Dsa Unicode C Reference Documentation

Dsa

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

HCkDsaW CkDsaW_Create(void);

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

void CkDsaW_Dispose(HCkDsaW handle);

Objects created by calling CkDsaW_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkDsaW_Dispose.

Properties

void CkDsaW_getDebugLogFilePath(HCkDsaW cHandle, HCkString retval);

void CkDsaW_putDebugLogFilePath(HCkDsaW cHandle, const wchar_t *newVal);

const wchar_t *CkDsaW_debugLogFilePath(HCkDsaW cHandle);

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.

int CkDsaW_getGroupSize(HCkDsaW cHandle);

void CkDsaW_putGroupSize(HCkDsaW cHandle, int newVal);

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.

void CkDsaW_getHash(HCkDsaW cHandle, HCkByteData retval);

void CkDsaW_putHash(HCkDsaW cHandle, HCkByteData newVal);

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.

void CkDsaW_getHexG(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_hexG(HCkDsaW cHandle);

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.

void CkDsaW_getHexP(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_hexP(HCkDsaW cHandle);

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.

void CkDsaW_getHexQ(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_hexQ(HCkDsaW cHandle);

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.

void CkDsaW_getHexX(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_hexX(HCkDsaW cHandle);

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

void CkDsaW_getHexY(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_hexY(HCkDsaW cHandle);

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.)

void CkDsaW_getLastErrorHtml(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_lastErrorHtml(HCkDsaW cHandle);

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.

void CkDsaW_getLastErrorText(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_lastErrorText(HCkDsaW cHandle);

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.

void CkDsaW_getLastErrorXml(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_lastErrorXml(HCkDsaW cHandle);

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.

BOOL CkDsaW_getLastMethodSuccess(HCkDsaW cHandle);

void CkDsaW_putLastMethodSuccess(HCkDsaW cHandle, BOOL newVal);

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.

void CkDsaW_getSignature(HCkDsaW cHandle, HCkByteData retval);

void CkDsaW_putSignature(HCkDsaW cHandle, HCkByteData newVal);

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

BOOL CkDsaW_getVerboseLogging(HCkDsaW cHandle);

void CkDsaW_putVerboseLogging(HCkDsaW cHandle, BOOL newVal);

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.

void CkDsaW_getVersion(HCkDsaW cHandle, HCkString retval);

const wchar_t *CkDsaW_version(HCkDsaW cHandle);

Version of the component/library, such as "9.4.1.42"

Methods

BOOL CkDsaW_FromDer(HCkDsaW cHandle, HCkByteData derData);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_FromDerFile(HCkDsaW cHandle, const wchar_t *path);

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

Returns TRUE for success, FALSE for failure.

Convert DSA DER Private Key to PEM

BOOL CkDsaW_FromEncryptedPem(HCkDsaW cHandle, const wchar_t *password, const wchar_t *pemData);

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.

BOOL CkDsaW_FromPem(HCkDsaW cHandle, const wchar_t *pemData);

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

Returns TRUE for success, FALSE for failure.

DSA Signature Create and Verify

BOOL CkDsaW_FromPublicDer(HCkDsaW cHandle, HCkByteData derData);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_FromPublicDerFile(HCkDsaW cHandle, const wchar_t *path);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_FromPublicPem(HCkDsaW cHandle, const wchar_t *pemData);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_FromXml(HCkDsaW cHandle, const wchar_t *xmlKey);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_GenKey(HCkDsaW cHandle, int numBits);

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.

DSA Generate Key

BOOL CkDsaW_GenKeyFromParamsDer(HCkDsaW cHandle, HCkByteData derBytes);

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.

BOOL CkDsaW_GenKeyFromParamsDerFile(HCkDsaW cHandle, const wchar_t *path);

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.

Generate new DSA Key from OpenSSL Parameters File

BOOL CkDsaW_GenKeyFromParamsPem(HCkDsaW cHandle, const wchar_t *pem);

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.

BOOL CkDsaW_GenKeyFromParamsPemFile(HCkDsaW cHandle, const wchar_t *path);

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.

BOOL CkDsaW_GetEncodedHash(HCkDsaW cHandle, const wchar_t *encoding, HCkString outStr);

const wchar_t *CkDsaW_getEncodedHash(HCkDsaW cHandle, const wchar_t *encoding);

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.

BOOL CkDsaW_GetEncodedSignature(HCkDsaW cHandle, const wchar_t *encoding, HCkString outStr);

const wchar_t *CkDsaW_getEncodedSignature(HCkDsaW cHandle, const wchar_t *encoding);

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.

BOOL CkDsaW_LoadText(HCkDsaW cHandle, const wchar_t *path, HCkString outStr);

const wchar_t *CkDsaW_loadText(HCkDsaW cHandle, const wchar_t *path);

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.

BOOL CkDsaW_SaveLastError(HCkDsaW cHandle, const wchar_t *path);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_SaveText(HCkDsaW cHandle, const wchar_t *strToSave, const wchar_t *path);

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.

BOOL CkDsaW_SetEncodedHash(HCkDsaW cHandle, const wchar_t *encoding, const wchar_t *encodedHash);

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.

BOOL CkDsaW_SetEncodedSignature(HCkDsaW cHandle, const wchar_t *encoding, const wchar_t *encodedSig);

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.

BOOL CkDsaW_SetEncodedSignatureRS(HCkDsaW cHandle, const wchar_t *encoding, const wchar_t *encodedR, const wchar_t *encodedS);

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.

BOOL CkDsaW_SetKeyExplicit(HCkDsaW cHandle, int groupSizeInBytes, const wchar_t *pHex, const wchar_t *qHex, const wchar_t *gHex, const wchar_t *xHex);

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.

BOOL CkDsaW_SetPubKeyExplicit(HCkDsaW cHandle, int groupSizeInBytes, const wchar_t *pHex, const wchar_t *qHex, const wchar_t *gHex, const wchar_t *yHex);

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.

BOOL CkDsaW_SignHash(HCkDsaW cHandle);

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.

DSA Signature Create and Verify

BOOL CkDsaW_ToDer(HCkDsaW cHandle, HCkByteData outBytes);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_ToDerFile(HCkDsaW cHandle, const wchar_t *path);

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

Returns TRUE for success, FALSE for failure.

DSA Generate Key

BOOL CkDsaW_ToEncryptedPem(HCkDsaW cHandle, const wchar_t *password, HCkString outStr);

const wchar_t *CkDsaW_toEncryptedPem(HCkDsaW cHandle, const wchar_t *password);

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

Returns TRUE for success, FALSE for failure.

DSA Generate Key

Convert DSA DER Private Key to PEM

BOOL CkDsaW_ToPem(HCkDsaW cHandle, HCkString outStr);

const wchar_t *CkDsaW_toPem(HCkDsaW cHandle);

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

Returns TRUE for success, FALSE for failure.

Convert DSA DER Private Key to PEM

BOOL CkDsaW_ToPublicDer(HCkDsaW cHandle, HCkByteData outBytes);

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

Returns TRUE for success, FALSE for failure.

BOOL CkDsaW_ToPublicDerFile(HCkDsaW cHandle, const wchar_t *path);

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

Returns TRUE for success, FALSE for failure.

DSA Generate Key

BOOL CkDsaW_ToPublicPem(HCkDsaW cHandle, HCkString outStr);

const wchar_t *CkDsaW_toPublicPem(HCkDsaW cHandle);

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

Returns TRUE for success, FALSE for failure.

DSA Generate Key

BOOL CkDsaW_ToXml(HCkDsaW cHandle, BOOL bPublicOnly, HCkString outStr);

const wchar_t *CkDsaW_toXml(HCkDsaW cHandle, BOOL bPublicOnly);

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.

DSA Generate Key

BOOL CkDsaW_UnlockComponent(HCkDsaW cHandle, const wchar_t *unlockCode);

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

Returns TRUE for success, FALSE for failure.

Diagnosing UnlockComponent Problems

UnlockComponent LastErrorText shows exact string passed to it.

Verify UnlockComponent Success w/ Permanent Unlock Code

LastErrorText Standard Information

BOOL CkDsaW_Verify(HCkDsaW cHandle);

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.

DSA Signature Create and Verify

BOOL CkDsaW_VerifyKey(HCkDsaW cHandle);

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

DSA Signature Create and Verify