diff --git a/src/lib/base/String.cpp b/src/lib/base/String.cpp
index dcc37e9a3..55dd06ffb 100644
--- a/src/lib/base/String.cpp
+++ b/src/lib/base/String.cpp
@@ -187,6 +187,38 @@ std::string toHex(const std::string &subject, int width, const char fill)
   return ss.str();
 }
 
+// clang-format off
+int fromHexChar(char c)
+{
+  switch (c) {
+    case '0': return 0;
+    case '1': return 1;
+    case '2': return 2;
+    case '3': return 3;
+    case '4': return 4;
+    case '5': return 5;
+    case '6': return 6;
+    case '7': return 7;
+    case '8': return 8;
+    case '9': return 9;
+    case 'a':
+    case 'A': return 10;
+    case 'b':
+    case 'B': return 11;
+    case 'c':
+    case 'C': return 12;
+    case 'd':
+    case 'D': return 13;
+    case 'e':
+    case 'E': return 14;
+    case 'f':
+    case 'F': return 15;
+    default:  return -1;
+  }
+  return -1;
+}
+// clang-format on
+
 void uppercase(std::string &subject)
 {
   std::transform(subject.begin(), subject.end(), subject.begin(), ::toupper);
diff --git a/src/lib/base/String.h b/src/lib/base/String.h
index 1af0841e1..0d63b1926 100644
--- a/src/lib/base/String.h
+++ b/src/lib/base/String.h
@@ -75,6 +75,13 @@ Return a new hexString
 */
 std::string toHex(const std::string &subject, int width, const char fill = '0');
 
+/**
+ * @brief fromHexChar Convert a single char to its hexidecmal value
+ * @param c input char 0-F
+ * @return The value of c in Hex or -1 for invalid hex chars
+ */
+int fromHexChar(char c);
+
 //! Convert to all uppercase
 /*!
 Convert each character in \c subject to uppercase
diff --git a/src/test/unittests/base/StringTests.cpp b/src/test/unittests/base/StringTests.cpp
index d57e93f83..ce5f4b975 100644
--- a/src/test/unittests/base/StringTests.cpp
+++ b/src/test/unittests/base/StringTests.cpp
@@ -59,6 +59,33 @@ TEST(StringTests, toHex_plaintext_hexString)
   EXPECT_EQ("666f6f626172", string::toHex("foobar", 2));
 }
 
+TEST(StringTests, fromHexChar_plaintext_hexString)
+{
+  EXPECT_EQ(-1, string::fromHexChar('z'));
+  EXPECT_EQ(0, string::fromHexChar('0'));
+  EXPECT_EQ(1, string::fromHexChar('1'));
+  EXPECT_EQ(2, string::fromHexChar('2'));
+  EXPECT_EQ(3, string::fromHexChar('3'));
+  EXPECT_EQ(4, string::fromHexChar('4'));
+  EXPECT_EQ(5, string::fromHexChar('5'));
+  EXPECT_EQ(6, string::fromHexChar('6'));
+  EXPECT_EQ(7, string::fromHexChar('7'));
+  EXPECT_EQ(8, string::fromHexChar('8'));
+  EXPECT_EQ(9, string::fromHexChar('9'));
+  EXPECT_EQ(10, string::fromHexChar('a'));
+  EXPECT_EQ(10, string::fromHexChar('A'));
+  EXPECT_EQ(11, string::fromHexChar('b'));
+  EXPECT_EQ(11, string::fromHexChar('B'));
+  EXPECT_EQ(12, string::fromHexChar('c'));
+  EXPECT_EQ(12, string::fromHexChar('C'));
+  EXPECT_EQ(13, string::fromHexChar('d'));
+  EXPECT_EQ(13, string::fromHexChar('D'));
+  EXPECT_EQ(14, string::fromHexChar('e'));
+  EXPECT_EQ(14, string::fromHexChar('E'));
+  EXPECT_EQ(15, string::fromHexChar('f'));
+  EXPECT_EQ(15, string::fromHexChar('F'));
+}
+
 TEST(StringTests, uppercase_lowercaseInput_uppercaseOutput)
 {
   std::string subject = "12foo3BaR";