Tip
假设，验签算法都采用 RS256。
生成 JWK 格式的密钥#
推荐使用 jwcrypto 库：
import json, uuid
from jwcrypto import jwk
key = jwk.JWK.generate(
kty='RSA',
size=2048,
alg='RS256',
use='sig',
kid=str(uuid.uuid4())
)
private_jwk = key.export(private_key=True, as_dict=True)
public_jwk = key.export(as_dict=True)
print('JWK 格式的私钥: ')
print(json.dumps(private_jwk, indent=2))
print('\nJWK 格式的公钥: ')
print(json.dumps(public_jwk, indent=2))生成 PEM 格式的密钥#
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization
key = rsa.generate_private_key(public_exponent=65537, key_size=2048)
with open("private.pem", "wb") as f:
f.write(key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption(),
))
with open("public.pem", "wb") as f:
f.write(key.public_key().public_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PublicFormat.SubjectPublicKeyInfo,
))注意，这其实并没有 openssl 命令来得方便：
openssl genrsa -out private.pem 2048
openssl rsa -in private.pem -pubout -out public.pemJWS 构造#
对于 PEM 格式的密钥：
import jwt
with open("private.pem", "rb") as f:
private_key = f.read()
with open("public.pem", "rb") as f:
public_key = f.read()
# 仅作为示例，并不完整
payload = {
"iss": "https://auth.example.com",
"role": "admin",
……
}
# 签名：用私钥
token = jwt.encode(
payload,
private_key,
algorithm="RS256",
headers={"kid": "key-2026-01", ……}, # # 仅作为示例，并不完整
)
print(token)对于 JWK 格式的密钥：
import json, uuid
from jwcrypto import jwk
from jwt.algorithms import RSAAlgorithm
key = jwk.JWK.generate(
kty='RSA',
size=2048,
alg='RS256',
use='sig',
kid=str(uuid.uuid4())
)
# 两个 JWK 格式的密钥
private_jwk = key.export(private_key=True, as_dict=True)
public_jwk = key.export(as_dict=True)
private_key = RSAAlgorithm.from_jwk(private_jwk)
public_key = RSAAlgorithm.from_jwk(public_jwk)
# payload 以及 header 均只作为示例
token = jwt.encode(
{"sub": "user-123", "role": 'admin', ……},
private_key,
algorithm="RS256",
headers={"alg": "RS256", "kid": "yzwqhV6VJRHiQoXrxSlGWorFE7m6TjjZEp8Kyijxl9w", ……}
)
print(token)
x5c 证书链#
Tip
对于该参数的详细介绍，请看 Header 参数注入。
import base64, hashlib, datetime as dt
import jwt
from cryptography import x509
from cryptography.x509.oid import NameOID
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import rsa
now = dt.datetime.now(dt.timezone.utc)
def name(cn):
return x509.Name([
x509.NameAttribute(NameOID.COUNTRY_NAME, "CN"),
x509.NameAttribute(NameOID.ORGANIZATION_NAME, "Example Corp"),
x509.NameAttribute(NameOID.COMMON_NAME, cn),
])
def key_usage(sign_certs: bool):
return x509.KeyUsage(
digital_signature=not sign_certs, content_commitment=False,
key_encipherment=False, data_encipherment=False, key_agreement=False,
key_cert_sign=sign_certs, crl_sign=sign_certs,
encipher_only=False, decipher_only=False,
)
# --- Root CA（实际生产中通常由验证方信任 CA 签发） ---
ca_key = rsa.generate_private_key(public_exponent=65537, key_size=2048)
ca_cert = (
x509.CertificateBuilder()
.subject_name(name("Demo Root CA"))
.issuer_name(name("Demo Root CA"))
.public_key(ca_key.public_key())
.serial_number(x509.random_serial_number())
.not_valid_before(now)
.not_valid_after(now + dt.timedelta(days=3650))
.add_extension(x509.BasicConstraints(ca=True, path_length=0), critical=True)
.add_extension(key_usage(sign_certs=True), critical=True)
.sign(ca_key, hashes.SHA256())
)
# --- JWT 签名用的 leaf 证书：公钥就放在这里 ---
signing_key = rsa.generate_private_key(public_exponent=65537, key_size=2048)
leaf_cert = (
x509.CertificateBuilder()
.subject_name(name("jwt-signer"))
.issuer_name(ca_cert.subject)
.public_key(signing_key.public_key()) # ← 公钥信息写入证书
.serial_number(x509.random_serial_number())
.not_valid_before(now)
.not_valid_after(now + dt.timedelta(days=365))
.add_extension(x509.BasicConstraints(ca=False, path_length=None), critical=True)
.add_extension(key_usage(sign_certs=False), critical=True)
.sign(ca_key, hashes.SHA256()) # 由 CA 签发
)
def der_b64(cert):
return base64.b64encode(cert.public_bytes(serialization.Encoding.DER)).decode()
leaf_der = leaf_cert.public_bytes(serialization.Encoding.DER)
x5c = [der_b64(leaf_cert), der_b64(ca_cert)] # leaf 在前，CA 在后
# 可选：证书 SHA-256 指纹（这个用 base64url、无补齐）
x5t_s256 = base64.urlsafe_b64encode(hashlib.sha256(leaf_der).digest()).rstrip(b"=").decode()
token = jwt.encode(
{"sub": "user-123", "iat": now, "exp": now + dt.timedelta(minutes=10)},
signing_key,
algorithm="RS256",
headers={"x5c": x5c, "x5t#S256": x5t_s256},
)
print(jwt.get_unverified_header(token))