Dsa Unicode C Reference Documentation
Dsa
Current Version: 10.0.0
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 instance = CkDsaW_Create(); // ... CkDsaW_Dispose(instance);
Creates an instance of the HCkDsaW object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.
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
DebugLogFilePath
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:
- a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
- the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
- there is an internal problem (bug) in the Chilkat code that causes the hang.
GroupSize
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.
topHash
void CkDsaW_putHash(HCkDsaW cHandle, const unsigned char *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.
topHexG
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.
topHexP
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.
topHexQ
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.
topHexX
The "X" part of a DSA private key returned as a hex-encoded SSH1-format bignum.
topHexY
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.)
topLastErrorHtml
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.
topLastErrorText
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.
LastErrorXml
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.
topLastMethodSuccess
void CkDsaW_putLastMethodSuccess(HCkDsaW cHandle, BOOL newVal);
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.
topSignature
void CkDsaW_putSignature(HCkDsaW cHandle, const unsigned char *newVal);
The signature created by calling SignHash. If verifying a signature, this may be set prior to calling the Verify method.
topUncommonOptions
void CkDsaW_putUncommonOptions(HCkDsaW cHandle, const wchar_t *newVal);
const wchar_t *CkDsaW_uncommonOptions(HCkDsaW cHandle);
This is a catch-all property to be used for uncommon needs. This property defaults to the empty string and should typically remain empty.
topVerboseLogging
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.
topVersion
const wchar_t *CkDsaW_version(HCkDsaW cHandle);
Methods
FromDer
Loads a DSA private key from in-memory DSA DER-encoded bytes.
Returns TRUE for success, FALSE for failure.
topFromDerFile
Loads a DSA private key from a DER-encoded file.
Returns TRUE for success, FALSE for failure.
FromEncryptedPem
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.
topFromPem
Loads a DSA private key from an in-memory unencrypted PEM-formatted string.
Returns TRUE for success, FALSE for failure.
FromPublicDer
Loads a DSA public key from an in-memory DER-encoded byte array.
Returns TRUE for success, FALSE for failure.
topFromPublicDerFile
FromPublicPem
Loads a DSA public-key from an in-memory PEM string.
Returns TRUE for success, FALSE for failure.
topFromXml
Loads a DSA public or private key from an in-memory XML string.
Returns TRUE for success, FALSE for failure.
topGenKey
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.
GenKey2
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.
topGenKeyFromParamsDer
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.
topGenKeyFromParamsDerFile
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.derThe newly generated key may be exported by calling one of the To* methods.
Returns TRUE for success, FALSE for failure.
GenKeyFromParamsPem
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.
topGenKeyFromParamsPemFile
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.
topGenKeyFromPQG
Generates a new DSA key from pre-chosen P, Q, and G params.
Returns TRUE for success, FALSE for failure.
topGetEncodedHash
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.
topGetEncodedSignature
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.
topLoadText
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.
topSaveText
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.
topSetEncodedHash
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.
topSetEncodedSignature
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.
topSetEncodedSignatureRS
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.
topSetKeyExplicit
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.
topSetPubKeyExplicit
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.
topSignHash
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.
ToDer
Writes the DSA private key to a DER-encoded byte array.
Returns TRUE for success, FALSE for failure.
topToDerFile
Writes the DSA private key to a DER-format file.
Returns TRUE for success, FALSE for failure.
ToEncryptedPem
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.
ToPem
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.
ToPublicDer
Writes the DSA public key to a DER-encoded byte array.
Returns TRUE for success, FALSE for failure.
topToPublicDerFile
Writes the DSA public key to a DER-format file.
Returns TRUE for success, FALSE for failure.
ToPublicPem
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.
ToXml
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.
Verify
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.
VerifyKey
Verifies that the public or private key contained in the calling Dsa object is valid. Returns TRUE if valid, otherwise returns FALSE.