deescuderoo / ECDSA-dotNET

Create keys, sign data and verify signatures using the ECDSA implementation from .NET

ECDSA-dotNET

Create keys, sign data and verify signatures using the ECDSA implementation from .NET

key_gen_cngkey.cs

Generates an ECDsaP256 key pair. The public key is exported in the clear to pkey. The private key under the name "key1" is stored using Microsoft Software Key Storage Provider as a User-key in folder \AppData\Roaming\Microsoft\Crypto\Keys. Relevant:

• https://msdn.microsoft.com/en-us/library/windows/desktop/bb204778(v=vs.85).aspx
• https://msdn.microsoft.com/en-us/library/windows/desktop/bb931355(v=vs.85).aspx
• https://msdn.microsoft.com/en-us/library/f5cs0acs.aspx

ECDsaP256 can be changed by

• ECDsaP384
• ECDsaP521

Relevant:

• https://msdn.microsoft.com/en-us/library/system.security.cryptography.cngalgorithm(v=vs.110).aspx

If there is already a key stored under the name "key1", the key is overwritten.

SYNTAX

key_gen_cngkey.exe

key_gen.cs

Generates an ECDsa key pair using curve brainpoolP256t1. To see available curves for this constructor run certutil –displayEccCurve. More info here:

• https://msdn.microsoft.com/en-us/library/windows/desktop/bb931354(v=vs.85).aspx

This allows the usage of more curves than NIST curves, but there is no support by Microsoft Software Key Storage Provider. As a consequence, either another KSP must be used, or keys must be exported on the clear, as done here. The program creates two files: pkey holding the public key using GenericPublicBlob format, and skey using Private Key Information Syntax Standard (PKCS #8) key BLOB.

SYNTAX

key_gen.exe

sign_cngkey.cs

Assuming key_gen_cngkey.cs has run successfully and a key under the name "key1" is already stored using Microsoft Software Key Storage Provider, signs a document doc with this key, generating a file called signature containing the signature of the document.

SYNTAX

sign_cngkey.exe doc

sign.cs

Signs a document doc with a key provided in a file skey, obtained by running key_gen.exe. This generates a file called signature containing the signature of the document.

SYNTAX

sign.exe doc skey

vrfy.cs

Given a document doc, a signature signature (either generated by sign_cngkey.exe doc or sign.exe doc skey) and a public key pkey (either generated by key_gen.exe or key_gen_cngkey.exe), returns information about the validity of the signature.

SYNTAX

vrfy.exe doc signature pkey