Getting Error as Signature Invalid while accessing contacts from address book

I am getting below error:

{"error":{"lang":"en-US","description":"Please provide valid credentials. OAuth oauth_problem=\"signature_invalid\", realm=\"yahooapis.com\""}}

while requesting below URL using OAuth:

http://social.yahooapis.com/v1/user/RCH4OZSPVOCC7W7DDJTYYPSFYY/contacts/

The authorization request header is somewhat like:

Authorization: OAuth realm="yahooapis.com" ,oauth_consumer_key="dj0yJmk9TE16NEh2TW5OSUNhJmQ9WVdrOVZsQXphVzFGTlRZbWNHbzlOVE00T0RZMU9EWXkmcz1jb25zdW1lcnNlY3JldCZ4PTJm" ,oauth_nonce="29198566-F1AD-9DCF-1935-CE27B06378F5" ,oauth_signature_method="HMAC-SHA1" ,oauth_timestamp="1354877171" ,oauth_token="A%3D8YoQOFfsgCDAjHz.PDOX2YAoY2BlIeOsqIdV7F01AXk.HjOhbjMrEOqTqD_WStN6sNPtaDmEa7cr2C8n7OnAIlULoC4TsTiDVGY.NxaLbkBLvVrMMf0J3gUVK3kQXpKKkvwCNinRQP7ISbaXmyRqFs9Y9IieRjJxo1Ad3oa47_1jYjwjSiSIjMKx4lpYmv1L_Yege20d4zaZ0nER3uUh_t8uSrifd7I88RtpwOu9cGvDVNK1Jgk8kxTm71m6yl_8DxA1WfjIDH9MPP4R2u_q2gHIwBy8nbON0XN0cYTS6kKHB2Zvz7xrmbf5CwRl6kOWdW7ZpdlUG9S5StVktL2rQr3MGeQAx.iGNuHeZrx3USSo9VdihyHxgdotNtDZQH40NRDc45kX95uMj1Yt8Z1cWLlfm6gFQ26QNJIEAV2pO4l_ZGkUzc1jehVSO6rGLVsaTSwuIdLkTVmigmoAW8n.YWtlE5N9US60hTTEB1YyFnJNoPgz.Jzs.wXNCUcv1pKKCKUnZdeLGiKp.Xt7MwsngOPt7q9WwLyZ1GEaDYWAGPyJhX3Sc1ksAT3oinpto8v42kasldmW2juJwThiv2GjJZnUHv2muKdMHVnoa4BVviePtPYWHpdq2pBZfvYiB8W0x00ku4tHqun2kmG1f4NvNhkpO0ODNHdZIMn5OFS4p89T0jU5u7BuwwPq06RTC3EGdwT4uhMA2HJ.8PxujgE0JhyMRiuG7Zs6qwZKD12eLX5H7Y7R9P_mkt6DyNcEtTQ_pQZex6p6_35xldLcDrCEWEWrNcRNRSRFwZzQw5PpHBzzM2KR" ,oauth_version="1.0" ,oauth_signature="%5BB%40b5f87c

Please suggest am I missing anything. I am using OAuth v2.0 with Google and it's working totally fine.

Thanks in advance.