S3 File upload

s3.md

Generate encoded policy and form signature

Run irb and execute the following commands with your bucket name and AWS secret key. You will need to save the encoded_policy string and the signature.

require 'base64'
require 'openssl'
require 'digest/sha1'

aws_secret_key = 'SKYBXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXJoYL'
policy_json = '{"expiration":"2020-01-01T00:00:00Z","conditions":[{"bucket":"omgttt-sscotth-io-images"},{"acl": "public-read"},["starts-with","$Content-Type",""],["starts-with","$key",""]]}'

encoded_policy = Base64.strict_encode64(policy_json).gsub('\n','')
signature = Base64.strict_encode64(OpenSSL::HMAC.digest(OpenSSL::Digest::Digest.new('sha1'),aws_secret_key,encoded_policy)).gsub('\n','')

Results in:

encoded_policy = eyJWZXJXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXdfV19
signature = alvIBnXXXXXXXXXXXXXXXXXXcsA=

Add CORS configuration to bucket permissions:

<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
    <CORSRule>
        <AllowedOrigin>*</AllowedOrigin>
        <AllowedMethod>GET</AllowedMethod>
        <AllowedMethod>POST</AllowedMethod>
        <AllowedMethod>PUT</AllowedMethod>
        <MaxAgeSeconds>3000</MaxAgeSeconds>
        <AllowedHeader>*</AllowedHeader>
    </CORSRule>
</CORSConfiguration>

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "Stmt1418963950000",
      "Effect": "Allow",
      "Action": [
        "s3:PutObject",
        "s3:PutObjectAcl"
      ],
      "Resource": [
        "arn:aws:s3:::omgttt-sscotth-io-images/*"
      ]
    }
  ]
}