如何验证由 openssl 创建的 pycrypto 签名？答案

【问题标题】：How to verify in pycrypto signature created by openssl?如何验证由 openssl 创建的 pycrypto 签名？
【发布时间】：2011-06-14 20:55:34
【问题描述】：

我在 openssl 中创建了私钥/公钥，并签署了一些数据：

openssl genrsa -out private.pem 1024
openssl rsa -in private.pem -out public.pem -outform PEM -pubout
echo 'data to sign' > data.txt
openssl dgst -md5 < data.txt > hash
openssl rsautl -sign -inkey private.pem -keyform PEM -in hash  > signature

现在在 python 中，我正在尝试验证这些数据：

pubKey = open('public.pem').read()
data = open('data.txt').read()
signature = open('signature').read()

from Crypto import PublicKey
key = PublicKey.RSA.importKey(pubKey)
pub = key.publickey()
hash = MD5.new(data).hexdigest()
# here, hash is same, as contents of 'hash' file
print pub.verify(hash, signature) # <-- here

问题是，pub.verify 期望第二个参数是具有较大数字的单元素列表。而且我不知道如何将文件signature 中的二进制数据转换为这个整数。每个关于 pycrypto 的例子都显示了 from pycrypto 生成的签名，key.sign() 以(1832273432...2340234L, ) 的形式生成正确的签名。但我不知道如何使用外部签名。

如果有必要，下面是附加信息，我不知道如何解释：

简要技术信息：

数字签名格式：PKCS#7 “Signed-Data”
公钥程序：DSS
密钥长度：512 – 1024 位
公开指数：2 +1
公钥格式：X.509 v3 证书
MD（消息摘要）算法：MD5 或 RIPEMD-160 16

【问题讨论】：

标签： python openssl python-2.x pycrypto

【解决方案1】：

Crypto.Signature 模块是您想要的。来自Crypto.Signature.PKCS1_v1_5 文档：

key = RSA.importKey(open('pubkey.der').read())
h = SHA.new(message)
verifier = PKCS1_v1_5.new(key)
if verifier.verify(h, signature):
   print "The signature is authentic."
else:
   print "The signature is not authentic."

【讨论】：

【解决方案2】：

我遇到了同样的问题，这里有两个示例，使用 openssl 和 python 生成和验证。希望这对某人有所帮助...

重击：

#!/bin/bash
# Generate keys
openssl genrsa -out priv.pem
# Export public key
openssl rsa -pubout -in priv.pem -out pub.pem
# Create test file
echo test123 > test.txt
# Create SHA1 signature
openssl dgst -sha1 -sign priv.pem -out test.txt.sig test.txt
# Verify SHA1 signature
openssl dgst -sha1 -verify pub.pem -signature test.txt.sig test.txt

Python：

#!/usr/bin/python
from Crypto.Signature import PKCS1_v1_5
from Crypto.PublicKey import RSA
from Crypto.Hash import SHA
from Crypto import Random
# Read public key from file
fd = open('pub.pem', 'r')
key_data = fd.read()
fd.close()
# Load public key
key = RSA.importKey(key_data)
# Read test file
fd = open('test.txt', 'r')
message = fd.read()
fd.close()
# Create SHA1 hash object
h = SHA.new(message)
# Create PKCS1 handler
cipher = PKCS1_v1_5.new(key)
# Read signature file
fd = open('test.txt.sig', 'r')
signature = fd.read()
fd.close()
# Verify signature
print cipher.verify(h, signature)
# Read private key from file
fd = open('priv.pem', 'r')
priv_key_data = fd.read()
fd.close()
# Load private key
priv_key = RSA.importKey(priv_key_data)
# Create PKCS1 handler
priv_cipher = PKCS1_v1_5.new(priv_key)
# Sign hash of test file content and compare
signature2 = priv_cipher.sign(h)
if signature == signature2:
    print "Match!! :)"

经过更多阅读后，我了解到 (https://en.wikipedia.org/wiki/PKCS_1) PKCS1_PSS 是应该用于创建签名的新方案。

两个脚本都需要一些改动：

重击：

#!/bin/bash
# Generate keys
openssl genrsa -out priv.pem
# Export public key
openssl rsa -pubout -in priv.pem -out pub.pem
# Create test file
echo test123 > test.txt
# Create SHA1 signature
openssl dgst -sha1 -sigopt rsa_padding_mode:pss -sigopt rsa_pss_saltlen:-1 -sign priv.pem -out test.txt.sig test.txt
# Verify SHA1 signature
openssl dgst -sha1 -sigopt rsa_padding_mode:pss -sigopt rsa_pss_saltlen:-1 -verify pub.pem -signature test.txt.sig test.txt

Python：

#!/usr/bin/python
from Crypto.Signature import PKCS1_PSS
from Crypto.PublicKey import RSA
from Crypto.Hash import SHA
from Crypto import Random
# Read public key from file
fd = open('pub.pem', 'r')
key_data = fd.read()
fd.close()
# Load public key
key = RSA.importKey(key_data)
# Read test file
fd = open('test.txt', 'r')
message = fd.read()
fd.close()
# Create SHA1 hash object
h = SHA.new(message)
# Create PKCS1 handler
cipher = PKCS1_PSS.new(key)
# Read signature file
fd = open('test.txt.sig', 'r')
signature = fd.read()
fd.close()
# Verify signature
print cipher.verify(h, signature)
# Read private key from file
fd = open('priv.pem', 'r')
priv_key_data = fd.read()
fd.close()
# Load private key
priv_key = RSA.importKey(priv_key_data)
# Create PKCS1 handler
priv_cipher = PKCS1_PSS.new(priv_key)
# Sign hash of test file content and compare
signature2 = priv_cipher.sign(h)
# PKCS1_PSS signatures always differ!
#if signature == signature2:
#    print "Match!! :)"

【讨论】：

【解决方案3】：

这是解决方案。

from Crypto.Util import number
signature  = number.bytes_to_long(signature) #Convert the signature to long
print pub.verify(hash, (signature,) ) #Pass tuple to verify

【讨论】：

显然这种方式不起作用 - 返回 False。我已经按照您的建议尝试过pastebin.com/uPtrwngm

【解决方案4】：

这篇文章给你最好的答案。 How do you verify an RSA SHA1 signature in Python?

pycrypto 无法验证 OpenSSL 创建的签名。你可以试试 M2Crypto。

【讨论】：