main.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <CSP_WinDef.h>
#include <CSP_WinCrypt.h>
#include <reader/tchar.h>
#include <WinCryptEx.h>

int main(void) {
    BOOL result;

    HCERTSTORE hStore = CertOpenSystemStore(0, "MY");
    // printf("hStore = %p\n", hStore);

    PCERT_CONTEXT pCertReceiver = CertFindCertificateInStore(
        hStore, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, 0,
        CERT_FIND_SUBJECT_STR_A, "CRYPTO-PRO", NULL
    );
    // printf("pCertReceiver = %p\n", pCertReceiver);
    // printf("pCertReceiver.hStore = %p\n", pCertReceiver->hCertStore);

    PCERT_CONTEXT pCertSender = CertFindCertificateInStore(
        hStore, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, 0,
        CERT_FIND_SUBJECT_STR_A, "test@example.com", NULL
    );
    // printf("pCertSender = %p\n", pCertSender);
    // printf("pCertSender.hStore = %p\n", pCertSender->hCertStore);

    HCRYPTPROV hSenderProv;
    DWORD senderPrivKeySpec;
    result = CryptAcquireCertificatePrivateKey(
        pCertSender, 0, NULL,
        &hSenderProv, &senderPrivKeySpec, NULL
    );
    printf("CryptAcquireCertificatePrivateKey = %d\n", result);
    printf("hSenderProv = %llu\n", hSenderProv);
    printf("senderPrivKeySpec = %d\n", senderPrivKeySpec);
    printf("\n");

    HCRYPTKEY hSenderPrivKey;
    result = CryptGetUserKey(hSenderProv, senderPrivKeySpec, &hSenderPrivKey);
    printf("CryptGetUserKey = %d\n", result);
    printf("hSenderPrivKey = %llu\n", hSenderPrivKey);
    printf("\n");

    HCRYPTKEY hReceiverPubKey;
    result = CryptImportPublicKeyInfoEx(
        hSenderProv, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
        &(pCertReceiver->pCertInfo->SubjectPublicKeyInfo), 0, 0, NULL, &hReceiverPubKey
    );
    printf("CryptImportPublicKeyInfoEx = %d\n", result);
    printf("hReceiverPubKey = %llu\n", hReceiverPubKey);
    printf("\n");

    DWORD recPubLen = 256;
    BYTE *recPubBuffer = (BYTE*)malloc(recPubLen);
    result = CryptExportKey(
        hReceiverPubKey, 0, PUBLICKEYBLOB, 0, recPubBuffer, &recPubLen
    );
    printf("CryptExportKey = %d\n", result);
    printf("recPubLen = %u\n", recPubLen);
    printf("GetLastError = %x\n", GetLastError());
    printf("\n");

    HCRYPTKEY hAgreeKey;
    result = CryptImportKey(
        hSenderProv, recPubBuffer, recPubLen,
        hSenderPrivKey, 0, &hAgreeKey
    );
    printf("CryptImportKey = %d\n", result);
    printf("hAgreeKey = %llu\n", hAgreeKey);
    printf("GetLastError = %x\n", GetLastError());
    printf("\n");
}