Question

How do I print the value stored in BIO object “time”. Basically I need to extract signed time.

ASN1_TYPE *asn1obj;         
if (!(asn1obj = PKCS7_get_signed_attribute(si, NID_pkcs9_signingTime))) {
    NSLog(@"Failed to retireve the signing time");
}else{
    if (asn1obj->type == V_ASN1_UTCTIME) {
        BIO * time = data=BIO_new(BIO_s_bio());
        i = ASN1_UTCTIME_print(time,asn1obj->value.utctime);
        NSLog(@"return value from ASN1_UTCTIME_print %d ",i);                   
    }
}

Thanks

Answer 1

This is how it get working

if (asn1obj->type == V_ASN1_UTCTIME) {

    NSLog(@"--------------------------->Retireve the signing time");
    BIO * time = data=BIO_new(BIO_s_bio());                  

    BIO_printf(bio_out,"\n");

    i = ASN1_UTCTIME_print(bio_out,asn1obj->value.utctime);   //used to display in console
    i = ASN1_UTCTIME_print(time,asn1obj->value.utctime);      //used to hold in BIO object

    BIO_printf(bio_out,"\n");

    BIO *mem = BIO_new(BIO_s_mem());              
    //pass this mem BIO to hold the data
    i = ASN1_UTCTIME_print(mem,asn1obj->value.utctime);       //converting asn1 to memory BIO

    //Extract the BUF_MEM structure from a memory BIO and then free up the BIO:

    BUF_MEM *bptr;
    BIO_get_mem_ptr(mem, &bptr);                  //converting memory BIO to BUF_MEM
    BIO_set_close(mem, BIO_NOCLOSE); /* So BIO_free() leaves BUF_MEM alone */

    char *buff = (char *)malloc(bptr->length);        //converting BUF_MEM  to Char * 
    memcpy(buff, bptr->data, bptr->length-1);         //to be used later
    buff[bptr->length-1] = 0;

    NSLog(@"--------------------------->%s",buff);        // this is my 
                                  // OUTPUT : Apr  5 14:30:53 2012 GM

    NSLog(@"--------------------------->End");
    BIO_free_all(mem);              
}

Hope this helps 🙂