Class: CarrierWaveDirect::Policies::Aws4HmacSha256

Inherits:
Base
  • Object
show all
Defined in:
lib/carrierwave_direct/policies/aws4_hmac_sha256.rb

Instance Attribute Summary

Attributes inherited from Base

#uploader

Instance Method Summary collapse

Methods inherited from Base

#initialize, #policy

Constructor Details

This class inherits a constructor from CarrierWaveDirect::Policies::Base

Instance Method Details

#algorithm ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 60

def algorithm
  'AWS4-HMAC-SHA256'
end

#clear! ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 64

def clear!
  super
  @timestamp = nil
end

#credential ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 56

def credential
  "#{uploader.aws_access_key_id}/#{timestamp.strftime("%Y%m%d")}/#{uploader.region}/s3/aws4_request"
end

#date ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 20

def date
  timestamp.strftime("%Y%m%dT%H%M%SZ")
end

#direct_fog_hash(policy_options = {}) ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 7

def direct_fog_hash(policy_options = {})
  {
    key:                uploader.key,
    acl:                uploader.acl,
    policy:             policy(policy_options),
    'X-Amz-Signature':  signature,
    'X-Amz-Credential': credential,
    'X-Amz-Algorithm':  algorithm,
    'X-Amz-Date':       date,
    uri:                uploader.direct_fog_url,
  }
end

#generate(options) {|conditions| ... } ⇒ Object

Yields:

  • (conditions) 


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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 24

def generate(options, &block)

  return @policy if @policy.present?
  conditions = []

  conditions << ["starts-with", "$utf8", ""] if options[:enforce_utf8]
  conditions << ["starts-with", "$key", uploader.key.sub(/#{Regexp.escape(CarrierWaveDirect::Uploader::FILENAME_WILDCARD)}\z/, "")]
  conditions << {'X-Amz-Algorithm' => algorithm}
  conditions << {'X-Amz-Credential' => credential}
  conditions << {'X-Amz-Date' => date }
  conditions << ["starts-with", "$Content-Type", ""] if uploader.will_include_content_type
  conditions << {"bucket" => uploader.fog_directory}
  conditions << {"acl" => uploader.acl}

  if uploader.use_action_status
    conditions << {"success_action_status" => uploader.success_action_status}
  else
    conditions << {"success_action_redirect" => uploader.success_action_redirect}
  end

  conditions << ["content-length-range", options[:min_file_size], options[:max_file_size]]

  yield conditions if block_given?

  @policy = Base64.encode64(
    {
      'expiration' => (Time.now + options[:expiration]).utc.iso8601,
      'conditions' => conditions
    }.to_json
  ).gsub("\n","")
end

#signature ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 69

def signature
  OpenSSL::HMAC.hexdigest(
    'sha256',
    signing_key,
    policy
  )
end

#signing_key(options = {}) ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 77

def signing_key(options = {})
  #AWS Signature Version 4
  kDate    = OpenSSL::HMAC.digest('sha256', "AWS4" + uploader.aws_secret_access_key, timestamp.strftime("%Y%m%d"))
  kRegion  = OpenSSL::HMAC.digest('sha256', kDate, uploader.region)
  kService = OpenSSL::HMAC.digest('sha256', kRegion, 's3')
  kSigning = OpenSSL::HMAC.digest('sha256', kService, "aws4_request")

  kSigning
end

#timestamp ⇒ Object 



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# File 'lib/carrierwave_direct/policies/aws4_hmac_sha256.rb', line 87

def timestamp
  @timestamp ||= Time.now.utc
end