ENUMALGS.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples.  
*       Copyright 1996 - 1998 Microsoft Corporation. 
*       All rights reserved.  
*       This source code is only intended as a supplement to  
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the  
*       Microsoft samples programs. 
\******************************************************************************/ 
 
#include <stdlib.h> 
#include <stdio.h> 
#include <ctype.h> 
#include <windows.h> 
#include <wincrypt.h> 
 
/*****************************************************************************/ 
void _cdecl main(int argc, char *argv[]) 
{ 
    HCRYPTPROV hProv = 0; 
    BYTE *ptr = NULL; 
    DWORD i; 
    ALG_ID aiAlgid; 
    DWORD dwBits; 
    DWORD dwNameLen; 
    CHAR szName[100];      // Often allocated dynamically. 
    BYTE pbData[1000];      // Often allocated dynamically. 
    DWORD dwDataLen; 
    DWORD dwFlags; 
    CHAR *pszAlgType = NULL; 
 
    // Get handle to the default provider. 
    if(!CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL, 0)) { 
        printf("Error %x during CryptAcquireContext!\n", GetLastError()); 
        goto done; 
    } 
 
    // Enumerate the supported algorithms. 
    for(i=0 ; ; i++) { 
// Set the CRYPT_FIRST flag the first time through the loop. 
if(i == 0) { 
    dwFlags = CRYPT_FIRST; 
} else { 
    dwFlags = 0; 
} 
 
// Retrieve information about an algorithm. 
dwDataLen = 1000; 
if(!CryptGetProvParam(hProv, PP_ENUMALGS, pbData, &dwDataLen, 0)) { 
    if(GetLastError() == ERROR_NO_MORE_ITEMS) { 
// Exit the loop. 
break; 
    } else { 
printf("Error %x reading algorithm!\n", GetLastError()); 
return; 
    } 
} 
 
// Extract algorithm information from 'pbData' buffer. 
ptr = pbData; 
aiAlgid = *(ALG_ID *)ptr; 
ptr += sizeof(ALG_ID); 
dwBits = *(DWORD *)ptr; 
ptr += sizeof(DWORD); 
dwNameLen = *(DWORD *)ptr; 
ptr += sizeof(DWORD); 
strncpy(szName, ptr,dwNameLen); 
 
// Determine algorithm type. 
switch(GET_ALG_CLASS(aiAlgid)) { 
    case ALG_CLASS_DATA_ENCRYPT: pszAlgType = "Encrypt  "; 
 break; 
    case ALG_CLASS_HASH: pszAlgType = "Hash     "; 
 break; 
    case ALG_CLASS_KEY_EXCHANGE: pszAlgType = "Exchange "; 
 break; 
    case ALG_CLASS_SIGNATURE: pszAlgType = "Signature"; 
 break; 
    default: pszAlgType = "Unknown  "; 
} 
 
// Print information about algorithm. 
printf("Name:%-14s Type:%s  Bits:%-4d Algid:%8.8xh\n", 
    szName, pszAlgType, dwBits, aiAlgid 
); 
    } 
 
    done: 
 
    // Release CSP handle. 
    if(hProv) CryptReleaseContext(hProv,0); 
}