How to manage memory in d2i_XX functions

Aftab Alam Thu, 14 Apr 2005 00:37:33 -0700

Hi All,

I’ve been finding it difficult to manage memory while using OpenSSL d2i functions.

I have written the following function to Sign OCSP request.

unsigned char *in = new unsigned char[OCSPRequestData.GetLength()];

memcpy(in, OCSPRequestData.GetData(), OCSPRequestData.GetLength());

pOCSPRequest = d2i_OCSP_REQUEST(NULL, &in, OCSPRequestData.GetLength());

now when I try to use

if(in)

delete[] in;

my application crashes and if I don’t delete then compiler tells me that it’s a memory leak.

More over if anyone can take a look at the code below and point out the place where I am not doing right to avoid memory leaks.

I have tried to free every memory though.

bool SignOCSPRequest(const std::string &strPFXPath, const std::string &strPFXPassword,

CAscByteArray &OCSPRequestData, CAscByteArray &signedOCSPRequestdata) {

bool bRetVal = true;

EVP_PKEY *pPrivateKey = NULL;

X509 *pSignerCert = NULL;

PKCS7 *pPKCS7 = NULL;

PKCS12 *pPKCS12 = NULL;

STACK_OF(X509) *pskSignerCertChain = NULL;

OCSP_REQUEST *pOCSPRequest = NULL;

const EVP_MD *pDigest;

// OpenSSL Algorithm Initialization process

SSLeay_add_all_algorithms();

// OpenSSL Error strings loading

ERR_load_crypto_strings();

// create OCSP request object from

unsigned char *in = new unsigned char[OCSPRequestData.GetLength()];

memcpy(in, OCSPRequestData.GetData(), OCSPRequestData.GetLength());

pOCSPRequest = d2i_OCSP_REQUEST(NULL, &in, OCSPRequestData.GetLength());

if(!pOCSPRequest)

{

m_strLastError = "Unable to create OCSP Request from Data";

bRetVal = false;

}

if(bRetVal != false)

{

// this obejct will contain the p12 file pointer.

FILE *pFile = NULL;

pFile = fopen(strPFXPath.c_str(),"rb");

if(!pFile)

{

m_strLastError = "Unable to open the PFX File at "+strPFXPath;

bRetVal = false;

}

if(bRetVal != false)

{

pPKCS12 = d2i_PKCS12_fp(pFile,NULL);

if(!pPKCS12)

{

m_strLastError = "d2i_PKCS12_fp failed for: "+strPFXPath;

bRetVal = false;

}

fclose(pFile);

if(bRetVal != false)

{

if(PKCS12_parse(pPKCS12, strPFXPassword.c_str(), &pPrivateKey,

&pSignerCert, &pskSignerCertChain) == PKCS12_ERROR)

{

m_strLastError = ERR_error_string(ERR_get_error(),NULL);

bRetVal = false;

}

if(bRetVal != false)

{

pDigest = EVP_get_digestbyname("sha1");

OCSP_request_sign(pOCSPRequest,pSignerCert,pPrivateKey,pDigest,NULL, 0);

int nSignedOCSPReqLen = i2d_OCSP_REQUEST(pOCSPRequest,NULL);

unsigned char *pDerEncodedOCSPReq = new unsigned char[nSignedOCSPReqLen];

i2d_OCSP_REQUEST(pOCSPRequest,&pDerEncodedOCSPReq);

pDerEncodedOCSPReq -= nSignedOCSPReqLen;

CAscByteArray bTempArray(pDerEncodedOCSPReq,nSignedOCSPReqLen);

signedOCSPRequestdata = bTempArray;

delete[] pDerEncodedOCSPReq;

}

//if(pDigest)

//EVP_MD_free(pDigest);

// EVP_MD_cleanup(pDigest);

if(pPKCS12)

PKCS12_free(pPKCS12);

if(pPrivateKey)

EVP_PKEY_free(pPrivateKey);

if(pOCSPRequest)

OCSP_REQUEST_free(pOCSPRequest);

if(pPKCS7)

PKCS7_free(pPKCS7);

if(pSignerCert)

X509_free(pSignerCert);

if(pskSignerCertChain)

sk_X509_free(pskSignerCertChain);

ERR_free_strings();

EVP_cleanup();

CRYPTO_cleanup_all_ex_data();

return bRetVal;

}

And I am using the code below to detect memory leaks

const long memAllocNum = 0; // Enter the memory block allocation number that Microsoft declares is a leak here.

// Set the debug flags for memory leak checking

_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG);

int debugFlag = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);

debugFlag = _CrtSetDbgFlag(debugFlag | _CRTDBG_LEAK_CHECK_DF );

// Set a breakpoint on the allocation request number

if ((memAllocNum > 0) && IsDebuggerPresent())

_CrtSetBreakAlloc(memAllocNum);

Regards

Muhammad Aftab Alam

How to manage memory in d2i_XX functions

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