如何从PEM文件加载RSA密钥并在python-crypto中使用它

Question

我还没有找到一种方法从PEM文件加载RSA私钥以在python-crypto(签名)中使用它.

python-openssl可以加载PEM文件,但是PKey对象不能用于检索与Crypto.PublicKey.construct()一起使用的密钥信息(p,q,...).

Answer 1

我推荐使用M2Crypto而不是python-crypto.无论如何,您将需要M2Crypto来解析PEM,其EVP api可以根据特定算法释放您的代码.

private = """
-----BEGIN RSA PRIVATE KEY-----
MIIBOwIBAAJBANQNY7RD9BarYRsmMazM1hd7a+u3QeMPFZQ7Ic+BmmeWHvvVP4Yj
yu1t6vAut7mKkaDeKbT3yiGVUgAEUaWMXqECAwEAAQJAIHCz8h37N4ScZHThYJgt
oIYHKpZsg/oIyRaKw54GKxZq5f7YivcWoZ8j7IQ65lHVH3gmaqKOvqdAVVt5imKZ
KQIhAPPsr9i3FxU+Mac0pvQKhFVJUzAFfKiG3ulVUdHgAaw/AiEA3ozHKzfZWKxH
gs8v8ZQ/FnfI7DwYYhJC0YsXb6NSvR8CIHymwLo73mTxsogjBQqDcVrwLL3GoAyz
V6jf+/8HvXMbAiEAj1b3FVQEboOQD6WoyJ1mQO9n/xf50HjYhqRitOnp6ZsCIQDS
AvkvYKc6LG8IANmVv93g1dyKZvU/OQkAZepqHZB2MQ==
-----END RSA PRIVATE KEY-----
"""    
message = "python-crypto sucks"

# Grab RSA parameters e, n
from M2Crypto import RSA, BIO
bio = BIO.MemoryBuffer(private)
rsa = RSA.load_key_bio(bio)
n, e = rsa.n, rsa.e

# In Python-crypto:
import Crypto.PublicKey.RSA
pycrypto_key = Crypto.PublicKey.RSA.construct((n, e))

# Use EVP api to sign message
from M2Crypto import EVP
key = EVP.load_key_string(private)
# if you need a different digest than the default 'sha1':
key.reset_context(md='sha256')
key.sign_init()
key.sign_update(message)
signature = key.sign_final()

# Use EVP api to verify signature
public = """
-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBANQNY7RD9BarYRsmMazM1hd7a+u3QeMP
FZQ7Ic+BmmeWHvvVP4Yjyu1t6vAut7mKkaDeKbT3yiGVUgAEUaWMXqECAwEAAQ==
-----END PUBLIC KEY-----
""" 
from M2Crypto import BIO, RSA, EVP
bio = BIO.MemoryBuffer(public)
rsa = RSA.load_pub_key_bio(bio)
pubkey = EVP.PKey()
pubkey.assign_rsa(rsa)
pubkey.reset_context(md="sha256")
pubkey.verify_init()
pubkey.verify_update(message)
assert pubkey.verify_final(signature) == 1

请参阅http://svn.osafoundation.org/m2crypto/trunk/tests/test_rsa.py,但我更喜欢使用与算法无关的EVP API http://svn.osafoundation.org/m2crypto/trunk/tests/test_evp.py.

如何验证Python中的RSA SHA1签名？解决了类似的问题.

Answer 2

这是(接近)你尝试做什么的？

public_key_filename = 'public_key.pem'
rsa = M2Crypto.RSA.load_pub_key(pk)

这应该工作.问题也可能在openssl上,当你只使用openssl(不是在Python中)时它是否有效？

链接到我Too Crypto