Dsa Delphi DLL Reference Documentation

Dsa

Current Version: 9.5.0.97

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).

Create/Dispose

var
myObject: HCkDsa;

begin
myObject := CkDsa_Create();

// ...

CkDsa_Dispose(myObject);
end;
function CkDsa_Create: HCkDsa; stdcall;

Creates an instance of the HCkDsa object and returns a handle (i.e. a Pointer). The handle is passed in the 1st argument for the functions listed on this page.

procedure CkDsa_Dispose(handle: HCkDsa); stdcall;

Objects created by calling CkDsa_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.

Properties

DebugLogFilePath
procedure CkDsa_getDebugLogFilePath(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
procedure CkDsa_putDebugLogFilePath(objHandle: HCkDsa; newPropVal: PWideChar); stdcall;
function CkDsa__debugLogFilePath(objHandle: HCkDsa): PWideChar; stdcall;

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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GroupSize
function CkDsa_getGroupSize(objHandle: HCkDsa): Integer; stdcall;
procedure CkDsa_putGroupSize(objHandle: HCkDsa; newPropVal: Integer); stdcall;

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.

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Hash
procedure CkDsa_getHash(objHandle: HCkDsa; outPropVal: HCkByteData); stdcall;
procedure CkDsa_putHash(objHandle: HCkDsa; newPropVal: HCkByteData); stdcall;

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.

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HexG
procedure CkDsa_getHexG(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__hexG(objHandle: HCkDsa): PWideChar; stdcall;

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.

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HexP
procedure CkDsa_getHexP(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__hexP(objHandle: HCkDsa): PWideChar; stdcall;

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.

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HexQ
procedure CkDsa_getHexQ(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__hexQ(objHandle: HCkDsa): PWideChar; stdcall;

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.

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HexX
procedure CkDsa_getHexX(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__hexX(objHandle: HCkDsa): PWideChar; stdcall;

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

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HexY
procedure CkDsa_getHexY(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__hexY(objHandle: HCkDsa): PWideChar; stdcall;

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.)

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LastErrorHtml
procedure CkDsa_getLastErrorHtml(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__lastErrorHtml(objHandle: HCkDsa): PWideChar; stdcall;

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
procedure CkDsa_getLastErrorText(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__lastErrorText(objHandle: HCkDsa): PWideChar; stdcall;

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
procedure CkDsa_getLastErrorXml(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__lastErrorXml(objHandle: HCkDsa): PWideChar; stdcall;

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
function CkDsa_getLastMethodSuccess(objHandle: HCkDsa): wordbool; stdcall;
procedure CkDsa_putLastMethodSuccess(objHandle: HCkDsa; newPropVal: wordbool); stdcall;

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.

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Signature
procedure CkDsa_getSignature(objHandle: HCkDsa; outPropVal: HCkByteData); stdcall;
procedure CkDsa_putSignature(objHandle: HCkDsa; newPropVal: HCkByteData); stdcall;

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

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UncommonOptions
procedure CkDsa_getUncommonOptions(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
procedure CkDsa_putUncommonOptions(objHandle: HCkDsa; newPropVal: PWideChar); stdcall;
function CkDsa__uncommonOptions(objHandle: HCkDsa): PWideChar; stdcall;
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.

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VerboseLogging
function CkDsa_getVerboseLogging(objHandle: HCkDsa): wordbool; stdcall;
procedure CkDsa_putVerboseLogging(objHandle: HCkDsa; newPropVal: wordbool); stdcall;

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.

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Version
procedure CkDsa_getVersion(objHandle: HCkDsa; outPropVal: HCkString); stdcall;
function CkDsa__version(objHandle: HCkDsa): PWideChar; stdcall;

Version of the component/library, such as "9.5.0.94"

More Information and Examples
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Methods

FromDer
function CkDsa_FromDer(objHandle: HCkDsa;
    derData: HCkByteData): wordbool; stdcall;

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

Returns True for success, False for failure.

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FromDerFile
function CkDsa_FromDerFile(objHandle: HCkDsa;
    path: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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FromEncryptedPem
function CkDsa_FromEncryptedPem(objHandle: HCkDsa;
    password: PWideChar;
    pemData: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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FromPem
function CkDsa_FromPem(objHandle: HCkDsa;
    pemData: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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FromPublicDer
function CkDsa_FromPublicDer(objHandle: HCkDsa;
    derData: HCkByteData): wordbool; stdcall;

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

Returns True for success, False for failure.

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FromPublicDerFile
function CkDsa_FromPublicDerFile(objHandle: HCkDsa;
    path: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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FromPublicPem
function CkDsa_FromPublicPem(objHandle: HCkDsa;
    pemData: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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FromXml
function CkDsa_FromXml(objHandle: HCkDsa;
    xmlKey: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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GenKey
function CkDsa_GenKey(objHandle: HCkDsa;
    numBits: Integer): wordbool; stdcall;

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 True for success, False for failure.

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GenKey2
function CkDsa_GenKey2(objHandle: HCkDsa;
    keyLenBits: Integer;
    modLenBits: Integer): wordbool; stdcall;
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 True for success, False for failure.

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GenKeyFromParamsDer
function CkDsa_GenKeyFromParamsDer(objHandle: HCkDsa;
    derBytes: HCkByteData): wordbool; stdcall;

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 True for success, False for failure.

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GenKeyFromParamsDerFile
function CkDsa_GenKeyFromParamsDerFile(objHandle: HCkDsa;
    path: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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GenKeyFromParamsPem
function CkDsa_GenKeyFromParamsPem(objHandle: HCkDsa;
    pem: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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GenKeyFromParamsPemFile
function CkDsa_GenKeyFromParamsPemFile(objHandle: HCkDsa;
    path: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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GenKeyFromPQG
function CkDsa_GenKeyFromPQG(objHandle: HCkDsa;
    pHex: PWideChar;
    qHex: PWideChar;
    gHex: PWideChar): wordbool; stdcall;
Introduced in version 9.5.0.90

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

Returns True for success, False for failure.

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GetEncodedHash
function CkDsa_GetEncodedHash(objHandle: HCkDsa;
    encoding: PWideChar;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__getEncodedHash(objHandle: HCkDsa;
    encoding: PWideChar): PWideChar; stdcall;

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 True for success, False for failure.

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GetEncodedSignature
function CkDsa_GetEncodedSignature(objHandle: HCkDsa;
    encoding: PWideChar;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__getEncodedSignature(objHandle: HCkDsa;
    encoding: PWideChar): PWideChar; stdcall;

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 True for success, False for failure.

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LoadText
function CkDsa_LoadText(objHandle: HCkDsa;
    path: PWideChar;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__loadText(objHandle: HCkDsa;
    path: PWideChar): PWideChar; stdcall;

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 True for success, False for failure.

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SaveText
function CkDsa_SaveText(objHandle: HCkDsa;
    strToSave: PWideChar;
    path: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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SetEncodedHash
function CkDsa_SetEncodedHash(objHandle: HCkDsa;
    encoding: PWideChar;
    encodedHash: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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SetEncodedSignature
function CkDsa_SetEncodedSignature(objHandle: HCkDsa;
    encoding: PWideChar;
    encodedSig: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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SetEncodedSignatureRS
function CkDsa_SetEncodedSignatureRS(objHandle: HCkDsa;
    encoding: PWideChar;
    encodedR: PWideChar;
    encodedS: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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SetKeyExplicit
function CkDsa_SetKeyExplicit(objHandle: HCkDsa;
    groupSizeInBytes: Integer;
    pHex: PWideChar;
    qHex: PWideChar;
    gHex: PWideChar;
    xHex: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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SetPubKeyExplicit
function CkDsa_SetPubKeyExplicit(objHandle: HCkDsa;
    groupSizeInBytes: Integer;
    pHex: PWideChar;
    qHex: PWideChar;
    gHex: PWideChar;
    yHex: PWideChar): wordbool; stdcall;

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 True for success, False for failure.

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SignHash
function CkDsa_SignHash(objHandle: HCkDsa): wordbool; stdcall;

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 True, the signature may be retrieved by either calling GetEncodedHash, or by accessing the Signature property.

Returns True for success, False for failure.

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ToDer
function CkDsa_ToDer(objHandle: HCkDsa;
    outBytes: HCkByteData): wordbool; stdcall;

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

Returns True for success, False for failure.

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ToDerFile
function CkDsa_ToDerFile(objHandle: HCkDsa;
    path: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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ToEncryptedPem
function CkDsa_ToEncryptedPem(objHandle: HCkDsa;
    password: PWideChar;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__toEncryptedPem(objHandle: HCkDsa;
    password: PWideChar): PWideChar; stdcall;

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

Returns True for success, False for failure.

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ToPem
function CkDsa_ToPem(objHandle: HCkDsa;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__toPem(objHandle: HCkDsa): PWideChar; stdcall;

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

Returns True for success, False for failure.

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ToPublicDer
function CkDsa_ToPublicDer(objHandle: HCkDsa;
    outBytes: HCkByteData): wordbool; stdcall;

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

Returns True for success, False for failure.

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ToPublicDerFile
function CkDsa_ToPublicDerFile(objHandle: HCkDsa;
    path: PWideChar): wordbool; stdcall;

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

Returns True for success, False for failure.

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ToPublicPem
function CkDsa_ToPublicPem(objHandle: HCkDsa;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__toPublicPem(objHandle: HCkDsa): PWideChar; stdcall;

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

Returns True for success, False for failure.

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ToXml
function CkDsa_ToXml(objHandle: HCkDsa;
    bPublicOnly: wordbool;
    outStr: HCkString): wordbool; stdcall;
function CkDsa__toXml(objHandle: HCkDsa;
    bPublicOnly: wordbool): PWideChar; stdcall;

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 True for success, False for failure.

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Verify
function CkDsa_Verify(objHandle: HCkDsa): wordbool; stdcall;

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 True for success, False for failure.

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VerifyKey
function CkDsa_VerifyKey(objHandle: HCkDsa): wordbool; stdcall;

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

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