3 files changed, 46 insertions, 1 deletions
diff --git a/base/string_util.cc b/base/string_util.cc
index eae60d2..45a4442 100644
--- a/base/string_util.cc
+++ b/base/string_util.cc
@@ -1532,3 +1532,32 @@ bool ElideString(const std::wstring& input, int max_len, std::wstring* output) {
 
   return true;
 }
+
+std::string HexEncode(const void* bytes, size_t size) {
+  static const char kHexChars[] = {
+      '0', '1', '2', '3', '4', '5', '6', '7',
+      '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+
+  if (size == 0)
+    return std::string();
+
+  std::string ret;
+  // For each byte, we print two characters.
+  ret.resize(size * 2);
+
+  const unsigned char* pos = reinterpret_cast<const unsigned char*>(bytes);
+  const unsigned char* end = pos + size;
+  std::string::iterator write = ret.begin();
+  while (pos < end) {
+    unsigned char b = *pos;
+    pos++;
+
+    write[0] = kHexChars[(b >> 4) & 0xf];
+    write++;
+
+    write[0] = kHexChars[b & 0xf];
+    write++;
+  }
+
+  return ret;
+}
diff --git a/base/string_util.h b/base/string_util.h
index 6d7ff94..68142cb 100644
--- a/base/string_util.h
+++ b/base/string_util.h
@@ -539,5 +539,13 @@ bool ElideString(const std::wstring& input, int max_len, std::wstring* output);
 bool MatchPattern(const std::wstring& string, const std::wstring& pattern);
 bool MatchPattern(const std::string& string, const std::string& pattern);
 
-#endif  // BASE_STRING_UTIL_H_
+// Returns a hex string representation of a binary buffer.
+// The returned hex string will be in upper case.
+// This function does not check if |size| is within reasonable limits since
+// it's written with trusted data in mind.
+// If you suspect that the data you want to format might be large,
+// the absolute max size for |size| should be is
+//   std::numeric_limits<size_t>::max() / 2
+std::string HexEncode(const void* bytes, size_t size);
 
+#endif  // BASE_STRING_UTIL_H_
diff --git a/base/string_util_unittest.cc b/base/string_util_unittest.cc
index 11c727d..0ca4438 100644
--- a/base/string_util_unittest.cc
+++ b/base/string_util_unittest.cc
@@ -1451,3 +1451,11 @@ TEST(StringUtilTest, ElideString) {
     EXPECT_TRUE(output == cases[i].output);
   }
 }
+
+TEST(StringUtilTest, HexEncode) {
+  std::string hex(HexEncode(NULL, 0));
+  EXPECT_EQ(hex.length(), 0U);
+  unsigned char bytes[] = {0x01, 0xff, 0x02, 0xfe, 0x03};
+  hex = HexEncode(bytes, sizeof(bytes));
+  EXPECT_EQ(hex.compare("01FF02FE03"), 0);
+}