没有名为OpenSSL.crypto和ImportError的模块：SignedJwtAssertionCredentials

Question

我正在尝试使用本地dev_appserver本地连接到BigQuery API，遵循本教程：https://developers.google.com/bigquery/authorization?hl=de#service-accounts 运行此网站上提到的代码，返回一个重要错误：

ImportError: cannot import name SignedJwtAssertionCredentials

所以我跟踪错误并发现（在oauth2client/client.py中）：

if HAS_CRYPTO:
  # PyOpenSSL and PyCrypto are not prerequisites for oauth2client, so if it is
  # missing then don't create the SignedJwtAssertionCredentials or the
  # verify_id_token() method.

  class SignedJwtAssertionCredentials(AssertionCredentials):

但我需要“签名的jwtassertioncredentials”！所以我进一步隔离了这个错误，发现（在oauth2client/crypt.py中）这一行实际上导致了这个问题：

from OpenSSL import crypto

我试过：

$ python
>>> import OpenSSL
>>> OpenSSL.__file__
'/usr/local/lib/python2.7/site-packages/OpenSSL/__init__.pyc'
>>> from OpenSSL import crypto
>>> crypto.__file__
'/usr/local/lib/python2.7/site-packages/OpenSSL/crypto.so'

它看起来很有前途，还检查了代码的sys.path：

['/Users/mattes/Developer/gae-projects/project123', 
 '/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine', 
 '/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine', 
 '/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7', 
 '/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload', '/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/lib/webapp2-2.5.2', 
'/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/lib/protorpc-1.0', 
'/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/lib/webob-1.1.1', 
'/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/lib/yaml-3.10']

无论如何，将"/usr/local/lib/python2.7/site-packages/OpenSSL"添加到sys.path或/Users/mattes/Developer/gae-projects/project123下的符号链接/usr/local/lib/python2.7/site-packages/OpenSSL都无法解决此问题。

/usr/local/lib/python2.7/site-packages/OpenSSL看起来像：

├── SSL.so
├── __init__.py
├── __init__.pyc
├── crypto.so
├── rand.so
├── test
│   ├── __init__.py
│   ├── __init__.pyc
│   ├── test_crypto.py
│   ├── test_crypto.pyc
│   ├── test_rand.py
│   ├── test_rand.pyc
│   ├── test_ssl.py
│   ├── test_ssl.pyc
│   ├── util.py
│   └── util.pyc
├── tsafe.py
├── tsafe.pyc
├── version.py
└── version.pyc

使用Mac 10.9 Mavericks，Python 2.7.5

有人能帮忙吗？

Answer 1

通过将pycrypto添加到我的app.yaml中的libraries部分修复了此问题：

libraries:

- name: pycrypto
  version: "latest"

Answer 2

要在GAE服务器上运行这个程序，我发现需要三个步骤：

1. 安装最新版本的Google API Client（或者至少安装oauth2client模块）。请注意，它们提供了一个以GAE为目标的下载。

2. 将.p12密钥文件转换为.pem格式（使用openssl命令行工具）

   openssl pkcs12  -nocerts -in cert.p12 -out cert.pem
   

3. 将PyCrypto库添加到app.yaml。

   libraries:
     - name: pycrypto
       version: "2.6"  # this could be "latest" if you are daring
   

对于dev_appserver，还需要在本地安装PyCrypto库，因为它不包含在SDK中。（API客户端库也支持OpenSSL，但我假设使用PyCrypto更接近运行时环境。）