1 files changed, 132 insertions, 0 deletions
diff --git a/gallery_dl/oauth.py b/gallery_dl/oauth.py
new file mode 100644
index 0000000..58126ac
--- /dev/null
+++ b/gallery_dl/oauth.py
@@ -0,0 +1,132 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2018 Mike Fährmann
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+"""OAuth helper functions and classes"""
+
+import hmac
+import time
+import base64
+import random
+import string
+import hashlib
+import urllib.parse
+
+import requests
+import requests.auth
+
+from . import text
+
+
+def nonce(size, alphabet=string.ascii_letters):
+    """Generate a nonce value with 'size' characters"""
+    return "".join(random.choice(alphabet) for _ in range(size))
+
+
+def quote(value, quote=urllib.parse.quote):
+    """Quote 'value' according to the OAuth1.0 standard"""
+    return quote(value, "~")
+
+
+def concat(*args):
+    """Concatenate 'args' as expected by OAuth1.0"""
+    return "&".join(quote(item) for item in args)
+
+
+class OAuth1Session(requests.Session):
+    """Extension to requests.Session to support OAuth 1.0"""
+
+    def __init__(self, consumer_key, consumer_secret,
+                 token=None, token_secret=None):
+
+        requests.Session.__init__(self)
+        self.auth = OAuth1Client(
+            consumer_key, consumer_secret,
+            token, token_secret,
+        )
+
+    def rebuild_auth(self, prepared_request, response):
+        if "Authorization" in prepared_request.headers:
+            del prepared_request.headers["Authorization"]
+            prepared_request.prepare_auth(self.auth)
+
+
+class OAuth1Client(requests.auth.AuthBase):
+    """OAuth1.0a authentication"""
+
+    def __init__(self, consumer_key, consumer_secret,
+                 token=None, token_secret=None):
+
+        self.consumer_key = consumer_key
+        self.consumer_secret = consumer_secret
+        self.token = token
+        self.token_secret = token_secret
+
+    def __call__(self, request):
+        oauth_params = [
+            ("oauth_consumer_key", self.consumer_key),
+            ("oauth_nonce", nonce(16)),
+            ("oauth_signature_method", "HMAC-SHA1"),
+            ("oauth_timestamp", str(int(time.time()))),
+            ("oauth_version", "1.0"),
+        ]
+        if self.token:
+            oauth_params.append(("oauth_token", self.token))
+
+        signature = self.generate_signature(request, oauth_params)
+        oauth_params.append(("oauth_signature", signature))
+
+        request.headers["Authorization"] = "OAuth " + ",".join(
+            key + '="' + value + '"' for key, value in oauth_params)
+
+        return request
+
+    def generate_signature(self, request, params):
+        """Generate 'oauth_signature' value"""
+        url, _, query = request.url.partition("?")
+
+        params = params.copy()
+        for key, value in text.parse_query(query).items():
+            params.append((quote(key), quote(value)))
+        params.sort()
+        query = "&".join("=".join(item) for item in params)
+
+        message = concat(request.method, url, query).encode()
+        key = concat(self.consumer_secret, self.token_secret or "").encode()
+        signature = hmac.new(key, message, hashlib.sha1).digest()
+
+        return quote(base64.b64encode(signature).decode())
+
+
+class OAuth1API():
+    """Base class for OAuth1.0 based API interfaces"""
+    API_KEY = None
+    API_SECRET = None
+
+    def __init__(self, extractor):
+        self.log = extractor.log
+        self.extractor = extractor
+
+        api_key = extractor.config("api-key", self.API_KEY)
+        api_secret = extractor.config("api-secret", self.API_SECRET)
+        token = extractor.config("access-token")
+        token_secret = extractor.config("access-token-secret")
+
+        if api_key and api_secret and token and token_secret:
+            self.log.debug("Using OAuth1.0 authentication")
+            self.session = OAuth1Session(
+                api_key, api_secret, token, token_secret)
+            self.api_key = None
+        else:
+            self.log.debug("Using api_key authentication")
+            self.session = extractor.session
+            self.api_key = api_key
+
+    def request(self, url, method="GET", *, expect=range(400, 500), **kwargs):
+        kwargs["expect"] = expect
+        kwargs["session"] = self.session
+        return self.extractor.request(url, method, **kwargs)