', TEST_CA_DIR, '-n', 'example.com', '-w'])
+    assert ret == 1
+    certfile = os.path.join(TEST_CA_DIR, 'example.com.pem')
+    assert os.path.isfile(certfile)
+    # remove now
+    os.remove(certfile)
+
+def test_create_root_already_exists():
+    ret = main([TEST_CA_ROOT])
+    # not created, already exists
+    assert ret == 1
+    # remove now
+    os.remove(TEST_CA_ROOT)
+
+def test_create_root_subdir():
+    # create a new cert in a subdirectory
+    subdir = os.path.join(TEST_CA_DIR, 'subdir')
+
+    ca_file = os.path.join(subdir, 'certauth_test_ca.pem')
+
+    ca = CertificateAuthority(ca_file, subdir, 'Test CA',
+                              cert_not_before=-60 * 60,
+                              cert_not_after=60 * 60 * 24 * 3)
+
+    assert os.path.isdir(subdir)
+    assert os.path.isfile(ca_file)
+
+    buff = ca.get_root_PKCS12()
+    assert len(buff) > 0
+
+    expected_not_before = datetime.datetime.utcnow() - datetime.timedelta(seconds=60 * 60)
+    expected_not_after = datetime.datetime.utcnow() + datetime.timedelta(seconds=60 * 60 * 24 * 3)
+
+    cert = crypto.load_pkcs12(buff).get_certificate()
+
+    actual_not_before = datetime.datetime.strptime(
+            cert.get_notBefore().decode('ascii'), '%Y%m%d%H%M%SZ')
+    actual_not_after = datetime.datetime.strptime(
+            cert.get_notAfter().decode('ascii'), '%Y%m%d%H%M%SZ')
+
+    time.mktime(expected_not_before.utctimetuple())
+    assert abs((time.mktime(actual_not_before.utctimetuple()) - time.mktime(expected_not_before.utctimetuple()))) < 10
+    assert abs((time.mktime(actual_not_after.utctimetuple()) - time.mktime(expected_not_after.utctimetuple()))) < 10
diff --git a/warcprox/certauth.py b/warcprox/certauth.py
new file mode 100644
index 0000000..ca433e3
--- /dev/null
+++ b/warcprox/certauth.py
@@ -0,0 +1,263 @@
+import logging
+import os
+
+from OpenSSL import crypto
+from OpenSSL.SSL import FILETYPE_PEM
+
+import random
+from argparse import ArgumentParser
+
+import threading
+
+# =================================================================
+# Valid for 3 years from now
+# Max validity is 39 months:
+# https://casecurity.org/2015/02/19/ssl-certificate-validity-periods-limited-to-39-months-starting-in-april/
+CERT_NOT_AFTER = 3 * 365 * 24 * 60 * 60
+
+CERTS_DIR = './ca/certs/'
+
+CERT_NAME = 'certauth sample CA'
+
+DEF_HASH_FUNC = 'sha256'
+
+
+# =================================================================
+class CertificateAuthority(object):
+    """
+    Utility class for signing individual certificate
+    with a root cert.
+
+    Static generate_ca_root() method for creating the root cert
+
+    All certs saved on filesystem. Individual certs are stored
+    in specified certs_dir and reused if previously created.
+    """
+
+    def __init__(self, ca_file, certs_dir, ca_name,
+                 overwrite=False,
+                 cert_not_before=0,
+                 cert_not_after=CERT_NOT_AFTER):
+
+        assert(ca_file)
+        self.ca_file = ca_file
+
+        assert(certs_dir)
+        self.certs_dir = certs_dir
+
+        assert(ca_name)
+        self.ca_name = ca_name
+
+        self._file_created = False
+
+        self.cert_not_before = cert_not_before
+        self.cert_not_after = cert_not_after
+
+        if not os.path.exists(certs_dir):
+            os.makedirs(certs_dir)
+
+        # if file doesn't exist or overwrite is true
+        # create new root cert
+        if (overwrite or not os.path.isfile(ca_file)):
+            self.cert, self.key = self.generate_ca_root(ca_file, ca_name)
+            self._file_created = True
+
+        # read previously created root cert
+        else:
+            self.cert, self.key = self.read_pem(ca_file)
+
+        self._lock = threading.Lock()
+
+    def cert_for_host(self, host, overwrite=False, wildcard=False):
+        with self._lock:
+            host_filename = os.path.join(self.certs_dir, host) + '.pem'
+
+            if not overwrite and os.path.exists(host_filename):
+                self._file_created = False
+                return host_filename
+
+            self.generate_host_cert(host, self.cert, self.key, host_filename,
+                                    wildcard)
+
+            self._file_created = True
+            return host_filename
+
+    def get_wildcard_cert(self, cert_host):
+        host_parts = cert_host.split('.', 1)
+        if len(host_parts) == 2 and '.' in host_parts[1]:
+            cert_host = host_parts[1]
+
+        certfile = self.cert_for_host(cert_host,
+                                      wildcard=True)
+
+        return certfile
+
+    def get_root_PKCS12(self):
+        p12 = crypto.PKCS12()
+        p12.set_certificate(self.cert)
+        p12.set_privatekey(self.key)
+        return p12.export()
+
+    def _make_cert(self, certname):
+        cert = crypto.X509()
+        cert.set_serial_number(random.randint(0, 2 ** 64 - 1))
+        cert.get_subject().CN = certname
+
+        cert.set_version(2)
+        cert.gmtime_adj_notBefore(self.cert_not_before)
+        cert.gmtime_adj_notAfter(self.cert_not_after)
+        return cert
+
+    def generate_ca_root(self, ca_file, ca_name, hash_func=DEF_HASH_FUNC):
+        # Generate key
+        key = crypto.PKey()
+        key.generate_key(crypto.TYPE_RSA, 2048)
+
+        # Generate cert
+        cert = self._make_cert(ca_name)
+
+        cert.set_issuer(cert.get_subject())
+        cert.set_pubkey(key)
+        cert.add_extensions([
+            crypto.X509Extension(b"basicConstraints",
+                                 True,
+                                 b"CA:TRUE, pathlen:0"),
+
+            crypto.X509Extension(b"keyUsage",
+                                 True,
+                                 b"keyCertSign, cRLSign"),
+
+            crypto.X509Extension(b"subjectKeyIdentifier",
+                                 False,
+                                 b"hash",
+                                 subject=cert),
+            ])
+        cert.sign(key, hash_func)
+
+        # Write cert + key
+        self.write_pem(ca_file, cert, key)
+        return cert, key
+
+    def generate_host_cert(self, host, root_cert, root_key, host_filename,
+                           wildcard=False, hash_func=DEF_HASH_FUNC):
+
+        host = host.encode('utf-8')
+
+        # Generate key
+        key = crypto.PKey()
+        key.generate_key(crypto.TYPE_RSA, 2048)
+
+        # Generate CSR
+        req = crypto.X509Req()
+        req.get_subject().CN = host
+        req.set_pubkey(key)
+        req.sign(key, hash_func)
+
+        # Generate Cert
+        cert = self._make_cert(host)
+
+        cert.set_issuer(root_cert.get_subject())
+        cert.set_pubkey(req.get_pubkey())
+
+        if wildcard:
+            DNS = b'DNS:'
+            alt_hosts = [DNS + host,
+                         DNS + b'*.' + host]
+
+            alt_hosts = b', '.join(alt_hosts)
+
+            cert.add_extensions([
+                crypto.X509Extension(b'subjectAltName',
+                                     False,
+                                     alt_hosts)])
+
+        cert.sign(root_key, hash_func)
+
+        # Write cert + key
+        self.write_pem(host_filename, cert, key)
+        return cert, key
+
+    def write_pem(self, filename, cert, key):
+        with open(filename, 'wb+') as f:
+            f.write(crypto.dump_privatekey(FILETYPE_PEM, key))
+
+            f.write(crypto.dump_certificate(FILETYPE_PEM, cert))
+
+    def read_pem(self, filename):
+        with open(filename, 'r') as f:
+            cert = crypto.load_certificate(FILETYPE_PEM, f.read())
+            f.seek(0)
+            key = crypto.load_privatekey(FILETYPE_PEM, f.read())
+
+        return cert, key
+
+
+# =================================================================
+def main(args=None):
+    parser = ArgumentParser(description='Certificate Authority Cert Maker Tools')
+
+    parser.add_argument('root_ca_cert',
+                        help='Path to existing or new root CA file')
+
+    parser.add_argument('-c', '--certname', action='store', default=CERT_NAME,
+                        help='Name for root certificate')
+
+    parser.add_argument('-n', '--hostname',
+                        help='Hostname certificate to create')
+
+    parser.add_argument('-d', '--certs-dir', default=CERTS_DIR,
+                        help='Directory for host certificates')
+
+    parser.add_argument('-f', '--force', action='store_true',
+                        help='Overwrite certificates if they already exist')
+
+    parser.add_argument('-w', '--wildcard_cert', action='store_true',
+                        help='add wildcard SAN to host: *.<host>, <host>')
+
+    r = parser.parse_args(args=args)
+
+    certs_dir = r.certs_dir
+    wildcard = r.wildcard_cert
+
+    root_cert = r.root_ca_cert
+    hostname = r.hostname
+
+    if not hostname:
+        overwrite = r.force
+    else:
+        overwrite = False
+
+    ca = CertificateAuthority(ca_file=root_cert,
+                              certs_dir=r.certs_dir,
+                              ca_name=r.certname,
+                              overwrite=overwrite)
+
+    # Just creating the root cert
+    if not hostname:
+        if ca._file_created:
+            print('Created new root cert: "' + root_cert + '"')
+            return 0
+        else:
+            print('Root cert "' + root_cert +
+                  '" already exists,' + ' use -f to overwrite')
+            return 1
+
+    # Sign a certificate for a given host
+    overwrite = r.force
+    host_filename = ca.cert_for_host(hostname,
+                                         overwrite, wildcard)
+
+    if ca._file_created:
+        print('Created new cert "' + hostname +
+              '" signed by root cert ' +
+              root_cert)
+        return 0
+
+    else:
+        print('Cert for "' + hostname + '" already exists,' +
+              ' use -f to overwrite')
+        return 1
+
+
+if __name__ == "__main__":  #pragma: no cover
+    main()
diff --git a/warcprox/controller.py b/warcprox/controller.py
index 8d670cb..fcd4ab7 100644
--- a/warcprox/controller.py
+++ b/warcprox/controller.py
@@ -31,7 +31,6 @@ import sys
 import gc
 import datetime
 import warcprox
-import certauth
 import functools
 import doublethink
 import importlib
diff --git a/warcprox/main.py b/warcprox/main.py
index 01bd189..d0bb1a6 100644
--- a/warcprox/main.py
+++ b/warcprox/main.py
@@ -39,7 +39,6 @@ import socket
 import traceback
 import signal
 import threading
-import certauth.certauth
 import yaml
 import warcprox
 import doublethink
diff --git a/warcprox/mitmproxy.py b/warcprox/mitmproxy.py
index e6af7ac..bc1c4b9 100644
--- a/warcprox/mitmproxy.py
+++ b/warcprox/mitmproxy.py
@@ -83,7 +83,8 @@ from urllib3.exceptions import TimeoutError, HTTPError, NewConnectionError
 import doublethink
 from cachetools import TTLCache
 from threading import RLock
-from certauth.certauth import CertificateAuthority
+
+from .certauth import CertificateAuthority
 
 class ProxyingRecorder(object):
     """