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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
.. hazmat::
RSA
===
.. currentmodule:: cryptography.hazmat.primitives.asymmetric.rsa
`RSA`_ is a `public-key`_ algorithm for encrypting and signing messages.
.. class:: RSAPrivateKey(p, q, private_exponent, dmp1, dmq1, iqmp, public_exponent, modulus)
.. versionadded:: 0.2
An RSA private key is required for decryption and signing of messages.
You should use :meth:`~generate` to generate new keys.
.. warning::
This method only checks a limited set of properties of its arguments.
Using an RSA private key that you do not trust or with incorrect
parameters may lead to insecure operation, crashes, and other undefined
behavior. We recommend that you only ever load private keys that were
generated with software you trust.
This class conforms to the
:class:`~cryptography.hazmat.primitives.interfaces.RSAPrivateKey`
interface.
:raises TypeError: This is raised when the arguments are not all integers.
:raises ValueError: This is raised when the values of ``p``, ``q``,
``private_exponent``, ``public_exponent``, or
``modulus`` do not match the bounds specified in
:rfc:`3447`.
.. classmethod:: generate(public_exponent, key_size, backend)
Generate a new ``RSAPrivateKey`` instance using ``backend``.
:param int public_exponent: The public exponent of the new key.
Usually one of the small Fermat primes 3, 5, 17, 257, 65537. If in
doubt you should `use 65537`_.
:param int key_size: The length of the modulus in bits. For keys
generated in 2014 this should be `at least 2048`_. (See page 41.)
Must be at least 512. Some backends may have additional
limitations.
:param backend: A
:class:`~cryptography.hazmat.backends.interfaces.RSABackend`
provider.
:return: A new instance of ``RSAPrivateKey``.
:raises cryptography.exceptions.UnsupportedInterface: This is raised if
the provided ``backend`` does not implement
:class:`~cryptography.hazmat.backends.interfaces.RSABackend`
.. method:: signer(padding, algorithm, backend)
.. versionadded:: 0.3
Sign data which can be verified later by others using the public key.
.. doctest::
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> from cryptography.hazmat.primitives.asymmetric import rsa, padding
>>> private_key = rsa.RSAPrivateKey.generate(
... public_exponent=65537,
... key_size=2048,
... backend=default_backend()
... )
>>> signer = private_key.signer(
... padding.PKCS1v15(),
... hashes.SHA256(),
... default_backend()
... )
>>> signer.update(b"this is some data I'd like")
>>> signer.update(b" to sign")
>>> signature = signer.finalize()
:param padding: An instance of a
:class:`~cryptography.hazmat.primitives.interfaces.AsymmetricPadding`
provider.
:param algorithm: An instance of a
:class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
provider.
:param backend: A
:class:`~cryptography.hazmat.backends.interfaces.RSABackend`
provider.
:returns:
:class:`~cryptography.hazmat.primitives.interfaces.AsymmetricSignatureContext`
:raises cryptography.exceptions.UnsupportedInterface: This is raised if
the provided ``backend`` does not implement
:class:`~cryptography.hazmat.backends.interfaces.RSABackend`
.. class:: RSAPublicKey(public_exponent, modulus)
.. versionadded:: 0.2
An RSA public key is required for encryption and verification of messages.
Normally you do not need to directly construct public keys because you'll
be loading them from a file, generating them automatically or receiving
them from a 3rd party.
This class conforms to the
:class:`~cryptography.hazmat.primitives.interfaces.RSAPublicKey`
interface.
:raises TypeError: This is raised when the arguments are not all integers.
:raises ValueError: This is raised when the values of ``public_exponent``
or ``modulus`` do not match the bounds specified in
:rfc:`3447`.
.. method:: verifier(signature, padding, algorithm, backend)
.. versionadded:: 0.3
Verify data was signed by the private key associated with this public
key.
.. doctest::
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> from cryptography.hazmat.primitives.asymmetric import rsa, padding
>>> private_key = rsa.RSAPrivateKey.generate(
... public_exponent=65537,
... key_size=2048,
... backend=default_backend()
... )
>>> signer = private_key.signer(padding.PKCS1v15(), hashes.SHA256(), default_backend())
>>> data= b"this is some data I'd like to sign"
>>> signer.update(data)
>>> signature = signer.finalize()
>>> public_key = private_key.public_key()
>>> verifier = public_key.verifier(signature, padding.PKCS1v15(), hashes.SHA256(), default_backend())
>>> verifier.update(data)
>>> verifier.verify()
:param bytes signature: The signature to verify.
:param padding: An instance of a
:class:`~cryptography.hazmat.primitives.interfaces.AsymmetricPadding`
provider.
:param algorithm: An instance of a
:class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
provider.
:param backend: A
:class:`~cryptography.hazmat.backends.interfaces.RSABackend`
provider.
:returns:
:class:`~cryptography.hazmat.primitives.interfaces.AsymmetricVerificationContext`
:raises cryptography.exceptions.UnsupportedInterface: This is raised if
the provided ``backend`` does not implement
:class:`~cryptography.hazmat.backends.interfaces.RSABackend`
.. _`RSA`: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
.. _`public-key`: https://en.wikipedia.org/wiki/Public-key_cryptography
.. _`use 65537`: http://www.daemonology.net/blog/2009-06-11-cryptographic-right-answers.html
.. _`at least 2048`: http://www.ecrypt.eu.org/documents/D.SPA.20.pdf
|
