Python cryptography.x509：验证由 CA（而不是根）签名的 python x509 模块生成的 x509 证书失败

Question

我编写了一个Python代码来使用加密库生成证书链。它涉及三个证书：根证书、中间证书和叶证书。根证书是自签名证书，中间证书由根私钥签名，叶证书由中间私钥签名。目前，当尝试使用 OpenSSL 验证签名时，根证书和中间证书的签名已成功验证。但是，叶证书的验证失败，并出现以下错误。 1 深度查找时出现错误 2：无法获取颁发者证书错误验证失败。 下面是我用来生成证书的代码。 请帮我找出问题所在。

from cryptography import x509
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.x509.oid import NameOID
import datetime
# --------------------------------------------------------------------------------------
#rootcert
root_private_key = ec.generate_private_key(ec.SECP256R1(), default_backend())

root_subject = root_issuer = x509.Name([
    x509.NameAttribute(NameOID.COMMON_NAME, u"RootCert")
])

builder = x509.CertificateBuilder().subject_name(
    root_subject
).issuer_name(
    root_issuer
).public_key(
    root_private_key.public_key()
).serial_number(
    x509.random_serial_number()
).not_valid_before(
    datetime.datetime.now()
).not_valid_after(
    datetime.datetime.now() + datetime.timedelta(days=365)
).add_extension(
    x509.BasicConstraints(ca=True, path_length=None), critical=True
).add_extension(
    x509.SubjectKeyIdentifier.from_public_key(root_private_key.public_key()), critical=False
).add_extension(
    x509.AuthorityKeyIdentifier.from_issuer_public_key(root_private_key.public_key()), critical=False
)

cert = builder.sign(
    root_private_key, 
    algorithm=hashes.SHA256(), 
    backend=default_backend()
)

der_cert = cert.public_bytes(encoding=serialization.Encoding.DER)

with open("rootcert.der", "wb") as der_file:
    der_file.write(der_cert)
    
    
    
# --------------------------------------------------------------------------------------
#IntermediateCert
    
    
device_private_key = ec.generate_private_key(ec.SECP256R1(), default_backend())

device_subject = x509.Name([
    x509.NameAttribute(NameOID.COMMON_NAME, u"IntermediateCert")])

device_issuer = root_issuer

builder = x509.CertificateBuilder().subject_name(
    device_subject
).issuer_name(
    device_issuer
).public_key(
    device_private_key.public_key()
).serial_number(
    x509.random_serial_number()
).not_valid_before(
    datetime.datetime.now()
).not_valid_after(
    datetime.datetime.now() + datetime.timedelta(days=365)
).add_extension(
    x509.BasicConstraints(ca=True, path_length=None), critical=True
).add_extension(
    x509.SubjectKeyIdentifier.from_public_key(device_private_key.public_key()), critical=False
).add_extension(
    x509.AuthorityKeyIdentifier.from_issuer_public_key(root_private_key.public_key()), critical=False
)

cert = builder.sign(
    root_private_key, 
    algorithm=hashes.SHA256(), 
    backend=default_backend()
)

der_cert = cert.public_bytes(encoding=serialization.Encoding.DER)

with open("IntermediateCert.der", "wb") as der_file:
    der_file.write(der_cert)


# --------------------------------------------------------------------------------------
#childcert

child_private_key = ec.generate_private_key(ec.SECP256R1(), default_backend())

child_subject = x509.Name([
    x509.NameAttribute(NameOID.COMMON_NAME, u"ChildCert")])

child_issuer = device_subject


builder = x509.CertificateBuilder().subject_name(
    child_subject
).issuer_name(
    child_issuer
).public_key(
    child_private_key.public_key()
).serial_number(
    x509.random_serial_number()
).not_valid_before(
    datetime.datetime.now()
).not_valid_after(
    datetime.datetime.now() + datetime.timedelta(days=365)
).add_extension(
    x509.BasicConstraints(ca=False, path_length=None), critical=True
).add_extension(
    x509.SubjectKeyIdentifier.from_public_key(child_private_key.public_key()), critical=False
).add_extension(
    x509.AuthorityKeyIdentifier.from_issuer_public_key(device_private_key.public_key()), critical=False
)

cert = builder.sign(
    device_private_key, 
    algorithm=hashes.SHA256(), 
    backend=default_backend()
)

der_cert = cert.public_bytes(encoding=serialization.Encoding.DER)

with open("childcert.der", "wb") as der_file:
    der_file.write(der_cert)

Answer 1

代码没有任何问题。我使用了错误的 openssl 命令来验证证书链。 正确使用的命令是

openssl verify -CAfile root.pem -untrusted inter.pem child.pem

。我以前没有使用 -untrusted 选项。有关 -untrusted 的更多解释可以在本期这里

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