(MODULE-7443) Safely deserialize stringified array

This ports PUP-8974, and the related follow-up maintenance commits from
the Puppet repo.

The augeas provider used Kernel#eval to convert stringified arrays to Ruby
arrays. For example, it extracted the array part of the "clause" below:

    onlyif => 'values HostKey == ["/etc/ssh/ssh_host_rsa_key"]'

and called Kernel#eval with '["/etc/ssh/ssh_host_rsa_key"]'. Using eval is
bad because it executes arbitrary code.

This commit changes the provider to convert the comma delimited string to
a Ruby array. This mostly maintains the functionality of the original
Kernel#eval (minus running arbitrary code) except for no longer handling
the \M-x, \M-\C-x, \M-\cx, \c\M-x, \c?, and \C-? escape sequences in
double-quoted strings, and \u{nnnn ...} is more lenient about whitespace.

1 files changed, 65 insertions, 0 deletions

diff --git a/spec/unit/provider/augeas/augeas_spec.rb b/spec/unit/provider/augeas/augeas_spec.rb
index 6166140..180f89c 100644
--- a/spec/unit/provider/augeas/augeas_spec.rb
+++ b/spec/unit/provider/augeas/augeas_spec.rb
@@ -262,6 +262,49 @@ describe Puppet::Type.type(:augeas).provider(:augeas) do
       command = ['values', 'fake value', "== ['set', 'of', 'values']"]
       expect(provider.process_values(command)).to eq(true)
     end
+    it 'returns true for an array match with double quotes and spaces' do
+      command = ['values', 'fake value', '==   [  "set"  ,  "of" , "values"  ]  ']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with internally escaped single quotes' do
+      provider.aug.stubs(:match).returns(['set', "o'values", 'here'])
+      provider.aug.stubs(:get).returns('set').then.returns("o'values").then.returns('here')
+      command = ['values', 'fake value', "== [ 'set', 'o\\'values', 'here']"]
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with octal character sequences' do
+      command = ['values', 'fake value', '== ["\\x73et", "of", "values"]']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with hex character sequences' do
+      command = ['values', 'fake value', '== ["\\163et", "of", "values"]']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with short unicode escape sequences' do
+      command = ['values', 'fake value', '== ["\\u0073et", "of", "values"]']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with single character long unicode escape sequences' do
+      command = ['values', 'fake value', '== ["\\u{0073}et", "of", "values"]']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with multi-character long unicode escape sequences' do
+      command = ['values', 'fake value', '== ["\\u{0073 0065 0074}", "of", "values"]']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an array match with literal backslashes' do
+      provider.aug.stubs(:match).returns(['set', 'o\\values', 'here'])
+      provider.aug.stubs(:get).returns('set').then.returns('o\\values').then.returns('here')
+      command = ['values', 'fake value', '== [ "set", "o\\\\values", "here"]']
+      expect(provider.process_values(command)).to eq(true)
+    end
 
     it 'returns false for an array non match' do
       command = ['values', 'fake value', "== ['this', 'should', 'not', 'match']"]
@@ -277,6 +320,18 @@ describe Puppet::Type.type(:augeas).provider(:augeas) do
       command = ['values', 'fake value', "!= ['this', 'should', 'not', 'match']"]
       expect(provider.process_values(command)).to eq(true)
     end
+
+    it 'returns true for an array non match with double quotes and spaces' do
+      command = ['values', 'fake value', '!=   [  "this"  ,  "should" ,"not",  "match"  ]  ']
+      expect(provider.process_values(command)).to eq(true)
+    end
+
+    it 'returns true for an empty array match' do
+      provider.aug.stubs(:match).returns([])
+      provider.aug.stubs(:get)
+      command = ['values', 'fake value', '== []']
+      expect(provider.process_values(command)).to eq(true)
+    end
   end
 
   describe 'match filters' do
@@ -322,6 +377,11 @@ describe Puppet::Type.type(:augeas).provider(:augeas) do
       expect(provider.process_match(command)).to eq(true)
     end
 
+    it 'returns true for an array match with double quotes and spaces' do
+      command = ['match', 'fake value', '==   [  "set"  ,  "of" , "values"  ]  ']
+      expect(provider.process_match(command)).to eq(true)
+    end
+
     it 'returns false for an array non match' do
       command = ['match', 'fake value', "== ['this', 'should', 'not', 'match']"]
       expect(provider.process_match(command)).to eq(false)
@@ -336,6 +396,11 @@ describe Puppet::Type.type(:augeas).provider(:augeas) do
       command = ['match', 'fake value', "!= ['this', 'should', 'not', 'match']"]
       expect(provider.process_match(command)).to eq(true)
     end
+
+    it 'returns true for an array non match with double quotes and spaces' do
+      command = ['match', 'fake value', '!=   [  "this"  ,  "should" ,"not",  "match"  ]  ']
+      expect(provider.process_match(command)).to eq(true)
+    end
   end
 
   describe 'need to run' do