Dsa PureBasic Reference Documentation

Dsa

Current Version: 10.1.2

Requires Chilkat Bundle License

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

obj.i = CkDsa::ckCreate()

; Make sure to dispose of the object when finished like this:
CkDsa::ckDispose(obj);

Properties

DebugLogFilePath

Declare.s ckDebugLogFilePath(obj.i)
Declare setCkDebugLogFilePath(obj.i, value.s)

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.

More Information and Examples

Example showing how to use DebugLogFilePath.

GroupSize

Declare.i ckGroupSize(obj.i)
Declare setCkGroupSize(obj.i, value.i)

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.

HexG

Declare.s ckHexG(obj.i) ; (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

Declare.s ckHexP(obj.i) ; (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

Declare.s ckHexQ(obj.i) ; (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

Declare.s ckHexX(obj.i) ; (read-only)

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

HexY

Declare.s ckHexY(obj.i) ; (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

Declare.s ckLastErrorHtml(obj.i) ; (read-only)

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.

LastErrorText

Declare.s ckLastErrorText(obj.i) ; (read-only)

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.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

Declare.s ckLastErrorXml(obj.i) ; (read-only)

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.

LastMethodSuccess

Declare.i ckLastMethodSuccess(obj.i)
Declare setCkLastMethodSuccess(obj.i, value.i)

Indicates the success or failure of the most recent method call: 1 means success, 0 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.

UncommonOptions

Declare.s ckUncommonOptions(obj.i)
Declare setCkUncommonOptions(obj.i, value.s)

Introduced in version 9.5.0.90

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string and should typically remain empty.

VerboseLogging

Declare.i ckVerboseLogging(obj.i)
Declare setCkVerboseLogging(obj.i, value.i)

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version

Declare.s ckVersion(obj.i) ; (read-only)

Version of the component/library, such as "10.1.0"

More Information and Examples

How to get the Chilkat version at runtime.

Methods

FromDerFile

Declare.i ckFromDerFile(obj.i, path.s)

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

Returns 1 for success, 0 for failure.

More Information and Examples

Convert DSA DER Private Key to PEM

FromEncryptedPem

Declare.i ckFromEncryptedPem(obj.i, password.s, pemData.s)

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

Declare.i ckFromPem(obj.i, pemData.s)

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

Returns 1 for success, 0 for failure.

More Information and Examples

DSA Signature Create and Verify

FromPublicDerFile

Declare.i ckFromPublicDerFile(obj.i, path.s)

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

Returns 1 for success, 0 for failure.

FromPublicPem

Declare.i ckFromPublicPem(obj.i, pemData.s)

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

Returns 1 for success, 0 for failure.

FromXml

Declare.i ckFromXml(obj.i, xmlKey.s)

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

Returns 1 for success, 0 for failure.

GenKey

Declare.i ckGenKey(obj.i, numBits.l)

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.

More Information and Examples

DSA Generate Key

GenKey2

Declare.i ckGenKey2(obj.i, keyLenBits.l, modLenBits.l)

Introduced in version 9.5.0.90

Generates a new DSA key that is keyLenBits bits in length with a modulus of size modLenBits bits. The keyLenBits should be at least 1024 bits and a multiple of 64. FIPS 186-4 specifies the key length (bits) and modulus size (bits) to have one of the values: (1024, 160), (2048, 224), (2048, 256), or (3072, 256).

Returns 1 for success, 0 for failure.

GenKeyFromParamsDerFile

Declare.i ckGenKeyFromParamsDerFile(obj.i, path.s)

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.

More Information and Examples

Generate new DSA Key from OpenSSL Parameters File

GenKeyFromParamsPem

Declare.i ckGenKeyFromParamsPem(obj.i, pem.s)

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

Declare.i ckGenKeyFromParamsPemFile(obj.i, path.s)

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.

GenKeyFromPQG

Declare.i ckGenKeyFromPQG(obj.i, pHex.s, qHex.s, gHex.s)

Introduced in version 9.5.0.90

Generates a new DSA key from pre-chosen P, Q, and G params.

Returns 1 for success, 0 for failure.

GetEncodedHash

Declare.s ckGetEncodedHash(obj.i, encoding.s)

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 an empty string on failure. Use the LastMethodSuccess property to check for success.

GetEncodedSignature

Declare.s ckGetEncodedSignature(obj.i, encoding.s)

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 an empty string on failure. Use the LastMethodSuccess property to check for success.

LoadText

Declare.s ckLoadText(obj.i, path.s)

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 an empty string on failure. Use the LastMethodSuccess property to check for success.

SaveText

Declare.i ckSaveText(obj.i, strToSave.s, path.s)

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

Declare.i ckSetEncodedHash(obj.i, encoding.s, encodedHash.s)

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

Declare.i ckSetEncodedSignature(obj.i, encoding.s, encodedSig.s)

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.

SetEncodedSignatureRS

Declare.i ckSetEncodedSignatureRS(obj.i, encoding.s, encodedR.s, encodedS.s)

Sets the bytes of the Signature property by providing the R and S values in encoded form. (The signature must be specified prior to calling the Verify method.) The R and S values may 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

Declare.i ckSetKeyExplicit(obj.i, groupSizeInBytes.l, pHex.s, qHex.s, gHex.s, xHex.s)

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

Declare.i ckSetPubKeyExplicit(obj.i, groupSizeInBytes.l, pHex.s, qHex.s, gHex.s, yHex.s)

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

Declare.i ckSignHash(obj.i)

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.

More Information and Examples

DSA Signature Create and Verify

ToDerFile

Declare.i ckToDerFile(obj.i, path.s)

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

Returns 1 for success, 0 for failure.

More Information and Examples

DSA Generate Key

ToEncryptedPem

Declare.s ckToEncryptedPem(obj.i, password.s)

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

Returns an empty string on failure. Use the LastMethodSuccess property to check for success.

More Information and Examples

DSA Generate Key Convert DSA DER Private Key to PEM

ToPem

Declare.s ckToPem(obj.i)

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

Returns an empty string on failure. Use the LastMethodSuccess property to check for success.

More Information and Examples

Convert DSA DER Private Key to PEM

ToPublicDerFile

Declare.i ckToPublicDerFile(obj.i, path.s)

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

Returns 1 for success, 0 for failure.

More Information and Examples

DSA Generate Key

ToPublicPem

Declare.s ckToPublicPem(obj.i)

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

Returns an empty string on failure. Use the LastMethodSuccess property to check for success.

More Information and Examples

DSA Generate Key

ToXml

Declare.s ckToXml(obj.i, bPublicOnly.l)

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 an empty string on failure. Use the LastMethodSuccess property to check for success.

More Information and Examples

DSA Get Key as XML

Verify

Declare.i ckVerify(obj.i)

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.

More Information and Examples

DSA Signature Create and Verify DSA R,S Signature Values

VerifyKey

Declare.i ckVerifyKey(obj.i)

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

More Information and Examples

DSA Signature Create and Verify