Ecc C# Reference Documentation

Ecc

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

  • secp256r1 (also known as P-256 and prime256v1)
  • secp384r1 (also known as P-384)
  • secp521r1 (also known as P-521)
  • secp256k1 (This is the curve used for Bitcoin)

Additional curves will be supported in the future.

Object Creation

Chilkat.Ecc obj = new Chilkat.Ecc();

Properties

public string DebugLogFilePath {get; set; }

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

public string LastErrorHtml {get; }

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

public string LastErrorText {get; }

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Concept of LastErrorText

LastErrorText Standard Information

public string LastErrorXml {get; }

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

public bool LastMethodSuccess {get; set; }

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of true indicates success, a value of false indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = true and failure = false.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to true. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

public bool VerboseLogging {get; set; }

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

public string Version {get; }

Version of the component/library, such as "9.5.0.63"

Methods

public PrivateKey GenEccKey(string curveName, Prng prng);

Introduced in version 9.5.0.52

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

The following curve names are accepted:

  • secp256r1 (also known as P-256 and prime256v1)
  • secp384r1 (also known as P-384)
  • secp521r1 (also known as P-521)
  • secp256k1 (This is the curve used for Bitcoin)

Returns null on failure

(C#) Generate an ECC Key

(Mono C#) Generate an ECC Key

(.NET Core C#) Generate an ECC Key

(PowerShell) Generate an ECC Key

public PrivateKey GenEccKey2(string curveName, string encodedK, string encoding);

Introduced in version 9.5.0.55

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

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

The following curve names are accepted:

  • secp256r1 (also known as P-256 and prime256v1)
  • secp384r1 (also known as P-384)
  • secp521r1 (also known as P-521)
  • secp256k1 (This is the curve used for Bitcoin)

Returns null on failure

(C#) Generate ECC Keys using Specified Values for K

(Mono C#) Generate ECC Keys using Specified Values for K

(.NET Core C#) Generate ECC Keys using Specified Values for K

(PowerShell) Generate ECC Keys using Specified Values for K

public bool SaveLastError(string path);

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

Returns true for success, false for failure.

public string SharedSecretENC(PrivateKey privKey, PublicKey pubKey, string encoding);

Introduced in version 9.5.0.52

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

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

Returns null on failure

List of Supported Encodings (Base64, Hex, etc.)

(C#) How to Generate an Elliptic Curve Shared Secret

(Mono C#) How to Generate an Elliptic Curve Shared Secret

(.NET Core C#) How to Generate an Elliptic Curve Shared Secret

(PowerShell) How to Generate an Elliptic Curve Shared Secret

public string SignHashENC(string encodedHash, string encoding, PrivateKey privkey, Prng prng);

Introduced in version 9.5.0.52

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

Returns null on failure

List of Supported Encodings (Base64, Hex, etc.)

(C#) ECDSA Sign Data and Verify Signature

(Mono C#) ECDSA Sign Data and Verify Signature

(.NET Core C#) ECDSA Sign Data and Verify Signature

(PowerShell) ECDSA Sign Data and Verify Signature

public int VerifyHashENC(string encodedHash, string encodedSig, string encoding, PublicKey pubkey);

Introduced in version 9.5.0.52

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

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

List of Supported Encodings (Base64, Hex, etc.)

(C#) ECDSA Sign Data and Verify Signature

(Mono C#) ECDSA Sign Data and Verify Signature

(.NET Core C#) ECDSA Sign Data and Verify Signature

(PowerShell) ECDSA Sign Data and Verify Signature