S3 signed URLs via the CLI for PUT using CURL?

Per the CLI's documentation, the generated presigned URLs are only usable for GETs.

I have this recipe saved for when I need to POST; if you need to PUT, you should be able to modify it to use generate_presigned_url() instead of generate_presigned_post(). Note that this uses the boto3 library with Python, so you will need to arrange to have that available for your Python install to access (e.g. pip install boto3). The output includes values formatted for both curl and httpie, which I hope will be useful.

Python script to get presigned POST URL:

import boto3
client = boto3.client("s3")

# get presigned info
# note other params can be passed here, including expiration
# see https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#S3.Client.generate_presigned_post
info = client.generate_presigned_post(Bucket="some-bucket", Key="filename.txt")

# print the "fields" out in the right format to feed to httpie
print(" ".join(f"{k}='{v}'" for (k, v) in info["fields"].items()))

# for curl, use this
print(" ".join(f"-F {k}='{v}'" for (k, v) in info["fields"].items()))

# confirm the URL
print(info["url"])

Below are examples of using the returned values. You will may need to remove the comment lines for your shell to be happy.

Use with httpie:

http --form -v \
  # this the the URL from Python output
  https://some-bucket.s3.amazonaws.com/ \
  # these are the copy/pasted fields from Python output
  key='filename.txt' AWSAccessKeyId='AKIA...EWS3' policy='eyJl...dfQ==' signature='RcU...XLw=' \
  # this is the file to upload
  file@local-filename.txt

Use with curl:

curl -X POST \
  # the copy/pasted fields
  -F key='filename.txt' -F AWSAccessKeyId='AKIA...EWS3' -F policy='eyJle...dfQ==' -F signature='RcU9...XLw=' \
  # the file to upload
  -F file=@local-filename.txt \
  # the URL
  https://some-bucket.s3.amazonaws.com/