libpodofo memory leak (some cleanup - UPDATED)

sample code to reproduce memory leak

//
//
// =====================================================================
// g++ sign.cpp   -o sign -I/usr/include/openssl -lssl -lpodofo -lcrypto
// =====================================================================
//

// OpenSSL includes
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pkcs12.h>
#include <openssl/pkcs7.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>

#include <podofo/podofo.h>

#include <iostream>

using namespace PoDoFo;

class Ossl {

private:
	SHA_CTX m_sha_ctx;
    EVP_PKEY* mp_pkey;      // private key
    X509* mp_x509;          // signing certificate
    STACK_OF(X509)* mp_ca;  // certificate chain up to the CA
    unsigned char * mp_p7Buf;
public:
	Ossl(){}
	~Ossl(){}

	void init(const char * file, const char * passwd) {
		OPENSSL_malloc_init();
		ERR_load_crypto_strings();
		OpenSSL_add_all_algorithms();

		FILE* fp = fopen(file, "rb");

		if (fp == NULL) {
			std::cout << "fp null" << std::endl;
			return;
		}
			

		PKCS12* p12 = d2i_PKCS12_fp(fp, NULL);

		fclose(fp);

		if (p12 == NULL) {
			std::cout << "p12 null" << std::endl;
			return;
		}

		mp_pkey = NULL;
		mp_x509 = NULL;
		mp_ca = NULL;

		int ok = PKCS12_parse(p12, passwd, &mp_pkey, &mp_x509, &mp_ca);

		if (ok == 0) {
			std::cout << "not ok" << std::endl;
			return;
		}
		
		PKCS12_free(p12);
		
		SHA1_Init(&m_sha_ctx);
		std::cout << "init ok" << std::endl;
	}
	
    void close() {
    
        if (mp_ca)
            sk_X509_pop_free(mp_ca, X509_free);
        if (mp_x509) {
            X509_free(mp_x509);
        }
        if (mp_pkey) {
            EVP_PKEY_free(mp_pkey);
        }
        if (mp_p7Buf) {
            free(mp_p7Buf);
        }
        ERR_free_strings();
    }

	void append(const char* data, int len) {
		SHA1_Update(&m_sha_ctx, data, len);
		return;
	}

	char * signature() {
		unsigned char sha_buffer[SHA_DIGEST_LENGTH];
	    memset((void*) sha_buffer, 0, SHA_DIGEST_LENGTH);
	    SHA1_Final(sha_buffer, &m_sha_ctx);
	    
	    PKCS7* p7 = PKCS7_new();
	    PKCS7_set_type(p7, NID_pkcs7_signed);
	    
	    PKCS7_SIGNER_INFO* p7Si = PKCS7_add_signature(p7, mp_x509, mp_pkey, EVP_sha1());
	    PKCS7_add_attrib_content_type(p7Si, OBJ_nid2obj(NID_pkcs7_data));
	    PKCS7_add0_attrib_signing_time(p7Si, NULL);
	    PKCS7_add1_attrib_digest(p7Si, (const unsigned char*) sha_buffer, SHA_DIGEST_LENGTH);
	    PKCS7_add_certificate(p7, mp_x509);

	    int c = 0;
	    for ( ; c < sk_X509_num(mp_ca); c++) {
	        X509* cert = sk_X509_value(mp_ca, c);
	        PKCS7_add_certificate(p7, cert);
	    }
	    PKCS7_set_detached(p7, 1);
	    PKCS7_content_new(p7, NID_pkcs7_data);
	    
	    PKCS7_SIGNER_INFO_sign(p7Si);
	    
	    mp_p7Buf = NULL;
	    int p7Len = i2d_PKCS7(p7, NULL);
	    unsigned char* p7Buf = (unsigned char*) calloc(1, p7Len + 1);
	    if (p7Buf != NULL) {
	        mp_p7Buf = p7Buf;
	        i2d_PKCS7(p7, &p7Buf);
	        std::cout << "p7Buf filled";
	    }
	    PKCS7_free(p7);
	    return (char *) p7Buf;
	}
};

using namespace PoDoFo;



#define CONVERSION_CONSTANT 0.002834645669291339

void CreateSimpleForm( PdfPage* pPage, PdfStreamedDocument* pDoc, const PdfData &signatureData )
{
    PdfPainter painter;
    PdfFont*   pFont = pDoc->CreateFont( "Courier" );

    painter.SetPage( pPage );
    painter.SetFont( pFont );
    painter.DrawText( 10000 * CONVERSION_CONSTANT, 280000 * CONVERSION_CONSTANT, "PoDoFo Sign Test" );
    painter.FinishPage();

	PdfSignatureField signField( pPage, PdfRect( 70000 * CONVERSION_CONSTANT, 10000 * CONVERSION_CONSTANT,
                                       50000 * CONVERSION_CONSTANT, 50000 * CONVERSION_CONSTANT ), pDoc );
    signField.SetFieldName("SignatureFieldName");
	signField.SetSignature(signatureData);
	signField.SetSignatureReason("I agree");
}


int main( int argc, char* argv[] ) 
{
    PdfPage*            pPage;

    if( argc != 4  )
    {
        printf("Usage: sign [output_filename] [pfx certificate] [password]\n");
        printf("       - Create a PDF ready to be signed\n");
        return 0;
    }

    PdfSignOutputDevice signer(argv[1]);
	// Reserve space for signature
    signer.SetSignatureSize(1024);

	PdfStreamedDocument writer( &signer, PoDoFo::ePdfVersion_1_5 );
    // Disable default appearance
    writer.GetAcroForm(ePdfCreateObject, ePdfAcroFormDefaultAppearance_None);

    pPage = writer.CreatePage( PdfPage::CreateStandardPageSize( ePdfPageSize_A4 ) );
    CreateSimpleForm( pPage, &writer, *signer.GetSignatureBeacon());

    writer.Close();

    // Adjust ByteRange for signature
    if(signer.HasSignaturePosition()) {
        signer.AdjustByteRange();
		
		// read data for signature and count it
		signer.Seek(0);

		Ossl * ossl = new Ossl();
		ossl->init(argv[2], argv[3]);

		// generate digest and count signature
		// use NSS, MS Crypto API or OpenSSL 
		// to generate signature in DER format
		char buff[65536];
		size_t len;
		while( (len = signer.ReadForSignature(buff, 65536))>0 )
		{
			ossl->append(buff, len);
		}

		// Paste signature to the file
        PdfData sigData(ossl->signature());
        signer.SetSignature(sigData);

        ossl->close();
        delete ossl;
    }

	signer.Flush();


    return 0;
}

Add ossl->close();

==9319== 65,536 bytes in 1 blocks are still reachable in loss record 6 of 6
==9319==    at 0x4C33B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==9319==    by 0x27AE19: PoDoFo::podofo_calloc(unsigned long, unsigned long) (PdfMemoryManagement.cpp:136)
==9319==    by 0x272392: PoDoFo::PdfSimpleEncoding::InitEncodingTable() (PdfEncoding.cpp:385)
==9319==    by 0x2729B0: PoDoFo::PdfSimpleEncoding::ConvertToEncoding(PoDoFo::PdfString const&, PoDoFo::PdfFont const*) const (PdfEncoding.cpp:474)
==9319==    by 0x2A9B76: PoDoFo::PdfFont::WriteStringToStream(PoDoFo::PdfString const&, PoDoFo::PdfStream*) (PdfFont.cpp:144)
==9319==    by 0x253EF0: PoDoFo::PdfPainter::DrawText(double, double, PoDoFo::PdfString const&, long) (PdfPainter.cpp:828)
==9319==    by 0x253512: PoDoFo::PdfPainter::DrawText(double, double, PoDoFo::PdfString const&) (PdfPainter.cpp:744)
==9319==    by 0x1F63DD: CreateSimpleForm(PoDoFo::PdfPage*, PoDoFo::PdfStreamedDocument*, PoDoFo::PdfData const&) (sign.cpp:139)
==9319==    by 0x1F66DD: main (sign.cpp:170)
==9319== 
==9319== LEAK SUMMARY:
==9319==    definitely lost: 7,549 bytes in 1 blocks
==9319==    indirectly lost: 0 bytes in 0 blocks
==9319==      possibly lost: 0 bytes in 0 blocks
==9319==    still reachable: 65,904 bytes in 5 blocks
==9319==         suppressed: 0 bytes in 0 blocks
==9319== 
==9319== For counts of detected and suppressed errors, rerun with: -v
==9319== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)