dec2hex: fix odd byte cropping issue

noraj · Mar 11, 2022 · bbac81e · bbac81e
1 parent 866b86b
commit bbac81e
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diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## [Unreleased]
+
+- Fix:
+  - dec2hex: fix odd byte cropping issue
+
 ## [2.1.0]
 
 - Chore:

diff --git a/lib/ctf_party/hex.rb b/lib/ctf_party/hex.rb
@@ -59,6 +59,8 @@ def dec2hex(opts = {})
     out = ('0' * (opts[:padding] - out.size)) + out if out.size < opts[:padding]
     # char case management
     out = out.upcase if opts[:case] == :upper
+    # so scan is safe, scan(/.{1,2}/) doesn't isolate alone byte in right order
+    out = '0' + out if out.size.odd?
     # adding prefix must be done after case change
     out = out.scan(/.{2}/).map { |x| opts[:prefixall] + x }.join
     return opts[:prefix] + out

diff --git a/test/test_string.rb b/test/test_string.rb
@@ -158,6 +158,8 @@ def test_hex_dec2hex
     assert_equal('0000000a', '10'.dec2hex(padding: 8))
     assert_equal('0xFF', '255'.dec2hex(prefix: '0x', case: :upper))
     assert_equal('\\x6e\\x6f\\x72\\x61\\x6a', '474316169578'.dec2hex(prefixall: '\\x'))
+    # verify no odd byte cropping issue
+    assert_equal('1f4a9','128169'.dec2hex)
   end
 
   skip def test_hex_dec2hex!