ECC Component

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The ECC (Elliptic Curve Cryptography) component implements ECDSA, EdDSA, ECDH, and ECIES operations.

Syntax

nsoftware.IPWorksEncrypt.Ecc

Remarks

The ECC (Elliptic Curve Cryptography) component implements ECDSA (Elliptic Curve Digital Signature Algorithm), EdDSA (Edwards-curve Digital Signature Algorithm), and ECDH (Elliptic Curve Diffie Hellman), and ECIES (Elliptic Curve Integrated Encryption Scheme) operations. The component supports the following common operations:

• CreateKey allows key creation using algorithms such as secp256r1, secp384r1, secp521r1, X25519, X448, Ed25519, Ed448, and more.
• ComputeSecret computes a shared secret between two parties using a public and private key (ECDH).
• Sign and VerifySignature provides a way to digitally sign data and verify signatures (ECDSA and EdDSA).
• Encrypt and Decrypt encrypt and decrypt data using a public and private key (ECIES).

The component is very flexible and offers many properties and configuration settings to configure the component. The sections below detail the use of the component for each of the major operations listed above.

Key Creation and Management

CreateKey creates a new public and private key.

When this method is called Key is populated with the generated key. The PublicKey and PrivateKey field hold the PEM formatted public and private key for ease of use. This is helpful for storing or transporting keys more easily.

The KeyAlgorithm parameter specifies the algorithm for which the key is intended to be used. Possible values are:

NIST, Koblitz, and Brainpool Curve Notes

Keys for use with NIST curves (secp256r1, secp384r1, secp521r1), Koblitz curves (secp160k1, secp192k1, secp224k1, secp256k1), and Brainpool curves are made up of a number of individual parameters.

The public key consists of the following parameters:

• Rx
• Ry

The private key consists of one value:

• K

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

Create Key Example (secp256r1 - PEM)

//Create a key using secp256r1 Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (secp256r1 - Raw Key Params)

//Create a key using secp256r1 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" byte[] K = ecc.Key.KB; //Private key param byte[] Rx = ecc.Key.RxB; //Public key param byte[] Ry = ecc.Key.RyB; //Public key param //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaSecp256r1; //This MUST be set manually when using key params directly ecc.Key.KB = K; ecc.Key.RxB = Rx; ecc.Key.RyB = Ry; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (Ed25519 - PEM)

//Create a key using Ed25519 Ecc ecc = new Ecc(); ecc.CreateKey("Ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Create Key Example (Ed25519 - Raw Key Params)

//Create a key using Ed25519 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("Ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" byte[] XPk = ecc.Key.XPkB; //Public key data byte[] XSk = ecc.Key.XSkB; //Secret key data //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaEd25519; //This MUST be set manually when using key params directly ecc.Key.XPkB = XPk; ecc.Key.XSkB = XSk; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Compute Secret (ECDH)

This method computes a shared secret using Elliptic Curve Diffie Hellman (ECDH).

When this method is called the component will use the public key specified by RecipientKey and the private key specified by Key to compute a shared secret, or secret agreement. The ComputeSecretKDF property specifies the Hash or HMAC algorithm that is applied to the raw secret. The resulting value is held by SharedSecret. The following properties are applicable when calling this method:

• Key (required)
• RecipientKey (required)
• ComputeSecretKDF (optional)

See ComputeSecretKDF for details on advanced settings that may be applicable for the chosen algorithm.

Keys created with the Ed25519 and Ed448 algorithms are not supported when calling this method.

Compute Secret Example

//Create a key for Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("X25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Create a key for Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("X25519"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Note: the public keys must be exchanged between parties by some mechanism //Create the shared secret on Party 1 ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; //Private key of this party ecc1.RecipientKey.PublicKey = ecc2_pub; //Public key of other party ecc1.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc1.ComputeSecret(); Console.WriteLine(ecc1.SharedSecret); //Create the shared secret on Party 2 ecc2.Reset(); ecc2.Key.PrivateKey = ecc2_priv; //Private key of this party ecc2.RecipientKey.PublicKey = ecc1_pub; //Public key of other party ecc2.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc2.ComputeSecret(); Console.WriteLine(ecc2.SharedSecret); //This will match the shared secret created by ecc1.

Signing (ECDSA and EdDSA)

Sign will create a hash signature using ECDSA or EdDSA. The component will use the key specified by Key to has the input data and sign the resulting hash.

Key must contain a private key created with a valid ECDSA or EdDSA algorithm. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for signing are:

• NIST Curves (secp256r1, secp384r1, secp521r1)
• Koblitz Curves (secp160k1, secp192k1, secp224k1, secp256k1)
• Brainpool Curves
• Ed25519 and Ed448

See CreateKey for details about key creation and algorithms.

When this method is called data will be read from the stream set by SetInputStream, InputFile, or InputMessage.

The hash to be signed will be computed using the specified HashAlgorithm. The computed hash is stored in the HashValue property. The signed hash is stored in the HashSignature property.

To sign as hash without first computing it set HashValue to a previously computed hash for the input data. Note: HashValue is not applicable when signing with a PureEdDSA algorithm such as "Ed25519" or "Ed448".

The Progress event will fire with updates for the hash computation progress only. The hash signature creation process is quick and does not require progress updates.

After calling Sign the public key must be sent to the recipient along with HashSignature and original input data so the other party may perform signature verification.

The following properties are applicable when calling this method:

• Key (required)
• HashAlgorithm (applicable to ECDSA only)
• HashEdDSA (applicable to EdDSA only)
• HashValue (not applicable to PureEdDSA)
• UseHex

The following properties are populated after calling this method:

• HashValue
• HashSignature

EdDSA Notes

When the Algorithm is Ed25519 or Ed448 the following additional parameters are applicable:

• HashEdDSA
• EdDSAContext

EdDSA keys can be used with a PureEdDSA algorithm (Ed25519/Ed448) or as HashEdDSA (Ed25519ph, Ed448ph) algorithm. This is controlled by the HashEdDSA property. By default the component uses the PureEdDSA algorithm.

The PureEdDSA algorithm requires two passes over the input data but provides collision resilience. The collision resilience of PureEdDSA means even if it is feasible to compute collisions for the hash function, the algorithm is still secure. When using PureEdDSA HashValue is not applicable.

When using a HashEdDSA algorithm the input is pre-hashed and supports a single pass over the data during the signing operation. To enable HashEdDSA set HashEdDSA to True.

To specify context data when using Ed25519 or Ed448 set EdDSAContext.

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Verifying (ECDSA and EdDSA)

VerifySignature will verify a hash signature and return True if successful or False otherwise.

Before calling this method specify the input file by setting SetInputStream, InputFile, or InputMessage.

A public key and the hash signature are required to perform the signature verification. Specify the public key in SignerKey. Specify the hash signature in HashSignature.

When this method is called the component will compute the hash for the specified file and populate HashValue. It will verify the signature using the specified SignerKey and HashSignature.

To verify the hash signature without first computing the hash simply specify HashValue before calling this method. Note: HashValue is not applicable when the message was signed with a PureEdDSA algorithm such as Ed25519 or Ed448.

The Progress event will fire with updates for the hash computation progress only. The hash signature verification process is quick and does not require progress updates.

The following properties are applicable when calling this method:

• HashSignature (required)
• SignerKey (required)
• EdDSAContext (applicable to EdDSA only)
• HashAlgorithm (applicable to ECDSA only)
• HashEdDSA (applicable to EdDSA only)
• HashValue (not applicable to PureEdDSA)
• UseHex

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Encrypting (ECIES)

Encrypt encrypts the specified data with the ECDSA public key specified in RecipientKey.

Encryption is performed using ECIES which requires an ECDSA key. RecipientKey must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

• NIST Curves (secp256r1, secp384r1, secp521r1)
• Koblitz Curves (secp160k1, secp192k1, secp224k1, secp256k1)
• Brainpool Curves

See CreateKey for details about key creation and algorithms.

When this method is called the component will encrypt the specified data using ECIES and the encrypted data will be output. To hex encode the output set UseHex to True.

The following properties are applicable when calling this method:

• EncryptionAlgorithm
• HMACAlgorithm
• HMACOptionalInfo
• HMACKeySize
• IV
• KDF
• KDFHashAlgorithm
• KDFOptionalInfo
• UseHex

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Decrypting (ECIES)

Decrypt decrypts the specified data with the ECDSA private key specified in Key.

Decryption is performed using ECIES which requires an ECDSA key. Key must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

• NIST Curves (secp256r1, secp384r1, secp521r1)
• Koblitz Curves (secp160k1, secp192k1, secp224k1, secp256k1)
• Brainpool Curves

See CreateKey for details about key creation and algorithms.

When this method is called the component will decrypt the specified data using ECIES and the decrypted data will be output. If the input data was originally hex encoded, set UseHex to True.

The following properties are applicable when calling this method:

• EncryptionAlgorithm
• HMACAlgorithm
• HMACOptionalInfo
• HMACKeySize
• IV
• KDF
• KDFHashAlgorithm
• KDFOptionalInfo
• UseHex

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

ComputeSecretKDF Property (ECC Component)

The key derivation function.

Syntax

• C#
• VB.NET

public EccComputeSecretKDFs ComputeSecretKDF { get; set; }

enum EccComputeSecretKDFs {
  ekdSHA1,
  ekdSHA256,
  ekdSHA384,
  ekdSHA512,
  ekdMD2,
  ekdMD4,
  ekdMD5,
  ekdHMACSHA1,
  ekdHMACSHA256,
  ekdHMACSHA384,
  ekdHMACSHA512,
  ekdHMACMD5,
  ekdTLS,
  ekdConcat
}

Public Property ComputeSecretKDF As EccComputeSecretKDFs

Enum EccComputeSecretKDFs
  ekdSHA1
  ekdSHA256
  ekdSHA384
  ekdSHA512
  ekdMD2
  ekdMD4
  ekdMD5
  ekdHMACSHA1
  ekdHMACSHA256
  ekdHMACSHA384
  ekdHMACSHA512
  ekdHMACMD5
  ekdTLS
  ekdConcat
End Enum

Default Value

1

Remarks

This property specifies the key derivation function (KDF) and algorithm to use when calling ComputeSecret.

Possible values are:

HMAC Notes

If an HMAC algorithm is selected HMACKey may optionally be set to specify the key.

TLS Notes

When set to TLS, TLSSeed and TLSLabel are required. In addition PrependSecret and AppendSecret are not applicable.

Concat Notes

If Concat is selected the following configuration settings are applicable:

• ConcatAlgorithmId (required)
• ConcatPartyUInfo (required)
• ConcatPartyVInfo (required)
• ConcatSuppPubInfo
• ConcatSuppPrivInfo
• ConcatHashAlgorithm

EncryptionAlgorithm Property (ECC Component)

The encryption algorithm to use.

Syntax

• C#
• VB.NET

public EccEncryptionAlgorithms EncryptionAlgorithm { get; set; }

enum EccEncryptionAlgorithms {
  iesAES,
  iesTripleDES,
  iesXOR
}

Public Property EncryptionAlgorithm As EccEncryptionAlgorithms

Enum EccEncryptionAlgorithms
  iesAES
  iesTripleDES
  iesXOR
End Enum

Default Value

0

Remarks

This setting specifies the encryption algorithm to use when Encrypt is called. This must also be set before calling Decrypt to match the algorithm used during the initial encryption.

Possible values are:

• 0 (iesAES - default)
• 1 (iesTripleDES)
• 2 (iesXOR)

AES Notes

HashAlgorithm Property (ECC Component)

The hash algorithm used for hash computation.

Syntax

• C#
• VB.NET

public EccHashAlgorithms HashAlgorithm { get; set; }

enum EccHashAlgorithms {
  ehaSHA1,
  ehaSHA224,
  ehaSHA256,
  ehaSHA384,
  ehaSHA512,
  ehaMD2,
  ehaMD4,
  ehaMD5,
  ehaMD5SHA1,
  ehaRIPEMD160
}

Public Property HashAlgorithm As EccHashAlgorithms

Enum EccHashAlgorithms
  ehaSHA1
  ehaSHA224
  ehaSHA256
  ehaSHA384
  ehaSHA512
  ehaMD2
  ehaMD4
  ehaMD5
  ehaMD5SHA1
  ehaRIPEMD160
End Enum

Default Value

2

Remarks

This property specifies the hash algorithm used for hash computation. This is only applicable when calling Sign or VerifySignature and Algorithm specifies a ECDSA key (NIST, Koblitz, or Brainpool curve). Possible values are:

When Algorithm specified an EdDSA key this setting is not applicable, as the hash algorithm is defined by the specification as SHA-512 for Ed25519 and SHAKE-256 for Ed448.

HashEdDSA Property (ECC Component)

Whether to use HashEdDSA when signing with an Ed25519 or Ed448 key.

Syntax

• C#
• VB.NET

public bool HashEdDSA { get; set; }

Public Property HashEdDSA As Boolean

Default Value

False

Remarks

This setting specifies whether to use the HashEdDSA algorithm when signing and verifying with Ed25519 or Ed448 keys.

If set to True the component will use the HashEdDSA algorithm (Ed25519ph or Ed448ph) when signing and verifying. When using a HashEdDSA algorithm the input is pre-hashed and supports a single pass over the data during the signing operation.

If set to False (Default) the component will use the PureEdDSA algorithm (Ed25519 or Ed448) when signing. The PureEdDSA requires two passes over the input data but provides collision resilience. The collision resilience of PureEdDSA means even if it is feasible to compute collisions for the hash function, the algorithm is still secure.

This property is only applicable when calling Sign and Algorithm is set to Ed25519 or Ed448.

If this property is set before calling Sign it must be set before calling VerifySignature.

HashSignature Property (ECC Component)

The hash signature.

Syntax

• C#
• VB.NET

public string HashSignature { get; set; }
public byte[] HashSignatureB { get; set; }

Public Property HashSignature As String
Public Property HashSignatureB As Byte()

Default Value

""

Remarks

This property holds the computed hash signature. This is populated after calling Sign. This must be set before calling VerifySignature.

HashValue Property (ECC Component)

The hash value of the data.

Syntax

• C#
• VB.NET

public string HashValue { get; set; }
public byte[] HashValueB { get; set; }

Public Property HashValue As String
Public Property HashValueB As Byte()

Default Value

""

Remarks

This property holds the computed hash value for the specified data. This is populated when calling Sign or VerifySignature when an input file is specified by setting SetInputStream, InputFile, or InputMessage.

Pre-existing hash values may be set to this property before calling Sign or VerifySignature. If you know the hash value prior to using the component you may specify the pre-computed hash value here.

This setting is not applicable to PureEdDSA algorithms. If Algorithm is Ed25519 or Ed448 and HashEdDSA is False (default), the PureEdDSA algorithm is use and HashValue is not applicable.

Hash Notes

The component will determine whether or not to recompute the hash based on the properties that are set. If a file is specified by SetInputStream, InputFile, or InputMessage the hash will be recomputed when calling Sign or VerifySignature. If the HashValue property is set the component will only sign the hash or verify the hash signature. Setting SetInputStream, InputFile, or InputMessage clears the HashValue property. Setting the HashValue property clears the input file selection.

HMACAlgorithm Property (ECC Component)

The HMAC algorithm to use during encryption.

Syntax

• C#
• VB.NET

public EccHMACAlgorithms HMACAlgorithm { get; set; }

enum EccHMACAlgorithms {
  iesHMACSHA1,
  iesHMACSHA224,
  iesHMACSHA256,
  iesHMACSHA384,
  iesHMACSHA512,
  iesHMACRIPEMD160
}

Public Property HMACAlgorithm As EccHMACAlgorithms

Enum EccHMACAlgorithms
  iesHMACSHA1
  iesHMACSHA224
  iesHMACSHA256
  iesHMACSHA384
  iesHMACSHA512
  iesHMACRIPEMD160
End Enum

Default Value

2

Remarks

This property specifies the HMAC algorithm to use when encrypting. The HMAC algorithm is used when Encrypt and Decrypt are called to protect and verify data. Possible values are:

• 0 (iesHMACSHA1)
• 1 (iesHMACSHA224)
• 2 (iesHMACSHA256 - Default)
• 3 (iesHMACSHA384)
• 4 (iesHMACSHA512)
• 5 (iesHMACRIPEMD160)

This property is only applicable when calling Encrypt or Decrypt.

InputFile Property (ECC Component)

The file to process.

Syntax

• C#
• VB.NET

public string InputFile { get; set; }

Public Property InputFile As String

Default Value

""

Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

InputMessage Property (ECC Component)

The message to process.

Syntax

• C#
• VB.NET

public string InputMessage { get; set; }
public byte[] InputMessageB { get; set; }

Public Property InputMessage As String
Public Property InputMessageB As Byte()

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

IV Property (ECC Component)

The initialization vector (IV) used when encrypting.

Syntax

• C#
• VB.NET

public string IV { get; set; }
public byte[] IVB { get; set; }

Public Property IV As String
Public Property IVB As Byte()

Default Value

""

Remarks

This property optionally specifies an IV to be used when calling Encrypt or Decrypt. If specified the IV is used by EncryptionAlgorithm during encryption.

If not specified the component will create an IV filled with null bytes (zeros). Since the encryption key is only used once the use of null bytes in the IV is considered acceptable and is a standard practice.

The length of the IV should be as follows:

This setting is not applicable when EncryptionAlgorithm is set to XOR.

KDF Property (ECC Component)

The key derivation function used during encryption and decryption.

Syntax

• C#
• VB.NET

public string KDF { get; set; }

Public Property KDF As String

Default Value

"KDF2"

Remarks

This property specifies the key derivation function (KDF) to use when encrypting and decrypting. Possible values are:

• "KDF1"
• "KDF2" (Default)

This property is only applicable when calling Encrypt or Decrypt.

KDFHashAlgorithm Property (ECC Component)

The KDF hash algorithm to use when encrypting and decrypting.

Syntax

• C#
• VB.NET

public EccKDFHashAlgorithms KDFHashAlgorithm { get; set; }

enum EccKDFHashAlgorithms {
  iesSHA1,
  iesSHA224,
  iesSHA256,
  iesSHA384,
  iesSHA512
}

Public Property KDFHashAlgorithm As EccKDFHashAlgorithms

Enum EccKDFHashAlgorithms
  iesSHA1
  iesSHA224
  iesSHA256
  iesSHA384
  iesSHA512
End Enum

Default Value

2

Remarks

This property specifies the hash algorithm to use in when deriving a key using the specified KDF. Possible values are:

• 0 (iesSHA1)
• 1 (iesSHA224)
• 2 (iesSHA256)
• 3 (iesSHA384)
• 4 (iesSHA512)

This property is only applicable when calling Encrypt or Decrypt.

Key Property (ECC Component)

The ECC key.

Syntax

• C#
• VB.NET

public ECCKey Key { get; set; }

Public Property Key As ECCKey

Remarks

This property specifies the ECC private key. This property must be set before calling Sign or ComputeSecret.

NIST, Koblitz, and Brainpool Curve Notes

Keys for use with NIST curves (secp256r1, secp384r1, secp521r1), Koblitz curves (secp160k1, secp192k1, secp224k1, secp256k1), and Brainpool curves are made up of a number of individual parameters.

The public key consists of the following parameters:

• Rx
• Ry

The private key consists of one value:

• K

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

OutputFile Property (ECC Component)

The output file when encrypting or decrypting.

Syntax

• C#
• VB.NET

public string OutputFile { get; set; }

Public Property OutputFile As String

Default Value

""

Remarks

This property specifies the file to which the output will be written when Encrypt or Decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

OutputMessage Property (ECC Component)

The output message when encrypting or decrypting.

Syntax

• C#
• VB.NET

public string OutputMessage { get; }
public byte[] OutputMessageB { get; }

Public ReadOnly Property OutputMessage As String
Public ReadOnly Property OutputMessageB As Byte()

Default Value

""

Remarks

This property will be populated with the output after calling Encrypt or Decrypt if OutputFile and SetOutputStream are not set.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

This property is read-only and not available at design time.

Overwrite Property (ECC Component)

Indicates whether or not the component should overwrite files.

Syntax

• C#
• VB.NET

public bool Overwrite { get; set; }

Public Property Overwrite As Boolean

Default Value

False

Remarks

This property indicates whether or not the component will overwrite OutputFile. If Overwrite is False, an error will be thrown whenever OutputFile exists before an operation. The default value is False.

RecipientKey Property (ECC Component)

The public key used to compute the shared secret.

Syntax

• C#
• VB.NET

public ECCKey RecipientKey { get; set; }

Public Property RecipientKey As ECCKey

Remarks

This property specifies the public key used to compute the shared secret. This must be set before calling ComputeSecret.

SharedSecret Property (ECC Component)

The computed shared secret.

Syntax

• C#
• VB.NET

public string SharedSecret { get; }
public byte[] SharedSecretB { get; }

Public ReadOnly Property SharedSecret As String
Public ReadOnly Property SharedSecretB As Byte()

Default Value

""

Remarks

This property holds the shared secret computed by ComputeSecret.

This property is read-only.

SignerKey Property (ECC Component)

The public key used to verify the signature.

Syntax

• C#
• VB.NET

public ECCKey SignerKey { get; set; }

Public Property SignerKey As ECCKey

Remarks

This property specifies the public key used to verify the signature. This public key corresponds to the private key used when creating the signature. This must be set before calling VerifySignature.

UseHex Property (ECC Component)

Whether binary values are hex encoded.

Syntax

• C#
• VB.NET

public bool UseHex { get; set; }

Public Property UseHex As Boolean

Default Value

False

Remarks

This setting specifies whether various calculated values are hex encoded. If set to False (Default) all data is provided as-is with no encoding.

If set to True certain properties are hex encoded when populated for ease of display, transport, and storage.

Compute Secret Notes

This property specifies whether SharedSecret is hex encoded when ComputeSecret is called.

Sign and Verify Notes

This property specifies whether HashValue and HashSignature are hex encoded.

If set to True, when Sign is called the component will compute the hash for the specified file and populate HashValue with the hex encoded hash value. It will then create the hash signature and populate HashSignature with the hex encoded hash signature value. If HashValue is specified directly it must be a hex encoded value.

If set to True, when VerifySignature is called the component will compute the hash value for the specified file and populate HashValue with the hex encoded hash value. It will then hex decode HashSignature and verify the signature. HashSignature must hold a hex encoded value. If HashValue is specified directly it must be a hex encoded value.

Encrypt and Decrypt Notes

If set to True, when Encrypt is called the component will perform the encryption as normal and then hex encode the output. OutputMessage or OutputFile will hold hex encoded data.

If set to True, when Decrypt is called the component will expect InputMessage or InputFile to hold hex encoded data. The component will then hex decode the data and perform decryption as normal.

ComputeSecret Method (ECC Component)

Computes a shared secret.

Syntax

• C#
• VB.NET

public void ComputeSecret();

Async Version
public async Task ComputeSecret();
public async Task ComputeSecret(CancellationToken cancellationToken);

Public Sub ComputeSecret()

Async Version
Public Sub ComputeSecret() As Task
Public Sub ComputeSecret(cancellationToken As CancellationToken) As Task

Remarks

This method computes a shared secret using Elliptic Curve Diffie Hellman (ECDH).

When this method is called the component will use the public key specified by RecipientKey and the private key specified by Key to compute a shared secret, or secret agreement. The ComputeSecretKDF property specifies the Hash or HMAC algorithm that is applied to the raw secret. The resulting value is held by SharedSecret. The following properties are applicable when calling this method:

• Key (required)
• RecipientKey (required)
• ComputeSecretKDF (optional)

See ComputeSecretKDF for details on advanced settings that may be applicable for the chosen algorithm.

Keys created with the Ed25519 and Ed448 algorithms are not supported when calling this method.

Compute Secret Example

//Create a key for Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("X25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Create a key for Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("X25519"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Note: the public keys must be exchanged between parties by some mechanism //Create the shared secret on Party 1 ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; //Private key of this party ecc1.RecipientKey.PublicKey = ecc2_pub; //Public key of other party ecc1.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc1.ComputeSecret(); Console.WriteLine(ecc1.SharedSecret); //Create the shared secret on Party 2 ecc2.Reset(); ecc2.Key.PrivateKey = ecc2_priv; //Private key of this party ecc2.RecipientKey.PublicKey = ecc1_pub; //Public key of other party ecc2.UseHex = true; //Hex encodes the shared secret bytes for easier display/storage ecc2.ComputeSecret(); Console.WriteLine(ecc2.SharedSecret); //This will match the shared secret created by ecc1.

Config Method (ECC Component)

Sets or retrieves a configuration setting.

Syntax

• C#
• VB.NET

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);

Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

CreateKey Method (ECC Component)

Creates a new key.

Syntax

• C#
• VB.NET

public void CreateKey(string keyAlgorithm);

Async Version
public async Task CreateKey(string keyAlgorithm);
public async Task CreateKey(string keyAlgorithm, CancellationToken cancellationToken);

Public Sub CreateKey(ByVal KeyAlgorithm As String)

Async Version
Public Sub CreateKey(ByVal KeyAlgorithm As String) As Task
Public Sub CreateKey(ByVal KeyAlgorithm As String, cancellationToken As CancellationToken) As Task

Remarks

CreateKey creates a new public and private key.

When this method is called Key is populated with the generated key. The PublicKey and PrivateKey field hold the PEM formatted public and private key for ease of use. This is helpful for storing or transporting keys more easily.

The KeyAlgorithm parameter specifies the algorithm for which the key is intended to be used. Possible values are:

NIST, Koblitz, and Brainpool Curve Notes

Keys for use with NIST curves (secp256r1, secp384r1, secp521r1), Koblitz curves (secp160k1, secp192k1, secp224k1, secp256k1), and Brainpool curves are made up of a number of individual parameters.

The public key consists of the following parameters:

• Rx
• Ry

The private key consists of one value:

• K

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

Create Key Example (secp256r1 - PEM)

//Create a key using secp256r1 Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (secp256r1 - Raw Key Params)

//Create a key using secp256r1 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("secp256r1"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1" byte[] K = ecc.Key.KB; //Private key param byte[] Rx = ecc.Key.RxB; //Public key param byte[] Ry = ecc.Key.RyB; //Public key param //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaSecp256r1; //This MUST be set manually when using key params directly ecc.Key.KB = K; ecc.Key.RxB = Rx; ecc.Key.RyB = Ry; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaSecp256r1"

Create Key Example (Ed25519 - PEM)

//Create a key using Ed25519 Ecc ecc = new Ecc(); ecc.CreateKey("Ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" string privKey = ecc.Key.PrivateKey; //PEM formatted key string pubKey = ecc.Key.PublicKey; //PEM formatted key //Load the saved key ecc.Reset(); ecc.Key.PublicKey = pubKey; ecc.Key.PrivateKey = privKey; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Create Key Example (Ed25519 - Raw Key Params)

//Create a key using Ed25519 and store/load the key using the individual params Ecc ecc = new Ecc(); ecc.CreateKey("Ed25519"); Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519" byte[] XPk = ecc.Key.XPkB; //Public key data byte[] XSk = ecc.Key.XSkB; //Secret key data //Load the saved key ecc.Reset(); ecc.Key.Algorithm = ECAlgorithms.eaEd25519; //This MUST be set manually when using key params directly ecc.Key.XPkB = XPk; ecc.Key.XSkB = XSk; Console.WriteLine(ecc.Key.Algorithm); //outputs enum value "eaEd25519"

Decrypt Method (ECC Component)

Decrypted the specified data.

Syntax

• C#
• VB.NET

public void Decrypt();

Async Version
public async Task Decrypt();
public async Task Decrypt(CancellationToken cancellationToken);

Public Sub Decrypt()

Async Version
Public Sub Decrypt() As Task
Public Sub Decrypt(cancellationToken As CancellationToken) As Task

Remarks

Decrypt decrypts the specified data with the ECDSA private key specified in Key.

Decryption is performed using ECIES which requires an ECDSA key. Key must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

• NIST Curves (secp256r1, secp384r1, secp521r1)
• Koblitz Curves (secp160k1, secp192k1, secp224k1, secp256k1)
• Brainpool Curves

See CreateKey for details about key creation and algorithms.

When this method is called the component will decrypt the specified data using ECIES and the decrypted data will be output. If the input data was originally hex encoded, set UseHex to True.

The following properties are applicable when calling this method:

• EncryptionAlgorithm
• HMACAlgorithm
• HMACOptionalInfo
• HMACKeySize
• IV
• KDF
• KDFHashAlgorithm
• KDFOptionalInfo
• UseHex

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt Method (ECC Component)

Encrypts the specified data.

Syntax

• C#
• VB.NET

public void Encrypt();

Async Version
public async Task Encrypt();
public async Task Encrypt(CancellationToken cancellationToken);

Public Sub Encrypt()

Async Version
Public Sub Encrypt() As Task
Public Sub Encrypt(cancellationToken As CancellationToken) As Task

Remarks

Encrypt encrypts the specified data with the ECDSA public key specified in RecipientKey.

Encryption is performed using ECIES which requires an ECDSA key. RecipientKey must contain an ECDSA key. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for encryption are:

• NIST Curves (secp256r1, secp384r1, secp521r1)
• Koblitz Curves (secp160k1, secp192k1, secp224k1, secp256k1)
• Brainpool Curves

See CreateKey for details about key creation and algorithms.

When this method is called the component will encrypt the specified data using ECIES and the encrypted data will be output. To hex encode the output set UseHex to True.

The following properties are applicable when calling this method:

• EncryptionAlgorithm
• HMACAlgorithm
• HMACOptionalInfo
• HMACKeySize
• IV
• KDF
• KDFHashAlgorithm
• KDFOptionalInfo
• UseHex

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Encrypt and Decrypt Example

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (AES with IV)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); //Use an IV (16 bytes for AES) - In a real environment this should be random byte[] IV = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc1.IVB = IV; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message and the IV to Party 2 //Decrypt the message using the private key for Party 2 and the IV ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesAES; ecc2.IVB = IV; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (XOR Encryption Algorithm)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.EncryptionAlgorithm = EccEncryptionAlgorithms.iesXOR; ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Encrypt and Decrypt Example (KDF Options)

//Create an ECDSA key on Party 2 Ecc ecc2 = new Ecc(); ecc2.CreateKey("secp256r1"); string ecc2_priv = ecc2.Key.PrivateKey; string ecc2_pub = ecc2.Key.PublicKey; //Transmit public key to Party 1 //Encrypt the message on Party 1 using public key from Party 2 Ecc ecc1 = new Ecc(); ecc1.KDF = "KDF1"; //Use KDF1 ecc1.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc1.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); //Hex encoded string ecc1.InputMessage = "hello ecc"; ecc1.RecipientKey.PublicKey = ecc2_pub; ecc1.UseHex = true; ecc1.Encrypt(); string encryptedMessage = ecc1.OutputMessage; //Transmit the encrypted message to Party 2 //Decrypt the message using the private key for Party 2 ecc2.KDF = "KDF1"; ecc2.KDFHashAlgorithm = EccKDFHashAlgorithms.iesSHA1; ecc2.Config("KDFOptionalInfo=202122232425262728292a2b2c2d2e2f"); ecc2.Key.PrivateKey = ecc2_priv; ecc2.InputMessage = encryptedMessage; ecc2.UseHex = true; ecc2.Decrypt(); Console.WriteLine(ecc2.OutputMessage);

Reset Method (ECC Component)

Resets the component

Syntax

• C#
• VB.NET

public void Reset();

Async Version
public async Task Reset();
public async Task Reset(CancellationToken cancellationToken);

Public Sub Reset()

Async Version
Public Sub Reset() As Task
Public Sub Reset(cancellationToken As CancellationToken) As Task

Remarks

When called, the component will reset all of its properties to their default values.

SetInputStream Method (ECC Component)

Sets the stream from which the component will read data to encrypt or decrypt.

Syntax

• C#
• VB.NET

public void SetInputStream(System.IO.Stream inputStream);

Async Version
public async Task SetInputStream(System.IO.Stream inputStream);
public async Task SetInputStream(System.IO.Stream inputStream, CancellationToken cancellationToken);

Public Sub SetInputStream(ByVal InputStream As System.IO.Stream)

Async Version
Public Sub SetInputStream(ByVal InputStream As System.IO.Stream) As Task
Public Sub SetInputStream(ByVal InputStream As System.IO.Stream, cancellationToken As CancellationToken) As Task

Remarks

This method sets the stream from which the component will read data to encrypt or decrypt.

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

SetOutputStream Method (ECC Component)

Sets the stream to which the component will write encrypted or decrypted data.

Syntax

• C#
• VB.NET

public void SetOutputStream(System.IO.Stream outputStream);

Async Version
public async Task SetOutputStream(System.IO.Stream outputStream);
public async Task SetOutputStream(System.IO.Stream outputStream, CancellationToken cancellationToken);

Public Sub SetOutputStream(ByVal OutputStream As System.IO.Stream)

Async Version
Public Sub SetOutputStream(ByVal OutputStream As System.IO.Stream) As Task
Public Sub SetOutputStream(ByVal OutputStream As System.IO.Stream, cancellationToken As CancellationToken) As Task

Remarks

This method sets the stream to which the component will write encrypted or decrypted data.

Input and Output Properties

The component will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Sign Method (ECC Component)

Creates a hash signature using ECDSA or EdDSA.

Syntax

• C#
• VB.NET

public void Sign();

Async Version
public async Task Sign();
public async Task Sign(CancellationToken cancellationToken);

Public Sub Sign()

Async Version
Public Sub Sign() As Task
Public Sub Sign(cancellationToken As CancellationToken) As Task

Remarks

Sign will create a hash signature using ECDSA or EdDSA. The component will use the key specified by Key to has the input data and sign the resulting hash.

Key must contain a private key created with a valid ECDSA or EdDSA algorithm. Algorithm is used to determine the eligibility of the key for this operation. Supported algorithms for signing are:

• NIST Curves (secp256r1, secp384r1, secp521r1)
• Koblitz Curves (secp160k1, secp192k1, secp224k1, secp256k1)
• Brainpool Curves
• Ed25519 and Ed448

See CreateKey for details about key creation and algorithms.

When this method is called data will be read from the stream set by SetInputStream, InputFile, or InputMessage.

The hash to be signed will be computed using the specified HashAlgorithm. The computed hash is stored in the HashValue property. The signed hash is stored in the HashSignature property.

To sign as hash without first computing it set HashValue to a previously computed hash for the input data. Note: HashValue is not applicable when signing with a PureEdDSA algorithm such as "Ed25519" or "Ed448".

The Progress event will fire with updates for the hash computation progress only. The hash signature creation process is quick and does not require progress updates.

After calling Sign the public key must be sent to the recipient along with HashSignature and original input data so the other party may perform signature verification.

The following properties are applicable when calling this method:

• Key (required)
• HashAlgorithm (applicable to ECDSA only)
• HashEdDSA (applicable to EdDSA only)
• HashValue (not applicable to PureEdDSA)
• UseHex

The following properties are populated after calling this method:

• HashValue
• HashSignature

EdDSA Notes

When the Algorithm is Ed25519 or Ed448 the following additional parameters are applicable:

• HashEdDSA
• EdDSAContext

EdDSA keys can be used with a PureEdDSA algorithm (Ed25519/Ed448) or as HashEdDSA (Ed25519ph, Ed448ph) algorithm. This is controlled by the HashEdDSA property. By default the component uses the PureEdDSA algorithm.

The PureEdDSA algorithm requires two passes over the input data but provides collision resilience. The collision resilience of PureEdDSA means even if it is feasible to compute collisions for the hash function, the algorithm is still secure. When using PureEdDSA HashValue is not applicable.

When using a HashEdDSA algorithm the input is pre-hashed and supports a single pass over the data during the signing operation. To enable HashEdDSA set HashEdDSA to True.

To specify context data when using Ed25519 or Ed448 set EdDSAContext.

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

VerifySignature Method (ECC Component)

Verifies the signature for the specified data.

Syntax

• C#
• VB.NET

public bool VerifySignature();

Async Version
public async Task<bool> VerifySignature();
public async Task<bool> VerifySignature(CancellationToken cancellationToken);

Public Function VerifySignature() As Boolean

Async Version
Public Function VerifySignature() As Task(Of Boolean)
Public Function VerifySignature(cancellationToken As CancellationToken) As Task(Of Boolean)

Remarks

VerifySignature will verify a hash signature and return True if successful or False otherwise.

Before calling this method specify the input file by setting SetInputStream, InputFile, or InputMessage.

A public key and the hash signature are required to perform the signature verification. Specify the public key in SignerKey. Specify the hash signature in HashSignature.

When this method is called the component will compute the hash for the specified file and populate HashValue. It will verify the signature using the specified SignerKey and HashSignature.

To verify the hash signature without first computing the hash simply specify HashValue before calling this method. Note: HashValue is not applicable when the message was signed with a PureEdDSA algorithm such as Ed25519 or Ed448.

The Progress event will fire with updates for the hash computation progress only. The hash signature verification process is quick and does not require progress updates.

The following properties are applicable when calling this method:

• HashSignature (required)
• SignerKey (required)
• EdDSAContext (applicable to EdDSA only)
• HashAlgorithm (applicable to ECDSA only)
• HashEdDSA (applicable to EdDSA only)
• HashValue (not applicable to PureEdDSA)
• UseHex

Sign And Verify Example (ECDSA)

//Create an ECDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("secp256r1"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - PureEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Sign And Verify Example (EdDSA - HashEdDSA)

//Create an EdDSA key on Party 1 Ecc ecc1 = new Ecc(); ecc1.CreateKey("ed25519"); string ecc1_priv = ecc1.Key.PrivateKey; string ecc1_pub = ecc1.Key.PublicKey; //Sign the data on Party 1 string originalData = "hello ecc"; ecc1.Reset(); ecc1.Key.PrivateKey = ecc1_priv; ecc1.InputMessage = originalData; ecc1.UseHex = true; //Hex encode the hash signature for ease of use. ecc1.HashEdDSA = true; //Use "ed25519ph" ecc1.Sign(); string hashSignature = ecc1.HashSignature; //Transmit the hash signature, public key, and original data to part 2 //Verify the data on Party 2 Ecc ecc2 = new Ecc(); ecc2.SignerKey.PublicKey = ecc1_pub; ecc2.InputMessage = originalData; ecc2.HashSignature = hashSignature; ecc2.HashEdDSA = true; ecc2.UseHex = true; //Decode the hex encoded hash signature bool isVerified = ecc2.VerifySignature();

Error Event (ECC Component)

Information about errors during data delivery.

Syntax

• C#
• VB.NET

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, EccErrorEventArgs e);

public class EccErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As EccErrorEventArgs)

Public Class EccErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Progress Event (ECC Component)

Fired as progress is made.

Syntax

• C#
• VB.NET

public event OnProgressHandler OnProgress;

public delegate void OnProgressHandler(object sender, EccProgressEventArgs e);

public class EccProgressEventArgs : EventArgs {
  public long BytesProcessed { get; }
  public int PercentProcessed { get; }
}

Public Event OnProgress As OnProgressHandler

Public Delegate Sub OnProgressHandler(sender As Object, e As EccProgressEventArgs)

Public Class EccProgressEventArgs Inherits EventArgs
  Public ReadOnly Property BytesProcessed As Long
  Public ReadOnly Property PercentProcessed As Integer
End Class

Remarks

This event is fired automatically as data is processed by the component.

The PercentProcessed parameter indicates the current status of the operation.

The BytesProcessed parameter holds the total number of bytes processed so far.

ECCKey Type

Contains the parameters for the ECC algorithm.

Remarks

This type is made up of fields that represent the private and public key parameters used by the ECC operations. The PrivateKey and PublicKey parameters hold a PEM formatted value for easy transport and storage of keys.

NIST, Koblitz, and Brainpool Curve Notes

Keys for use with NIST curves (secp256r1, secp384r1, secp521r1), Koblitz curves (secp160k1, secp192k1, secp224k1, secp256k1), and Brainpool curves are made up of a number of individual parameters.

The public key consists of the following parameters:

• Rx
• Ry

The private key consists of one value:

• K

Curve25519 and Curve448 Notes

Keys for use with Curve25519 or Curve448 are made up of a private key and public key field.

XPk holds the public key.

XSk holds the private key.

Fields

Constructors

• C#
• VB.NET

public ECCKey();

Public ECCKey()

The default constructor creates a new ECCKey instance but does not assign a public or private key.

• C#
• VB.NET

public ECCKey(byte[] rx, byte[] ry, int algorithm);

Public ECCKey(ByVal Rx As Byte(), ByVal Ry As Byte(), ByVal Algorithm As Integer)

The public key constructor assigns an existing public key.

• C#
• VB.NET

public ECCKey(byte[] K, byte[] rx, byte[] ry, int algorithm);

Public ECCKey(ByVal K As Byte(), ByVal Rx As Byte(), ByVal Ry As Byte(), ByVal Algorithm As Integer)

The private key constructor assigns an existing private key.

Config Settings (ECC Component)

ECC Config Settings

Base Config Settings

Trappable Errors (ECC Component)

ECC Errors