Boto3: SignatureDoesNotMatch error when calling the PutObject operation for S3 upload

[rehmanzile]

I am using python 3.5 with boto3==1.2.4 and botocore==1.3.29 on a Mac OSX Version 10.11.13.

I am experiencing the following issue:

An error occurred (SignatureDoesNotMatch) when calling the PutObject operation: The request signature we calculated does not match the signature you provided. Check your key and signing method.>

Here is the code:

self.session = Session(aws_access_key_id=self.api_key,
                                     aws_secret_access_key=self.api_secret_key,
                                     region_name=self.region_name)
self.s3_o = self.session.resource('s3')

bucket_o = self.s3_o.Bucket(container_name)
sample = "this should work"
bucket_o.put_object(Key='test1234', Body=sample)

What am I doing wrong? Thanks in advance for your help.

[jamesls]

It looks like you're explicitly providing an access_key and secret_key. Can you confirm:

1) Do those credentials works for other S3 methods?
2) Do those credentials work for other non-S3 methods?

[rehmanzile]

It is successful if I don't provide the access_key and secret_key explicitly to the Session class. I have setup the .aws directory in my home directory:

$ tree .aws
.aws
├── config
└── credentials

0 directories, 2 files

I would like to parametrize it via environment variables and hence the keys are provided.

[jamesls]

That would suggest that the access_key and secret_key you are providing to the session are not correct or are being modified in some way. I would double check the mechanism in which you're populating self.api_key and self.api_secret_key.

I've tried this out locally, and when I provide hard coded credentials to the Session object, I can confirm that they are being used as expected.

[rehmanzile]

Apologies. My mistake! One character was missing for the secret key. It's working now. Thanks!

[rainbowhat]

Apologies. My mistake! One character was missing for the secret key. It's working now. Thanks!

OH MY GOD, I CAN'T BELIEVE I MADE THIS MISTAKE TOO! Now I can finally drink some water.

[n1ngu]

2020 and I still reproduced this issue.

It's totally my bad but does anyone agree that the error message is misleading? What about an exception related to authentication and not object signature?

[ryandagg]

I also left the last character off...