Chilkat HOME .NET Core C# Android™ AutoIt C C# C++ Chilkat2-Python CkPython Classic ASP DataFlex Delphi ActiveX Delphi DLL Go Java Lianja Mono C# Node.js Objective-C PHP ActiveX PHP Extension Perl PowerBuilder PowerShell PureBasic Ruby SQL Server Swift 2 Swift 3,4,5... Tcl Unicode C Unicode C++ VB.NET VBScript Visual Basic 6.0 Visual FoxPro Xojo Plugin
(Unicode C) ECDSA Sign Data and Get Raw R and S ValuesDemonstrates getting the raw R and S value of an ECDSA signature.
#include <C_CkCrypt2W.h> #include <C_CkPrivateKeyW.h> #include <C_CkPrngW.h> #include <C_CkEccW.h> #include <C_CkAsnW.h> #include <C_CkXmlW.h> #include <C_CkBinDataW.h> void ChilkatSample(void) { HCkCrypt2W crypt; const wchar_t *hash1; HCkPrivateKeyW privKey; BOOL success; HCkPrngW prng; HCkEccW ecdsa; const wchar_t *ecdsaSigBase64; HCkAsnW asn; HCkXmlW xml; HCkBinDataW bd; const wchar_t *r; const wchar_t *s; // This example requires the Chilkat API to have been previously unlocked. // See Global Unlock Sample for sample code. // To create an ECDSA signature, the data first needs to be hashed. Then the hash // is signed. crypt = CkCrypt2W_Create(); CkCrypt2W_putHashAlgorithm(crypt,L"SHA256"); CkCrypt2W_putCharset(crypt,L"utf-8"); CkCrypt2W_putEncodingMode(crypt,L"base64"); // Hash a string. hash1 = CkCrypt2W_hashStringENC(crypt,L"The quick brown fox jumps over the lazy dog"); wprintf(L"hash1 = %s\n",hash1); // ----------------------------------------------------------- // An ECDSA private key is used for signing. The public key is for signature verification. // Load our ECC private key. // Our private key file contains this: // // -----BEGIN PRIVATE KEY----- // MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg3J8q/24D1sEKGdP9 // 72MGYElLGpw/a56Y3t6pfON3uhShRANCAATlSmoizyhAwoYZAOuFBATl07/1RR54 // a1Dzfm16grxJe666AGKR+bSs24hk7TEpaeCTvT8YOOM3l+xKFg7zq6Q9 // -----END PRIVATE KEY----- privKey = CkPrivateKeyW_Create(); success = CkPrivateKeyW_LoadPemFile(privKey,L"qa_data/ecc/secp256r1-key-pkcs8.pem"); if (success != TRUE) { wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privKey)); CkCrypt2W_Dispose(crypt); CkPrivateKeyW_Dispose(privKey); return; } // Sign the hash.. prng = CkPrngW_Create(); ecdsa = CkEccW_Create(); ecdsaSigBase64 = CkEccW_signHashENC(ecdsa,hash1,L"base64",privKey,prng); if (CkEccW_getLastMethodSuccess(ecdsa) != TRUE) { wprintf(L"%s\n",CkEccW_lastErrorText(ecdsa)); CkCrypt2W_Dispose(crypt); CkPrivateKeyW_Dispose(privKey); CkPrngW_Dispose(prng); CkEccW_Dispose(ecdsa); return; } // The ECDSA signature is ASN.1 that contains a sequence of 2 large integers (r and s) // For example: // SEQUENCE (2 elem) // INTEGER (255 bit) 792134D9B4AD82D5431ED03835A88E2596EB35E5B13054BD9B05A0069281ACC9 // INTEGER (255 bit) 481E758CC1E3CBF825537EC3D9A2CA627E5FAD1137BBEA65DF38658DCB0A9ED5 wprintf(L"Base64 ECDSA signature = %s\n",ecdsaSigBase64); // If the raw R and S values are needed, here's how to get them: asn = CkAsnW_Create(); success = CkAsnW_LoadEncoded(asn,ecdsaSigBase64,L"base64"); if (success == FALSE) { wprintf(L"%s\n",CkAsnW_lastErrorText(asn)); CkCrypt2W_Dispose(crypt); CkPrivateKeyW_Dispose(privKey); CkPrngW_Dispose(prng); CkEccW_Dispose(ecdsa); CkAsnW_Dispose(asn); return; } // The R and X will be in hexidecimal in the XML. xml = CkXmlW_Create(); CkXmlW_LoadXml(xml,CkAsnW_asnToXml(asn)); wprintf(L"%s\n",CkXmlW_getXml(xml)); // The XML looks like this: // <sequence> // <int>792134D9B4AD82D5431ED03835A88E2596EB35E5B13054BD9B05A0069281ACC9</int> // <int>481E758CC1E3CBF825537EC3D9A2CA627E5FAD1137BBEA65DF38658DCB0A9ED5</int> // </sequence> // Copy raw R and S hex values into a Chilkat BinData object. bd = CkBinDataW_Create(); r = CkXmlW_getChildContent(xml,L"int[0]"); s = CkXmlW_getChildContent(xml,L"int[1]"); CkBinDataW_AppendEncoded(bd,r,L"hex"); CkBinDataW_AppendEncoded(bd,s,L"hex"); wprintf(L"Number of bytes in bd: %d\n",CkBinDataW_getNumBytes(bd)); CkCrypt2W_Dispose(crypt); CkPrivateKeyW_Dispose(privKey); CkPrngW_Dispose(prng); CkEccW_Dispose(ecdsa); CkAsnW_Dispose(asn); CkXmlW_Dispose(xml); CkBinDataW_Dispose(bd); } |
© 2000-2024 Chilkat Software, Inc. All Rights Reserved.