XmlDSig Lianja Reference Documentation

XmlDSig

Current Version: 9.5.0.75

An API for validating XML Digital Signatures. Use the XmlDSigGen class for creating XML Digital Signatures.

Object Creation

loObject = createobject("CkXmlDSig")

Properties

DebugLogFilePath
DebugLogFilePath As Character

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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LastErrorHtml
LastErrorHtml As Character (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
LastErrorText As Character (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
LastErrorXml As Character (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
LastMethodSuccess As Boolean
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of .T. indicates success, a value of .F. indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = .T. and failure = .F..
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to .T.. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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NumReferences
NumReferences As Numeric (read-only)
Introduced in version 9.5.0.69

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.

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NumSignatures
NumSignatures As Numeric (read-only)
Introduced in version 9.5.0.69

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.

More Information and Examples
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Selector
Selector As Numeric
Introduced in version 9.5.0.69

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.

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VerboseLogging
VerboseLogging As Boolean

If set to .T., then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is .F.. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
Version As Character (read-only)

Version of the component/library, such as "9.5.0.63"

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Methods

CanonicalizeFragment
CanonicalizeFragment(xml As Character, fragmentId As Character, version As Character, prefixList As Character, withComments As Boolean) As Character

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 XML
  • "EXCL_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 .T., then XML comments are included in the output. If withComments is .F., then XML comments are excluded from the output.

Returns .F. on failure

More Information and Examples
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CanonicalizeXml
CanonicalizeXml(xml As Character, version As Character, withComments As Boolean) As Character

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 XML
  • "EXCL_C14N" -- for Exclusive Canonical XML

If withComments is .T., then XML comments are included in the output. If withComments is .F., then XML comments are excluded from the output.

Returns .F. on failure

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GetKeyInfo
GetKeyInfo() As CkXml
Introduced in version 9.5.0.69

Returns the KeyInfo XML for the signature indicated by the Selector property. Returns .F. if no KeyInfo exists.

Returns .F. on failure

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GetPublicKey
GetPublicKey() As CkPublicKey
Introduced in version 9.5.0.69

Returns the public key from the KeyInfo XML for the signature indicated by the Selector property. Returns .F. if no KeyInfo exists, or if no public key is actually contained in the KeyInfo.

Returns .F. on failure

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IsReferenceExternal
IsReferenceExternal(index As Numeric) As Boolean
Introduced in version 9.5.0.69

Returns .T. if the reference at index is external. Each external reference would first need to be provided by the application prior to validating the signature.

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LoadSignature
LoadSignature(xmlSig As Character) As Boolean
Introduced in version 9.5.0.69

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 .T. for success, .F. for failure.

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LoadSignatureBd
LoadSignatureBd(binData As CkBinData) As Boolean
Introduced in version 9.5.0.69

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 .T. for success, .F. for failure.

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LoadSignatureSb
LoadSignatureSb(sbXmlSig As CkStringBuilder) As Boolean
Introduced in version 9.5.0.69

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 .T. for success, .F. for failure.

More Information and Examples
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ReferenceUri
ReferenceUri(index As Numeric) As Character
Introduced in version 9.5.0.69

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.

Returns .F. on failure

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SaveLastError
SaveLastError(path As Character) As Boolean

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns .T. for success, .F. for failure.

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SetHmacKey
SetHmacKey(key As Character, encoding As Character) As Boolean
Introduced in version 9.5.0.69

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 .T. for success, .F. for failure.

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SetPublicKey
SetPublicKey(pubKey As CkPublicKey) As Boolean
Introduced in version 9.5.0.69

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 .T. for success, .F. for failure.

More Information and Examples
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SetRefDataBd
SetRefDataBd(index As Numeric, binData As CkBinData) As Boolean
Introduced in version 9.5.0.69

Provides the binary data for the external reference at index.

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SetRefDataFile
SetRefDataFile(index As Numeric, path As Character) As Boolean
Introduced in version 9.5.0.69

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.

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SetRefDataSb
SetRefDataSb(index As Numeric, sb As CkStringBuilder, charset As Character) As Boolean
Introduced in version 9.5.0.69

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.)

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UseCertVault
UseCertVault(certVault As CkXmlCertVault) As Boolean
Introduced in version 9.5.0.69

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 .T. for success, .F. for failure.

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VerifyReferenceDigest
VerifyReferenceDigest(index As Numeric) As Boolean
Introduced in version 9.5.0.69

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.

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VerifySignature
VerifySignature(verifyReferenceDigests As Boolean) As Boolean
Introduced in version 9.5.0.69

Verifies the signature indicated by the Selector property. If verifyReferenceDigests is .T., then the digest of each Reference within the signature's SignedInfo is also validated.

Returns .T. for success, .F. for failure.

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