Amazon S3 - How to fix 'The request signature we calculated does not match the signature' error?

Question

After two days of debugging, I finally discovered the problem...

The key I was assigning to the object started with a period i.e. ..\images\ABC.jpg, and this caused the error to occur.

I wish the API provides more meaningful and relevant error message, alas, I hope this will help someone else out there!

I get this error with the wrong credentials. I think there were invisible characters when I pasted it originally.

I had the same problem when tried to copy an object with some UTF8 characters. Below is a JS example:

var s3 = new AWS.S3();

s3.copyObject({
    Bucket: 'somebucket',
    CopySource: 'path/to/Weird_file_name_ðÓpíu.jpg',
    Key: 'destination/key.jpg',
    ACL: 'authenticated-read'
}, cb);

Solved by encoding the CopySource with encodeURIComponent()

I had the same error in nodejs. But adding signatureVersion in s3 constructor helped me:

const s3 = new AWS.S3({
  apiVersion: '2006-03-01',
  signatureVersion: 'v4',
});

This error seems to occur mostly if there is a space before or after your secret key

Actually in Java i was getting same error.After spending 4 hours to debug it what i found that that the problem was in meta data in S3 Objects as there was space while sitting cache controls in s3 files.This space was allowed in 1.6.* version but in 1.11.* it is disallowed and thus was throwing the signature mismatch error

My AccessKey had some special characters in that were not properly escaped.

I didn't check for special characters when I did the copy/paste of the keys. Tripped me up for a few mins.

A simple backslash fixed it. Example (not my real access key obviously):

secretAccessKey: 'Gk/JCK77STMU6VWGrVYa1rmZiq+Mn98OdpJRNV614tM'

becomes

secretAccessKey: 'Gk\/JCK77STMU6VWGrVYa1rmZiq\+Mn98OdpJRNV614tM'