ChilkatDsa ActiveX Reference

ChilkatDsa

The Digital Signature Algorithm (DSA) is a United States Federal Government standard or FIPS for digital signatures. It was proposed by the National Institute of Standards and Technology (NIST) in August 1991 for use in their Digital Signature Standard (DSS).

Object Creation

(Visual Basic 6.0)
Dim obj As New ChilkatDsa
(ASP)
set obj = Server.CreateObject("Chilkat.Dsa")
(VBScript)
set obj = CreateObject("Chilkat.Dsa")
(Delphi)
obj := TChilkatDsa.Create(Self);
(FoxPro)
loObject = CreateObject('Chilkat.Dsa')
(SQL Server)
EXEC @hr = sp_OACreate 'Chilkat.Dsa', @obj OUT
(Javascript)
var obj = new ActiveXObject("Chilkat.Dsa");

Properties

GroupSize As Long

The group size (in bits) to be used in DSA key generation. The default value is 160 and corresponds to the fact that SHA-1 is used in signature generation. This property setting should not be changed. It exists for future expansion when additional underlying hash algorithms are supported.

Hash As Variant

The hash to be signed or verified via the SignHash and Verify methods. In both cases, the Hash should be set prior to calling SignHash or Verify. This property may also be set via the SetEncodedHash method.

HexG As String (read-only)

The "G" part of a public or private DSA key returned as a hex-encoded SSH1-format bignum. The "G" is the generator. DSA key params consist of G, P, and Q.

HexP As String (read-only)

The "P" part of a public or private DSA key returned as a hex-encoded SSH1-format bignum. The "P" is a large prime. DSA key params consist of G, P, and Q.

HexQ As String (read-only)

The "Q" part of a public or private DSA key returned as a hex-encoded SSH1-format bignum. DSA key params consist of G, P, and Q.

HexX As String (read-only)

The "X" part of a DSA private key returned as a hex-encoded SSH1-format bignum.

HexY As String (read-only)

The "Y" part of a DSA public key returned as a hex-encoded SSH1-format bignum. (The "Y" value is also accessible w/ a private key, but the "X" value is not available in a DSA public key.)

LastErrorHtml As String (read-only)

Error information in HTML format for the last method called.

LastErrorText As String (read-only)

Error information in plain-text format for the last method called.

LastErrorXml As String (read-only)

Error information in XML format for the last method called.

Signature As Variant

The signature created by calling SignHash. If verifying a signature, this may be set prior to calling the Verify method.

Version As String (read-only)

A version string such as "1.3.0"

Methods

FromDer(derData As Variant) As Long

Loads a DSA private key from in-memory DSA DER encoded bytes.

Returns 1 for success, 0 for failure.

FromDerFile(filename As String) As Long

Loads a DSA private key from a DER-encoded file.

Returns 1 for success, 0 for failure.

FromEncryptedPem(password As String, pemData As String) As Long

Loads a DSA private key from an in-memory encrypted PEM-formatted string. If the PEM passed to this method is unencrypted, the password is ignored and the PEM is simply loaded.

Returns 1 for success, 0 for failure.

FromPem(pemData As String) As Long

Loads a DSA private key from an in-memory unencrypted PEM-formatted string.

Returns 1 for success, 0 for failure.

FromPublicDer(derData As Variant) As Long

Loads a DSA public key from an in-memory DER-encoded byte array.

Returns 1 for success, 0 for failure.

FromPublicDerFile(filename As String) As Long

Loads a DSA public key from a DER-encoded file.

Returns 1 for success, 0 for failure.

FromPublicPem(pemData As String) As Long

Loads a DSA public-key from an in-memory PEM string.

Returns 1 for success, 0 for failure.

FromXml(xmlKey As String) As Long

Loads a DSA public or private key from an in-memory XML string.

Returns 1 for success, 0 for failure.

GenKey(numBits As Long) As Long

Generates a new DSA key that is numBits bits in length. The numBits should be at least 1024 bits and a multiple of 64. Typical values are 1024 and 2048. The newly generated key may be exported by calling one of the To* methods.

Returns 1 for success, 0 for failure.

GenKeyFromParamsDer(derBytes As Variant) As Long

Generates a new DSA key from in-memory DER parameters created by OpenSSL. The newly generated key may be exported by calling one of the To* methods.

Returns 1 for success, 0 for failure.

GenKeyFromParamsDerFile(filename As String) As Long

Generates a new DSA key from a DER-format parameters file created by OpenSSL. An example of using OpenSSL to generate DSA parameters in DER format is:

openssl dsaparam -outform DER 1024 < seedData.xml > dsaparam.der

The newly generated key may be exported by calling one of the To* methods.

Returns 1 for success, 0 for failure.

GenKeyFromParamsPem(pem As String) As Long

Generates a new DSA key from parameters (PEM formatted string) created by OpenSSL. The newly generated key may be exported by calling one of the To* methods.

Returns 1 for success, 0 for failure.

GenKeyFromParamsPemFile(filename As String) As Long

Generates a new DSA key from a PEM parameters file created by OpenSSL. The newly generated key may be exported by calling one of the To* methods.

OpenSSL provides the ability to generate DSA key parameters. For example:

openssl dsaparam 1024 < seedData.txt > dsaparam.pem

Here is a sample DSA parameters PEM:

-----BEGIN DSA PARAMETERS-----
MIIBHgKBgQCXIAx4XzLVZ5ZqOFzdsYWVyH/6E/mVPw4TgMZS6Wxajnbdn1/CUBzE
RWTUp8SguTSDpjC1Q/nyno0G6Q96VoW+PUXv8qUph8vbSaEdsjYO/8jSfzkGfvsa
cucr1ythfNyk63aZAKzxeutOmsVe77l6pZI96ROjWF5iizuUB4WgmwIVANxM70wH
8iPPYVzPZqtXCB66I2SnAoGAIbW2VYRjRdoA7trJgmnfWakghKwV1WyaYrotqeDE
07/dipp0cNuY0IAJgSmqLHlAkNa2ZNI/c1mNxcwhYzZrnn8CXIqrYmtI33w0PYCx
KHPqj7puhddFwYS/rFiyWAN0jtCMHlfCVzFGbSzach5QQraPV9YApJXy+ORJ8VPU
/zo=
-----END DSA PARAMETERS-----

Returns 1 for success, 0 for failure.

GetEncodedHash(encoding As String) As String

Returns the bytes of the Hash property as a hex or base64 encoded string. The encoding should be set to either "hex" or "base64".

Returns a null on failure

GetEncodedSignature(encoding As String) As String

Returns the bytes of the Signature property as a hex or base64 encoded string. The encoding should be set to either "hex" or "base64". The Signature property is set when SignHash is called.

Returns a null on failure

LoadText(filename As String, outStr As String) As Long

Convenience method to load the entire contents of a text file into a string. It is assumed that the text contains ANSI encoded character data.

Returns 1 for success, 0 for failure.

SaveLastError(logFilename As String) As Long

Saves the last error information to an XML formatted file.

SaveText(strToSave As String, filename As String) As Long

Convenience method to save a string to a text file. The text is saved using the ANSI character encoding.

Returns 1 for success, 0 for failure.

SetEncodedHash(encoding As String, encodedHash As String) As Long

Provides a way to set the Hash property by passing an encoded string. The encoding can be "hex" or "base64". The encodedHash contains the encoded bytes of the hash that will be signed or verified via the SignHash and Verify methods.

Returns 1 for success, 0 for failure.

SetEncodedSignature(encoding As String, encodedSig As String) As Long

Sets the bytes of the Signature property. (The signature must be specified prior to calling the Verify method.) This method allows for the signature to be set via a hex or base64 encoded string. The encoding should be set to either "hex" or "base64".

Returns 1 for success, 0 for failure.

SetKeyExplicit(groupSizeInBytes As Long, pHex As String, qHex As String, gHex As String, xHex As String) As Long

Sets the DSA object's private key from explicitly provided pHex, qHex, gHex, and xHex values. The groupSizeInBytes specifies the group size (in bytes). It is typically equal to 20, which is the length of the underlying hash function (SHA-1) for signing. The pHex, qHex, gHex, and xHex values are hex-encoded SSH1-format bignums.

Returns 1 for success, 0 for failure.

SetPubKeyExplicit(groupSizeInBytes As Long, pHex As String, qHex As String, gHex As String, yHex As String) As Long

Sets the DSA object's private key from explicitly provided pHex, qHex, gHex, and yHex values. The groupSizeInBytes specifies the group size (in bytes). It is typically equal to 20, which is the length of the underlying hash function (SHA-1) for signing. The pHex, qHex, gHex, and yHex values are hex-encoded SSH1-format bignums.

Returns 1 for success, 0 for failure.

SignHash() As Long

Signs a hash using the digital signature algorithm. Before calling this method, set the hash to be signed by either calling SetEncodedHash or by setting the Hash property. If SignHash returns 1, the signature may be retrieved by either calling GetEncodedHash, or by accessing the Signature property.

Returns 1 for success, 0 for failure.

ToDer() As Variant

Writes the DSA private key to a DER-encoded byte array.

Returns a zero-length byte array (as a Variant) on failure

ToDerFile(filename As String) As Long

Writes the DSA private key to a DER-format file.

Returns 1 for success, 0 for failure.

ToEncryptedPem(password As String) As String

Writes the DSA private key to an in-memory encrypted PEM string.

Returns a null on failure

ToPem() As String

Writes the DSA private key to an in-memory PEM string.

Returns a null on failure

ToPublicDer() As Variant

Writes the DSA public key to a DER-encoded byte array.

Returns a zero-length byte array (as a Variant) on failure

ToPublicDerFile(filename As String) As Long

Writes the DSA public key to a DER-format file.

Returns 1 for success, 0 for failure.

ToPublicPem() As String

Writes the DSA public key to an in-memory PEM string.

Returns a null on failure

ToXml(bPublicOnly As Long) As String

Writes the DSA private or public key to an in-memory XML string. The bPublicOnly determines whether the public or private key is written.

Returns a null on failure

UnlockComponent(unlockCode As String) As Long

Unlocks the component. This must be called once prior to calling any other method.

Returns 1 for success, 0 for failure.

Verify() As Long

Verifies a DSA signature. The Hash and Signature properties must be set prior to calling this method. (These properties may also be set via the SetEncodedHash and SetEncodedSignature methods.)

Returns 1 for success, 0 for failure.

VerifyKey() As Long

Verifies that the public or private key contained in the calling Dsa object is valid. Returns 1 if valid, otherwise returns 0.