Dkim Excel Class Module Reference Documentation

Dkim

DomainKeys API for creating and verifying DKIM-Signature and DomainKey-Signature MIME (email) header fields. This API is included with the "Chilkat MIME" license. ("Chilkat MIME" may be referred to as "Chilkat S/MIME" on some chilkatsoft.com web pages. They are the same product.)

Object Creation

Dim oDkim As Chilkat.Dkim
Set oDkim = Chilkat.NewDkim

Properties

AbortCurrent As Long

Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

DebugLogFilePath As String

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.

DkimAlg As String

The signing algorithm to be used in creating the DKIM-Signature. Possible values are "rsa-sha256" and "rsa-sha1". The default value is "rsa-sha256".

DkimBodyLengthCount As Long

Optional body length count to set a maximum number of body bytes to be hashed when creating the DKIM-Signature field. The default value is 0, indicating that the entire body should be hashed.

DkimCanon As String

Canonicalization algorithm to be used for both header and body when creating the DKIM-Signature. Possible values are "simple" and "relaxed". The default value is "relaxed".

DkimDomain As String

The domain name of the signing domain when creating the DKIM-Signature.

DkimHeaders As String

A colon-separated list of header field names that identify headers presented to the signing algorithm when creating the DKIM-Signature. The default value is: "mime-version:date:message-id:subject:from:to:content-type".

DkimSelector As String

The selector to be used to form the DNS query for the public key. This property applies to creating a DKIM-Signature. For example, if the selector is "reykjavik" and the domain is "example-code.com", then the DNS query would be for "reykjavik._domainkey.example-code.com".

DomainKeyAlg As String

The signing algorithm to be used in creating the DomainKey-Signature. The only possible value is "rsa-sha1". The default value is "rsa-sha1".

DomainKeyCanon As String

Canonicalization algorithm to be used for when creating the DomainKey-Signature. Possible values are "simple" and "nofws". The default value is "nofws".

DomainKeyDomain As String

The domain name of the signing domain when creating the DomainKey-Signature.

DomainKeyHeaders As String

A colon-separated list of header field names that identify headers presented to the signing algorithm when creating the DomainKey-Signature. The default value is: "mime-version:date:message-id:subject:from:to:content-type".

DomainKeySelector As String

The selector to be used to form the DNS query for the public key. This property applies to creating a DomainKey-Signature. For example, if the selector is "reykjavik" and the domain is "example-code.com", then the DNS query would be for "reykjavik._domainkey.example-code.com".

LastErrorHtml As String (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.

LastErrorText As String (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.

Concept of LastErrorText

LastErrorText Standard Information

LastErrorXml As String (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.

LastMethodSuccess As Long

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False 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 = True and failure = False.
  • 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 True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

VerboseLogging As Long

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 As String (read only)

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

Methods

DkimSign(mimeData As BinData) As Long

Introduced in version 9.5.0.71

Constructs and prepends a DKIM-Signature header to the MIME passed in mimeData. Prior to calling this method, your program must set both the DkimDomain and DkimSelector properties, and it must load a private key by calling SetDkimPrivateKey.

Returns True for success, False for failure.

DkimVerify(sigIndex As Long, mimeData As BinData) As Long

Introduced in version 9.5.0.71

Verifies the Nth DKIM-Signature header in the mimeData. (In most cases, there is only one signature.) The 1st signature is at sigIndex 0.

Important: Many anti-virus programs, such as AVG, will modify the MIME of an email as it is received. This will cause DKIM signature verification to fail because the body of the MIME is modified.

Returns True for success, False for failure.

DomainKeySign(mimeData As BinData) As Long

Introduced in version 9.5.0.71

Constructs and prepends a DomainKey-Signature header to the MIME passed in mimeData. Prior to calling this method, your program must set both the DomainKeyDomain and DomainKeySelector properties, and it must load a private key by calling SetDomainKeyPrivateKey.

Returns True for success, False for failure.

DomainKeyVerify(sigIndex As Long, mimeData As BinData) As Long

Introduced in version 9.5.0.71

Verifies the Nth DomainKey-Signature header in the mimeData. (In most cases, there is only one signature.) The 1st signature is at sigIndex 0.

Important: Many anti-virus programs, such as AVG, will modify the MIME of an email as it is received. This will cause DomainKey signature verification to fail because the body of the MIME is modified.

Returns True for success, False for failure.

LoadPublicKey(selector As String, domain As String, publicKey As String) As Long

Caches a public key to be used for verifying DKIM and DomainKey signatures for a given selector and domain. The publicKey is a string containing an RSA public key in any text format, such as XML, PEM, etc. This method will automatically detect the format and load the public key correctly. This method is useful for testing DKIM and DomainKey verification when your public key has not yet been installed in DNS.

Returns True for success, False for failure.

LoadPublicKeyFile(selector As String, domain As String, publicKeyFilepath As String) As Long

Caches a public key to be used for verifying DKIM and DomainKey signatures for a given selector and domain. The publicKeyFilepath is a filepath of an RSA public key in any format. This method will automatically detect the format and load the public key correctly. This method is useful for testing DKIM and DomainKey verification when your public key has not yet been installed in DNS.

Returns True for success, False for failure.

PrefetchPublicKey(selector As String, domain As String) As Long

Useful if your application is going to verify many emails from a single domain (or a few domains). This eliminates the need to do a DNS lookup to fetch the public key each time an email's DKIM or DomainKey signature is verified.

This method may be called multiple times -- once for each selector/domain to be pre-fetched. The verify methods (VerifyDkimSignature and VerifyDomainKeySignature) will use a pre-fetched key if the selector and domain match.

Returns True for success, False for failure.

SetDkimPrivateKey(privateKey As PrivateKey) As Long

Introduced in version 9.5.0.71

Sets the private key file to be used for creating a DKIM-Signature.

Returns True for success, False for failure.

SetDomainKeyPrivateKey(privateKey As PrivateKey) As Long

Introduced in version 9.5.0.71

Sets the private key file to be used for creating a DomainKey-Signature.

Returns True for success, False for failure.

UnlockComponent(unlockCode As String) As Long

Unlocks the component allowing for the full functionality to be used. If this method unexpectedly returns False, examine the contents of the LastErrorText property to determine the reason for failure.

Returns True for success, False for failure.

Diagnosing UnlockComponent Problems

UnlockComponent LastErrorText shows exact string passed to it.

Verify UnlockComponent Success w/ Purchased Unlock Code

LastErrorText Standard Information