from __future__ import (absolute_import, print_function, division) import os import ssl import time import datetime from six.moves import filter import ipaddress import sys from pyasn1.type import univ, constraint, char, namedtype, tag from pyasn1.codec.der.decoder import decode from pyasn1.error import PyAsn1Error import OpenSSL from .utils import Serializable # Default expiry must not be too long: https://github.com/mitmproxy/mitmproxy/issues/815 DEFAULT_EXP = 94608000 # = 24 * 60 * 60 * 365 * 3 # Generated with "openssl dhparam". It's too slow to generate this on startup. DEFAULT_DHPARAM = b""" -----BEGIN DH PARAMETERS----- MIICCAKCAgEAyT6LzpwVFS3gryIo29J5icvgxCnCebcdSe/NHMkD8dKJf8suFCg3 O2+dguLakSVif/t6dhImxInJk230HmfC8q93hdcg/j8rLGJYDKu3ik6H//BAHKIv j5O9yjU3rXCfmVJQic2Nne39sg3CreAepEts2TvYHhVv3TEAzEqCtOuTjgDv0ntJ Gwpj+BJBRQGG9NvprX1YGJ7WOFBP/hWU7d6tgvE6Xa7T/u9QIKpYHMIkcN/l3ZFB chZEqVlyrcngtSXCROTPcDOQ6Q8QzhaBJS+Z6rcsd7X+haiQqvoFcmaJ08Ks6LQC ZIL2EtYJw8V8z7C0igVEBIADZBI6OTbuuhDwRw//zU1uq52Oc48CIZlGxTYG/Evq o9EWAXUYVzWkDSTeBH1r4z/qLPE2cnhtMxbFxuvK53jGB0emy2y1Ei6IhKshJ5qX IB/aE7SSHyQ3MDHHkCmQJCsOd4Mo26YX61NZ+n501XjqpCBQ2+DfZCBh8Va2wDyv A2Ryg9SUz8j0AXViRNMJgJrr446yro/FuJZwnQcO3WQnXeqSBnURqKjmqkeFP+d8 6mk2tqJaY507lRNqtGlLnj7f5RNoBFJDCLBNurVgfvq9TCVWKDIFD4vZRjCrnl6I rD693XKIHUCWOjMh1if6omGXKHH40QuME2gNa50+YPn1iYDl88uDbbMCAQI= -----END DH PARAMETERS----- """ def create_ca(o, cn, exp): key = OpenSSL.crypto.PKey() key.generate_key(OpenSSL.crypto.TYPE_RSA, 2048) cert = OpenSSL.crypto.X509() cert.set_serial_number(int(time.time() * 10000)) cert.set_version(2) cert.get_subject().CN = cn cert.get_subject().O = o cert.gmtime_adj_notBefore(-3600 * 48) cert.gmtime_adj_notAfter(exp) cert.set_issuer(cert.get_subject()) cert.set_pubkey(key) cert.add_extensions([ OpenSSL.crypto.X509Extension( b"basicConstraints", True, b"CA:TRUE" ), OpenSSL.crypto.X509Extension( b"nsCertType", False, b"sslCA" ), OpenSSL.crypto.X509Extension( b"extendedKeyUsage", False, b"serverAuth,clientAuth,emailProtection,timeStamping,msCodeInd,msCodeCom,msCTLSign,msSGC,msEFS,nsSGC" ), OpenSSL.crypto.X509Extension( b"keyUsage", True, b"keyCertSign, cRLSign" ), OpenSSL.crypto.X509Extension( b"subjectKeyIdentifier", False, b"hash", subject=cert ), ]) cert.sign(key, "sha256") return key, cert def dummy_cert(privkey, cacert, commonname, sans): """ Generates a dummy certificate. privkey: CA private key cacert: CA certificate commonname: Common name for the generated certificate. sans: A list of Subject Alternate Names. Returns cert if operation succeeded, None if not. """ ss = [] for i in sans: try: ipaddress.ip_address(i.decode("ascii")) except ValueError: ss.append(b"DNS: %s" % i) else: ss.append(b"IP: %s" % i) ss = b", ".join(ss) cert = OpenSSL.crypto.X509() cert.gmtime_adj_notBefore(-3600 * 48) cert.gmtime_adj_notAfter(DEFAULT_EXP) cert.set_issuer(cacert.get_subject()) if commonname is not None: cert.get_subject().CN = commonname cert.set_serial_number(int(time.time() * 10000)) if ss: cert.set_version(2) cert.add_extensions( [OpenSSL.crypto.X509Extension(b"subjectAltName", False, ss)]) cert.set_pubkey(cacert.get_pubkey()) cert.sign(privkey, "sha256") return SSLCert(cert) # DNTree did not pass TestCertStore.test_sans_change and is temporarily replaced by a simple dict. # # class _Node(UserDict.UserDict): # def __init__(self): # UserDict.UserDict.__init__(self) # self.value = None # # # class DNTree: # """ # Domain store that knows about wildcards. DNS wildcards are very # restricted - the only valid variety is an asterisk on the left-most # domain component, i.e.: # # *.foo.com # """ # def __init__(self): # self.d = _Node() # # def add(self, dn, cert): # parts = dn.split(".") # parts.reverse() # current = self.d # for i in parts: # current = current.setdefault(i, _Node()) # current.value = cert # # def get(self, dn): # parts = dn.split(".") # current = self.d # for i in reversed(parts): # if i in current: # current = current[i] # elif "*" in current: # return current["*"].value # else: # return None # return current.value class CertStoreEntry(object): def __init__(self, cert, privatekey, chain_file): self.cert = cert self.privatekey = privatekey self.chain_file = chain_file class CertStore(object): """ Implements an in-memory certificate store. """ def __init__( self, default_privatekey, default_ca, default_chain_file, dhparams): self.default_privatekey = default_privatekey self.default_ca = default_ca self.default_chain_file = default_chain_file self.dhparams = dhparams self.certs = dict() @staticmethod def load_dhparam(path): # netlib<=0.10 doesn't generate a dhparam file. # Create it now if neccessary. if not os.path.exists(path): with open(path, "wb") as f: f.write(DEFAULT_DHPARAM) bio = OpenSSL.SSL._lib.BIO_new_file(path.encode(sys.getfilesystemencoding()), b"r") if bio != OpenSSL.SSL._ffi.NULL: bio = OpenSSL.SSL._ffi.gc(bio, OpenSSL.SSL._lib.BIO_free) dh = OpenSSL.SSL._lib.PEM_read_bio_DHparams( bio, OpenSSL.SSL._ffi.NULL, OpenSSL.SSL._ffi.NULL, OpenSSL.SSL._ffi.NULL) dh = OpenSSL.SSL._ffi.gc(dh, OpenSSL.SSL._lib.DH_free) return dh @classmethod def from_store(cls, path, basename): ca_path = os.path.join(path, basename + "-ca.pem") if not os.path.exists(ca_path): key, ca = cls.create_store(path, basename) else: with open(ca_path, "rb") as f: raw = f.read() ca = OpenSSL.crypto.load_certificate( OpenSSL.crypto.FILETYPE_PEM, raw) key = OpenSSL.crypto.load_privatekey( OpenSSL.crypto.FILETYPE_PEM, raw) dh_path = os.path.join(path, basename + "-dhparam.pem") dh = cls.load_dhparam(dh_path) return cls(key, ca, ca_path, dh) @staticmethod def create_store(path, basename, o=None, cn=None, expiry=DEFAULT_EXP): if not os.path.exists(path): os.makedirs(path) o = o or basename cn = cn or basename key, ca = create_ca(o=o, cn=cn, exp=expiry) # Dump the CA plus private key with open(os.path.join(path, basename + "-ca.pem"), "wb") as f: f.write( OpenSSL.crypto.dump_privatekey( OpenSSL.crypto.FILETYPE_PEM, key)) f.write( OpenSSL.crypto.dump_certificate( OpenSSL.crypto.FILETYPE_PEM, ca)) # Dump the certificate in PEM format with open(os.path.join(path, basename + "-ca-cert.pem"), "wb") as f: f.write( OpenSSL.crypto.dump_certificate( OpenSSL.crypto.FILETYPE_PEM, ca)) # Create a .cer file with the same contents for Android with open(os.path.join(path, basename + "-ca-cert.cer"), "wb") as f: f.write( OpenSSL.crypto.dump_certificate( OpenSSL.crypto.FILETYPE_PEM, ca)) # Dump the certificate in PKCS12 format for Windows devices with open(os.path.join(path, basename + "-ca-cert.p12"), "wb") as f: p12 = OpenSSL.crypto.PKCS12() p12.set_certificate(ca) p12.set_privatekey(key) f.write(p12.export()) with open(os.path.join(path, basename + "-dhparam.pem"), "wb") as f: f.write(DEFAULT_DHPARAM) return key, ca def add_cert_file(self, spec, path): with open(path, "rb") as f: raw = f.read() cert = SSLCert( OpenSSL.crypto.load_certificate( OpenSSL.crypto.FILETYPE_PEM, raw)) try: privatekey = OpenSSL.crypto.load_privatekey( OpenSSL.crypto.FILETYPE_PEM, raw) except Exception: privatekey = self.default_privatekey self.add_cert( CertStoreEntry(cert, privatekey, path), spec ) def add_cert(self, entry, *names): """ Adds a cert to the certstore. We register the CN in the cert plus any SANs, and also the list of names provided as an argument. """ if entry.cert.cn: self.certs[entry.cert.cn] = entry for i in entry.cert.altnames: self.certs[i] = entry for i in names: self.certs[i] = entry @staticmethod def asterisk_forms(dn): if dn is None: return [] parts = dn.split(b".") parts.reverse() curr_dn = b"" dn_forms = [b"*"] for part in parts[:-1]: curr_dn = b"." + part + curr_dn # .example.com dn_forms.append(b"*" + curr_dn) # *.example.com if parts[-1] != b"*": dn_forms.append(parts[-1] + curr_dn) return dn_forms def get_cert(self, commonname, sans): """ Returns an (cert, privkey, cert_chain) tuple. commonname: Common name for the generated certificate. Must be a valid, plain-ASCII, IDNA-encoded domain name. sans: A list of Subject Alternate Names. """ potential_keys = self.asterisk_forms(commonname) for s in sans: potential_keys.extend(self.asterisk_forms(s)) potential_keys.append((commonname, tuple(sans))) name = next( filter(lambda key: key in self.certs, potential_keys), None ) if name: entry = self.certs[name] else: entry = CertStoreEntry( cert=dummy_cert( self.default_privatekey, self.default_ca, commonname, sans), privatekey=self.default_privatekey, chain_file=self.default_chain_file) self.certs[(commonname, tuple(sans))] = entry return entry.cert, entry.privatekey, entry.chain_file class _GeneralName(univ.Choice): # We are only interested in dNSNames. We use a default handler to ignore # other types. # TODO: We should also handle iPAddresses. componentType = namedtype.NamedTypes( namedtype.NamedType('dNSName', char.IA5String().subtype( implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2) ) ), ) class _GeneralNames(univ.SequenceOf): componentType = _GeneralName() sizeSpec = univ.SequenceOf.sizeSpec + \ constraint.ValueSizeConstraint(1, 1024) class SSLCert(Serializable): def __init__(self, cert): """ Returns a (common name, [subject alternative names]) tuple. """ self.x509 = cert def __eq__(self, other): return self.digest("sha256") == other.digest("sha256") def __ne__(self, other): return not self.__eq__(other) def get_state(self): return self.to_pem() def set_state(self, state): self.x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, state) @classmethod def from_state(cls, state): return cls.from_pem(state) @classmethod def from_pem(cls, txt): x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, txt) return cls(x509) @classmethod def from_der(cls, der): pem = ssl.DER_cert_to_PEM_cert(der) return cls.from_pem(pem) def to_pem(self): return OpenSSL.crypto.dump_certificate( OpenSSL.crypto.FILETYPE_PEM, self.x509) def digest(self, name): return self.x509.digest(name) @property def issuer(self): return self.x509.get_issuer().get_components() @property def notbefore(self): t = self.x509.get_notBefore() return datetime.datetime.strptime(t.decode("ascii"), "%Y%m%d%H%M%SZ") @property def notafter(self): t = self.x509.get_notAfter() return datetime.datetime.strptime(t.decode("ascii"), "%Y%m%d%H%M%SZ") @property def has_expired(self): return self.x509.has_expired() @property def subject(self): return self.x509.get_subject().get_components() @property def serial(self): return self.x509.get_serial_number() @property def keyinfo(self): pk = self.x509.get_pubkey() types = { OpenSSL.crypto.TYPE_RSA: "RSA", OpenSSL.crypto.TYPE_DSA: "DSA", } return ( types.get(pk.type(), "UNKNOWN"), pk.bits() ) @property def cn(self): c = None for i in self.subject: if i[0] == b"CN": c = i[1] return c @property def altnames(self): """ Returns: All DNS altnames. """ # tcp.TCPClient.convert_to_ssl assumes that this property only contains DNS altnames for hostname verification. altnames = [] for i in range(self.x509.get_extension_count()): ext = self.x509.get_extension(i) if ext.get_short_name() == b"subjectAltName": try: dec = decode(ext.get_data(), asn1Spec=_GeneralNames()) except PyAsn1Error: continue for i in dec[0]: altnames.append(i[0].asOctets()) return altnames