SecureString Dart Reference Documentation
CkSecureString
Current Version: 11.6.1
Chilkat.SecureString
Store sensitive text in a form that is decrypted only when needed for
access, modification, comparison, or hashing.
Append clear-text strings,
Set
Set
Retrieve the current hash value in an encoding such as hex or Base64, or
verify a supplied encoded hash with
Compare two secure strings with 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
Append safely
StringBuilder content, or another
SecureString; the value is then re-encrypted.
Read-only protection
ReadOnly to prevent later modification of the secure
string.
Hash maintenance
MaintainHash to a supported hash algorithm such as
sha256, sha512, sha1, or
md5.
Hash output and verification
VerifyHash.
Compare and access
SecStrEquals, or call
Access when the clear-text value is required.
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.
VerifyHash depends on MaintainHash having already
been set so the object maintains an internal hash for the current secure
string value.
Object Creation
// pubspec.yaml:
// dependencies:
// chilkat: ^11.6.1
import 'package:chilkat/chilkat.dart';
// Once per process, before any other Chilkat call:
Chilkat.unlockBundle('Anything for 30-day trial'); // shorthand for CkGlobal().unlockBundle(..)
final secureString = CkSecureString();
// ... the native object is released when `secureString` is garbage collected, or now with secureString.dispose().Creates the underlying native Chilkat object. Use a CkSecureString only from the isolate that created it: Chilkat objects cannot be sent between isolates. Every call is synchronous; in a Flutter app, run long operations (network, large files) inside Isolate.run, creating the Chilkat objects inside the isolate.
Releases the native object immediately instead of waiting for garbage collection (useful for a large CkBinData or an open socket). Calling it more than once is harmless; any other use of the object afterwards throws a StateError. isDisposed tells whether it has been called.
Errors
A method that can fail throws a ChilkatException: a method whose only outcome is success or failure returns void and throws on failure; a method producing a String or an object returns it and throws where Chilkat would have returned null. The exception carries the object's LastErrorText at the time of the failure (lastErrorText), the class and method names (className, methodName) and a one-line message. Properties never throw, and methods that answer a question (has..., is..., ...) return a plain bool.
try {
secureString.someMethod(...);
} on ChilkatException catch (e) {
print(e); // CkSecureString.someMethod failed: <reason>
print(e.lastErrorText); // the full Chilkat log of the failed call
}Properties
DebugLogFilePath
String get debugLogFilePath
set debugLogFilePath(String value)
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
LastErrorHtml
String get lastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
String get lastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
String get lastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
bool get lastMethodSuccess
set lastMethodSuccess(bool value)
Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
MaintainHash
String get maintainHash
set maintainHash(String value)
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.
ReadOnly
bool get readOnly
set readOnly(bool value)
Can be set to true to make this secure string read-only (cannot be modified).
VerboseLogging
bool get verboseLogging
set verboseLogging(bool value)
If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
String get version
Methods
Access
Returns the clear-text string value.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
Append
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 normally on success; throws a ChilkatException on failure.
AppendSb
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 normally on success; throws a ChilkatException on failure.
AppendSecure
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 normally on success; throws a ChilkatException on failure.
HashVal
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
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
LoadFile
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 normally on success; throws a ChilkatException on failure.
SecStrEquals
Returns true if the secStr equals the contents of this secure string.
Returns normally on success; throws a ChilkatException on failure.
VerifyHash
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
Returns normally on success; throws a ChilkatException on failure.