Module: Mixlib::Authentication::SignedHeaderAuth

Included in:
SignatureVerification, SigningObject
Defined in:
lib/mixlib/authentication/signedheaderauth.rb

Constant Summary collapse

NULL_ARG = 
Object.new
ALGORITHM_FOR_VERSION = 
{
  "1.0" => "sha1",
  "1.1" => "sha1",
  "1.3" => "sha256",
}.freeze()
SUPPORTED_ALGORITHMS =

Use of SUPPORTED_ALGORITHMS and SUPPORTED_VERSIONS is deprecated. Use ALGORITHM_FOR_VERSION instead

["sha1"].freeze
SUPPORTED_VERSIONS = 
["1.0", "1.1"].freeze
DEFAULT_SIGN_ALGORITHM = 
"sha1".freeze
DEFAULT_PROTO_VERSION = 
"1.0".freeze

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.signing_object(args = {}) ⇒ Object

signing_object

This is the intended interface for signing requests with the Opscode/Chef signed header protocol. This wraps the constructor for a Struct that contains the relevant information about your request.

Signature Parameters:

These parameters are used to generate the canonical representation of the request, which is then hashed and encrypted to generate the request’s signature. These options are all required, with the exception of ‘:body` and `:file`, which are alternate ways to specify the request body (you must specify one of these).

  • ‘:http_method`: HTTP method as a lowercase symbol, e.g., `:get | :put | :post | :delete`

  • ‘:path`: The path part of the URI, e.g., `URI.parse(uri).path`

  • ‘:body`: An object representing the body of the request. Use an empty String for bodiless requests.

  • ‘:timestamp`: A String representing the time in any format understood by `Time.parse`. The server may reject the request if the timestamp is not close to the server’s current time.

  • ‘:user_id`: The user or client name. This is used by the server to lookup the public key necessary to verify the signature.

  • ‘:file`: An IO object (must respond to `:read`) to be used as the request body.

Protocol Versioning Parameters:

  • ‘:proto_version`: The version of the signing protocol to use. Currently defaults to 1.0, but version 1.1 is also available.

Other Parameters:

These parameters are accepted but not used in the computation of the signature.

  • ‘:host`: The host part of the URI



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 75

def self.signing_object(args = {})
  SigningObject.new(args[:http_method],
                    args[:path],
                    args[:body],
                    args[:host],
                    args[:timestamp],
                    args[:user_id],
                    args[:file],
                    args[:proto_version],
                    args[:headers]
                   )
end

Instance Method Details

#algorithm ⇒ Object 



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 88

def algorithm
  ALGORITHM_FOR_VERSION[proto_version] || DEFAULT_SIGN_ALGORITHM
end

#canonicalize_request(sign_algorithm = algorithm, sign_version = proto_version) ⇒ Object

Takes HTTP request method & headers and creates a canonical form to create the signature

Parameters



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 192

def canonicalize_request(sign_algorithm = algorithm, sign_version = proto_version)
  digest = validate_sign_version_digest!(sign_algorithm, sign_version)
  canonical_x_ops_user_id = canonicalize_user_id(user_id, sign_version, digest)
  case sign_version
  when "1.3"
    [
      "Method:#{http_method.to_s.upcase}",
      "Path:#{canonical_path}",
      "X-Ops-Content-Hash:#{hashed_body(digest)}",
      "X-Ops-Sign:version=#{sign_version}",
      "X-Ops-Timestamp:#{canonical_time}",
      "X-Ops-UserId:#{canonical_x_ops_user_id}",
      "X-Ops-Server-API-Version:#{server_api_version}",
    ].join("\n")
  else
    [
      "Method:#{http_method.to_s.upcase}",
      "Hashed Path:#{digester.hash_string(canonical_path, digest)}",
      "X-Ops-Content-Hash:#{hashed_body(digest)}",
      "X-Ops-Timestamp:#{canonical_time}",
      "X-Ops-UserId:#{canonical_x_ops_user_id}",
    ].join("\n")
  end
end

#do_sign(private_key, digest, sign_algorithm, sign_version) ⇒ Object

private



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 247

def do_sign(private_key, digest, sign_algorithm, sign_version)
  string_to_sign = canonicalize_request(sign_algorithm, sign_version)
  Mixlib::Authentication::Log.debug "String to sign: '#{string_to_sign}'"
  case sign_version
  when "1.3"
    private_key.sign(digest.new, string_to_sign)
  else
    private_key.private_encrypt(string_to_sign)
  end
end

#hashed_body(digest = OpenSSL::Digest::SHA1) ⇒ Object 



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 163

def hashed_body(digest = OpenSSL::Digest::SHA1)
  # This is weird. sign() is called with the digest type and signing
  # version. These are also expected to be properties of the object.
  # Hence, we're going to assume the one that is passed to sign is
  # the correct one and needs to passed through all the functions
  # that do any sort of digest.
  if @hashed_body_digest != nil && @hashed_body_digest != digest
    raise "hashed_body must always be called with the same digest"
  else
    @hashed_body_digest = digest
  end
  # Hash the file object if it was passed in, otherwise hash based on
  # the body.
  # TODO: tim 2009-12-28: It'd be nice to just remove this special case,
  # always sign the entire request body, using the expanded multipart
  # body in the case of a file being include.
  @hashed_body ||= if self.file && self.file.respond_to?(:read)
                     digester.hash_file(self.file, digest)
                   else
                     digester.hash_string(self.body, digest)
                   end
end

#proto_version ⇒ Object 



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 92

def proto_version
  DEFAULT_PROTO_VERSION
end

#sign(private_key, sign_algorithm = algorithm, sign_version = proto_version) ⇒ Object

Build the canonicalized request based on the method, other headers, etc. compute the signature from the request, using the looked-up user secret

Parameters

private_key<OpenSSL::PKey::RSA>

user’s RSA private key.



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 100

def sign(private_key, sign_algorithm = algorithm, sign_version = proto_version)
  digest = validate_sign_version_digest!(sign_algorithm, sign_version)
  # Our multiline hash for authorization will be encoded in multiple header
  # lines - X-Ops-Authorization-1, ... (starts at 1, not 0!)
  header_hash = {
    "X-Ops-Sign" => "algorithm=#{sign_algorithm};version=#{sign_version};",
    "X-Ops-Userid" => user_id,
    "X-Ops-Timestamp" => canonical_time,
    "X-Ops-Content-Hash" => hashed_body(digest),
  }

  signature = Base64.encode64(do_sign(private_key, digest, sign_algorithm, sign_version)).chomp
  signature_lines = signature.split(/\n/)
  signature_lines.each_index do |idx|
    key = "X-Ops-Authorization-#{idx + 1}"
    header_hash[key] = signature_lines[idx]
  end

  Mixlib::Authentication::Log.debug "Header hash: #{header_hash.inspect}"

  header_hash
end

#validate_sign_version_digest!(sign_algorithm, sign_version) ⇒ Object 



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# File 'lib/mixlib/authentication/signedheaderauth.rb', line 123

def validate_sign_version_digest!(sign_algorithm, sign_version)
  if ALGORITHM_FOR_VERSION[sign_version].nil?
    raise AuthenticationError,
      "Unsupported version '#{sign_version}'"
  end

  if ALGORITHM_FOR_VERSION[sign_version] != sign_algorithm
    raise AuthenticationError,
      "Unsupported algorithm #{sign_algorithm} for version '#{sign_version}'"
  end

  case sign_algorithm
  when "sha1"
    OpenSSL::Digest::SHA1
  when "sha256"
    OpenSSL::Digest::SHA256
  else
    # This case should never happen
    raise "Unknown algorithm #{sign_algorithm}"
  end
end