File: _openssl_crypt.py

package info (click to toggle)
python-oauth2client 2.0.1-3~bpo8%2B1
  • links: PTS, VCS
  • area: main
  • in suites: jessie-backports
  • size: 1,108 kB
  • sloc: python: 8,964; makefile: 188; sh: 55
file content (139 lines) | stat: -rw-r--r-- 4,558 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""OpenSSL Crypto-related routines for oauth2client."""

import base64

from OpenSSL import crypto

from oauth2client._helpers import _parse_pem_key
from oauth2client._helpers import _to_bytes


class OpenSSLVerifier(object):
    """Verifies the signature on a message."""

    def __init__(self, pubkey):
        """Constructor.

        Args:
            pubkey: OpenSSL.crypto.PKey, The public key to verify with.
        """
        self._pubkey = pubkey

    def verify(self, message, signature):
        """Verifies a message against a signature.

        Args:
        message: string or bytes, The message to verify. If string, will be
                 encoded to bytes as utf-8.
        signature: string or bytes, The signature on the message. If string,
                   will be encoded to bytes as utf-8.

        Returns:
            True if message was signed by the private key associated with the
            public key that this object was constructed with.
        """
        message = _to_bytes(message, encoding='utf-8')
        signature = _to_bytes(signature, encoding='utf-8')
        try:
            crypto.verify(self._pubkey, signature, message, 'sha256')
            return True
        except crypto.Error:
            return False

    @staticmethod
    def from_string(key_pem, is_x509_cert):
        """Construct a Verified 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:
            Verifier instance.

        Raises:
            OpenSSL.crypto.Error: if the key_pem can't be parsed.
        """
        key_pem = _to_bytes(key_pem)
        if is_x509_cert:
            pubkey = crypto.load_certificate(crypto.FILETYPE_PEM, key_pem)
        else:
            pubkey = crypto.load_privatekey(crypto.FILETYPE_PEM, key_pem)
        return OpenSSLVerifier(pubkey)


class OpenSSLSigner(object):
    """Signs messages with a private key."""

    def __init__(self, pkey):
        """Constructor.

        Args:
            pkey: OpenSSL.crypto.PKey (or equiv), The private key to sign with.
        """
        self._key = pkey

    def sign(self, message):
        """Signs a message.

        Args:
            message: bytes, Message to be signed.

        Returns:
            string, The signature of the message for the given key.
        """
        message = _to_bytes(message, encoding='utf-8')
        return crypto.sign(self._key, message, 'sha256')

    @staticmethod
    def from_string(key, password=b'notasecret'):
        """Construct a Signer instance from a string.

        Args:
            key: string, private key in PKCS12 or PEM format.
            password: string, password for the private key file.

        Returns:
            Signer instance.

        Raises:
            OpenSSL.crypto.Error if the key can't be parsed.
        """
        key = _to_bytes(key)
        parsed_pem_key = _parse_pem_key(key)
        if parsed_pem_key:
            pkey = crypto.load_privatekey(crypto.FILETYPE_PEM, parsed_pem_key)
        else:
            password = _to_bytes(password, encoding='utf-8')
            pkey = crypto.load_pkcs12(key, password).get_privatekey()
        return OpenSSLSigner(pkey)


def pkcs12_key_as_pem(private_key_bytes, private_key_password):
    """Convert the contents of a PKCS#12 key to PEM using pyOpenSSL.

    Args:
        private_key_bytes: Bytes. PKCS#12 key in DER format.
        private_key_password: String. Password for PKCS#12 key.

    Returns:
        String. PEM contents of ``private_key_bytes``.
    """
    private_key_password = _to_bytes(private_key_password)
    pkcs12 = crypto.load_pkcs12(private_key_bytes, private_key_password)
    return crypto.dump_privatekey(crypto.FILETYPE_PEM,
                                  pkcs12.get_privatekey())