module AWS::Core::Signature::Version4

Public Class Methods

included(base) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 23
def self.included base
  base.send(:include, Signer)
end

Public Instance Methods

add_authorization!(credentials) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 27
def add_authorization! credentials
  datetime = Time.now.utc.strftime("%Y%m%dT%H%M%SZ")
  headers['content-type'] ||= 'application/x-www-form-urlencoded'
  headers['host'] = host
  headers['x-amz-date'] = datetime
  headers['x-amz-security-token'] = credentials.session_token if
    credentials.session_token
  headers['x-amz-content-sha256'] ||= hexdigest(body || '')
  headers['authorization'] = authorization(credentials, datetime)
end

Protected Instance Methods

authorization(credentials, datetime) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 40
def authorization credentials, datetime
  parts = []
  parts << "AWS4-HMAC-SHA256 Credential=#{credentials.access_key_id}/#{credential_string(datetime)}"
  parts << "SignedHeaders=#{signed_headers}"
  parts << "Signature=#{signature(credentials, datetime)}"
  parts.join(', ')
end
canonical_header_values(values) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 106
def canonical_header_values values
  values = [values] unless values.is_a?(Array)
  values.map(&:to_s).join(',').gsub(%r\s+/, ' ').strip
end
canonical_headers() click to toggle source
# File lib/aws/core/signature/version_4.rb, line 97
def canonical_headers
  headers = []
  self.headers.each_pair do |k,v|
    headers << [k,v] unless k == 'authorization'
  end
  headers = headers.sort_by(&:first)
  headers.map{|k,v| "#{k}:#{canonical_header_values(v)}" }.join("\n")
end
canonical_request() click to toggle source
# File lib/aws/core/signature/version_4.rb, line 75
def canonical_request
  parts = []
  parts << http_method
  parts << path
  parts << querystring
  parts << canonical_headers + "\n"
  parts << signed_headers
  parts << headers['x-amz-content-sha256']
  parts.join("\n")
end
credential_string(datetime) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 66
def credential_string datetime
  parts = []
  parts << datetime[0,8]
  parts << region
  parts << service
  parts << 'aws4_request'
  parts.join("/")
end
hexdigest(value) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 111
def hexdigest value
  digest = Digest::SHA256.new
  if value.respond_to?(:read)
    chunk = nil
    chunk_size = 1024 * 1024 # 1 megabyte
    digest.update(chunk) while chunk = value.read(chunk_size)
    value.rewind
  else
    digest.update(value)
  end
  digest.hexdigest
end
hexhmac(key, value) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 128
def hexhmac key, value
  OpenSSL::HMAC.hexdigest(OpenSSL::Digest::Digest.new('sha256'), key, value)
end
hmac(key, value) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 124
def hmac key, value
  OpenSSL::HMAC.digest(OpenSSL::Digest::Digest.new('sha256'), key, value)
end
service() click to toggle source
# File lib/aws/core/signature/version_4.rb, line 86
def service
  # this method is implemented in the request class for each service
  raise NotImplementedError
end
signature(credentials, datetime) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 48
def signature credentials, datetime
  k_secret = credentials.secret_access_key
  k_date = hmac("AWS4" + k_secret, datetime[0,8])
  k_region = hmac(k_date, region)
  k_service = hmac(k_region, service)
  k_credentials = hmac(k_service, 'aws4_request')
  hexhmac(k_credentials, string_to_sign(datetime))
end
signed_headers() click to toggle source
# File lib/aws/core/signature/version_4.rb, line 91
def signed_headers
  to_sign = headers.keys.map{|k| k.to_s.downcase }
  to_sign.delete('authorization')
  to_sign.sort.join(";")
end
string_to_sign(datetime) click to toggle source
# File lib/aws/core/signature/version_4.rb, line 57
def string_to_sign datetime
  parts = []
  parts << 'AWS4-HMAC-SHA256'
  parts << datetime
  parts << credential_string(datetime)
  parts << hexdigest(canonical_request)
  parts.join("\n")
end