OpenSSL Verify

#include<stdio.h>
#include<openssl/x509.h>
#include<openssl/err.h>
#include<string.h>
#include<openssl/pem.h>
#include<openssl/bio.h>


X509 * parse_cert(char * pem_cert)
{
        X509 *cert=NULL;
        int inlen=strlen(pem_cert);
        unsigned char *der_cert = malloc(inlen);
        //printf("%s \n",pem_cert);
        BIO *bio_buf = BIO_new(BIO_s_mem());
        BIO_write(bio_buf,pem_cert,inlen);
        BIO *b64 = BIO_new(BIO_f_base64());
        BIO_push(b64,bio_buf);
        BIO_set_flags(b64,BIO_FLAGS_BASE64_NO_NL);
        int len,total_len=0;
        unsigned char *der_cert_write=der_cert;
        while((len=BIO_read(b64,der_cert_write,inlen))>0)
        {
                //printf("%d byte read \n",len);
                total_len+=len;
                der_cert_write+=len;
        }
        printf("%d \n",total_len);
        cert = (X509 *) d2i_X509(NULL,&der_cert,total_len);
        if(!cert)
        {
                printf("Error: %s \n",ERR_error_string(ERR_get_error(),NULL));
                exit(255);
        }
        return cert;
}

int main(int argc,char **argv)
{
        ERR_load_crypto_strings();
        X509 *cert,*end_entity;
        X509_STORE *store= X509_STORE_new();
        //if(X509_STORE_load_locations(store,"/etc/ssl/certs/ca-certificates.crt",NULL)!=1)
        //      printf("error in loading certificate store \n");
        int i;
        end_entity = parse_cert(argv[1]);
        STACK_OF(X509) *stack = sk_X509_new_null();
        for(i=2;i<argc-1;i++)
        {
                cert=parse_cert(argv[i]);
                sk_X509_push(stack,cert);
        }
        cert=parse_cert(argv[argc-1]);
        if(!strcmp(X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0),X509_NAME_oneline(X509_get_issuer_name(cert), NULL, 0)))
        {
                X509_STORE_add_cert(store,cert);
        }
        else
        {
                sk_X509_push(stack,cert);
        }
        X509_STORE_CTX *ctx = X509_STORE_CTX_new();
        if(!ctx)
                printf("unable to create store ctx \n");
        if(X509_STORE_CTX_init(ctx,store,end_entity,stack)!=1)
                printf("unable to init ctx \n");
        //printf("%s \n",X509_NAME_oneline(X509_get_subject_name(end_entity),NULL,0));
        //printf("befre verify %x %x %x %x \n",ctx,store,end_entity,stack);
        X509_STORE_set_default_paths(store);
        int rc=X509_verify_cert(ctx);
        if(rc == 1)
                printf("ok \n");
        else
                printf("validation error %d %s at depth %d \n",rc,X509_verify_cert_error_string(X509_STORE_CTX_get_error(ctx)),X509_STORE_CTX_get_error_depth(ctx));
}