ECC Class

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

Syntax

class ipworksencrypt.ECC

Remarks

The ECC (Elliptic Curve Cryptography) class 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 class supports the following common operations:

• create_key allows key creation using algorithms such as secp256r1, secp384r1, secp521r1, X25519, X448, Ed25519, Ed448, and more.
• compute_secret computes a shared secret between two parties using a public and private key (ECDH).
• sign and verify_signature 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 class is very flexible and offers many properties and configuration settings to configure the class. The sections below detail the use of the class for each of the major operations listed above.

Key Creation and Management

create_key creates a new public and private key.

When this method is called key is populated with the generated key. The key_public_key and key_private_key property 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:

• key_rx
• key_ry

The private key consists of one value:

• keyk

Curve25519 and Curve448 Notes

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

key_x_pk holds the public key.

key_x_sk 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 class will use the public key specified by recipient_key_public_key and the private key specified by key to compute a shared secret, or secret agreement. The compute_secret_kdf property specifies the Hash or HMAC algorithm that is applied to the raw secret. The resulting value is held by shared_secret. The following properties are applicable when calling this method:

• key (required)
• recipient_key_public_key (required)
• compute_secret_kdf (optional)

See compute_secret_kdf 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 class 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. key_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 create_key for details about key creation and algorithms.

When this method is called data will be read from the input_file or input_message.

The hash to be signed will be computed using the specified hash_algorithm. The computed hash is stored in the hash_value property. The signed hash is stored in the hash_signature property.

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

The on_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 hash_signature and original input data so the other party may perform signature verification.

The following properties are applicable when calling this method:

• key (required)
• hash_algorithm (applicable to ECDSA only)
• hash_ed_dsa (applicable to EdDSA only)
• hash_value (not applicable to PureEdDSA)
• use_hex

The following properties are populated after calling this method:

• hash_value
• hash_signature

EdDSA Notes

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

• hash_ed_dsa
• EdDSAContext

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

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

Before calling this method specify the input file by setting input_file or input_message.

A public key and the hash signature are required to perform the signature verification. Specify the public key in signer_key. Specify the hash signature in hash_signature.

When this method is called the class will compute the hash for the specified file and populate hash_value. It will verify the signature using the specified signer_key and hash_signature.

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

The on_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:

• hash_signature (required)
• signer_key (required)
• EdDSAContext (applicable to EdDSA only)
• hash_algorithm (applicable to ECDSA only)
• hash_ed_dsa (applicable to EdDSA only)
• hash_value (not applicable to PureEdDSA)
• use_hex

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 recipient_key.

Encryption is performed using ECIES which requires an ECDSA key. recipient_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 create_key for details about key creation and algorithms.

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

The following properties are applicable when calling this method:

• encryption_algorithm
• hmac_algorithm
• HMACOptionalInfo
• HMACKeySize
• iv
• kdf
• kdf_hash_algorithm
• KDFOptionalInfo
• use_hex

Input and Output Properties

The class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

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. 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 create_key for details about key creation and algorithms.

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

The following properties are applicable when calling this method:

• encryption_algorithm
• hmac_algorithm
• HMACOptionalInfo
• HMACKeySize
• iv
• kdf
• kdf_hash_algorithm
• KDFOptionalInfo
• use_hex

Input and Output Properties

The class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

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

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

Method List

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

Event List

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

Config Settings

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

compute_secret_kdf Property

The key derivation function.

Syntax

def get_compute_secret_kdf() -> int: ...
def set_compute_secret_kdf(value: int) -> None: ...

compute_secret_kdf = property(get_compute_secret_kdf, set_compute_secret_kdf)

Default Value

1

Remarks

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

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

encryption_algorithm Property

The encryption algorithm to use.

Syntax

def get_encryption_algorithm() -> int: ...
def set_encryption_algorithm(value: int) -> None: ...

encryption_algorithm = property(get_encryption_algorithm, set_encryption_algorithm)

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

When encryption_algorithm is set to iesAES AES CBC with a default key size of 256 bits is used. To specify a different key size set EncryptionKeySize.

hash_algorithm Property

The hash algorithm used for hash computation.

Syntax

def get_hash_algorithm() -> int: ...
def set_hash_algorithm(value: int) -> None: ...

hash_algorithm = property(get_hash_algorithm, set_hash_algorithm)

Default Value

2

Remarks

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

When key_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.

hash_ed_dsa Property

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

Syntax

def get_hash_ed_dsa() -> bool: ...
def set_hash_ed_dsa(value: bool) -> None: ...

hash_ed_dsa = property(get_hash_ed_dsa, set_hash_ed_dsa)

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 class 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 class 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 key_algorithm is set to Ed25519 or Ed448.

If this property is set before calling sign it must be set before calling verify_signature.

hash_signature Property

The hash signature.

Syntax

def get_hash_signature() -> bytes: ...
def set_hash_signature(value: bytes) -> None: ...

hash_signature = property(get_hash_signature, set_hash_signature)

Default Value

""

Remarks

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

hash_value Property

The hash value of the data.

Syntax

def get_hash_value() -> bytes: ...
def set_hash_value(value: bytes) -> None: ...

hash_value = property(get_hash_value, set_hash_value)

Default Value

""

Remarks

This property holds the computed hash value for the specified data. This is populated when calling sign or verify_signature when an input file is specified by setting input_file or input_message.

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

This setting is not applicable to PureEdDSA algorithms. If key_algorithm is Ed25519 or Ed448 and hash_ed_dsa is False (default), the PureEdDSA algorithm is use and hash_value is not applicable.

Hash Notes

The class will determine whether or not to recompute the hash based on the properties that are set. If a file is specified by input_file or input_message the hash will be recomputed when calling sign or verify_signature. If the hash_value property is set the class will only sign the hash or verify the hash signature. Setting input_file or input_message clears the hash_value property. Setting the hash_value property clears the input file selection.

hmac_algorithm Property

The HMAC algorithm to use during encryption.

Syntax

def get_hmac_algorithm() -> int: ...
def set_hmac_algorithm(value: int) -> None: ...

hmac_algorithm = property(get_hmac_algorithm, set_hmac_algorithm)

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.

input_file Property

The file to process.

Syntax

def get_input_file() -> str: ...
def set_input_file(value: str) -> None: ...

input_file = property(get_input_file, set_input_file)

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 class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

input_message Property

The message to process.

Syntax

def get_input_message() -> bytes: ...
def set_input_message(value: bytes) -> None: ...

input_message = property(get_input_message, set_input_message)

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

iv Property

The initialization vector (IV) used when encrypting.

Syntax

def get_iv() -> bytes: ...
def set_iv(value: bytes) -> None: ...

iv = property(get_iv, set_iv)

Default Value

""

Remarks

This property optionally specifies an IV to be used when calling encrypt or decrypt. If specified the iv is used by encryption_algorithm during encryption.

If not specified the class 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 encryption_algorithm is set to XOR.

kdf Property

The key derivation function used during encryption and decryption.

Syntax

def get_kdf() -> str: ...
def set_kdf(value: str) -> None: ...

kdf = property(get_kdf, set_kdf)

Default Value

"KDF2"

Remarks

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

• "KDF1"
• "KDF2" (Default)

The kdf_hash_algorithm specifies the hash algorithm used in conjunction with the specified KDF.

This property is only applicable when calling encrypt or decrypt.

kdf_hash_algorithm Property

The KDF hash algorithm to use when encrypting and decrypting.

Syntax

def get_kdf_hash_algorithm() -> int: ...
def set_kdf_hash_algorithm(value: int) -> None: ...

kdf_hash_algorithm = property(get_kdf_hash_algorithm, set_kdf_hash_algorithm)

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_algorithm Property

This property holds the algorithm associated with the key.

Syntax

def get_key_algorithm() -> int: ...
def set_key_algorithm(value: int) -> None: ...

key_algorithm = property(get_key_algorithm, set_key_algorithm)

Default Value

0

Remarks

This property holds the algorithm associated with the key. Possible values are:

• 0 (eaSecp256r1)
• 1 (eaSecp384r1)
• 2 (eaSecp521r1)
• 3 (eaEd25519)
• 4 (eaEd448)
• 5 (eaX25519)
• 6 (eaX448)
• 7 (eaSecp160k1)
• 8 (eaSecp192k1)
• 9 (eaSecp224k1)
• 10 (eaSecp256k1)
• 11 (eaBrainpoolP160r1)
• 12 (eaBrainpoolP192r1)
• 13 (eaBrainpoolP224r1)
• 14 (eaBrainpoolP256r1)
• 15 (eaBrainpoolP320r1)
• 16 (eaBrainpoolP384r1)
• 17 (eaBrainpoolP512r1)
• 18 (eaBrainpoolP160t1)
• 19 (eaBrainpoolP192t1)
• 20 (eaBrainpoolP224t1)
• 21 (eaBrainpoolP256t1)
• 22 (eaBrainpoolP320t1)
• 23 (eaBrainpoolP384t1)
• 24 (eaBrainpoolP512t1)

When assigning a key using the PEM formatted key_private_key and key_public_key the key_algorithm property will be automatically updated with the key algorithm.

When assigning a key using the raw key parameters (keyk, key_rx, and key_ry for NIST or key_x_pk, and key_x_sk for Curve25519/Curve448) the key_algorithm property must be set manually to the key algorithm.

The following table summarizes the supported operations for keys created with each algorithm:

keyk Property

Represent the private key (K) parameter.

Syntax

def get_keyk() -> bytes: ...
def set_keyk(value: bytes) -> None: ...

keyk = property(get_keyk, set_keyk)

Default Value

""

Remarks

Represent the private key (K) parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

key_private_key Property

This property is a PEM formatted private key.

Syntax

def get_key_private_key() -> str: ...
def set_key_private_key(value: str) -> None: ...

key_private_key = property(get_key_private_key, set_key_private_key)

Default Value

""

Remarks

This property is a PEM formatted private key. The purpose of this property is to allow easier management of the private key parameters by using only a single value.

key_public_key Property

This property is a PEM formatted public key.

Syntax

def get_key_public_key() -> str: ...
def set_key_public_key(value: str) -> None: ...

key_public_key = property(get_key_public_key, set_key_public_key)

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

key_rx Property

Represents the public key's Rx parameter.

Syntax

def get_key_rx() -> bytes: ...
def set_key_rx(value: bytes) -> None: ...

key_rx = property(get_key_rx, set_key_rx)

Default Value

""

Remarks

Represents the public key's Rx parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

key_ry Property

Represents the public key's Ry parameter.

Syntax

def get_key_ry() -> bytes: ...
def set_key_ry(value: bytes) -> None: ...

key_ry = property(get_key_ry, set_key_ry)

Default Value

""

Remarks

Represents the public key's Ry parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

key_x_pk Property

Holds the public key data.

Syntax

def get_key_x_pk() -> bytes: ...
def set_key_x_pk(value: bytes) -> None: ...

key_x_pk = property(get_key_x_pk, set_key_x_pk)

Default Value

""

Remarks

Holds the public key data.

Note: This value is only applicable when using Curve25519 or Curve448.

key_x_sk Property

Holds the private key data.

Syntax

def get_key_x_sk() -> bytes: ...
def set_key_x_sk(value: bytes) -> None: ...

key_x_sk = property(get_key_x_sk, set_key_x_sk)

Default Value

""

Remarks

Holds the private key data.

Note: This value is only applicable when using Curve25519 or Curve448.

output_file Property

The output file when encrypting or decrypting.

Syntax

def get_output_file() -> str: ...
def set_output_file(value: str) -> None: ...

output_file = property(get_output_file, set_output_file)

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 class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

output_message Property

The output message when encrypting or decrypting.

Syntax

def get_output_message() -> bytes: ...

output_message = property(get_output_message, None)

Default Value

""

Remarks

This property will be populated with the output after calling encrypt or decrypt if output_file is not set.

This property is only applicable to encrypt and decrypt.

Input and Output Properties

The class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

This property is read-only.

overwrite Property

Indicates whether or not the class should overwrite files.

Syntax

def get_overwrite() -> bool: ...
def set_overwrite(value: bool) -> None: ...

overwrite = property(get_overwrite, set_overwrite)

Default Value

FALSE

Remarks

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

recipient_key_algorithm Property

This property holds the algorithm associated with the key.

Syntax

def get_recipient_key_algorithm() -> int: ...
def set_recipient_key_algorithm(value: int) -> None: ...

recipient_key_algorithm = property(get_recipient_key_algorithm, set_recipient_key_algorithm)

Default Value

0

Remarks

This property holds the algorithm associated with the key. Possible values are:

• 0 (eaSecp256r1)
• 1 (eaSecp384r1)
• 2 (eaSecp521r1)
• 3 (eaEd25519)
• 4 (eaEd448)
• 5 (eaX25519)
• 6 (eaX448)
• 7 (eaSecp160k1)
• 8 (eaSecp192k1)
• 9 (eaSecp224k1)
• 10 (eaSecp256k1)
• 11 (eaBrainpoolP160r1)
• 12 (eaBrainpoolP192r1)
• 13 (eaBrainpoolP224r1)
• 14 (eaBrainpoolP256r1)
• 15 (eaBrainpoolP320r1)
• 16 (eaBrainpoolP384r1)
• 17 (eaBrainpoolP512r1)
• 18 (eaBrainpoolP160t1)
• 19 (eaBrainpoolP192t1)
• 20 (eaBrainpoolP224t1)
• 21 (eaBrainpoolP256t1)
• 22 (eaBrainpoolP320t1)
• 23 (eaBrainpoolP384t1)
• 24 (eaBrainpoolP512t1)

When assigning a key using the PEM formatted recipient_key_private_key and recipient_key_public_key the recipient_key_algorithm property will be automatically updated with the key algorithm.

When assigning a key using the raw key parameters (recipient_keyk, recipient_key_rx, and recipient_key_ry for NIST or recipient_key_x_pk, and recipient_key_x_sk for Curve25519/Curve448) the recipient_key_algorithm property must be set manually to the key algorithm.

The following table summarizes the supported operations for keys created with each algorithm:

recipient_key_public_key Property

This property is a PEM formatted public key.

Syntax

def get_recipient_key_public_key() -> str: ...
def set_recipient_key_public_key(value: str) -> None: ...

recipient_key_public_key = property(get_recipient_key_public_key, set_recipient_key_public_key)

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

recipient_key_rx Property

Represents the public key's Rx parameter.

Syntax

def get_recipient_key_rx() -> bytes: ...
def set_recipient_key_rx(value: bytes) -> None: ...

recipient_key_rx = property(get_recipient_key_rx, set_recipient_key_rx)

Default Value

""

Remarks

Represents the public key's Rx parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

recipient_key_ry Property

Represents the public key's Ry parameter.

Syntax

def get_recipient_key_ry() -> bytes: ...
def set_recipient_key_ry(value: bytes) -> None: ...

recipient_key_ry = property(get_recipient_key_ry, set_recipient_key_ry)

Default Value

""

Remarks

Represents the public key's Ry parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

recipient_key_x_pk Property

Holds the public key data.

Syntax

def get_recipient_key_x_pk() -> bytes: ...
def set_recipient_key_x_pk(value: bytes) -> None: ...

recipient_key_x_pk = property(get_recipient_key_x_pk, set_recipient_key_x_pk)

Default Value

""

Remarks

Holds the public key data.

Note: This value is only applicable when using Curve25519 or Curve448.

shared_secret Property

The computed shared secret.

Syntax

def get_shared_secret() -> bytes: ...

shared_secret = property(get_shared_secret, None)

Default Value

""

Remarks

This property holds the shared secret computed by compute_secret.

This property is read-only.

signer_key_algorithm Property

This property holds the algorithm associated with the key.

Syntax

def get_signer_key_algorithm() -> int: ...
def set_signer_key_algorithm(value: int) -> None: ...

signer_key_algorithm = property(get_signer_key_algorithm, set_signer_key_algorithm)

Default Value

0

Remarks

This property holds the algorithm associated with the key. Possible values are:

• 0 (eaSecp256r1)
• 1 (eaSecp384r1)
• 2 (eaSecp521r1)
• 3 (eaEd25519)
• 4 (eaEd448)
• 5 (eaX25519)
• 6 (eaX448)
• 7 (eaSecp160k1)
• 8 (eaSecp192k1)
• 9 (eaSecp224k1)
• 10 (eaSecp256k1)
• 11 (eaBrainpoolP160r1)
• 12 (eaBrainpoolP192r1)
• 13 (eaBrainpoolP224r1)
• 14 (eaBrainpoolP256r1)
• 15 (eaBrainpoolP320r1)
• 16 (eaBrainpoolP384r1)
• 17 (eaBrainpoolP512r1)
• 18 (eaBrainpoolP160t1)
• 19 (eaBrainpoolP192t1)
• 20 (eaBrainpoolP224t1)
• 21 (eaBrainpoolP256t1)
• 22 (eaBrainpoolP320t1)
• 23 (eaBrainpoolP384t1)
• 24 (eaBrainpoolP512t1)

When assigning a key using the PEM formatted signer_key_private_key and signer_key_public_key the signer_key_algorithm property will be automatically updated with the key algorithm.

When assigning a key using the raw key parameters (signer_keyk, signer_key_rx, and signer_key_ry for NIST or signer_key_x_pk, and signer_key_x_sk for Curve25519/Curve448) the signer_key_algorithm property must be set manually to the key algorithm.

The following table summarizes the supported operations for keys created with each algorithm:

signer_key_public_key Property

This property is a PEM formatted public key.

Syntax

def get_signer_key_public_key() -> str: ...
def set_signer_key_public_key(value: str) -> None: ...

signer_key_public_key = property(get_signer_key_public_key, set_signer_key_public_key)

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

signer_key_rx Property

Represents the public key's Rx parameter.

Syntax

def get_signer_key_rx() -> bytes: ...
def set_signer_key_rx(value: bytes) -> None: ...

signer_key_rx = property(get_signer_key_rx, set_signer_key_rx)

Default Value

""

Remarks

Represents the public key's Rx parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

signer_key_ry Property

Represents the public key's Ry parameter.

Syntax

def get_signer_key_ry() -> bytes: ...
def set_signer_key_ry(value: bytes) -> None: ...

signer_key_ry = property(get_signer_key_ry, set_signer_key_ry)

Default Value

""

Remarks

Represents the public key's Ry parameter.

Note: This value is only applicable when using an NIST, Koblitz, or Brainpool curve.

signer_key_x_pk Property

Holds the public key data.

Syntax

def get_signer_key_x_pk() -> bytes: ...
def set_signer_key_x_pk(value: bytes) -> None: ...

signer_key_x_pk = property(get_signer_key_x_pk, set_signer_key_x_pk)

Default Value

""

Remarks

Holds the public key data.

Note: This value is only applicable when using Curve25519 or Curve448.

use_hex Property

Whether binary values are hex encoded.

Syntax

def get_use_hex() -> bool: ...
def set_use_hex(value: bool) -> None: ...

use_hex = property(get_use_hex, set_use_hex)

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 shared_secret is hex encoded when compute_secret is called.

Sign and Verify Notes

This property specifies whether hash_value and hash_signature are hex encoded.

If set to True, when sign is called the class will compute the hash for the specified file and populate hash_value with the hex encoded hash value. It will then create the hash signature and populate hash_signature with the hex encoded hash signature value. If hash_value is specified directly it must be a hex encoded value.

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

Encrypt and Decrypt Notes

If set to True, when encrypt is called the class will perform the encryption as normal and then hex encode the output. output_message or output_file will hold hex encoded data.

If set to True, when decrypt is called the class will expect input_message or input_file to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.

compute_secret Method

Computes a shared secret.

Syntax

def compute_secret() -> None: ...

Remarks

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

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

• key (required)
• recipient_key_public_key (required)
• compute_secret_kdf (optional)

See compute_secret_kdf 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

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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.

create_key Method

Creates a new key.

Syntax

def create_key(key_algorithm: str) -> None: ...

Remarks

create_key creates a new public and private key.

When this method is called key is populated with the generated key. The key_public_key and key_private_key property 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:

• key_rx
• key_ry

The private key consists of one value:

• keyk

Curve25519 and Curve448 Notes

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

key_x_pk holds the public key.

key_x_sk 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

Decrypted the specified data.

Syntax

def decrypt() -> None: ...

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. 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 create_key for details about key creation and algorithms.

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

The following properties are applicable when calling this method:

• encryption_algorithm
• hmac_algorithm
• HMACOptionalInfo
• HMACKeySize
• iv
• kdf
• kdf_hash_algorithm
• KDFOptionalInfo
• use_hex

Input and Output Properties

The class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

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

Encrypts the specified data.

Syntax

def encrypt() -> None: ...

Remarks

encrypt encrypts the specified data with the ECDSA public key specified in recipient_key.

Encryption is performed using ECIES which requires an ECDSA key. recipient_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 create_key for details about key creation and algorithms.

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

The following properties are applicable when calling this method:

• encryption_algorithm
• hmac_algorithm
• HMACOptionalInfo
• HMACKeySize
• iv
• kdf
• kdf_hash_algorithm
• KDFOptionalInfo
• use_hex

Input and Output Properties

The class 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

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

Resets the class.

Syntax

def reset() -> None: ...

Remarks

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

sign Method

Creates a hash signature using ECDSA or EdDSA.

Syntax

def sign() -> None: ...

Remarks

sign will create a hash signature using ECDSA or EdDSA. The class 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. key_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 create_key for details about key creation and algorithms.

When this method is called data will be read from the input_file or input_message.

The hash to be signed will be computed using the specified hash_algorithm. The computed hash is stored in the hash_value property. The signed hash is stored in the hash_signature property.

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

The on_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 hash_signature and original input data so the other party may perform signature verification.

The following properties are applicable when calling this method:

• key (required)
• hash_algorithm (applicable to ECDSA only)
• hash_ed_dsa (applicable to EdDSA only)
• hash_value (not applicable to PureEdDSA)
• use_hex

The following properties are populated after calling this method:

• hash_value
• hash_signature

EdDSA Notes

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

• hash_ed_dsa
• EdDSAContext

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

verify_signature Method

Verifies the signature for the specified data.

Syntax

def verify_signature() -> bool: ...

Remarks

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

Before calling this method specify the input file by setting input_file or input_message.

A public key and the hash signature are required to perform the signature verification. Specify the public key in signer_key. Specify the hash signature in hash_signature.

When this method is called the class will compute the hash for the specified file and populate hash_value. It will verify the signature using the specified signer_key and hash_signature.

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

The on_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:

• hash_signature (required)
• signer_key (required)
• EdDSAContext (applicable to EdDSA only)
• hash_algorithm (applicable to ECDSA only)
• hash_ed_dsa (applicable to EdDSA only)
• hash_value (not applicable to PureEdDSA)
• use_hex

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();

on_error Event

Fired when information is available about errors during data delivery.

Syntax

class ECCErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class ECC:
@property
def on_error() -> Callable[[ECCErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[ECCErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

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

on_progress Event

Fired as progress is made.

Syntax

class ECCProgressEventParams(object):
  @property
  def bytes_processed() -> int: ...

  @property
  def percent_processed() -> int: ...

# In class ECC:
@property
def on_progress() -> Callable[[ECCProgressEventParams], None]: ...
@on_progress.setter
def on_progress(event_hook: Callable[[ECCProgressEventParams], None]) -> None: ...

Remarks

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

The PercentProcessed parameter indicates the current status of the operation.

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

ECC Config Settings

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the config method.

ECC Config Settings

Base Config Settings

ECC Errors

ECC Errors

	102   No Key specified.
	104   Cannot read or write file.
	111   OutputFile already exists and Overwrite is False.
	120   Invalid curve.
	124   HashSignature must be specified.
	304   Cannot write file.
	305   Cannot read file.
	306   Cannot create file.
	1401   Specified ECC parameters are invalid.
	1402   Missing hash value.
	1403   Public key must be specified.
	1404   Key must be specified.
	1405   HashSignature must be specified.
	1406   Invalid key size.
	1407   Invalid TLS seed. TLSSeed must be 64 bytes long.
	1408   Invalid TLS label.
	1409   Unsupported key format.
	1410   Unsupported curve.