Trying for hours to get a request token using Google OAuthGetRequestToken but it always returns "signature_invalid".

For a test I use the oAuth Playground to successfully request the token. Here are the results:

Signature base string

  GET&https%3A%2F%2Fwww.google.com%2Faccounts%2FOAuthGetRequestToken&oauth_callback%3Dhttp%253A%252F%252Fgooglecodesamples.com%252Foauth_playground%252Findex.php%26oauth_consumer_key%3Dwww.embeddedanalytics.com%26oauth_nonce%3D56aa884162ed21815a0406725c79cf79%26oauth_signature_method%3DRSA-SHA1%26oauth_timestamp%3D1321417095%26oauth_version%3D1.0%26scope%3Dhttps%253A%252F%252Fwww.google.com%252Fanalytics%252Ffeeds%252F

Request/Response

GET /accounts/OAuthGetRequestToken?scope=https%3A%2F%2Fwww.google.com%2Fanalytics%2Ffeeds%2F HTTP/1.1
Host: www.google.com
Accept: */*
Authorization: OAuth oauth_version="1.0", oauth_nonce="56aa884162ed21815a0406725c79cf79", oauth_timestamp="1321417095", oauth_consumer_key="www.embeddedanalytics.com", oauth_callback="http%3A%2F%2Fgooglecodesamples.com%2Foauth_playground%2Findex.php", oauth_signature_method="RSA-SHA1", oauth_signature="qRtorIaSFaQdOXW1u6eMQlY9LT2j7ThG5kgkcD6rDcW4MIvzluslFgYRNTuRvnaruraNpItjojtgsrK9deYRKoHBGOlU27SsWy6jECxKczcSECl3cVAcjk7dvbywFMDkgi1ZhTZ5Q%2BFoD60HoVQUYnGUbOO0jPXI48LfkiA5ZN4%3D"

HTTP/1.1 200 OK
Content-Type: text/plain; charset=UTF-8
Date: Wed, 16 Nov 2011 04:18:15 GMT
Expires: Wed, 16 Nov 2011 04:18:15 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Content-Length: 118
Server: GSE

oauth_token=4%2FmO86qZzixayI2NoUc-hewC--D53R&oauth_token_secret=r0PReF9D83w1d6uP0nyQQm9c&oauth_callback_confirmed=true

I am using Fiddler to trace my calls. It returns the Signature base string:

GET&https%3A%2F%2Fwww.google.com%2Faccounts%2FOAuthGetRequestToken&oauth_callback%3Dhttp%253A%252F%252Fgooglecodesamples.com%252Foauth_playground%252Findex.php%26oauth_consumer_key%3Dwww.embeddedanalytics.com%26oauth_nonce%3Dl9Jydzjyzt2fJfM3ltY5yrxxYy2uh1U7%26oauth_signature_method%3DRSA-SHA1%26oauth_timestamp%3D1321417107%26oauth_version%3D1.0%26scope%3Dhttps%253A%252F%252Fwww.google.com%252Fanalytics%252Ffeeds%252F

Aside from the oauth_timestamp and oauth_nonce (which should be different), the base string are pretty much identical.

Anyone know what I am doing wrong?

Update 11/20/2011 Thinking it might be something wrong with my RSA-SHA signing, I have since tried HMAC-SHA. It gives the same results. I thought it might be beneficial to include the Fiddler results (I added carriage returns to have it format better).

GET https://www.google.com/accounts/OAuthGetRequestToken?
scope=https%3A%2F%2Fwww.google.com%2Fanalytics%2Ffeeds%2F HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Authorization: OAuth oauth_version="1.0",
oauth_nonce="7C4C900EAACC9C7B62E399A91B81D8DC",
oauth_timestamp="1321845418",
oauth_consumer_key="www.embeddedanalytics.com",
oauth_signature_method="HMAC-SHA1",
oauth_signature="ows%2BbFTNSR8jVZo53rGBB8%2BfwFM%3D"
Host: www.google.com
Accept: */*
Accept-Encoding: identity

Response

HTTP/1.1 400 Bad Request
Content-Type: text/plain; charset=UTF-8
Date: Mon, 21 Nov 2011 03:16:57 GMT
Expires: Mon, 21 Nov 2011 03:16:57 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Content-Length: 358
Server: GSE

signature_invalid
base_string:GET&https%3A%2F%2Fwww.google.com%2Faccounts%2FOAuthGetRequestToken
&oauth_consumer_key%3Dwww.embeddedanalytics.com
%26oauth_nonce%3D7C4C900EAACC9C7B62E399A91B81D8DC
%26oauth_signature_method%3DHMAC-SHA1
%26oauth_timestamp%3D1321845418
%26oauth_version%3D1.0
%26scope%3Dhttps%253A%252F%252Fwww.google.com%252Fanalytics%252Ffeeds%252F