Minimal dependency upload to s3 using curl, openssl, base64, and file.

upload-to-s3.sh

#!/bin/bash

target_bucket=some-bucket-name-here

upload-file() {
        local file_to_upload="$1" bucket="$2"

        # metadata
        contentType=$(file --brief --mime-type "$file_to_upload")
        dateValue=$(date -R)
        filepath="/${bucket}/${file_to_upload}"
        signature_string="PUT\n\n${contentType}\n${dateValue}\n${filepath}"

        #s3 keys
        s3_access_key=$(cat ~/.s3-access-key)
        s3_secret_key=$(cat ~/.s3-secret-key)

        #prepare signature hash to be sent in Authorization header
        signature_hash=$(echo -en "${signature_string}" | openssl sha1 -hmac "${s3_secret_key}" -binary | base64)

        # actual curl command to do PUT operation on s3
        curl -X PUT -T "${file_to_upload}" \
          -H "Host: ${bucket}.s3.amazonaws.com" \
          -H "Date: ${dateValue}" \
          -H "Content-Type: ${contentType}" \
          -H "Authorization: AWS ${s3_access_key}:${signature_hash}" \
          https://${bucket}.s3.amazonaws.com/${file_to_upload}
}

upload-file "$1" ${target_bucket}