module Mixlib::Authentication::SignedHeaderAuth
Constants
- ALGORITHM_FOR_VERSION
- DEFAULT_PROTO_VERSION
- DEFAULT_SIGN_ALGORITHM
- NULL_ARG
- SUPPORTED_ALGORITHMS
Use of
SUPPORTED_ALGORITHMS
andSUPPORTED_VERSIONS
is deprecated. UseALGORITHM_FOR_VERSION
instead- SUPPORTED_VERSIONS
Public Class Methods
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`
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`:body`: An object representing the body of the request. Use an empty String for bodiless requests.
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`: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.
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`: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
# 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
Public Instance Methods
# File lib/mixlib/authentication/signedheaderauth.rb, line 87 def algorithm ALGORITHM_FOR_VERSION[proto_version] || DEFAULT_SIGN_ALGORITHM end
Takes HTTP request method & headers and creates a canonical form to create the signature
Parameters¶ ↑
# File lib/mixlib/authentication/signedheaderauth.rb, line 212 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
Low-level RSA signature implementation used in {#sign}.
@api private @param rsa_key [OpenSSL::PKey::RSA] User's RSA key. If `use_ssh_agent` is
true, this must have the public key portion populated. If `use_ssh_agent` is false, this must have the private key portion populated.
@param digest [Class] Sublcass of OpenSSL::Digest to use while signing. @param sign_algorithm [String] Hash algorithm to use while signing. @param sign_version [String] Version number of the signing protocol to use. @param use_ssh_agent [Boolean] If true, use ssh-agent for request signing. @return [String]
# File lib/mixlib/authentication/signedheaderauth.rb, line 277 def do_sign(rsa_key, digest, sign_algorithm, sign_version, use_ssh_agent) string_to_sign = canonicalize_request(sign_algorithm, sign_version) Mixlib::Authentication.logger.trace "String to sign: '#{string_to_sign}'" case sign_version when "1.3" if use_ssh_agent do_sign_ssh_agent(rsa_key, string_to_sign) else raise AuthenticationError, "RSA private key is required to sign requests, but a public key was provided" unless rsa_key.private? rsa_key.sign(digest.new, string_to_sign) end else raise AuthenticationError, "Agent signing mode requires signing protocol version 1.3 or newer" if use_ssh_agent raise AuthenticationError, "RSA private key is required to sign requests, but a public key was provided" unless rsa_key.private? rsa_key.private_encrypt(string_to_sign) end end
Low-level signing logic for using ssh-agent. This requires the user has already set up ssh-agent and used ssh-add to load in a (possibly encrypted) RSA private key. ssh-agent supports keys other than RSA, however they are not supported as Chef's protocol explicitly requires RSA keys/sigs.
@api private @param rsa_key [OpenSSL::PKey::RSA] User's RSA public key. @param string_to_sign [String] String data to sign with the requested key. @return [String]
# File lib/mixlib/authentication/signedheaderauth.rb, line 306 def do_sign_ssh_agent(rsa_key, string_to_sign) # First try loading net-ssh as it is an optional dependency. begin require "net/ssh" unless defined?(Net::SSH) rescue LoadError => e # ???: Since agent mode is explicitly enabled, should we even catch # this in the first place? Might be cleaner to let the LoadError bubble. raise AuthenticationError, "net-ssh gem is not available, unable to use ssh-agent signing: #{e.message}" end # Try to connect to ssh-agent. begin agent = Net::SSH::Authentication::Agent.connect rescue Net::SSH::Authentication::AgentNotAvailable => e raise AuthenticationError, "Could not connect to ssh-agent. Make sure the SSH_AUTH_SOCK environment variable is set and ssh-agent is running: #{e.message}" end begin ssh2_signature = agent.sign(rsa_key.public_key, string_to_sign, Net::SSH::Authentication::Agent::SSH_AGENT_RSA_SHA2_256) rescue Net::SSH::Authentication::AgentError => e raise AuthenticationError, "Unable to sign request with ssh-agent. Make sure your key is loaded with ssh-add: #{e.class.name} #{e.message})" end # extract signature from SSH Agent response => skip first 20 bytes for RSA keys # "\x00\x00\x00\frsa-sha2-256\x00\x00\x01\x00" # (see http://api.libssh.org/rfc/PROTOCOL.agent for details) ssh2_signature[20..-1] end
# File lib/mixlib/authentication/signedheaderauth.rb, line 181 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. @hashed_body_digest = nil unless defined?(@hashed_body_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 file&.respond_to?(:read) digester.hash_file(file, digest) else digester.hash_string(body, digest) end end
# File lib/mixlib/authentication/signedheaderauth.rb, line 91 def proto_version DEFAULT_PROTO_VERSION end
Build the canonicalized request based on the method, other headers, etc. compute the signature from the request, using the looked-up user secret
@param rsa_key [OpenSSL::PKey::RSA] User's RSA key. If `use_ssh_agent` is
true, this must have the public key portion populated. If `use_ssh_agent` is false, this must have the private key portion populated.
@param use_ssh_agent [Boolean] If true, use ssh-agent for request signing.
# File lib/mixlib/authentication/signedheaderauth.rb, line 102 def sign(rsa_key, sign_algorithm = algorithm, sign_version = proto_version, **opts) # Backwards compat stuff. if sign_algorithm.is_a?(Hash) # Was called like sign(key, sign_algorithm: 'foo', other: 'bar') opts.update(sign_algorithm) opts[:sign_algorithm] ||= algorithm opts[:sign_version] ||= sign_version else # Was called like sign(key, 'foo', '1.3', other: 'bar') Mixlib::Authentication.logger.warn("Using deprecated positional arguments for sign(), please update to keyword arguments (from #{caller[1][/^(.*:\d+):in /, 1]})") unless sign_algorithm == algorithm opts[:sign_algorithm] ||= sign_algorithm opts[:sign_version] ||= sign_version end sign_algorithm = opts[:sign_algorithm] sign_version = opts[:sign_version] use_ssh_agent = opts[:use_ssh_agent] 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(rsa_key, digest, sign_algorithm, sign_version, use_ssh_agent)).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.logger.trace "Header hash: #{header_hash.inspect}" header_hash end
# File lib/mixlib/authentication/signedheaderauth.rb, line 141 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
Private Instance Methods
# File lib/mixlib/authentication/signedheaderauth.rb, line 237 def canonicalize_user_id(user_id, proto_version, digest = OpenSSL::Digest::SHA1) case proto_version when "1.1" # and 1.2 if that ever gets implemented digester.hash_string(user_id, digest) else # versions 1.0 and 1.3 user_id end end
# File lib/mixlib/authentication/signedheaderauth.rb, line 262 def digester Mixlib::Authentication::Digester end
Parses signature version information, algorithm used, etc.
Parameters¶ ↑
# File lib/mixlib/authentication/signedheaderauth.rb, line 252 def parse_signing_description parts = signing_description.strip.split(";").inject({}) do |memo, part| field_name, field_value = part.split("=") memo[field_name.to_sym] = field_value.strip memo end Mixlib::Authentication.logger.trace "Parsed signing description: #{parts.inspect}" parts end