Minor optimization.
- Add 1000 entries buffered channel for walkerCh.
- Reset marker after the lexical order has reached and
compare only if the marker is set.
Incoming request params in presigned can come in different order
for different implementations. Rather than verifying a full string
we should verify individual params instead.
This patch fixes an incompatibility issue with AWS SDK Java.
Fixes#1059 - Thanks to @notnoopci for reporting this problem.
Golang http server strips off 'Expect' header, if the
client sent this as part of signed headers we need to
handle otherwise we would see a signature mismatch.
`aws-cli` sets this as part of signed headers which is
a bad idea since servers trying to implement AWS
Signature version '4' will all encounter this issue.
According to
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.20
Expect header is always of form:
Expect = "Expect" ":" 1#expectation
expectation = "100-continue" | expectation-extension
So it safe to assume that '100-continue' is what would
be sent, for the time being keep this work around.
