MD5

Parameters

Name	Type	Required	Description
`string`	string	Yes	String to evaluate
`charset`	string	No	Character set to use when evaluating the string, such as `ASCII` or `UTF-8`

Show test script

<script runat="server">
Platform.Load("core", "1.1.5");

/*
 * Chapter: Parameters — Platform.Function.MD5(string[, charset])
 *
 * Proves:
 *   1. The Platform.Function member exists and is invocable with 1 argument.
 *   2. The return type is string.
 *   3. charset is optional: omitted and explicit UTF-8 agree.
 *   4. The documented charset values ASCII and UTF-8 are accepted.
 *   5. Charset matching is case-insensitive for "utf-8".
 *   6. Invalid, empty, null and undefined charset values throw.
 *   7. The bare-name MD5 form is absent and invocation throws.
 *   8. The documented arity is enforced: 0 and 3 arguments throw.
 *
 * EXPECTED OUTPUT: every line starts with PASS. A FAIL means the runtime no
 * longer matches the documented claim and the page must be revised.
 */

function assert(id, actual, expected) {
    Platform.Response.Write((actual === expected ? "PASS " : "FAIL ") + id + " -> [" + actual + "]\n");
}
function assertThrows(id, fn) {
    var threw = false;
    try { fn(); } catch (ex) { threw = true; }
    Platform.Response.Write((threw ? "PASS " : "FAIL ") + id + " -> " + (threw ? "threw" : "did NOT throw") + "\n");
}

var oneArg = Platform.Function.MD5("Hello World");
assert("1-argument Platform.Function.MD5 call succeeds", oneArg, "b10a8db164e0754105b7a99be72e3fe5");
assert("typeof the result is string", String(typeof oneArg), "string");

var utf8 = Platform.Function.MD5("Hello World", "UTF-8");
var ascii = Platform.Function.MD5("Hello World", "ASCII");
assert("UTF-8 charset is accepted", utf8, "b10a8db164e0754105b7a99be72e3fe5");
assert("ASCII charset is accepted", ascii, "b10a8db164e0754105b7a99be72e3fe5");
assert("omitted charset defaults to UTF-8 for ASCII input", oneArg, utf8);
assert("ASCII and UTF-8 agree for ASCII input", ascii, utf8);
assert("lowercase utf-8 charset is accepted", Platform.Function.MD5("Hello World", "utf-8"), utf8);

assert("bare-name MD5 is undefined", String(typeof MD5), "undefined");

/* Potentially throwing cases are last. */
assertThrows("invalid charset throws", function () { return Platform.Function.MD5("abc", "NO-SUCH-CHARSET"); });
assertThrows("empty charset throws", function () { return Platform.Function.MD5("abc", ""); });
assertThrows("null charset throws", function () { return Platform.Function.MD5("abc", null); });
assertThrows("undefined charset throws", function () { var u; return Platform.Function.MD5("abc", u); });
assertThrows("0-argument Platform form throws", function () { return Platform.Function.MD5(); });
assertThrows("3-argument Platform form throws", function () { return Platform.Function.MD5("abc", "UTF-8", "extra"); });
assertThrows("bare-name MD5 invocation throws", function () { return MD5("abc"); });
</script>

Description

Returns an MD5 hash of the given input string. Use the optional charset parameter when the input string contains characters outside ASCII range.

MD5 is a one-way hash, not encryption. Do not use it to store passwords or protect sensitive data.

Show test script

<script runat="server">
Platform.Load("core", "1.1.5");

/*
 * Chapter: Description — returns a lowercase 32-character hexadecimal MD5
 * hash; the optional charset controls non-ASCII byte encoding.
 *
 * Proves:
 *   1. Known deterministic MD5 vectors match independent reference values.
 *   2. Every result is a lowercase, 32-character hexadecimal string.
 *   3. Omitted charset and UTF-8 agree for non-ASCII input.
 *   4. ASCII replaces a non-ASCII character before hashing, so its result
 *      differs from UTF-8 and matches the independent MD5 of "caf?".
 *   5. Empty string, null and undefined all hash as the empty string.
 *   6. Numbers are converted to their decimal string form.
 *   7. Booleans are converted to capitalized "True" / "False" strings.
 *   8. Array input throws instead of being coerced.
 *
 * EXPECTED OUTPUT: every line starts with PASS.
 */

function assert(id, actual, expected) {
    Platform.Response.Write((actual === expected ? "PASS " : "FAIL ") + id + " -> [" + actual + "]\n");
}
function assertThrows(id, fn) {
    var threw = false;
    try { fn(); } catch (ex) { threw = true; }
    Platform.Response.Write((threw ? "PASS " : "FAIL ") + id + " -> " + (threw ? "threw" : "did NOT throw") + "\n");
}

/* Independent RFC-style reference vectors. */
assert("MD5('') known vector", Platform.Function.MD5(""), "d41d8cd98f00b204e9800998ecf8427e");
assert("MD5('abc') known vector", Platform.Function.MD5("abc"), "900150983cd24fb0d6963f7d28e17f72");
assert("MD5('Hello World') known vector", Platform.Function.MD5("Hello World"), "b10a8db164e0754105b7a99be72e3fe5");

var hash = Platform.Function.MD5("abc");
var hex = "0123456789abcdef";
var bad = 0;
var i;
for (i = 0; i < hash.length; i++) {
    if (hex.indexOf(hash.charAt(i)) < 0) { bad = bad + 1; }
}
assert("result length is exactly 32", String(hash.length), "32");
assert("result contains lowercase hexadecimal characters only", String(bad), "0");
assert("result equals its lowercase form", hash === hash.toLowerCase() ? "true" : "false", "true");
assert("result does not equal its uppercase form", hash === hash.toUpperCase() ? "true" : "false", "false");

var cafeUtf8 = Platform.Function.MD5("caf\u00e9", "UTF-8");
assert("UTF-8 non-ASCII vector", cafeUtf8, "07117fe4a1ebd544965dc19573183da2");
assert("omitted charset defaults to UTF-8 for non-ASCII input", Platform.Function.MD5("caf\u00e9"), cafeUtf8);
assert("ASCII non-ASCII vector matches MD5('caf?')", Platform.Function.MD5("caf\u00e9", "ASCII"), "333027b148fc48b3494f9b895f9c857a");
assert("ASCII and UTF-8 differ for non-ASCII input", Platform.Function.MD5("caf\u00e9", "ASCII") === cafeUtf8 ? "true" : "false", "false");

assert("null input hashes as the empty string", Platform.Function.MD5(null), "d41d8cd98f00b204e9800998ecf8427e");
var undef;
assert("undefined input hashes as the empty string", Platform.Function.MD5(undef), "d41d8cd98f00b204e9800998ecf8427e");
assert("number input is converted to decimal text", Platform.Function.MD5(123), "202cb962ac59075b964b07152d234b70");
assert("boolean input is converted to capitalized text", Platform.Function.MD5(true), "f827cf462f62848df37c5e1e94a4da74");

/* Potentially throwing case is last. */
assertThrows("array input throws", function () { return Platform.Function.MD5([1, 2]); });
</script>

Examples

Hash a value from a Data Extension

var normalStr = Platform.Function.Lookup("ForMD5Info", "HashData", "HashKey", "stringValue");
var hashedStr = Platform.Function.MD5(normalStr);
Write(hashedStr);

Hash with explicit character set

var hashedStr = Platform.Function.MD5("Hello World", "UTF-8");
Write(hashedStr); // "b10a8db164e0754105b7a99be72e3fe5"

Show test script

<script runat="server">
Platform.Load("core", "1.1.5");

/*
 * Chapter: Examples — hash a value held in a variable and hash with an
 * explicit UTF-8 charset.
 *
 * Proves:
 *   1. A normal string value held in a variable produces the expected hash.
 *   2. The explicit UTF-8 example returns the documented literal.
 *   3. The returned value is a genuine string that Write() can emit and on
 *      which string operations work.
 *
 * NOT ASSERTED: the Platform.Function.Lookup("ForMD5Info", ...) call. It
 * depends on a data extension fixture that does not exist in the verification
 * business unit. The MD5 half of that example is asserted with an equivalent
 * normal string variable.
 *
 * EXPECTED OUTPUT: every line starts with PASS.
 */

function assert(id, actual, expected) {
    Platform.Response.Write((actual === expected ? "PASS " : "FAIL ") + id + " -> [" + actual + "]\n");
}

var normalStr = "abc";
var hashedStr = Platform.Function.MD5(normalStr);
assert("a normal string variable hashes to the known literal", hashedStr, "900150983cd24fb0d6963f7d28e17f72");
assert("typeof the example result is string", String(typeof hashedStr), "string");
assert("string operations work on the example result", hashedStr.substring(0, 8), "90015098");
Platform.Response.Write("PASS Write(hashedStr) emitted -> [" + hashedStr + "]\n");

var explicit = Platform.Function.MD5("Hello World", "UTF-8");
assert("explicit UTF-8 example matches its documented result", explicit, "b10a8db164e0754105b7a99be72e3fe5");
</script>

Syntax

Parameters

Description

Examples

Hash a value from a Data Extension

Hash with explicit character set

See Also

See Also