的修改

Question

我有一个RSA公钥和一个签名的X509证书。如何检查密钥是否已签署证书？（我的例子恰好是一张自签名证书。）

这就是我现在正在做的事情：

生成自签名证书并使用openssl cli转换为DER编码：

（我在实际申请中期待DER）

Crypto.Util.asn1.DerSequence

将其解码为>>> from Crypto.Util.asn1 import DerSequence >>> from Crypto.PublicKey import RSA >>> der = open('self.der').read() >>> cert = DerSequence() >>> cert.decode(der) 905L >>> # according to RFC5280, this is a 3-length sequence: >>> # tbsCertificate, signatureAlgorithm, signatureValue >>> # "tbs" == "to be signed" >>> len(cert) 3个实例。

>>> tbscert = DerSequence()
>>> tbscert.decode(cert[0])
>>> subjectPublicKeyInfo = tbscert[6]
>>> rsa_key = RSA.importKey(subjectPublicKeyInfo)
>>> >>> rsa_key
<_RSAobj @0x7fb27287d128 n(2048),e>

然后我拉出RSA公钥：

int()

然后我拉出签名

这很烦人。我正在使用另一个库来再次解码DER，因为这个让我更方便地表示签名值的“位串”编码。现在，我将值的base-2字符串表示复制并粘贴到long以获得RSA.verify()（>>> from pyasn1_modules import rfc2437,rfc2459 >>> from pyasn1.codec.der import decoder >>> cert2,rest = decoder.decode(der, asn1Spec=rfc2459.Certificate()) >>> sig_bits = cert2.getComponentByName("signatureValue") >>> sig_bits BitString("'10101110101100111010100000111001000110111111101001110000100111110111011111111110011010110101001001110110111011011001110001010000111001001001110111001110011101000000100000001100001101000111000110010100110101000110111101110001011011001001100011110011010101011100000001010111101110111001110011010011110101101001110101110100011111011111110001110001110100000110110100010000001010111010000100101110101001110000111001100010011110110100101001010000101001110101101111100111001111000010111001110000000101000000011110011110000110000101101101110110101101110101011110101111111000101011001000010000110100111111001011111100110011011011001001111110000000110100000001101000011010010100001100110100001001000111001011111100000011000101001100001010101001111000001010100101010101000100001000100011101111100101010010001111001110100001011110101100010111001010100010001011100000100101110001011101100010010111100010111110010010110111111100100100101010010000000010001011111110011000011000101000001000000000000011111101110010101100100000010111111110101000110010101111100101011101000010010110101000101101110001001101101000110101110011101011111100010000101001111011100100100010101001011011110001110000000000010011011111011110100000111001100010100000100001101111110010000111100110110110000001010010110011010111100101110101000001111001010011101001101101101101011000100010011110000101010110111011100010100011110101100110101011010111000011111000001111111111000101101101011110010111100101011100010000111011101101010101001011101101111011001001110000010011001111010001011110000011001011000110100011100000100100111000111100000010000001001001010001100000010011110100000111010010100001101001111111001111110111010001101010110100001100111010101000010000101000000111100001001001000100011100110010110101001110111101000101101011011100000010010000100111001100001110010101000100000010010111110001100011110010000100001000101100011000011000110010110011100010100010111011011111111010000001001100000100011010000000110111100111010101001110101000011111011000100010111101100110100010101111000110111110'B") >>> bit_string = '10101110101100111010100000111001000110111111101001110000100111110111011111111110011010110101001001110110111011011001110001010000111001001001110111001110011101000000100000001100001101000111000110010100110101000110111101110001011011001001100011110011010101011100000001010111101110111001110011010011110101101001110101110100011111011111110001110001110100000110110100010000001010111010000100101110101001110000111001100010011110110100101001010000101001110101101111100111001111000010111001110000000101000000011110011110000110000101101101110110101101110101011110101111111000101011001000010000110100111111001011111100110011011011001001111110000000110100000001101000011010010100001100110100001001000111001011111100000011000101001100001010101001111000001010100101010101000100001000100011101111100101010010001111001110100001011110101100010111001010100010001011100000100101110001011101100010010111100010111110010010110111111100100100101010010000000010001011111110011000011000101000001000000000000011111101110010101100100000010111111110101000110010101111100101011101000010010110101000101101110001001101101000110101110011101011111100010000101001111011100100100010101001011011110001110000000000010011011111011110100000111001100010100000100001101111110010000111100110110110000001010010110011010111100101110101000001111001010011101001101101101101011000100010011110000101010110111011100010100011110101100110101011010111000011111000001111111111000101101101011110010111100101011100010000111011101101010101001011101101111011001001110000010011001111010001011110000011001011000110100011100000100100111000111100000010000001001001010001100000010011110100000111010010100001101001111111001111110111010001101010110100001100111010101000010000101000000111100001001001000100011100110010110101001110111101000101101011011100000010010000100111001100001110010101000100000010010111110001100011110010000100001000101100011000011000110010110011100010100010111011011111111010000001001100000100011010000000110111100111010101001110101000011111011000100010111101100110100010101111000110111110' >>> len(bit_string) 2048 >>> sig_long = int(bit_string, 2) 22054057292543290008991218833668878365914778519473463062473060546762899555976103489048033910135613221569150796460758806399269198735780309519101363051388009338597879536630494212385605300708879019160215628821483902624509955250980351374010304684207884550324020859785789812498991361733361061223150200173076263554090698006436248180914014712709890577579243572383188197634606581121383593473899061397708617253275982314075801792358481980896751043809539358665686019958496887281091997170247998458556812030465091755579654010246474389968142047627934047174316731806191431717418170761689395728146445291177267566370799362894264463806L方法所期望的内容）。

>>> import Crypto.Hash.SHA256
>>> comp_hash = Crypto.Hash.SHA256.new(cert[0]).digest()
>>> comp_hash
'\xa3t\x84\xd6\xf5\xfe\x16\xb9\xdb(&\x12\xb3m^+\x94\xa7bZ\xf9s\xf7\xbay\xa1j\xa3Y\xea\xa8\x7f'

然后我计算“待签名证书”的SHA256哈希：

verify()

然后>>> rsa_key.verify(comp_hash, (sig_long, None)) False方法告诉我签名不匹配。

public WebDriver driver;

我希望有一种更好的方式（这甚至不起作用），但我花了好几个小时看PyCrypto和PyOpenSSL并没有找到它。

的修改

这个类似的S.O.几年前的问题没有答案：Verify SSL/X.509 certificate is signed by another certificate

Answer 1

我想有一种方法可以创建一个X509StoreContext，其中只包含一个与我要检查的公钥相对应的证书。

>>> from OpenSSL import crypto
>>> x509_self_signed # already loaded
<OpenSSL.crypto.X509 object at 0x7fcc4049c9b0>
>>> cert_store = crypto.X509Store()
>>> cert_store.add_cert(x509_self_signed)
>>> store_ctx = crypto.X509StoreContext(cert_store, x509_self_signed)
>>> store_ctx.verify_certificate()
>>> # ^ that raises an exception if it fails to verify

verify_certificate()仅在一年多前被添加到PyOpenSSL，所以也许这就是为什么很难找到... https://github.com/pyca/pyopenssl/pull/155

在Python中验证X509证书上的签名

的修改

1 个答案: