The method signature must be generated by taking the query string, and creating a HMAC-SHA256 signature using your API key as the secret key.
salesforce way of generating signature
String algorithmName = 'RSA'; String key = ''; Blob privateKey = EncodingUtil.base64Decode(key); Blob input = Blob.valueOf('12345qwerty'); Crypto.sign(algorithmName, input, privateKey);
its not working. I am not able to get the meaning of first line, I have referred this links http://blog.jeffdouglas.com/2010/07/06/using-rsa-sha1-with-salesforce-crypto-class/ enter link description here
what should be proper value of input :: any random value OR some meaningful value