problem with sftp rpm

Hi all
I downloaded 'sftp-0.9.9-4.src.rpm' and when I run the command "rpm -ivh sftp-0.9.9-4.src.rpm", it gives the following warning on my system(linux):

warning: sftp-0.9.9-4.src.rpm: Header V3 DSA signature: NOKEY, key ID 1bbd5459
1:sftp warning: user builder does not exist - using root
warning: user builder does not exist - using root)
warning: user builder does not exist - using root)
########################################### [100%]

After this when I run "rpmbuild -ba sftp.specs" from /usr/src/redhat/SPECS dir, following error is displayed:

error: failed to stat /usr/src/redhat/SPECS/sftp.specs: No such file or directory


can any one tell me what could be the problem and how to correct it?

Thanks