Another API call failing....

[David Clarke]

CryptAcquireCertificatePrivateKey is failing even thought the cert context is valid.

This entire crypto TLS thing is quite confusing!

#COMPILE EXE
#DIM ALL

#INCLUDE "win32api.inc"
'------------------------------------------------------------------------------
FUNCTION GetErrorMessage (BYVAL errorCode AS DWORD) AS STRING

LOCAL errorBuffer AS STRINGZ * 1024
LOCAL numChars AS DWORD

numChars = FormatMessage(%FORMAT_MESSAGE_FROM_SYSTEM OR %FORMAT_MESSAGE_IGNORE_INSERTS, BYVAL %NULL, errorCode, %LANG_USER_DEFAULT, errorBuffer, SIZEOF(errorBuffer), BYVAL %NULL)

IF numChars THEN
FUNCTION = LEFT$(errorBuffer, numChars)
ELSE
FUNCTION = "Error " & STR$(errorCode)
END IF

END FUNCTION
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
FUNCTION PBMAIN () AS LONG

LOCAL result AS DWORD
LOCAL errorMessage AS STRING * 1024
LOCAL hFileStoreHandle AS DWORD
LOCAL Cert_File_Name AS STRINGZ * 255
LOCAL pCertContext AS CERT_CONTEXT PTR
LOCAL pvFindPara AS STRINGZ *255
LOCAL szName AS ASCIIZ * 256
LOCAL hProv AS DWORD 'ptr
LOCAL dwKeySpec AS DWORD
LOCAL pfCallerFreeProv AS DWORD


Cert_File_Name = "comm.crt"
hFileStoreHandle = CertOpenStore(BYVAL %CERT_STORE_PROV_FILENAME_A, 0, 0, 0, Cert_File_Name)
errorMessage = GetErrorMessage(GetLasterror)

pCertContext = CertFindCertificateInStore(hFileStoreHandle, %X509_ASN_ENCODING OR %PKCS_7_ASN_ENCODING, 0, 0, pvFindPara, 0)

'Next line is to prove we have the "asp-emu" Cert - you can look at the szName
result = CertGetNameString(pCertContext, %CERT_NAME_SIMPLE_DISPLAY_TYPE, 0, BYVAL %NULL, szName, SIZEOF(szName))

result = CryptAcquireCertificatePrivateKey(pCertContext, %CRYPT_ACQUIRE_SILENT_FLAG OR %CRYPT_ACQUIRE_ALLOW_NCRYPT_KEY_FLAG, %NULL, hProv, dwKeySpec, pfCallerFreeProv)

errorMessage = GetErrorMessage(GetLasterror)

END FUNCTION​

[Pierre Bellisle]

Look at my answer to this question at
CryptAcquireCertificatePrivateKey

[David Clarke]

Thanks Pierre:
I looked but didn't find solution.