Alexa请求验证在python中

Question

我致力于处理Alexa语音意图的服务.我需要验证每个请求的签名,我几乎成功了.唯一不起作用的部分是证书链的验证.

从文档中我知道:

此证书链按顺序由(1)Amazon签名证书和(2)一个或多个其他证书组成,这些证书为根证书颁发机构(CA)证书创建信任链.

我的代码看起来像这样:

certificates = pem.parse_file("chain.pem")
store = crypto.X509Store()
for cert in certificates[:-1]:
    loaded_cert = crypto.load_certificate(crypto.FILETYPE_PEM,
                                          cert.as_bytes())
    store.add_cert(loaded_cert)

intermediate_cert = crypto.load_certificate(
    crypto.FILETYPE_PEM,
    certificates[-1].as_bytes()
)
# Create a certificate context
store_ctx = crypto.X509StoreContext(store, intermediate_cert)

# Verify the certificate
store_ctx.verify_certificate()

我收到以下错误:

OpenSSL.crypto.X509StoreContextError: [20, 0, 'unable to get local issuer certificate']

我不知道我做错了什么,也许有人已经实现了这个并且可以提示.

Answer 1

首先,获得所有证书的CA Issuer 'chain.pem':

for cert in pem.parse_file("chain.pem"):
    CA_cert = crypto.load_certificate(crypto.FILETYPE_PEM, cert.as_bytes())
    print('CA_cert:\nissuer :{}\nsubject:{}'.
        format(CA_cert.get_subject(), CA_cert.get_issuer()))

输出,例如:

CA_cert:
issuer :<X509Name object '/C=US/O=thawte, Inc./OU=Certification Services Division/OU=(c) 2006 thawte, Inc. - For authorized use only/CN=thawte Primary Root CA'>
subject:<X509Name object '/C=US/O=thawte, Inc./OU=Certification Services Division/OU=(c) 2006 thawte, Inc. - For authorized use only/CN=thawte Primary Root CA'>

此显示的示例证书是自签名证书.

添加所有显示发行人到CA_store,然后做.verify_certificate了所有的证书'chain.pem'.

CA_store = crypto.X509Store()
for _pem in ['issuer_1.pem', 'issuer_2.pem']:
    for cert in pem.parse_file(_pem):
        CA_store.add_cert(
            crypto.load_certificate(crypto.FILETYPE_PEM, cert.as_bytes())
        )

for cert in pem.parse_file("chain.pem"):
    try:
        crypto.X509StoreContext(CA_store,
                                crypto.load_certificate(crypto.FILETYPE_PEM, cert.as_bytes())
                                ).verify_certificate()
    except X509StoreContextError as exp:
        cert = exp.certificate
        print('X509StoreContextError:{}\ncertificate\n\tissuer :{}\n\tsubject:{}'.
            format(exp.args, cert.get_issuer(), cert.get_subject()))

用Python测试:3.4.2 - OpenSSL:17.0.0 - 加密:1.8.2 - cffi:1.10.0