Merge pull request #1 from skoobasteeve/python-package

Convert to Python package

.gitignore

@@ -0,0 +1,165 @@
+sf_private_key.pem
+test.py
+auth_test.py
+test/*
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/#use-with-ide
+.pdm.toml
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/

Lambda/Dockerfile

@@ -1,24 +0,0 @@
-FROM public.ecr.aws/lambda/python:3.9
-
-# Install the function's dependencies using file requirements.txt
-# from your project folder.
-RUN yum install -y \
-gcc \
-gcc-c++ \
-Cython \
-make \
-libxml2 \
-libxslt \
-xmlsec1 \
-xmlsec1-devel \
-xmlsec1-openssl \
-libtool-ltdl-devel
-
-COPY requirements.txt  .
-RUN  pip3 install -r requirements.txt --target "${LAMBDA_TASK_ROOT}"
-
-# Copy function code
-COPY lambda_function/* ${LAMBDA_TASK_ROOT}/
-
-# Set the CMD to your handler (could also be done as a parameter override outside of the Dockerfile)
-CMD [ "lambda_function.lambda_handler" ] 

Lambda/lambda_function.py

@@ -1,139 +0,0 @@
-#!/usr/bin/env python3
-
-import base64
-import json
-import sys
-import os
-import requests
-import xmlsec
-import boto3
-from lxml import etree
-from datetime import datetime, timedelta
-
-
-region = os.environ.get('AWS_REGION')
-secret_id= os.environ.get('SECRET_ID')
-template_file = 'sf_saml_template.xml'
-private_keyfile = '/tmp/successfactors-private.pem'
-
-def get_secret(region, secret_name, session):
-
-    client = session.client(
-        service_name='secretsmanager',
-        region_name=region
-    )
-
-    try:
-        get_secret_value_response = client.get_secret_value(
-            SecretId=secret_name
-        )
-
-        if 'SecretString' in get_secret_value_response:
-            secret = get_secret_value_response['SecretString']
-
-    except Exception as x:
-        print(x)
-        sys.exit(1)
-
-    return secret
-
-
-def get_access_token(sf_url, company_id, client_id, assertion):
-
-    token_request = dict(
-        client_id=client_id,
-        company_id=company_id,
-        grant_type='urn:ietf:params:oauth:grant-type:saml2-bearer',
-        assertion=assertion
-    )
-    response = requests.post(f"{sf_url}/oauth/token", data=token_request)
-    token_data = response.json()
-    return token_data['access_token']
-
-
-def generate_assertion(sf_root_url, user_id, client_id, template_file):
-    issue_instant = datetime.utcnow()
-    auth_instant = issue_instant
-    not_valid_before = issue_instant - timedelta(minutes=10)
-    not_valid_after = issue_instant + timedelta(minutes=10)
-
-    audience = 'www.successfactors.com'
-
-    context = dict(
-        issue_instant=issue_instant.isoformat(),
-        auth_instant=auth_instant.isoformat(),
-        not_valid_before=not_valid_before.isoformat(),
-        not_valid_after=not_valid_after.isoformat(),
-        sf_root_url=sf_root_url,
-        audience=audience,
-        user_id=user_id,
-        client_id=client_id,
-        session_id='mock_session_index',
-    )
-    saml_template = open(template_file).read()
-
-    return saml_template.format(**context)
-
-
-def sign_assertion(xml_string, private_key):
-    key = xmlsec.Key.from_file(private_key, xmlsec.KeyFormat.PEM)
-
-    root = etree.fromstring(xml_string)
-    signature_node = xmlsec.tree.find_node(root, xmlsec.Node.SIGNATURE)
-
-    sign_context = xmlsec.SignatureContext()
-    sign_context.key = key
-    sign_context.sign(signature_node)
-
-    return etree.tostring(root)
-
-
-def auth(sf_url, sf_company_id, sf_oauth_client_id,
-         sf_admin_user, sf_saml_private_key, template_file):
-
-    unsigned_assertion = generate_assertion(sf_url,
-                                            sf_admin_user,
-                                            sf_oauth_client_id,
-                                            template_file)
-
-    signed_assertion = sign_assertion(unsigned_assertion, sf_saml_private_key)
-    signed_assertion_b64 = base64.b64encode(signed_assertion).replace(b'\n', b'')
-    access_token = get_access_token(sf_url,
-                                    sf_company_id,
-                                    sf_oauth_client_id,
-                                    signed_assertion_b64)
-
-    return access_token
-
-
-def lambda_handler(event, context):
-
-    session = boto3.session.Session()
-
-    print(event)
-
-    if event['rawPath'] == '/token':
-        body = json.loads(event['body'])
-        sf_url = body['odata_url']
-        sf_company_id = body['company_id']
-        sf_oauth_client_id = body['oauth_client_id']
-        sf_admin_user = body['admin_user']
-
-        private_key = get_secret(region,
-                                 secret_id,
-                                 session)
-
-        with open(private_keyfile, 'w') as f:
-            f.write(private_key)
-
-        token = auth(sf_url, sf_company_id, sf_oauth_client_id, sf_admin_user,
-                     private_keyfile, template_file)
-
-        payload = {
-            "token": token
-        }
-
-        return {
-            'statusCode': 200,
-            'body': json.dumps(payload)
-        }

Lambda/requirements.txt

@@ -1,3 +0,0 @@
-requests
-lxml
-xmlsec

README.md

@@ -1,49 +1,62 @@
-# SuccessFactors + Python
-Authenticate with and use the SAP SuccessFactors API with Python.
+# SuccessFactors Auth
+Authenticate with the SAP SuccessFactors API with OAuth2 and Python.
 
-## Authentcation
-
-### How to use
+## How to use
 
 1. Create an OAuth application in SuccessFactors.
 2. Download the private key and copy the Client ID.
-3. Clone this repo and copy `sf_auth.py` and `sf_saml_template.xml` into your Python project directory.
-4. Import `sf_auth` into your project.
-5. Install all the requirements listed in `requirements.txt` in this repo.
-6. Call the `sf_auth.auth()` function in your Python project. You'll need to pass the following parameters:
+3. Install the Python module:
+   ``` shell
+   pip install successfactors_auth
+   ```
+4. Import `successfactors_auth` into your Python >=3.9 project.
+5. Call the `successfactors_auth.auth()` function in your Python project. You'll need to pass the following parameters:
     - `sf_url`: Base API url of your SuccessFactors instance, e.g. "https://api55.sapsf.eu".
     - `sf_company_id`: SuccessFactors company ID.
     - `sf_oauth_client_id`: The Client ID for the OAuth application you created earlier.
     - `sf_admin_user`: An admin user in SuccessFactors that has access to the OAuth application.
     - `sf_saml_private_key`: Path to the private key file you downloaded when you created the OAuth application.
-    - `template_file`: Path to the template file from this repo.
 
-    Example:
-    ``` python
-    #!/usr/bin/env python
+### Example
 
-    import requests
-    import sf_auth
+``` python
+#!/usr/bin/env python
 
-    sf_url = 'https://your.base.url.com'
-    sf_company_id = 'your-company-id'
-    sf_oauth_client_id = 'OAUTH-CLIENT-ID'
-    sf_admin_user = 'your_admin_user'
-    sf_saml_private_key = 'your_app_private_key.pem'
-    template_file = 'sf_saml_template.xml'
+import requests
+import successfactors_auth
 
-    token = sf_auth.auth(sf_url, sf_company_id, sf_oauth_client_id, sf_admin_user, sf_saml_private_key, sf_saml_template)
+sf_url = 'https://your.base.url.com'
+sf_company_id = 'your-company-id'
+sf_oauth_client_id = 'your_app_client_id'
+sf_admin_user = 'your_admin_user'
+sf_saml_private_key = 'your_app_private_key.pem'
 
-    headers = {
-        "Accept: application/json",
-        f"Authorization: {token}"
-    }
+token = successfactors_auth.auth(
+    sf_url,
+    sf_company_id,
+    sf_oauth_client_id,
+    sf_admin_user,
+    sf_saml_private_key,
+    sf_saml_template
+    )
 
-    request = requests.get(f"{sf_url}/User", headers=headers)
+headers = {
+    "Accept: application/json",
+    f"Authorization: {token}"
+}
 
-    print(request.json())
-    ```
+request = requests.get(f"{sf_url}/User", headers=headers)
+user = request.json()
 
-### Using as an AWS Lambda function w/ API Gateway
+print(user)
+```
 
-Coming soon...
+## Background
+
+I wrote this module because I was forced to deal with the *horrific* SAP SuccessFactors API at my job, and I wanted to make sure other devs/sysadmins wouldn't have to feel the pain that I felt.  
+
+Once you get authenticated, getting the information you want is a whole new level of suffering. I hope to publish some more examples in the form of a blog post or docs in this repo.
+
+## Contributing
+
+All contributions welcome! Feel free to file an [issue](https://github.com/skoobasteeve/successfactors_auth/issues) or open a [pull request](https://github.com/skoobasteeve/successfactors_auth/pulls).

pyproject.toml

@@ -0,0 +1,22 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "successfactors_auth"
+version = "0.0.5"
+authors = [
+  { name="Ray Lyon", email="ray@raylyon.net" },
+]
+description = "Authenticate to the SuccessFactors API."
+readme = "README.md"
+requires-python = ">=3.9"
+classifiers = [
+    "Programming Language :: Python :: 3",
+    "License :: OSI Approved :: Apache Software License",
+    "Operating System :: OS Independent",
+]
+
+[project.urls]
+"Homepage" = "https://github.com/skoobasteeve/successfactors_auth"
+"Bug Tracker" = "https://github.com/skoobasteeve/successfactors_auth/issues"

src/successfactors_auth/auth.py

@@ -10,39 +10,44 @@ Bearer token.
 
 Derived from: https://github.com/mtrdesign/python-saml-example
 
-This script requires the following additional files:
--SAML template XML
+This module requires the following additional files:
 -Private key file for a previously created SuccessFactors OAuth2 application
 
 Required packages:
-pip install requests lxml xmlsec
+requests
+lxml
+xmlsec
 
 Example:
 #!/usr/bin/env python3
 
-import sf_auth
+import successfactors_auth
 
-token = sf_auth.auth(
+token = successfactors_auth.auth(
             SF_URL,
             SF_COMPANY_ID,
             SF_OAUTH_CLIENT_ID,
             SF_ADMIN_USER,
             SF_OAUTH_PRIVATE_KEY_FILE,
-            SAML_TEMPLATE_FILE
         )
 '''
 
 import base64
+from datetime import datetime, timedelta
+from importlib import resources as impresources
 import requests
 import xmlsec
 from lxml import etree
-from datetime import datetime, timedelta
+
+from . import templates
 
 
-# Send POST request to SuccessFactors containing the generated
-# SAML assertion and other details, then receive a token in response
-def get_access_token(sf_url, company_id, client_id, assertion):
-
+def get_access_token(sf_url: str, company_id: str, client_id: str,
+                     assertion: str) -> str:
+    """
+    Send POST request to SuccessFactors containing the generated
+    SAML assertion and other details, then receive a token in response
+    """
     # Request body
     token_request = dict(
         client_id=client_id,
@@ -50,13 +55,17 @@ def get_access_token(sf_url, company_id, client_id, assertion):
         grant_type='urn:ietf:params:oauth:grant-type:saml2-bearer',
         assertion=assertion
     )
-    response = requests.post(f"{sf_url}/oauth/token", data=token_request)
+    response = requests.post(f"{sf_url}/oauth/token", data=token_request,
+                             timeout=15)
     token_data = response.json()
     return token_data['access_token']
 
 
-# Generate SAML assertion from the template XML
-def generate_assertion(sf_root_url, user_id, client_id, template_file):
+def generate_assertion(sf_root_url: str, user_id: str, client_id: str,
+                       template_file: str) -> str:
+    """
+    Generate SAML assertion from the template XML
+    """
     # Calculate valid time values for the assertion's validity
     issue_instant = datetime.utcnow()
     auth_instant = issue_instant
@@ -78,14 +87,16 @@ def generate_assertion(sf_root_url, user_id, client_id, template_file):
         session_id='mock_session_index',
     )
     # Open the template file
-    saml_template = open(template_file).read()
+    saml_template = open(template_file, encoding="utf-8").read()
 
     # Fill the values into the template and return in
     return saml_template.format(**context)
 
 
-# Sign the SAML assertion using a private key file
-def sign_assertion(xml_string, private_key):
+def sign_assertion(xml_string: str, private_key: str) -> str:
+    """
+    Sign the SAML assertion using a private key file
+    """
     # Import key file
     key = xmlsec.Key.from_file(private_key, xmlsec.KeyFormat.PEM)
 
@@ -102,8 +113,14 @@ def sign_assertion(xml_string, private_key):
     return etree.tostring(root)
 
 
-def auth(sf_url, sf_company_id, sf_oauth_client_id,
-         sf_admin_user, sf_saml_private_key, template_file):
+def auth(sf_url: str, sf_company_id: str, sf_oauth_client_id: str,
+         sf_admin_user: str, sf_saml_private_key: str) -> str:
+    """
+    Request an API access token by generating a signed SAML assertion
+    and using it to authenticate with SuccessFactors.
+    """
+
+    template_file = impresources.files(templates) / 'sf_saml_template.xml'
 
     # Generate SAML assertion XML from template file
     unsigned_assertion = generate_assertion(sf_url,