diff --git a/tf_fuzz/utility/string_ops.cpp b/tf_fuzz/utility/string_ops.cpp
new file mode 100644
index 0000000..9c14140
--- /dev/null
+++ b/tf_fuzz/utility/string_ops.cpp
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2019-2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include "string_ops.hpp"
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+
+using namespace std;
+
+// Replace first occurrence of find_str within orig of replace_str:
+size_t find_replace_1st (const string &find_str, const string &replace_str,
+                         string &orig) {
+    size_t where = 0;
+    where = orig.find(find_str, where);
+    if (where != string::npos) {
+        orig.replace(where, find_str.length(), replace_str);
+    }
+    return where;
+}
+
+// Replace all occurrences of find_str in "this" string, with replace_str:
+size_t find_replace_all (const string &find_str, const string &replace_str,
+                         string &orig) {
+    size_t where = 0;
+    do {
+        where = orig.find(find_str, where);
+        if (where != string::npos) {
+            orig.replace(where, find_str.length(), replace_str);
+        }
+    } while (where != string::npos);
+    return where;
+}
+
+
+string formalize (string input, string prefix) {
+    // First capitalize the input string:
+    for (auto cp = input.begin();  cp < input.end();  cp++) {
+        *cp = (char) toupper (*cp);
+    }
+    // If it already begins with the prefix...
+    if (input.substr (0, prefix.length()) == prefix) {
+        // then return it as capitalized:
+        return input;
+    } else {
+        // If not, prefix it with that prefix:
+        return prefix + input;
+    }
+}
+
+/* This implementation assumes ASCII character encoding and no "special characters" --
+   loosely speaking, "English." */
+string string_or_hex (string input, int clump_size) {
+    uint32_t n_alphanum = 0;  // the number of alphanumeric characters
+    bool prose = true;  // the string is alphanumeric, space, or common punctuation
+    ostringstream hex_stream;
+
+    for (auto cp = input.begin();  cp < input.end();  cp++) {
+        if ((int) *cp < 0) {
+            prose = false;
+            break;
+        }
+        if (   (*cp >= '0' && *cp <= '9')
+            || (*cp >= 'a' && *cp <= 'z') || (*cp >= 'A' && *cp <= 'Z')
+            || (*cp == ' ') || (*cp == ',') || (*cp == '.')
+            || (*cp == '?') || (*cp == '!')
+           ) {
+            n_alphanum++;
+        }
+    }
+    if (   prose  // so far at least!
+        && (  (input.length() - n_alphanum) // number of chars that are not "English"
+            < (input.length() >> 3)  // 1/8 of the length of the string
+       )   ) {
+        return input;  // take it at face-value
+    }
+    // It's not run-of-the-mill text, so create a hex string:
+    int i = 0;
+    for (auto cp = input.begin();  cp < input.end();  cp++) {
+        hex_stream << setfill('0') << setw(2) << hex << (((unsigned) *cp) & 0xff);
+        if (++i >= clump_size) {
+            hex_stream << " ";
+            i = 0;
+        }
+    }
+    return hex_stream.str();
+}
+
+string binary_from_hex (string input) {
+    stringstream hex_stream;
+    uint8_t aByte;  // each byte as we grab it
+    string result = "";
+    string holder_string = "";
+
+    hex_stream.str(input);
+    hex_stream.width(2);
+    while (!hex_stream.eof()) {
+        hex_stream >> skipws >> setw(2) >> holder_string;
+        try {   // TODO:  May not catch all bad-chars.
+            aByte = stoi(holder_string, 0, 16);
+        }
+        catch (const invalid_argument &arg_err) {
+            cerr << "Error 2345:  Non-hexadecimal character found in binary-data string ("
+                 << arg_err.what() << endl;
+            exit (2345);
+        }
+        result += aByte;
+    }
+    return result;
+}