---
product: Chilkat
product_version: 11.7.0
language: js
language_label: JavaScript
class: SecureString
license: free
deprecated: false
reference_html: https://www.chilkatsoft.com/refdoc/jsSecureStringRef.html
---
# Chilkat SecureString — JavaScript — v11.7.0

> Chilkat 11.7.0 · language=js · class=SecureString
> Other versions: replace `11.7.0` in this URL. Other languages: `https://www.chilkatsoft.com/ai-docs/v/11.7.0/<lang>/classes/SecureString.md`.
> Language-wide rules (install, unlock, error model, strings/bytes): `https://www.chilkatsoft.com/ai-docs/v/11.7.0/js/guide.md`.

## Purpose

**Store, append, compare, hash, verify, and securely access sensitive string values.**

`Chilkat.SecureString` holds sensitive text in an encrypted in-memory form while still allowing controlled operations on the value. It can append clear-text strings, append text from a `StringBuilder`, append another `SecureString`, load text from a file, return the clear-text value when needed, compare secure strings, mark the value read-only, maintain a hash of the current value, and verify a supplied hash against that maintained value.

**Encrypted in-memory value**

Store sensitive text in a form that is decrypted only when needed for access, modification, comparison, or hashing.

**Append safely**

Append clear-text strings, `StringBuilder` content, or another `SecureString`; the value is then re-encrypted.

**Read-only protection**

Set `ReadOnly` to prevent later modification of the secure string.

**Hash maintenance**

Set `MaintainHash` to a supported hash algorithm such as `sha256`, `sha512`, `sha1`, or `md5`.

**Hash output and verification**

Retrieve the current hash value in an encoding such as hex or Base64, or verify a supplied encoded hash with `VerifyHash`.

**Compare and access**

Compare two secure strings with `SecStrEquals`, or call `Access` when the clear-text value is required.

**Common pattern:** Create a `SecureString`, load or append the sensitive text, set `MaintainHash` if later verification is needed, and optionally set `ReadOnly` after the final value is established. Use `Access` only at the point where the clear-text string is actually needed, and check `LastErrorText` if an append, file load, hash, or verification operation fails.

**Hash note:** `VerifyHash` depends on `MaintainHash` having already been set so the object maintains an internal hash for the current secure string value.

## Object creation, unlocking and error handling

**Object Creation**

Note: This is intended for running within a [Chilkat.Js embedded JavaScript engine](https://www.chilkatsoft.com/chilkat_javascript_engine.asp).

```
var obj = new CkSecureString();
```

Call `Global.UnlockBundle` once at the start of the program, before using this or any other Chilkat class. Any string unlocks a fully functional 30-day trial; a purchased unlock code is used in production. See `guide.md` for the exact code in JavaScript.

How failure is reported depends on the method's return type and is stated in the note under each method below. In every case the diagnostic text is in the `LastErrorText` property of the object whose method was called.

## Members common to every Chilkat class

Documented once per language in `common-members.md`; listed here so this page is self-contained.

| Property | Signature | Access | Meaning |
|---|---|---|---|
| `DebugLogFilePath` | `DebugLogFilePath` | read/write | If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. |
| `LastErrorHtml` | `LastErrorHtml` | read-only | Provides HTML-formatted information about the last called method or property. |
| `LastErrorText` | `LastErrorText` | read-only | Provides plain text information about the last called method or property. |
| `LastErrorXml` | `LastErrorXml` | read-only | Provides XML-formatted information about the last called method or property. |
| `LastMethodSuccess` | `LastMethodSuccess` | read/write | Indicates the success or failure of the most recent method call: `true` means success, `false` means failure. |
| `VerboseLogging` | `VerboseLogging` | read/write | If set to `true`, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. |
| `Version` | `Version` | read-only | Version of the component/library, such as "10.1.0" |

## Member index

| Member | Kind | Signature |
|---|---|---|
| `MaintainHash` | property, read/write | `MaintainHash` |
| `ReadOnly` | property, read/write | `ReadOnly` |
| `Access` | method | `var strVal = Access();` |
| `Append` | method | `var success = Append(str);` |
| `AppendSb` | method | `var success = AppendSb(sb);` |
| `AppendSecure` | method | `var success = AppendSecure(secStr);` |
| `HashVal` | method | `var strVal = HashVal(encoding);` |
| `LoadFile` | method | `var success = LoadFile(path, charset);` |
| `SecStrEquals` | method | `var success = SecStrEquals(secStr);` |
| `VerifyHash` | method | `var success = VerifyHash(hashVal, encoding);` |

## Properties

### SecureString.MaintainHash

`Chilkat 11.7.0 · js · SecureString · MaintainHash · property · read/write · since 9.5.0.71`

```javascript
MaintainHash
```

· `string`

If set to the name of a hash algorithm, then a hash of the current string value is maintained. This allows for the hash to be verified via the VerifyHash method. Possible hash algorithm names are `sha1`, `sha256`, `sha384`, `sha512`, `md5`, `md2`, `ripemd160`, `ripemd128`,`ripemd256`, and `ripemd320`.

### SecureString.ReadOnly

`Chilkat 11.7.0 · js · SecureString · ReadOnly · property · read/write · since 9.5.0.71`

```javascript
ReadOnly
```

· `boolean`

Can be set to `true` to make this secure string read-only (cannot be modified).

## Methods

### SecureString.Access

`Chilkat 11.7.0 · js · SecureString · Access · method · since 9.5.0.71`

```javascript
var strVal = Access();
```

· return: `string`

Returns the clear-text string value.

Returns `null` on failure

### SecureString.Append

`Chilkat 11.7.0 · js · SecureString · Append · method · since 9.5.0.71`

```javascript
var success = Append(str);
```

· return: `boolean`; `true` for success, `false` for failure  
· str: `string`

Appends a clear-text string to this secure string. The in-memory data will be decrypted, the string will be appended, and then it will be re-encrypted. Can return `false` if the string has been marked as read-only via the ReadOnly property.

Returns true for success, false for failure.

### SecureString.AppendSb

`Chilkat 11.7.0 · js · SecureString · AppendSb · method · since 9.5.0.71`

```javascript
var success = AppendSb(sb);
```

· return: `boolean`; `true` for success, `false` for failure  
· sb: `CkStringBuilder`

Appends a clear-text string contained in a StringBuilder to this secure string. The in-memory data will be decrypted, the string will be appended, and then it will be re-encrypted. Can return `false` if the string has been marked as read-only via the ReadOnly property.

Returns true for success, false for failure.

### SecureString.AppendSecure

`Chilkat 11.7.0 · js · SecureString · AppendSecure · method · since 9.5.0.71`

```javascript
var success = AppendSecure(secStr);
```

· return: `boolean`; `true` for success, `false` for failure  
· secStr: `CkSecureString`

Appends the contents of a secure string to this secure string. The in-memory data will be decrypted, the secure string will be appended, and then it will be re-encrypted. Can return `false` if this string has been marked as read-only via the ReadOnly property.

Returns true for success, false for failure.

### SecureString.HashVal

`Chilkat 11.7.0 · js · SecureString · HashVal · method · since 9.5.0.71`

```javascript
var strVal = HashVal(encoding);
```

· return: `string`  
· encoding: `string`

Returns the hash value for the current value of this secure string. The `encoding` specifies the encoding to be used. It can be any of the binary encoding algorithms, such as `base64`, `hex`, and many more listed at [Chilkat Binary Encodings](https://www.chilkatsoft.com/binary_encodings.asp)

Returns `null` on failure

### SecureString.LoadFile

`Chilkat 11.7.0 · js · SecureString · LoadFile · method · since 9.5.0.71`

```javascript
var success = LoadFile(path, charset);
```

· return: `boolean`; `true` for success, `false` for failure  
· path: `string`  
· charset: `string`

Loads the contents of a file into this secure string. The current contents of this object are replaced with the new text from the file.

Returns true for success, false for failure.

### SecureString.SecStrEquals

`Chilkat 11.7.0 · js · SecureString · SecStrEquals · method · since 9.5.0.71`

```javascript
var success = SecStrEquals(secStr);
```

· return: `boolean`; `true` for success, `false` for failure  
· secStr: `CkSecureString`

Returns `true` if the `secStr` equals the contents of this secure string.

Returns true for success, false for failure.

### SecureString.VerifyHash

`Chilkat 11.7.0 · js · SecureString · VerifyHash · method · since 9.5.0.71`

```javascript
var success = VerifyHash(hashVal, encoding);
```

· return: `boolean`; `true` for success, `false` for failure  
· hashVal: `string`  
· encoding: `string`

Verifies the `hashVal` against the hash value stored for the current value of this secure string. The MaintainHash property must've previously been set for this secure string to maintain an internal hash. The `encoding` specifies the encoding of the `hashVal`. It can be any of the binary encoding algorithms, such as `base64`, `hex`, and many more listed at [Chilkat Binary Encodings](https://www.chilkatsoft.com/binary_encodings.asp)

Returns true for success, false for failure.

## Related classes

[`StringBuilder`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/js/classes/StringBuilder.md)