Python pyasn1.codec.der.decoder 模块，decode() 实例源码

def _load_pkcs1_der(cls, keyfile):
        r'''Loads a key in PKCS#1 DER format.

        @param keyfile: contents of a DER-encoded file that contains the public
            key.
        @return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.decodestring(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        '''

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        '''Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        @param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        @return: a PublicKey object
        '''

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def _key_identifier_from_public_key(public_key):
    # This is a very slow way to do this.
    serialized = public_key.public_bytes(
        serialization.Encoding.DER,
        serialization.PublicFormat.SubjectPublicKeyInfo
    )
    spki, remaining = decoder.decode(
        serialized, asn1Spec=_SubjectPublicKeyInfo()
    )
    assert not remaining
    # the univ.BitString object is a tuple of bits. We need bytes and
    # pyasn1 really doesn't want to give them to us. To get it we'll
    # build an integer and convert that to bytes.
    bits = 0
    for bit in spki.getComponentByName("subjectPublicKey"):
        bits = bits << 1 | bit

    data = utils.int_to_bytes(bits)
    return hashlib.sha1(data).digest()

def _load_pkcs1_der(cls, keyfile):
        """Loads a key in PKCS#1 DER format.

        :param keyfile: contents of a DER-encoded file that contains the public
            key.
        :return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.standard_b64decode(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        """

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        """Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        :param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        :return: a PublicKey object

        """

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def _load_pkcs1_der(cls, keyfile):
        r'''Loads a key in PKCS#1 DER format.

        @param keyfile: contents of a DER-encoded file that contains the public
            key.
        @return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.decodestring(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        '''

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        '''Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        @param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        @return: a PublicKey object
        '''

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def _load_pkcs1_der(cls, keyfile):
        """Loads a key in PKCS#1 DER format.

        :param keyfile: contents of a DER-encoded file that contains the public
            key.
        :return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.standard_b64decode(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        """

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        """Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        :param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        :return: a PublicKey object

        """

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def _load_pkcs1_der(cls, keyfile):
        """Loads a key in PKCS#1 DER format.

        :param keyfile: contents of a DER-encoded file that contains the public
            key.
        :return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.standard_b64decode(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        """

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        """Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        :param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        :return: a PublicKey object

        """

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def getCNfromSSLSock(self, sslSock):
        derCert = sslSock.getpeercert(True)

        self.log.debug("CN Extraction: Doing Stuff")
        m2crypt_cert = M2Crypto.X509.load_cert_der_string(derCert)
        #print m2crypt_cert.as_text()
        print m2crypt_cert.get_pubkey() 
        buff = decoder.decode(derCert,asn1Spec=certType)[0].\
               getComponentByName('tbsCertificate').\
               getComponentByName('subject').\
               getComponentByType(RDNSequence().getTagSet())


        #print buff.__class__.__name__
        #print buff.prettyPrint()
        for item in buff:
            if item[0].getComponentByName('type') == (2, 5, 4, 3):
                cn = item[0].getComponentByName('value')
                break
        for item in cn:
            if item != None:
                return str(item)

def _load_pkcs1_der(cls, keyfile):
        """Loads a key in PKCS#1 DER format.

        :param keyfile: contents of a DER-encoded file that contains the public
            key.
        :return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.standard_b64decode(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        """

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        """Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        :param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        :return: a PublicKey object

        """

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def _key_identifier_from_public_key(public_key):
    # This is a very slow way to do this.
    serialized = public_key.public_bytes(
        serialization.Encoding.DER,
        serialization.PublicFormat.SubjectPublicKeyInfo
    )
    spki, remaining = decoder.decode(
        serialized, asn1Spec=_SubjectPublicKeyInfo()
    )
    assert not remaining
    # the univ.BitString object is a tuple of bits. We need bytes and
    # pyasn1 really doesn't want to give them to us. To get it we'll
    # build an integer and convert that to bytes.
    bits = 0
    for bit in spki.getComponentByName("subjectPublicKey"):
        bits = bits << 1 | bit

    data = utils.int_to_bytes(bits)
    return hashlib.sha1(data).digest()

def _key_identifier_from_public_key(public_key):
    # This is a very slow way to do this.
    serialized = public_key.public_bytes(
        serialization.Encoding.DER,
        serialization.PublicFormat.SubjectPublicKeyInfo
    )
    spki, remaining = decoder.decode(
        serialized, asn1Spec=_SubjectPublicKeyInfo()
    )
    assert not remaining
    # the univ.BitString object is a tuple of bits. We need bytes and
    # pyasn1 really doesn't want to give them to us. To get it we'll
    # build an integer and convert that to bytes.
    bits = 0
    for bit in spki.getComponentByName("subjectPublicKey"):
        bits = bits << 1 | bit

    data = utils.int_to_bytes(bits)
    return hashlib.sha1(data).digest()

def _key_identifier_from_public_key(public_key):
    # This is a very slow way to do this.
    serialized = public_key.public_bytes(
        serialization.Encoding.DER,
        serialization.PublicFormat.SubjectPublicKeyInfo
    )
    spki, remaining = decoder.decode(
        serialized, asn1Spec=_SubjectPublicKeyInfo()
    )
    assert not remaining
    # the univ.BitString object is a tuple of bits. We need bytes and
    # pyasn1 really doesn't want to give them to us. To get it we'll
    # build an integer and convert that to bytes.
    bits = 0
    for bit in spki.getComponentByName("subjectPublicKey"):
        bits = bits << 1 | bit

    data = utils.int_to_bytes(bits)
    return hashlib.sha1(data).digest()

def _load_pkcs1_der(cls, keyfile):
        """Loads a key in PKCS#1 DER format.

        :param keyfile: contents of a DER-encoded file that contains the public
            key.
        :return: a PublicKey object

        First let's construct a DER encoded key:

        >>> import base64
        >>> b64der = 'MAwCBQCNGmYtAgMBAAE='
        >>> der = base64.standard_b64decode(b64der)

        This loads the file:

        >>> PublicKey._load_pkcs1_der(der)
        PublicKey(2367317549, 65537)

        """

        from pyasn1.codec.der import decoder
        from rsa.asn1 import AsnPubKey

        (priv, _) = decoder.decode(keyfile, asn1Spec=AsnPubKey())
        return cls(n=int(priv['modulus']), e=int(priv['publicExponent']))

def load_pkcs1_openssl_der(cls, keyfile):
        """Loads a PKCS#1 DER-encoded public key file from OpenSSL.

        :param keyfile: contents of a DER-encoded file that contains the public
            key, from OpenSSL.
        :return: a PublicKey object

        """

        from rsa.asn1 import OpenSSLPubKey
        from pyasn1.codec.der import decoder
        from pyasn1.type import univ

        (keyinfo, _) = decoder.decode(keyfile, asn1Spec=OpenSSLPubKey())

        if keyinfo['header']['oid'] != univ.ObjectIdentifier('1.2.840.113549.1.1.1'):
            raise TypeError("This is not a DER-encoded OpenSSL-compatible public key")

        return cls._load_pkcs1_der(keyinfo['key'][1:])

def decodeChallengeSecurityBlob(data):
    try:
        d, _ = decoder.decode(data, asn1Spec = NegotiationToken())
        nt = d.getComponentByName('negTokenTarg')

        token = nt.getComponentByName('responseToken')
        if not token:
            raise BadSecurityBlobError('NTLMSSP_CHALLENGE security blob does not contain responseToken field')

        provider_oid = nt.getComponentByName('supportedMech')
        if provider_oid and str(provider_oid) != '1.3.6.1.4.1.311.2.2.10':  # This OID is defined in [MS-NLMP]: 1.9
            raise UnsupportedSecurityProvider('Security provider "%s" is not supported by pysmb' % str(provider_oid))

        result = nt.getComponentByName('negResult')
        return int(result), str(token)
    except Exception, ex:
        raise BadSecurityBlobError(str(ex))

def parseOcspResponse(ocspResponse):
    responseStatus = ocspResponse.getComponentByName('responseStatus')
    assert responseStatus == rfc2560.OCSPResponseStatus('successful'), responseStatus.prettyPrint()
    responseBytes = ocspResponse.getComponentByName('responseBytes')
    responseType = responseBytes.getComponentByName('responseType')
    assert responseType == rfc2560.id_pkix_ocsp_basic, responseType.prettyPrint()

    response = responseBytes.getComponentByName('response')

    basicOCSPResponse, _ = decoder.decode(
        response, asn1Spec=rfc2560.BasicOCSPResponse()
    )

    tbsResponseData = basicOCSPResponse.getComponentByName('tbsResponseData')

    response0 = tbsResponseData.getComponentByName('responses').getComponentByPosition(0)

    return (
        tbsResponseData.getComponentByName('producedAt'),
        response0.getComponentByName('certID'),
        response0.getComponentByName('certStatus').getName(),
        response0.getComponentByName('thisUpdate')
    )

def decode(data: bytes) -> KkdcpRequest:
    """Decode a KDC-PROXY-MESSAGE"""
    try:
        req, err = decoder.decode(data, asn1Spec=model.KdcProxyMessage())
    except error.PyAsn1Error:
        raise ParserError("Invalid request")

    if err:
        raise ParserError("Invalid request")

    message = req.getComponentByName('kerb-message').asOctets()
    domain = req.getComponentByName('target-domain').asOctets()

    # TODO: Check if the request is valid here

    return KkdcpRequest(message, domain)

def decodeChallengeSecurityBlob(data):
    try:
        d, _ = decoder.decode(data, asn1Spec = NegotiationToken())
        nt = d.getComponentByName('negTokenTarg')

        token = nt.getComponentByName('responseToken')
        if not token:
            raise BadSecurityBlobError('NTLMSSP_CHALLENGE security blob does not contain responseToken field')

        provider_oid = nt.getComponentByName('supportedMech')
        if provider_oid and str(provider_oid) != '1.3.6.1.4.1.311.2.2.10':  # This OID is defined in [MS-NLMP]: 1.9
            raise UnsupportedSecurityProvider('Security provider "%s" is not supported by pysmb' % str(provider_oid))

        result = nt.getComponentByName('negResult')
        return int(result), str(token)
    except Exception, ex:
        raise BadSecurityBlobError(str(ex))

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def from_string(cls, key_pem, is_x509_cert):
        """Construct an RsaVerifier instance from a string.

        Args:
            key_pem: string, public key in PEM format.
            is_x509_cert: bool, True if key_pem is an X509 cert, otherwise it
                          is expected to be an RSA key in PEM format.

        Returns:
            RsaVerifier instance.

        Raises:
            ValueError: if the key_pem can't be parsed. In either case, error
                        will begin with 'No PEM start marker'. If
                        ``is_x509_cert`` is True, will fail to find the
                        "-----BEGIN CERTIFICATE-----" error, otherwise fails
                        to find "-----BEGIN RSA PUBLIC KEY-----".
        """
        key_pem = _to_bytes(key_pem)
        if is_x509_cert:
            der = rsa.pem.load_pem(key_pem, 'CERTIFICATE')
            asn1_cert, remaining = decoder.decode(der, asn1Spec=Certificate())
            if remaining != b'':
                raise ValueError('Unused bytes', remaining)

            cert_info = asn1_cert['tbsCertificate']['subjectPublicKeyInfo']
            key_bytes = _bit_list_to_bytes(cert_info['subjectPublicKey'])
            pubkey = rsa.PublicKey.load_pkcs1(key_bytes, 'DER')
        else:
            pubkey = rsa.PublicKey.load_pkcs1(key_pem, 'PEM')
        return cls(pubkey)

def from_string(cls, key, password='notasecret'):
        """Construct an RsaSigner instance from a string.

        Args:
            key: string, private key in PEM format.
            password: string, password for private key file. Unused for PEM
                      files.

        Returns:
            RsaSigner instance.

        Raises:
            ValueError if the key cannot be parsed as PKCS#1 or PKCS#8 in
            PEM format.
        """
        key = _from_bytes(key)  # pem expects str in Py3
        marker_id, key_bytes = pem.readPemBlocksFromFile(
            six.StringIO(key), _PKCS1_MARKER, _PKCS8_MARKER)

        if marker_id == 0:
            pkey = rsa.key.PrivateKey.load_pkcs1(key_bytes,
                                                 format='DER')
        elif marker_id == 1:
            key_info, remaining = decoder.decode(
                key_bytes, asn1Spec=_PKCS8_SPEC)
            if remaining != b'':
                raise ValueError('Unused bytes', remaining)
            pkey_info = key_info.getComponentByName('privateKey')
            pkey = rsa.key.PrivateKey.load_pkcs1(pkey_info.asOctets(),
                                                 format='DER')
        else:
            raise ValueError('No key could be detected.')

        return cls(pkey)

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != 'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def _decrypt_rep(data, key, spec, enc_spec, msg_type):
    rep = decode(data, asn1Spec=spec)[0]
    rep_enc = str(rep['enc-part']['cipher'])
    #print rep_enc
    rep_enc = decrypt(key[0], key[1], msg_type, rep_enc)

    # MAGIC
    if rep_enc[:20] == '31337313373133731337':
        return rep_enc[20:22], None

    rep_enc = decode(rep_enc, asn1Spec=enc_spec)[0]

    return rep, rep_enc

def _extract_data(data, spec):
    rep = decode(data, asn1Spec=spec)[0]

    return rep

#used in implicit authentication

def decrypt_ticket_enc_part(ticket, key):
    ticket_enc = str(ticket['enc-part']['cipher'])
    ticket_enc = decrypt(key[0], key[1], 2, ticket_enc)
    return decode(ticket_enc, asn1Spec=EncTicketPart())[0]

def iter_authorization_data(ad):
    if ad is None:
        return
    for block in ad:
        yield block
        if block['ad-type'] == AD_IF_RELEVANT:
            for subblock in iter_authorization_data(decode(str(block['ad-data']), asn1Spec=AuthorizationData())[0]):
                yield subblock

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def decode_dss_signature(signature):
    try:
        data, remaining = decoder.decode(signature, asn1Spec=_DSSSigValue())
    except PyAsn1Error:
        raise ValueError("Invalid signature data. Unable to decode ASN.1")

    if remaining:
        raise ValueError(
            "The signature contains bytes after the end of the ASN.1 sequence."
        )

    r = int(data.getComponentByName('r'))
    s = int(data.getComponentByName('s'))
    return (r, s)

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def _get_subj_alt_name(cls, peer_cert):
        '''Extract subjectAltName DNS name settings from certificate extensions

        @param peer_cert: peer certificate in SSL connection.  subjectAltName
        settings if any will be extracted from this
        @type peer_cert: OpenSSL.crypto.X509
        '''
        # Search through extensions
        dns_name = []
        general_names = SubjectAltName()
        for i in range(peer_cert.get_extension_count()):
            ext = peer_cert.get_extension(i)
            ext_name = ext.get_short_name()
            if ext_name == cls.SUBJ_ALT_NAME_EXT_NAME:
                # PyOpenSSL returns extension data in ASN.1 encoded form
                ext_dat = ext.get_data()
                decoded_dat = der_decoder.decode(ext_dat, 
                                                 asn1Spec=general_names)

                for name in decoded_dat:
                    if isinstance(name, SubjectAltName):
                        for entry in range(len(name)):
                            component = name.getComponentByPosition(entry)
                            dns_name.append(str(component.getComponent()))

        return dns_name

def decode_dss_signature(signature):
    try:
        data, remaining = decoder.decode(signature, asn1Spec=_DSSSigValue())
    except PyAsn1Error:
        raise ValueError("Invalid signature data. Unable to decode ASN.1")

    if remaining:
        raise ValueError(
            "The signature contains bytes after the end of the ASN.1 sequence."
        )

    r = int(data.getComponentByName('r'))
    s = int(data.getComponentByName('s'))
    return (r, s)

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != 'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != 'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != b'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != 'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def get_subj_alt_name(peer_cert):
    # Search through extensions
    dns_name = []
    if not SUBJ_ALT_NAME_SUPPORT:
        return dns_name

    general_names = SubjectAltName()
    for i in range(peer_cert.get_extension_count()):
        ext = peer_cert.get_extension(i)
        ext_name = ext.get_short_name()
        if ext_name != 'subjectAltName':
            continue

        # PyOpenSSL returns extension data in ASN.1 encoded form
        ext_dat = ext.get_data()
        decoded_dat = der_decoder.decode(ext_dat,
                                         asn1Spec=general_names)

        for name in decoded_dat:
            if not isinstance(name, SubjectAltName):
                continue
            for entry in range(len(name)):
                component = name.getComponentByPosition(entry)
                if component.getName() != 'dNSName':
                    continue
                dns_name.append(str(component.getComponent()))

    return dns_name

def from_string(cls, key_pem, is_x509_cert):
        """Construct an RsaVerifier instance from a string.

        Args:
            key_pem: string, public key in PEM format.
            is_x509_cert: bool, True if key_pem is an X509 cert, otherwise it
                          is expected to be an RSA key in PEM format.

        Returns:
            RsaVerifier instance.

        Raises:
            ValueError: if the key_pem can't be parsed. In either case, error
                        will begin with 'No PEM start marker'. If
                        ``is_x509_cert`` is True, will fail to find the
                        "-----BEGIN CERTIFICATE-----" error, otherwise fails
                        to find "-----BEGIN RSA PUBLIC KEY-----".
        """
        key_pem = _helpers._to_bytes(key_pem)
        if is_x509_cert:
            der = rsa.pem.load_pem(key_pem, 'CERTIFICATE')
            asn1_cert, remaining = decoder.decode(der, asn1Spec=Certificate())
            if remaining != b'':
                raise ValueError('Unused bytes', remaining)

            cert_info = asn1_cert['tbsCertificate']['subjectPublicKeyInfo']
            key_bytes = _bit_list_to_bytes(cert_info['subjectPublicKey'])
            pubkey = rsa.PublicKey.load_pkcs1(key_bytes, 'DER')
        else:
            pubkey = rsa.PublicKey.load_pkcs1(key_pem, 'PEM')
        return cls(pubkey)