mirror of
https://gitee.com/dify_ai/dify.git
synced 2024-12-09 14:48:04 +08:00
278 lines
10 KiB
Python
278 lines
10 KiB
Python
# -*- coding: utf-8 -*-
|
|
#
|
|
# Cipher/PKCS1_OAEP.py : PKCS#1 OAEP
|
|
#
|
|
# ===================================================================
|
|
# The contents of this file are dedicated to the public domain. To
|
|
# the extent that dedication to the public domain is not available,
|
|
# everyone is granted a worldwide, perpetual, royalty-free,
|
|
# non-exclusive license to exercise all rights associated with the
|
|
# contents of this file for any purpose whatsoever.
|
|
# No rights are reserved.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
|
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
|
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
# SOFTWARE.
|
|
# ===================================================================
|
|
|
|
from Crypto.Signature.pss import MGF1
|
|
import Crypto.Hash.SHA1
|
|
|
|
from Crypto.Util.py3compat import bord, _copy_bytes
|
|
import Crypto.Util.number
|
|
from Crypto.Util.number import ceil_div, bytes_to_long, long_to_bytes
|
|
from Crypto.Util.strxor import strxor
|
|
from Crypto import Random
|
|
from hashlib import sha1
|
|
import gmpy2
|
|
|
|
class PKCS1OAEP_Cipher:
|
|
"""Cipher object for PKCS#1 v1.5 OAEP.
|
|
Do not create directly: use :func:`new` instead."""
|
|
|
|
def __init__(self, key, hashAlgo, mgfunc, label, randfunc):
|
|
"""Initialize this PKCS#1 OAEP cipher object.
|
|
|
|
:Parameters:
|
|
key : an RSA key object
|
|
If a private half is given, both encryption and decryption are possible.
|
|
If a public half is given, only encryption is possible.
|
|
hashAlgo : hash object
|
|
The hash function to use. This can be a module under `Crypto.Hash`
|
|
or an existing hash object created from any of such modules. If not specified,
|
|
`Crypto.Hash.SHA1` is used.
|
|
mgfunc : callable
|
|
A mask generation function that accepts two parameters: a string to
|
|
use as seed, and the lenth of the mask to generate, in bytes.
|
|
If not specified, the standard MGF1 consistent with ``hashAlgo`` is used (a safe choice).
|
|
label : bytes/bytearray/memoryview
|
|
A label to apply to this particular encryption. If not specified,
|
|
an empty string is used. Specifying a label does not improve
|
|
security.
|
|
randfunc : callable
|
|
A function that returns random bytes.
|
|
|
|
:attention: Modify the mask generation function only if you know what you are doing.
|
|
Sender and receiver must use the same one.
|
|
"""
|
|
self._key = key
|
|
|
|
if hashAlgo:
|
|
self._hashObj = hashAlgo
|
|
else:
|
|
self._hashObj = Crypto.Hash.SHA1
|
|
|
|
if mgfunc:
|
|
self._mgf = mgfunc
|
|
else:
|
|
self._mgf = lambda x,y: MGF1(x,y,self._hashObj)
|
|
|
|
self._label = _copy_bytes(None, None, label)
|
|
self._randfunc = randfunc
|
|
|
|
def can_encrypt(self):
|
|
"""Legacy function to check if you can call :meth:`encrypt`.
|
|
|
|
.. deprecated:: 3.0"""
|
|
return self._key.can_encrypt()
|
|
|
|
def can_decrypt(self):
|
|
"""Legacy function to check if you can call :meth:`decrypt`.
|
|
|
|
.. deprecated:: 3.0"""
|
|
return self._key.can_decrypt()
|
|
|
|
def encrypt(self, message):
|
|
"""Encrypt a message with PKCS#1 OAEP.
|
|
|
|
:param message:
|
|
The message to encrypt, also known as plaintext. It can be of
|
|
variable length, but not longer than the RSA modulus (in bytes)
|
|
minus 2, minus twice the hash output size.
|
|
For instance, if you use RSA 2048 and SHA-256, the longest message
|
|
you can encrypt is 190 byte long.
|
|
:type message: bytes/bytearray/memoryview
|
|
|
|
:returns: The ciphertext, as large as the RSA modulus.
|
|
:rtype: bytes
|
|
|
|
:raises ValueError:
|
|
if the message is too long.
|
|
"""
|
|
|
|
# See 7.1.1 in RFC3447
|
|
modBits = Crypto.Util.number.size(self._key.n)
|
|
k = ceil_div(modBits, 8) # Convert from bits to bytes
|
|
hLen = self._hashObj.digest_size
|
|
mLen = len(message)
|
|
|
|
# Step 1b
|
|
ps_len = k - mLen - 2 * hLen - 2
|
|
if ps_len < 0:
|
|
raise ValueError("Plaintext is too long.")
|
|
# Step 2a
|
|
lHash = sha1(self._label).digest()
|
|
# Step 2b
|
|
ps = b'\x00' * ps_len
|
|
# Step 2c
|
|
db = lHash + ps + b'\x01' + _copy_bytes(None, None, message)
|
|
# Step 2d
|
|
ros = self._randfunc(hLen)
|
|
# Step 2e
|
|
dbMask = self._mgf(ros, k-hLen-1)
|
|
# Step 2f
|
|
maskedDB = strxor(db, dbMask)
|
|
# Step 2g
|
|
seedMask = self._mgf(maskedDB, hLen)
|
|
# Step 2h
|
|
maskedSeed = strxor(ros, seedMask)
|
|
# Step 2i
|
|
em = b'\x00' + maskedSeed + maskedDB
|
|
# Step 3a (OS2IP)
|
|
em_int = bytes_to_long(em)
|
|
# Step 3b (RSAEP)
|
|
m_int = gmpy2.powmod(em_int, self._key.e, self._key.n)
|
|
# Step 3c (I2OSP)
|
|
c = long_to_bytes(m_int, k)
|
|
return c
|
|
|
|
def decrypt(self, ciphertext):
|
|
"""Decrypt a message with PKCS#1 OAEP.
|
|
|
|
:param ciphertext: The encrypted message.
|
|
:type ciphertext: bytes/bytearray/memoryview
|
|
|
|
:returns: The original message (plaintext).
|
|
:rtype: bytes
|
|
|
|
:raises ValueError:
|
|
if the ciphertext has the wrong length, or if decryption
|
|
fails the integrity check (in which case, the decryption
|
|
key is probably wrong).
|
|
:raises TypeError:
|
|
if the RSA key has no private half (i.e. you are trying
|
|
to decrypt using a public key).
|
|
"""
|
|
# See 7.1.2 in RFC3447
|
|
modBits = Crypto.Util.number.size(self._key.n)
|
|
k = ceil_div(modBits,8) # Convert from bits to bytes
|
|
hLen = self._hashObj.digest_size
|
|
# Step 1b and 1c
|
|
if len(ciphertext) != k or k<hLen+2:
|
|
raise ValueError("Ciphertext with incorrect length.")
|
|
# Step 2a (O2SIP)
|
|
ct_int = bytes_to_long(ciphertext)
|
|
# Step 2b (RSADP)
|
|
# m_int = self._key._decrypt(ct_int)
|
|
m_int = gmpy2.powmod(ct_int, self._key.d, self._key.n)
|
|
# Complete step 2c (I2OSP)
|
|
em = long_to_bytes(m_int, k)
|
|
# Step 3a
|
|
lHash = sha1(self._label).digest()
|
|
# Step 3b
|
|
y = em[0]
|
|
# y must be 0, but we MUST NOT check it here in order not to
|
|
# allow attacks like Manger's (http://dl.acm.org/citation.cfm?id=704143)
|
|
maskedSeed = em[1:hLen+1]
|
|
maskedDB = em[hLen+1:]
|
|
# Step 3c
|
|
seedMask = self._mgf(maskedDB, hLen)
|
|
# Step 3d
|
|
seed = strxor(maskedSeed, seedMask)
|
|
# Step 3e
|
|
dbMask = self._mgf(seed, k-hLen-1)
|
|
# Step 3f
|
|
db = strxor(maskedDB, dbMask)
|
|
# Step 3g
|
|
one_pos = hLen + db[hLen:].find(b'\x01')
|
|
lHash1 = db[:hLen]
|
|
invalid = bord(y) | int(one_pos < hLen)
|
|
hash_compare = strxor(lHash1, lHash)
|
|
for x in hash_compare:
|
|
invalid |= bord(x)
|
|
for x in db[hLen:one_pos]:
|
|
invalid |= bord(x)
|
|
if invalid != 0:
|
|
raise ValueError("Incorrect decryption.")
|
|
# Step 4
|
|
return db[one_pos + 1:]
|
|
|
|
def new(key, hashAlgo=None, mgfunc=None, label=b'', randfunc=None):
|
|
"""Return a cipher object :class:`PKCS1OAEP_Cipher` that can be used to perform PKCS#1 OAEP encryption or decryption.
|
|
|
|
:param key:
|
|
The key object to use to encrypt or decrypt the message.
|
|
Decryption is only possible with a private RSA key.
|
|
:type key: RSA key object
|
|
|
|
:param hashAlgo:
|
|
The hash function to use. This can be a module under `Crypto.Hash`
|
|
or an existing hash object created from any of such modules.
|
|
If not specified, `Crypto.Hash.SHA1` is used.
|
|
:type hashAlgo: hash object
|
|
|
|
:param mgfunc:
|
|
A mask generation function that accepts two parameters: a string to
|
|
use as seed, and the lenth of the mask to generate, in bytes.
|
|
If not specified, the standard MGF1 consistent with ``hashAlgo`` is used (a safe choice).
|
|
:type mgfunc: callable
|
|
|
|
:param label:
|
|
A label to apply to this particular encryption. If not specified,
|
|
an empty string is used. Specifying a label does not improve
|
|
security.
|
|
:type label: bytes/bytearray/memoryview
|
|
|
|
:param randfunc:
|
|
A function that returns random bytes.
|
|
The default is `Random.get_random_bytes`.
|
|
:type randfunc: callable
|
|
"""
|
|
|
|
if randfunc is None:
|
|
randfunc = Random.get_random_bytes
|
|
return PKCS1OAEP_Cipher(key, hashAlgo, mgfunc, label, randfunc)
|
|
|
|
|
|
def new(key, hashAlgo=None, mgfunc=None, label=b'', randfunc=None):
|
|
"""Return a cipher object :class:`PKCS1OAEP_Cipher` that can be used to perform PKCS#1 OAEP encryption or decryption.
|
|
|
|
:param key:
|
|
The key object to use to encrypt or decrypt the message.
|
|
Decryption is only possible with a private RSA key.
|
|
:type key: RSA key object
|
|
|
|
:param hashAlgo:
|
|
The hash function to use. This can be a module under `Crypto.Hash`
|
|
or an existing hash object created from any of such modules.
|
|
If not specified, `Crypto.Hash.SHA1` is used.
|
|
:type hashAlgo: hash object
|
|
|
|
:param mgfunc:
|
|
A mask generation function that accepts two parameters: a string to
|
|
use as seed, and the lenth of the mask to generate, in bytes.
|
|
If not specified, the standard MGF1 consistent with ``hashAlgo`` is used (a safe choice).
|
|
:type mgfunc: callable
|
|
|
|
:param label:
|
|
A label to apply to this particular encryption. If not specified,
|
|
an empty string is used. Specifying a label does not improve
|
|
security.
|
|
:type label: bytes/bytearray/memoryview
|
|
|
|
:param randfunc:
|
|
A function that returns random bytes.
|
|
The default is `Random.get_random_bytes`.
|
|
:type randfunc: callable
|
|
"""
|
|
|
|
if randfunc is None:
|
|
randfunc = Random.get_random_bytes
|
|
return PKCS1OAEP_Cipher(key, hashAlgo, mgfunc, label, randfunc)
|
|
|