XmlDSig Dart Reference Documentation
CkXmlDSig
Current Version: 11.6.1
Chilkat.XmlDSig
Load an XML document containing one or more digital signatures and
inspect the signature structure before verification.
Work with documents that contain multiple signatures by selecting the
specific signature to inspect or verify.
Verify the cryptographic signature over the canonicalized
Check individual
Extract
Canonicalize XML for signature analysis and add an
For an extended overview, see
XmlDSig Class Overview.
Load, inspect, canonicalize, and verify XML Digital Signatures.
Chilkat.XmlDSig loads and verifies XML Digital Signatures. It
can inspect signed XML, select among multiple signatures in one document,
verify the overall SignatureValue, verify individual
Reference digests, handle external references, extract
KeyInfo, retrieve embedded certificates or public keys,
canonicalize XML, and add an EncapsulatedTimeStamp to an
existing signature.
Load signed XML
Select a signature
Verify SignatureValue
SignedInfo block.
Verify Reference digests
Reference digest values to confirm that
each signed item still matches what was originally signed.
Certificates and keys
KeyInfo, embedded signing certificates, or public
keys used to validate the signature.
Canonicalization and timestamps
EncapsulatedTimeStamp when timestamping an existing
signature.
SignatureValue, then verify the individual reference
digests. Use XmlDSig for verification and inspection; use
Chilkat.XmlDSigGen when creating new XML Digital Signatures.
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 xmlDSig = CkXmlDSig();
// ... the native object is released when `xmlDSig` is garbage collected, or now with xmlDSig.dispose().Creates the underlying native Chilkat object. Use a CkXmlDSig 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 {
xmlDSig.someMethod(...);
} on ChilkatException catch (e) {
print(e); // CkXmlDSig.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.
ExternalRefDirs
String get externalRefDirs
set externalRefDirs(String value)
May contain a set of directory paths specifying where referenced external files are located. Directory paths should be separated using a semicolon character. The default value of this property is the empty string which means no directories are automatically searched.
This property can be used if the external file referenced in the XML signature has the same filename as the file in the local filesystem.
IgnoreExternalRefs
bool get ignoreExternalRefs
set ignoreExternalRefs(bool value)
If true, then ignore failures caused by external references not being available. This allows for the XML signature to be at least partially validated if the external referenced files are not available. The default value of this property is false.
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.
NumReferences
int get numReferences
The number of data objects referenced in the XML digital signature. A data object may be self-contained within the loaded XML signature, or it may be an external URI reference. An application can check each reference to see if it's external by calling IsReferenceExternal, and can get each reference URI by calling ReferenceUri.
NumSignatures
int get numSignatures
The number of digital signatures found within the loaded XML. Each digital signature is composed of XML having the following structure:
<Signature ID?>
<SignedInfo>
<CanonicalizationMethod/>
<SignatureMethod/>
(<Reference URI? >
(<Transforms>)?
<DigestMethod>
<DigestValue>
</Reference>)+
</SignedInfo>
<SignatureValue>
(<KeyInfo>)?
(<Object ID?>)*
</Signature>
Note: The Signature and other XML tags may be namespace prefixed.
The Selector property is used to select which XML signature is in effect when validating or calling other methods or properties.
RefFailReason
int get refFailReason
Indicates the failure reason for the last call to VerifyReferenceDigest. Possible values are:
- 0: No failure, the reference digest was valid.
- 1: The computed digest differs from the digest stored in the XML.
- 2: An external file is referenced, but it is unavailable for computing the digest.
- 3: The index argument passed to VerifyReferenceDigest was out of range.
- 4: Unable to find the Signature.
- 5: A transformation specified some sort of XML canonicalization that is not supported.
- 99: Unknown. (Should never get this value.)
Selector
int get selector
set selector(int value)
If the loaded XML contains multiple signatures, this property can be set to specify which signature is in effect when calling other methods or properties. In most cases, the loaded XML contains a single signature and this property will remain at the default value of 0.
UncommonOptions
String get uncommonOptions
set uncommonOptions(String value)
This is a catch-all property to be used for uncommon needs. This property defaults to the empty string, and should typically remain empty.
topVerboseLogging
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
AddEncapsulatedTimeStamp
Adds an EncapsulatedTimeStamp to the signature indicated by the Selector property. The updated signed XML with the added EncapsulatedTimeStamp is returned in sbOut. See the example below for details.
Returns normally on success; throws a ChilkatException on failure.
CanonicalizeFragment
Applies XML canonicalization to a fragment of the passed-in XML, and returns the canonicalized XML string. The fragmentId identifies the XML element where output begins. It is the XML element having an id attribute equal to fragmentId. The version may be one of the following:
C14N-- for Inclusive Canonical XMLEXCL_C14N-- for Exclusive Canonical XML
The prefixList only applies when the version is set to EXCL_C14N. The prefixList may be an empty string, or a SPACE separated list of namespace prefixes. It is the InclusiveNamespaces PrefixList, which is the list of namespaces that are propagated from ancestor elements for canonicalization purposes.
If withComments is true, then XML comments are included in the output. If withComments is false, then XML comments are excluded from the output.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
CanonicalizeXml
Applies XML canonicalization to the passed-in XML, and returns the canonicalized XML string. The version may be one of the following:
C14N-- for Inclusive Canonical XMLEXCL_C14N-- for Exclusive Canonical XML
If withComments is true, then XML comments are included in the output. If withComments is false, then XML comments are excluded from the output.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
GetCerts
Returns the certificates found in the signature indicated by the Selector property. The base64 representation of each certificate is returned.
Returns normally on success; throws a ChilkatException on failure.
GetKeyInfo
Returns the KeyInfo XML for the signature indicated by the Selector property. Returns null if no KeyInfo exists.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
GetPublicKey
Returns the public key from the KeyInfo XML for the signature indicated by the Selector property. Returns null if no KeyInfo exists, or if no public key is actually contained in the KeyInfo.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
HasEncapsulatedTimeStamp
Returns true if the signature indicated by the Selector property contains an EncapsulatedTimeStamp. Otherwise returns false.
IsReferenceExternal
Returns true if the reference at index is external. Each external reference would first need to be provided by the application prior to validating the signature.
LoadSignature
Loads an XML document containing 1 or more XML digital signatures. An application would first load XML containing digital signature(s), then validate. After loading, it is also possible to use various methods and properties to get information about the signature, such as the key info, references, etc. If external data is referenced by the signature, it may be necessary to provide the referenced data prior to validating.
Note: When loading an XML document, the Selector property is automatically reset to 0, and the NumSignatures property is set to the number of XML digital signatures found.
Returns normally on success; throws a ChilkatException on failure.
LoadSignatureBd
Loads an XML document containing one or more XML digital signatures from the contents of a BinData object. An application would first load the XML, then validate. After loading, it is also possible to use various methods and properties to get information about the signature, such as the key info, references, etc. If external data is referenced by the signature, it may be necessary to provide the referenced data prior to validating.
Note: When loading an XML document, the Selector property is automatically reset to 0, and the NumSignatures property is set to the number of XML digital signatures found.
Returns normally on success; throws a ChilkatException on failure.
LoadSignatureSb
Loads an XML document containing one or more XML digital signatures from the contents of a StringBuilder object. An application would first load the XML, then validate. After loading, it is also possible to use various methods and properties to get information about the signature, such as the key info, references, etc. If external data is referenced by the signature, it may be necessary to provide the referenced data prior to validating.
Note: When loading an XML document, the Selector property is automatically reset to 0, and the NumSignatures property is set to the number of XML digital signatures found.
Returns normally on success; throws a ChilkatException on failure.
ReferenceUri
Returns the URI of the Nth reference specified by index. (The 1st reference is at index 0.) URI's beginning with a pound sign ('#') are internal references.
Throws a ChilkatException on failure (where the description says null is returned, the Dart method throws instead).
SetHmacKey
Sets the HMAC key to be used if the Signature used an HMAC signing algorithm. The encoding specifies the encoding of key, and can be hex, base64, ascii, or any of the binary encodings supported by Chilkat in the link below.
Returns normally on success; throws a ChilkatException on failure.
SetHttpObj
Sets the HTTP object to be used to communicate with OCSP responders, CRL distribution points, or timestamp authority (TSA) servers if needed. The http is used to send the requests, and it allows for connection related settings and timeouts to be set. For example, if HTTP or SOCKS proxies are required, these features can be specified on the http.
SetPublicKey
Sets the public key to be used for verifying the signature indicated by the Selector property. A public key only needs to be explicitly provided by the application for those XML signatures where the public key is not already available within the KeyInfo of the Signature. In some cases, the KeyInfo within the Signature contains information about what public key was used for signing. The application can use this information to retrieve the matching public key and provide it via this method.
Returns normally on success; throws a ChilkatException on failure.
SetRefDataBd
Provides the binary data for the external reference at index.
Returns normally on success; throws a ChilkatException on failure.
SetRefDataFile
Provides the data for the external reference at index. When validating the signature, the data contained in path will be streamed to compute the digest for validation.
Returns normally on success; throws a ChilkatException on failure.
SetRefDataSb
Provides the text data for the external reference at index. The charset specifies the byte representation of the text, such as utf-8, utf-16, windows-1252, etc. (If in doubt, try utf-8 first.)
Returns normally on success; throws a ChilkatException on failure.
UseCertVault
Adds an XML certificate vault to the object's internal list of sources to be searched for certificates having public keys when verifying an XML signature. A single XML certificate vault may be used. If UseCertVault is called multiple times, only the last certificate vault will be used, as each call to UseCertVault will replace the certificate vault provided in previous calls.
Returns normally on success; throws a ChilkatException on failure.
VerifyReferenceDigest
This method allows for an application to verify the digest for each reference separately. This can be helpful if the full XMLDSIG validation fails, then one can test each referenced data's digest to see which, if any, fail to match.
VerifySignature
Verifies the signature indicated by the Selector property. If verifyReferenceDigests is true, then the digest of each Reference within the signature's SignedInfo is also validated.
Returns normally on success; throws a ChilkatException on failure.