[Python] Python HTTP signature update (#5154)

* improve python documentation and add import to __init__package.mustache

* improve python documentation and add import to __init__package.mustache

* add signing_info parameter conditionally

* add code comments and remove 'Content-Length' header from example

* Remove debug log statement

* set access_token to None by default

* set access_token to None by default

* fix unit tests for Python experimental

* fix trailing space

Author: sebastien-rosset

configuration.mustache

@@ -31,11 +31,16 @@ class Configuration(object):
       The dict value is an API key prefix when generating the auth data.
     :param username: Username for HTTP basic authentication
     :param password: Password for HTTP basic authentication
-    :param signing_info: Configuration parameters for HTTP signature.
+{{#hasHttpSignatureMethods}}
+    :param signing_info: Configuration parameters for the HTTP signature security scheme.
         Must be an instance of {{{packageName}}}.signing.HttpSigningConfiguration
+{{/hasHttpSignatureMethods}}
 
+{{#hasAuthMethods}}
     :Example:
+{{#hasApiKeyMethods}}
 
+    API Key Authentication Example.
     Given the following security scheme in the OpenAPI specification:
       components:
         securitySchemes:
@@ -51,12 +56,32 @@ class Configuration(object):
       )
     The following cookie will be added to the HTTP request:
        Cookie: JSESSIONID abc123
+{{/hasApiKeyMethods}}
+{{#hasHttpBasicMethods}}
+
+    HTTP Basic Authentication Example.
+    Given the following security scheme in the OpenAPI specification:
+      components:
+        securitySchemes:
+          http_basic_auth:
+            type: http
+            scheme: basic
 
     Configure API client with HTTP basic authentication:
       conf = {{{packageName}}}.Configuration(
           username='the-user',
           password='the-password',
       )
+{{/hasHttpBasicMethods}}
+{{#hasHttpSignatureMethods}}
+
+    HTTP Signature Authentication Example.
+    Given the following security scheme in the OpenAPI specification:
+      components:
+        securitySchemes:
+          http_basic_auth:
+            type: http
+            scheme: signature
 
     Configure API client with HTTP signature authentication. Use the 'hs2019' signature scheme,
     sign the HTTP requests with the RSA-SSA-PSS signature algorithm, and set the expiration time
@@ -83,18 +108,22 @@ class Configuration(object):
                                       signing.HEADER_DATE,
                                       signing.HEADER_DIGEST,
                                       'Content-Type',
-                                      'Content-Length',
                                       'User-Agent'
                                      ],
             signature_max_validity = datetime.timedelta(minutes=5)
         )
       )
+{{/hasHttpSignatureMethods}}
+{{/hasAuthMethods}}
     """
 
     def __init__(self, host="{{{basePath}}}",
                  api_key=None, api_key_prefix=None,
                  username=None, password=None,
-                 signing_info=None):
+{{#hasHttpSignatureMethods}}
+                 signing_info=None,
+{{/hasHttpSignatureMethods}}
+                 ):
         """Constructor
         """
         self.host = host
@@ -123,19 +152,21 @@ class Configuration(object):
         self.password = password
         """Password for HTTP basic authentication
         """
+{{#hasHttpSignatureMethods}}
         if signing_info is not None:
             signing_info.host = host
         self.signing_info = signing_info
         """The HTTP signing configuration
         """
+{{/hasHttpSignatureMethods}}
 {{#hasOAuthMethods}}
-        self.access_token = ""
+        self.access_token = None
         """access token for OAuth/Bearer
         """
 {{/hasOAuthMethods}}
 {{^hasOAuthMethods}}
 {{#hasBearerMethods}}
-        self.access_token = ""
+        self.access_token = None
         """access token for OAuth/Bearer
         """
 {{/hasBearerMethods}}

python-experimental/__init__package.mustache

@@ -20,6 +20,9 @@ from {{packageName}}.api_client import ApiClient
 
 # import Configuration
 from {{packageName}}.configuration import Configuration
+{{#hasHttpSignatureMethods}}
+from {{packageName}}.signing import HttpSigningConfiguration
+{{/hasHttpSignatureMethods}}
 
 # import exceptions
 from {{packageName}}.exceptions import OpenApiException

python-experimental/signing.mustache

@@ -15,18 +15,35 @@ import re
 from six.moves.urllib.parse import urlencode, urlparse
 from time import mktime
 
+# The constants below define a subset of HTTP headers that can be included in the
+# HTTP signature scheme. Additional headers may be included in the signature.
+
+# The '(request-target)' header is a calculated field that includes the HTTP verb,
+# the URL path and the URL query.
 HEADER_REQUEST_TARGET = '(request-target)'
+# The time when the HTTP signature was generated.
 HEADER_CREATED = '(created)'
+# The time when the HTTP signature expires. The API server should reject HTTP requests
+# that have expired.
 HEADER_EXPIRES = '(expires)'
+# The 'Host' header.
 HEADER_HOST = 'Host'
+# The 'Date' header.
 HEADER_DATE = 'Date'
-HEADER_DIGEST = 'Digest'  # RFC 3230, include digest of the HTTP request body.
+# When the 'Digest' header is included in the HTTP signature, the client automatically
+# computes the digest of the HTTP request body, per RFC 3230.
+HEADER_DIGEST = 'Digest'
+# The 'Authorization' header is automatically generated by the client. It includes
+# the list of signed headers and a base64-encoded signature.
 HEADER_AUTHORIZATION = 'Authorization'
 
+# The constants below define the cryptographic schemes for the HTTP signature scheme.
 SCHEME_HS2019 = 'hs2019'
 SCHEME_RSA_SHA256 = 'rsa-sha256'
 SCHEME_RSA_SHA512 = 'rsa-sha512'
 
+# The constants below define the signature algorithms that can be used for the HTTP
+# signature scheme.
 ALGORITHM_RSASSA_PSS = 'RSASSA-PSS'
 ALGORITHM_RSASSA_PKCS1v15 = 'RSASSA-PKCS1-v1_5'
 
@@ -364,5 +381,4 @@ class HttpSigningConfiguration(object):
         auth_str = auth_str + "headers=\"{0}\",signature=\"{1}\"".format(
                                                 headers_value, signed_msg.decode('ascii'))
 
-        print("AUTH: {0}".format(auth_str))
         return auth_str