int ASN1_verify(i2d_of_void *i2d, X509_ALGOR *a, ASN1_BIT_STRING *signature,
		char *data, EVP_PKEY *pkey)
	{
	EVP_MD_CTX ctx;
	const EVP_MD *type;
	unsigned char *p,*buf_in=NULL;
	int ret= -1,i,inl;

	EVP_MD_CTX_init(&ctx);
	i=OBJ_obj2nid(a->algorithm);
	type=EVP_get_digestbyname(OBJ_nid2sn(i));
	if (type == NULL)
		{
		ASN1err(ASN1_F_ASN1_VERIFY,ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
		goto err;
		}
	
	inl=i2d(data,NULL);
	buf_in=OPENSSL_malloc((unsigned int)inl);
	if (buf_in == NULL)
		{
		ASN1err(ASN1_F_ASN1_VERIFY,ERR_R_MALLOC_FAILURE);
		goto err;
		}
	p=buf_in;

	i2d(data,&p);
	if (!EVP_VerifyInit_ex(&ctx,type, NULL))
		{
		ASN1err(ASN1_F_ASN1_VERIFY,ERR_R_EVP_LIB);
		ret=0;
		goto err;
		}
	EVP_VerifyUpdate(&ctx,(unsigned char *)buf_in,inl);

	OPENSSL_cleanse(buf_in,(unsigned int)inl);
	OPENSSL_free(buf_in);

	if (EVP_VerifyFinal(&ctx,(unsigned char *)signature->data,
			(unsigned int)signature->length,pkey) <= 0)
		{
		ASN1err(ASN1_F_ASN1_VERIFY,ERR_R_EVP_LIB);
		ret=0;
		goto err;
		}
	/* we don't need to zero the 'ctx' because we just checked
	 * public information */
	/* memset(&ctx,0,sizeof(ctx)); */
	ret=1;
err:
	EVP_MD_CTX_cleanup(&ctx);
	return(ret);
	}

This weakness pertains to the use of cryptographic functions that are weak, misconfigured, or outdated, which undermines the intended protection of encrypted data and communications.