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

Question

I have searched on the web for over two days now, and probably have looked through most of the online documented scenarios and workarounds, but nothing worked for me so far.

I am on AWS SDK for PHP V2.8.7 running on PHP 5.3.

I am trying to connect to my Amazon S3 bucket with the following code:

// Create a `Aws` object using a configuration file
$aws = Aws::factory('config.php');

// Get the client from the service locator by namespace
$s3Client = $aws->get('s3');

$bucket = "xxx";
$keyname = "xxx";

try {
    $result = $s3Client->putObject(array(
        'Bucket' => $bucket,
        'Key' => $keyname,
        'Body' => 'Hello World!'
    ));

    $file_error = false;
} catch (Exception $e) {
    $file_error = true;

    echo $e->getMessage();

    die();
}

My config.php file is as follows:

return [
    // Bootstrap the configuration file with AWS specific features
    'includes' => ['_aws'],
    'services' => [
        // All AWS clients extend from 'default_settings'. Here we are
        // overriding 'default_settings' with our default credentials and
        // providing a default region setting.
        'default_settings' => [
            'params' => [
                'credentials' => [
                    'key'    => 'key',
                    'secret' => 'secret'
                ]
            ]
        ]
    ]
];

It is producing the following error:

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

I've already checked my access key and secret at least 20 times, generated new ones, used different methods to pass in the information (i.e. profile and including credentials in code) but nothing is working at the moment.

Answer 1

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!

Answer 2

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

Answer 3

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',
});

Answer 4

I've just encountered this and, I'm a little embarrassed to say, it was because I was using an HTTP POST request instead of PUT.

Despite my embarrassment, I thought I'd share in case it saves somebody an hour of head scratching.

Answer 5

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()

Answer 6

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'

Answer 7

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

Answer 8

For Python set - signature_version s3v4

s3 = boto3.client(
   's3',
   aws_access_key_id='AKIAIO5FODNN7EXAMPLE',
   aws_secret_access_key='ABCDEF+c2L7yXeGvUyrPgYsDnWRRC1AYEXAMPLE',
   config=Config(signature_version='s3v4')
)

Answer 9

In my case I was using s3.getSignedUrl('getObject') when I needed to be using s3.getSignedUrl('putObject') (because I'm using a PUT to upload my file), which is why the signatures didn't match.

Answer 10

In a previous version of the aws-php-sdk, prior to the deprecation of the S3Client::factory() method, you were allowed to place part of the file path, or Key as it is called in the S3Client->putObject() parameters, on the bucket parameter. I had a file manager in production use, using the v2 SDK. Since the factory method still worked, I did not revisit this module after updating to ~3.70.0. Today I spent the better part of two hours debugging why I had started receiving this error, and it ended up being due to the parameters I was passing (which used to work):

$s3Client = new S3Client([
    'profile' => 'default',
    'region' => 'us-east-1',
    'version' => '2006-03-01'
]);
$result = $s3Client->putObject([
    'Bucket' => 'awesomecatpictures/catsinhats',
    'Key' => 'whitecats/white_cat_in_hat1.png',
    'SourceFile' => '/tmp/asdf1234'
]);

I had to move the catsinhats portion of my bucket/key path to the Key parameter, like so:

$s3Client = new S3Client([
    'profile' => 'default',
    'region' => 'us-east-1',
    'version' => '2006-03-01'
]);
$result = $s3Client->putObject([
    'Bucket' => 'awesomecatpictures',
    'Key' => 'catsinhats/whitecats/white_cat_in_hat1.png',
    'SourceFile' => '/tmp/asdf1234'
]);

What I believe is happening is that the Bucket name is now being URL Encoded. After further inspection of the exact message I was receiving from the SDK, I found this:

Error executing PutObject on https://s3.amazonaws.com/awesomecatpictures%2Fcatsinhats/whitecats/white_cat_in_hat1.png

AWS HTTP error: Client error: PUT https://s3.amazonaws.com/awesomecatpictures%2Fcatsinhats/whitecats/white_cat_in_hat1.png resulted in a 403 Forbidden

This shows that the / I provided to my Bucket parameter has been through urlencode() and is now %2F.

The way the Signature works is fairly complicated, but the issue boils down to the bucket and key are used to generate the encrypted signature. If they do not match exactly on both the calling client, and within AWS, then the request will be denied with a 403. The error message does actually point out the issue:

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

So, my Key was wrong because my Bucket was wrong.

Answer 11

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

Answer 12

For me I used axios and by deafult it sends header

content-type: application/x-www-form-urlencoded

so i change to send:

content-type: application/octet-stream

and also had to add this Content-Type to AWS signature

const params = {
    Bucket: bucket,
    Key: key,
    Expires: expires,
    ContentType: 'application/octet-stream'
}

const s3 = new AWS.S3()
s3.getSignedUrl('putObject', params)

Answer 13

Another possible issue might be that the meta values contain non US-ASCII characters. For me it helped to UrlEncode the values when adding them to the putRequest:

request.Metadata.Add(AmzMetaPrefix + "artist", HttpUtility.UrlEncode(song.Artist));
request.Metadata.Add(AmzMetaPrefix + "title", HttpUtility.UrlEncode(song.Title));

Answer 14

I had the same issue, the problem I had was I imported the wrong environment variable, which means that my secret key for AWS was wrong. Based on reading all the answers, I would verify that all your access ID and secret key is right and there are no additional characters or anything.

Answer 15

If none of the other mentioned solution works for you , then try using

aws configure

This command (Getting started with the AWS CLI) will open a set of options asking for keys, region and output format.

Hope this helps!

Answer 16

In my case I parsed an S3 url into its components.

For example:

Url:    s3://bucket-name/path/to/file

Was parsed into:

Bucket: bucket-name
Path:   /path/to/file

Having the path part containing a leading '/' failed the request.

Answer 17

I had the same issue. I had the default method, PUT set to define the pre-signed URL but was trying to perform a GET. The error was due to method mismatch.

Answer 18

When I gave the wrong secret key which is of value "secret" knowingly, it gave this error. I was expecting some valid error message details like "authentication failed" or something

Answer 19

Most of the time it happens because of the wrong key (AWS_SECRET_ACCESS_KEY). Please cross verify your AWS_SECRET_ACCESS_KEY. Hope it will work...

Answer 20

This issue happened to me because I was accidentally assigning the value of the ACCESS_KEY_ID to SECRET_ACCESS_KEY_ID. Once this was fixed everything worked fine.

Answer 21

I just experienced this uploading an image to S3 using the AWS SDK with React Native. It turned out to be caused by the ContentEncoding parameter.

Removing that parameter "fixed" the issue.

Answer 22

generating a fresh access key worked for me.

Answer 23

After debugging and spending a lot of time, in my case, the issue was with the access_key_id and secret_access_key, just double check your credentials or generate new one if possible and make sure you are passing the credentials in params.

Answer 24

Like others, I also had the similar issue but in java sdk v1. For me, below 2 fixes helped me.

1. My key to object looked like this /path/to/obj/. In this, i first removed the / in the beginning.
2. Further, point 1 alone did not solve the issue. I upgraded my sdk version from 1.9.x to 1.11.x

After applying both the fixes, it worked. So my suggestion is not slog it out. If nothing else is working, just try upgrading the lib.

Answer 25

I have spent 8 hours trying to fix this issue. For me, everything mentioned in all answers were fine. The keys were correct and tested through CLI. I was using SDK V3 which is the latest and doesn't need the signature version. It finally turned out to be passing a wrong object in the Body! (not a text nor a array buffer). Yes, it's one of the most stupid error messages that I have ever seen in my 16 years career. AWS sometimes drives me crazy.

Answer 26

I had a similar error, but for me it seemed to be caused by re-using an IAM user to work with S3 in two different Elastic Beanstalk environments. I treated the symptom by creating an identically permissioned IAM user for each environment and that made the error go away.

Answer 27

I don't know if anyone came to this issue while trying to test the outputted URL in browser but if you are using Postman and try to copy the generated url of AWS from the RAW tab, because of escaping backslashes you are going to get the above error.

Use the Pretty tab to copy and paste the url to see if it actually works.

I run into this issue recently and this solution solved my issue. It's for testing purposes to see if you actually retrieve the data through the url.

This answer is a reference to those who try to generate a download, temporary link from AWS or generally generate a URL from AWS to use.

Answer 28

If you are a Android developer and is using the signature function from AWS sample code, you are most likely wondering why the ListS3Object works but not the GetS3Object. This is because when you set the setDoOutput(true) and using GET HTTP method, Android's HttpURLConnection switches the request to a POST. Thus, invalidating your signature. Check my original post of the issue.

Answer 29

I was getting this error in our shared environment where the SDK was being used, but using the same key/secret and the aws cli, it worked fine. The build system script had a space after the key and secret and session keys, which the code read in as well. So the fix for me was to adjust the build script to remove the spaces after the variables being used.

Just adding this for anyone who might miss that frustrating invisible space at the end of their creds.

Answer 30

I encountered the same error message when using the Amazon SES SDK to instantiate an AmazonSimpleEmailServiceClient object and subsequently GetSendStatistics.

I was using my administrative level IAM users credentials to connect ... which failed with the familiar error: "The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details."

I resolved this by creating an Access Key under the My Security Credentials for my IAM user. When I used the credentials from the new access key, my connection to Amazon SES via the SDK worked.