aws/aws-sdk-net — pull request #41 by faisalmansoor (2013-10-04 19:46:06+00:00)
Title: Path in Keys should be separated by '/'

Most the .Net functions, like Path.Combine, use '\' as path separator, but, AWS expects Unix style paths. Since key is used to calculate the signature, difference in path separator results in confusing signature mismatch exception.

Amazon.S3.AmazonS3Exception : The request signature we calculated does not match the signature you provided. Check your key and signing method.