CryptEnumProviderTypesA function (wincrypt.h)
Provider types include PROV_RSA_FULL, PROV_RSA_SCHANNEL, and PROV_DSS.
Syntax
BOOL CryptEnumProviderTypesA(
[in] DWORD dwIndex,
[in] DWORD *pdwReserved,
[in] DWORD dwFlags,
[out] DWORD *pdwProvType,
[out] LPSTR szTypeName,
[in, out] DWORD *pcbTypeName
);
Parameters
[in] dwIndex
Index of the next provider type to be enumerated.
[in] pdwReserved
Reserved for future use and must be NULL.
[in] dwFlags
Reserved for future use and must be zero.
[out] pdwProvType
Address of the DWORD value designating the enumerated provider type.
[out] szTypeName
A pointer to a buffer that receives the data from the enumerated provider type. This is a string including the terminating NULL character. Some provider types do not have display names, and in this case no name is returned and the returned value pointed to by pcbTypeName is zero.
This parameter can be NULL to get the size of the name for memory allocation purposes. For more information, see Retrieving Data of Unknown Length.
[in, out] pcbTypeName
A pointer to a DWORD value specifying the size, in bytes, of the buffer pointed to by the pszTypeName parameter. When the function returns, the DWORD value contains the number of bytes stored or to be stored in the buffer. Some provider types do not have display names, and in this case no name is returned and the returned value pointed to by pcbTypeName is zero.
Return value
If the function succeeds, the return value is nonzero (TRUE).
If the function fails, the return value is zero (FALSE). For extended error information, call GetLastError.
The error codes prefaced by NTE are generated by the particular CSP being used. Some possible error codes follow.
Return code | Description |
---|---|
|
There are no more items to enumerate. |
|
The operating system ran out of memory. |
|
The dwFlags parameter has an unrecognized value. |
|
Something was wrong with the type registration. |
Remarks
This function enumerates the provider types available on a computer. Providers for any specific provider type can be enumerated using CryptEnumProviders.
Examples
The following example shows a loop listing all available cryptographic service provider types.
#include <stdio.h>
#include <windows.h>
#include <Wincrypt.h>
#pragma comment(lib, "advapi32.lib")
void main()
{
// Copyright (C) Microsoft. All rights reserved.
// Declare and initialize variables.
DWORD dwIndex;
DWORD dwType;
DWORD cbName;
LPTSTR pszName;
//--------------------------------------------------------------
// Print header lines for provider types.
printf("Listing Available Provider Types:\n");
printf("Provider type\tProvider Type Name\n");
printf("_____________\t_____________________________________\n");
// Loop through enumerating provider types.
dwIndex = 0;
while(CryptEnumProviderTypes(
dwIndex,
NULL,
0,
&dwType,
NULL,
&cbName
))
{
//-----------------------------------------------------------
// cbName returns the length of the name of the next
// provider type. Allocate memory in a buffer to retrieve
// that name.
if (!(pszName = (LPTSTR)LocalAlloc(LMEM_ZEROINIT, cbName)))
{
printf("ERROR - LocalAlloc failed.\n");
exit(1);
}
//-----------------------------------------------------------
// Get the provider type name.
if (CryptEnumProviderTypes(
dwIndex++,
NULL,
NULL,
&dwType,
pszName,
&cbName))
{
printf (" %4.0d\t%s\n",dwType, pszName);
}
else
{
printf("ERROR - CryptEnumProviderTypes\n");
exit(1);
}
LocalFree(pszName);
} // End of while loop.
}
For another example that uses the CryptEnumProviderTypes function, see Example C Program: Enumerating CSP Providers and Provider Types.
Note
The wincrypt.h header defines CryptEnumProviderTypes as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows XP [desktop apps only] |
Minimum supported server | Windows Server 2003 [desktop apps only] |
Target Platform | Windows |
Header | wincrypt.h |
Library | Advapi32.lib |
DLL | Advapi32.dll |