[rubygems/rubygems] Add CHECKSUMS for each gem in lockfile

We lock the checksum for each resolved spec under a new CHECKSUMS
section in the lockfile.

If the locked spec does not resolve for the local platform, we preserve
the locked checksum, similar to how we preserve specs.

Checksum locking only makes sense on install. The compact index
information is only available then.

https://github.com/rubygems/rubygems/commit/bde37ca6bf

6 files changed, 117 insertions, 1 deletions

diff --git a/lib/bundler/checksum.rb b/lib/bundler/checksum.rb
new file mode 100644
index 0000000000..2e0a80cac2
--- /dev/null
+++ b/lib/bundler/checksum.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Bundler
+  class Checksum
+    attr_reader :name, :version, :platform
+    attr_accessor :checksum
+
+    SHA256 = /\Asha256-([a-z0-9]{64}|[A-Za-z0-9+\/=]{44})\z/.freeze
+
+    def initialize(name, version, platform, checksum = nil)
+      @name     = name
+      @version  = version
+      @platform = platform || Gem::Platform::RUBY
+      @checksum = checksum
+
+      if @checksum && @checksum !~ SHA256
+        raise ArgumentError, "invalid checksum (#{@checksum})"
+      end
+    end
+
+    def match_spec?(spec)
+      name == spec.name &&
+        version == spec.version &&
+        platform.to_s == spec.platform.to_s
+    end
+
+    def to_lock
+      out = String.new
+
+      if platform == Gem::Platform::RUBY
+        out << "  #{name} (#{version})"
+      else
+        out << "  #{name} (#{version}-#{platform})"
+      end
+
+      out << " #{checksum}" if checksum
+      out << "\n"
+
+      out
+    end
+  end
+end
diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index d9c2670d6d..6b066051d8 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -15,6 +15,7 @@ module Bundler
       :dependencies,
       :locked_deps,
       :locked_gems,
+      :locked_checksums,
       :platforms,
       :ruby_version,
       :lockfile,
@@ -92,6 +93,7 @@ module Bundler
         @locked_bundler_version = @locked_gems.bundler_version
         @locked_ruby_version = @locked_gems.ruby_version
         @originally_locked_specs = SpecSet.new(@locked_gems.specs)
+        @locked_checksums = @locked_gems.checksums
 
         if unlock != true
           @locked_deps    = @locked_gems.dependencies
@@ -112,6 +114,7 @@ module Bundler
         @originally_locked_specs = @locked_specs
         @locked_sources = []
         @locked_platforms = []
+        @locked_checksums = []
       end
 
       locked_gem_sources = @locked_sources.select {|s| s.is_a?(Source::Rubygems) }
diff --git a/lib/bundler/endpoint_specification.rb b/lib/bundler/endpoint_specification.rb
index 863544b1f9..4c41285043 100644
--- a/lib/bundler/endpoint_specification.rb
+++ b/lib/bundler/endpoint_specification.rb
@@ -104,6 +104,11 @@ module Bundler
       @remote_specification = spec
     end
 
+    def to_checksum
+      digest = "sha256-#{checksum}" if checksum
+      Bundler::Checksum.new(name, version, platform, digest)
+    end
+
     private
 
     def _remote_specification
diff --git a/lib/bundler/lazy_specification.rb b/lib/bundler/lazy_specification.rb
index c9b161dc0e..b4aadb0b5c 100644
--- a/lib/bundler/lazy_specification.rb
+++ b/lib/bundler/lazy_specification.rb
@@ -76,6 +76,18 @@ module Bundler
       out
     end
 
+    #def materialize_for_checksum
+      #if @specification
+        #yield
+      #else
+        #materialize_for_installation
+
+        #yield
+
+        #@specification = nil
+      #end
+    #end
+
     def materialize_for_installation
       source.local!
 
@@ -134,6 +146,20 @@ module Bundler
       " #{source.revision[0..6]}"
     end
 
+    def to_checksum
+      return nil unless @specification
+
+      #
+      # See comment about #ruby_platform_materializes_to_ruby_platform?
+      # If the old lockfile format is present where there is no specific
+      # platform, then we should skip locking checksums as it is not
+      # deterministic which platform variant is locked.
+      #
+      return nil unless ruby_platform_materializes_to_ruby_platform?
+
+      @specification.to_checksum
+    end
+
     private
 
     def use_exact_resolved_specifications?
diff --git a/lib/bundler/lockfile_generator.rb b/lib/bundler/lockfile_generator.rb
index f7ba51b3e6..11e8e3f103 100644
--- a/lib/bundler/lockfile_generator.rb
+++ b/lib/bundler/lockfile_generator.rb
@@ -19,6 +19,7 @@ module Bundler
       add_sources
       add_platforms
       add_dependencies
+      add_checksums
       add_locked_ruby_version
       add_bundled_with
 
@@ -65,6 +66,24 @@ module Bundler
       end
     end
 
+    def add_checksums
+      out << "\nCHECKSUMS\n"
+
+      definition.resolve.sort_by(&:full_name).each do |spec|
+        checksum = spec.to_checksum if spec.respond_to?(:to_checksum)
+
+        #if spec.is_a?(LazySpecification)
+          #spec.materialize_for_checksum do
+            #checksum ||= spec.to_checksum if spec.respond_to?(:to_checksum)
+          #end
+        #end
+
+        checksum ||= definition.locked_checksums.find {|c| c.match_spec?(spec) }
+
+        out << checksum.to_lock if checksum
+      end
+    end
+
     def add_locked_ruby_version
       return unless locked_ruby_version = definition.locked_ruby_version
       add_section("RUBY VERSION", locked_ruby_version.to_s)
diff --git a/lib/bundler/lockfile_parser.rb b/lib/bundler/lockfile_parser.rb
index 31f57f14e8..fc331a928c 100644
--- a/lib/bundler/lockfile_parser.rb
+++ b/lib/bundler/lockfile_parser.rb
@@ -2,10 +2,11 @@
 
 module Bundler
   class LockfileParser
-    attr_reader :sources, :dependencies, :specs, :platforms, :bundler_version, :ruby_version
+    attr_reader :sources, :dependencies, :specs, :platforms, :bundler_version, :ruby_version, :checksums
 
     BUNDLED      = "BUNDLED WITH"
     DEPENDENCIES = "DEPENDENCIES"
+    CHECKSUMS    = "CHECKSUMS"
     PLATFORMS    = "PLATFORMS"
     RUBY         = "RUBY VERSION"
     GIT          = "GIT"
@@ -21,6 +22,7 @@ module Bundler
       Gem::Version.create("1.10") => [BUNDLED].freeze,
       Gem::Version.create("1.12") => [RUBY].freeze,
       Gem::Version.create("1.13") => [PLUGIN].freeze,
+      Gem::Version.create("2.4.0") => [CHECKSUMS].freeze,
     }.freeze
 
     KNOWN_SECTIONS = SECTIONS_BY_VERSION_INTRODUCED.values.flatten!.freeze
@@ -64,6 +66,7 @@ module Bundler
       @sources      = []
       @dependencies = {}
       @parse_method = nil
+      @checksums    = []
       @specs        = {}
 
       if lockfile.match?(/<<<<<<<|=======|>>>>>>>|\|\|\|\|\|\|\|/)
@@ -77,6 +80,8 @@ module Bundler
           parse_source(line)
         elsif line == DEPENDENCIES
           @parse_method = :parse_dependency
+        elsif line == CHECKSUMS
+          @parse_method = :parse_checksum
         elsif line == PLATFORMS
           @parse_method = :parse_platform
         elsif line == RUBY
@@ -144,6 +149,7 @@ module Bundler
       (?:#{space}\(([^-]*)                               # Space, followed by version
       (?:-(.*))?\))?                                     # Optional platform
       (!)?                                               # Optional pinned marker
+      (?:#{space}(.*))?                                  # Optional checksum
       $                                                  # Line end
     /xo.freeze
 
@@ -176,6 +182,21 @@ module Bundler
       @dependencies[dep.name] = dep
     end
 
+    def parse_checksum(line)
+      if line =~ NAME_VERSION
+        spaces = $1
+        return unless spaces.size == 2
+        name = $2
+        version = $3
+        platform = $4
+        checksum = $6
+
+        version = Gem::Version.new(version)
+        platform = platform ? Gem::Platform.new(platform) : Gem::Platform::RUBY
+        @checksums << Bundler::Checksum.new(name, version, platform, checksum)
+      end
+    end
+
     def parse_spec(line)
       return unless line =~ NAME_VERSION
       spaces = $1