我的问题是Google P12凭据中的证书是什么？
我用Python编写了以下程序，该程序采用P12（PFX）格式的Google服务帐户凭据文件。该程序提取私钥和证书。
创建Google Access令牌时，私钥用于对JWT进行签名（有关从P12凭据创建访问令牌的信息，请参见此article）。我找不到该证书的用处。
注意：此代码也适用于普通SSL PFX证书捆绑包。 CA放在单独的文件中。
'''
Convert a Google P12 (PFX) service account into private key and certificate.
Convert an SSL Certifcate (PFX) into private key, certificate and CAs.
'''
import os
import OpenSSL.crypto
def write_CAs(filename, p12):
''' Write the Certificate Authorities, if any, to filename '''
ca = p12.get_ca_certificates()
if ca is None:
return
if os.path.exists(filename):
os.remove(filename)
print('Creating Certificate CA File:', filename)
with open(filename, 'wb') as f:
for cert in ca:
f.write(OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_PEM, cert))
def pfx_to_pem(pfx_path, pfx_password, pkey_path, pem_path, pem_ca_path):
'''
Decrypt the P12 (PFX) file and create a private key file and certificate file.
Input:
pfx_path INPUT: This is the Google P12 file or SSL PFX certificate file
pfx_password INPUT: Password used to protect P12 (PFX)
pkey_path INPUT: File name to write the Private Key to
pem_path INPUT: File name to write the Certificate to
pem_ca_path INPUT: File name to write the Certificate Authorities to
'''
print('Opening:', pfx_path)
with open(pfx_path, 'rb') as f_pfx:
pfx = f_pfx.read()
print('Loading P12 (PFX) contents:')
p12 = OpenSSL.crypto.load_pkcs12(pfx, pfx_password)
print('Creating Private Key File:', pkey_path)
with open(pkey_path, 'wb') as f:
# Write Private Key
f.write(OpenSSL.crypto.dump_privatekey(OpenSSL.crypto.FILETYPE_PEM, p12.get_privatekey()))
print('Creating Certificate File:', pem_path)
with open(pem_path, 'wb') as f:
# Write Certificate
f.write(OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_PEM, p12.get_certificate()))
# Google P12 does not have certifiate authorities but SSL PFX certificates do
write_CAs(pem_ca_path, p12)
# Start here
pfx_to_pem(
'compute-engine.p12', # Google Service Account P12 file
'notasecret', # P12 file password
'compute-engine.key', # Filename to write private key
'compute-engine.pem', # Filename to write certificate
'compute-engine_ca.pem')# Filename to write CAs if present
答案 0 :(得分：1)
对于Google服务帐户凭据，该证书用于验证签名的JWT。
Signed JWT用于从Google的OAuth 2.0服务器请求访问令牌。
P12格式的服务帐户凭据包括证书作为PKCS＃12捆绑包。 Json格式的服务帐户凭据具有可在Google网站上获得的证书。
以下代码是使用Google P12凭据创建签名JWT，然后对其进行验证并显示内容的示例。
'''
This program verifies a Signed JWT created by Google Service Account P12 credentials
First a JWT is signed with the P12 Private Key.
The certificate is extracted from the P12 file and used to verify the signature
'''
import json
import time
import base64
import jwt
import OpenSSL.crypto
# Google Endpoint for creating OAuth 2.0 Access Tokens from Signed-JWT
auth_url = "https://www.googleapis.com/oauth2/v4/token"
# Set how long this token will be valid in seconds
expires_in = 3600 # Expires in 1 hour
#scopes = "https://www.googleapis.com/auth/cloud-platform"
scopes = "https://www.googleapis.com/auth/devstorage.read_only"
# Details on the Google Service Account. The email must match the Google Console.
sa_filename = 'compute-engine.p12'
sa_password = 'notasecret'
sa_email = 'developer-123456@developer.gserviceaccount.com'
# You can control what is verified in the JWT. For example to allow expired JWTs
# set 'verify_exp' to False
options = {
'verify_signature': True,
'verify_exp': True,
'verify_nbf': True,
'verify_iat': True,
'verify_aud': True,
'require_exp': False,
'require_iat': False,
'require_nbf': False
}
aud = 'https://www.googleapis.com/oauth2/v4/token'
def load_private_key(p12_path, p12_password):
''' Read the private key and return as base64 encoded '''
# print('Opening:', p12_path)
with open(p12_path, 'rb') as f:
data = f.read()
# print('Loading P12 (PFX) contents:')
p12 = OpenSSL.crypto.load_pkcs12(data, p12_password)
# Dump the Private Key in PKCS#1 PEM format
pkey = OpenSSL.crypto.dump_privatekey(
OpenSSL.crypto.FILETYPE_PEM,
p12.get_privatekey())
# return the private key
return pkey
def load_public_key(p12_path, p12_password):
''' Read the public key and return as base64 encoded '''
# print('Opening:', p12_path)
with open(p12_path, 'rb') as f:
p12_data = f.read()
# print('Loading P12 (PFX) contents:')
p12 = OpenSSL.crypto.load_pkcs12(p12_data, p12_password)
public_key = OpenSSL.crypto.dump_publickey(
OpenSSL.crypto.FILETYPE_PEM,
p12.get_certificate().get_pubkey())
# print(public_key)
return public_key
def create_signed_jwt(p12_path, p12_password, p12_email, scope):
''' Create an AccessToken from a service account p12 credentials file '''
pkey = load_private_key(p12_path, p12_password)
issued = int(time.time())
expires = issued + expires_in # expires_in is in seconds
# Note: this token expires and cannot be refreshed. The token must be recreated
# JWT Headers
additional_headers = {
"alg": "RS256",
"typ": "JWT" # Google uses SHA256withRSA
}
# JWT Payload
payload = {
"iss": p12_email, # Issuer claim
"sub": p12_email, # Issuer claim
"aud": auth_url, # Audience claim
"iat": issued, # Issued At claim
"exp": expires, # Expire time
"scope": scope # Permissions
}
# Encode the headers and payload and sign creating a Signed JWT (JWS)
sig = jwt.encode(payload, pkey, algorithm="RS256", headers=additional_headers)
# print(sig)
return sig
def pad(data):
""" pad base64 string """
missing_padding = len(data) % 4
data += '=' * (4 - missing_padding)
return data
def print_jwt(signed_jwt):
""" Print a JWT Header and Payload """
s = signed_jwt.decode('utf-8').split('.')
print('Header:')
h = base64.urlsafe_b64decode(pad(s[0])).decode('utf-8')
print(json.dumps(json.loads(h), indent=4))
print('Payload:')
p = base64.urlsafe_b64decode(pad(s[1])).decode('utf-8')
print(json.dumps(json.loads(p), indent=4))
def verify_signed_jwt(signed_jwt):
'''
This function takes a Signed JWT and verifies it using a Google P12 service account.
'''
# Get the Public Key
public_key = load_public_key(sa_filename, sa_password)
# Verify the Signed JWT
r = jwt.decode(signed_jwt, public_key, algorithms=["RS256"], audience=aud, options=options)
print('Decoded JWT:')
print(json.dumps(r, indent=4))
if __name__ == '__main__':
s_jwt = create_signed_jwt(sa_filename, sa_password, sa_email, scopes)
print_jwt(s_jwt)
verify_signed_jwt(s_jwt)