Ecc VB.NET Reference Documentation

Ecc

Current Version: 10.1.2

Requires Chilkat Bundle License

Elliptical Curve Cryptography class for generating ECDSA keys, computing shared secrets, and creating and verifying ECDSA signatures. Supports the following curves:

secp256r1 (also known as P-256 and prime256v1)
secp384r1 (also known as P-384)
secp521r1 (also known as P-521)
secp256k1 (This is the curve used for Bitcoin)
secp192r1
secp224r1
brainpoolP160r1
brainpoolP192r1
brainpoolP192r1
brainpoolP224r1
brainpoolP256r1
brainpoolP320r1
brainpoolP384r1
brainpoolP512r1

Additional curves will be supported in the future.

Object Creation

Dim obj As New Chilkat.Ecc()

Properties

AsnFormat

AsnFormat As Boolean

Introduced in version 9.5.0.97

If True, the ECDSA signatures produced by this object will use ASN.1 format. Otherwise the ECDSA signature will be a concatenation of the two raw byte arrays for r and s.

ECDSA signatures have two equal sized parts, r and s. There are two common formats for encoding the signature:

(a) Concatenating the raw byte array of r and s
(b) Encoding both into a structured ASN.1 / DER sequence.

The default value of this property is True, which is to use ASN.1, which is the behavior of earlier versions of Chilkat before this property was added.

More Information and Examples

Create ECSDA Signature using Raw r and s Format (not ASN.1)

DebugLogFilePath

DebugLogFilePath As String

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.

LastErrorHtml

LastErrorHtml As String (ReadOnly)

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

LastErrorText As String (ReadOnly)

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

LastErrorXml As String (ReadOnly)

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

LastMethodSuccess As Boolean

Indicates the success or failure of the most recent method call: True means success, False 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.

VerboseLogging

VerboseLogging As Boolean

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.

Version

Version As String (ReadOnly)

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

GenEccKey

Function GenEccKey(ByVal curveName As String, ByVal prng As Prng) As PrivateKey

Introduced in version 9.5.0.52

Generates an ECDSA private key. The curveName specifies the curve name which determines the key size. The prng provides a source for generating the random private key.

The following curve names are accepted:

secp256r1 (also known as P-256 and prime256v1)
secp384r1 (also known as P-384)
secp521r1 (also known as P-521)
secp256k1 (This is the curve used for Bitcoin)
secp192r1
secp224r1
brainpoolP160r1
brainpoolP192r1
brainpoolP192r1
brainpoolP224r1
brainpoolP256r1
brainpoolP320r1
brainpoolP384r1
brainpoolP512r1

Returns Nothing on failure

More Information and Examples

Generate an ECC Key Generate Brainpool EC Keys (BP256R1, BP384R1, BP512R1, ...)

GenEccKey2

Function GenEccKey2(ByVal curveName As String, ByVal encodedK As String, ByVal encoding As String) As PrivateKey

Introduced in version 9.5.0.55

Generates an ECDSA private key using a specified value for K. The curveName specifies the curve name which determines the key size. The encodedK is the encoded value of the private key. The encoding is the encoding used for encodedK, which can be "hex", "base64", "decimal", etc.

Note: This method is typically used for testing -- such as when the same private key is desired to produce results identical from run to run.

The following curve names are accepted:

secp256r1 (also known as P-256 and prime256v1)
secp384r1 (also known as P-384)
secp521r1 (also known as P-521)
secp256k1 (This is the curve used for Bitcoin)
secp192r1
secp224r1
brainpoolP160r1
brainpoolP192r1
brainpoolP192r1
brainpoolP224r1
brainpoolP256r1
brainpoolP320r1
brainpoolP384r1
brainpoolP512r1

Returns Nothing on failure

More Information and Examples

Generate ECC Keys using Specified Values for K

SharedSecretENC

Function SharedSecretENC(ByVal privKey As PrivateKey, ByVal pubKey As PublicKey, ByVal encoding As String) As String

Introduced in version 9.5.0.52

Computes a shared secret given a private and public key. For example, Alice and Bob can compute the identical shared secret by doing the following: Alice sends Bob her public key, and Bob calls SharedSecretENC with his private key and Alice's public key. Bob sends Alice his public key, and Alice calls SharedSecretENC with her private key and Bob's public key. Both calls to SharedSecretENC will produce the same result. The resulting bytes are returned in encoded string form (hex, base64, etc) as specified by encoding.

Note: The private and public keys must both be keys on the same ECDSA curve.

Returns Nothing on failure

More Information and Examples

List of Supported Encodings (Base64, Hex, etc.)How to Generate an Elliptic Curve Shared Secret

SignBd

Function SignBd(ByVal bdData As BinData, ByVal hashAlg As String, ByVal encoding As String, ByVal privKey As PrivateKey, ByVal prng As Prng) As String

Introduced in version 9.5.0.85

This method is the same as SignHashENC, except the actual data to be signed and the name of the hash algorithm is passed in. The following hash algorithms are supported: sha256, sha384, and sha512.

Returns Nothing on failure

More Information and Examples

ECDSA Sign and Verify Data using Different Hash Algorithms

SignBdUsingCert

Function SignBdUsingCert(ByVal bdData As BinData, ByVal hashAlg As String, ByVal encoding As String, ByVal cert As Cert) As String

Introduced in version 9.5.0.91

Same as SignBd, but instead uses the private key of a certificate (assuming the cert's private key is ECDSA).

Returns Nothing on failure

SignHashENC

Function SignHashENC(ByVal encodedHash As String, ByVal encoding As String, ByVal privkey As PrivateKey, ByVal prng As Prng) As String

Introduced in version 9.5.0.52

Computes an ECDSA signature on a hash. ECDSA signatures are computed and verified on the hashes of data (such as SHA1, SHA256, etc.). The hash of the data is passed in encodedHash. The encoding, such as "base64", "hex", etc. is passed in encoding. The ECDSA private key is passed in the 3rd argument (privkey). Given that creating an ECDSA signature involves the generation of random numbers, a PRNG is passed in the 4th argument (prng). The signature is returned as an encoded string using the encoding specified by the encoding argument.

Returns Nothing on failure

More Information and Examples

List of Supported Encodings (Base64, Hex, etc.)ECDSA Sign Data and Verify Signature

SignHashUsingCert

Function SignHashUsingCert(ByVal encodedHash As String, ByVal encoding As String, ByVal cert As Cert) As String

Introduced in version 10.1.0

Computes an ECDSA signature on a hash. ECDSA signatures are computed and verified on the hashes of data (such as SHA1, SHA256, etc.). The hash of the data is passed in encodedHash. The encoding, such as "base64", "hex", etc. is passed in encoding. The certificate having a private key is passed in cert. The signature is returned as an encoded string using the encoding specified by the encoding argument.

Returns Nothing on failure

VerifyBd

Function VerifyBd(ByVal bdData As BinData, ByVal hashAlg As String, ByVal encodedSig As String, ByVal encoding As String, ByVal pubkey As PublicKey) As Integer

Introduced in version 9.5.0.85

This method is the same as VerifyHashENC, except the actual data to be verified and the name of the hash algorithm is passed in. The following hash algorithms are supported: sha256, sha384, and sha512.

More Information and Examples

ECDSA Sign and Verify Data using Different Hash Algorithms

VerifyHashENC

Function VerifyHashENC(ByVal encodedHash As String, ByVal encodedSig As String, ByVal encoding As String, ByVal pubkey As PublicKey) As Integer

Introduced in version 9.5.0.52

Verifies an ECDSA signature. ECDSA signatures are computed and verified on the hashes of data (such as SHA1, SHA256, etc.). The hash of the data is passed in encodedHash. The encoded signature is passed in encodedSig. The encoding of both the hash and signature, such as "base64", "hex", etc. is passed in encoding. The ECDSA public key is passed in the last argument (pubkey).

The method returns 1 for a valid signature, 0 for an invalid signature, and -1 for any other failure.

More Information and Examples

List of Supported Encodings (Base64, Hex, etc.)ECDSA Sign Data and Verify Signature