Re: simple ASN1 sequence - not quite understanding what goes wrong

[Dirk-Willem van Gulik <dirkx@xxxxxxxxxxxxxx>]

Answering my own question - I forgot the END of sequence in the marco.

Functional code below.

Dw.

On 28 Aug 2020, at 15:49, Dirk-Willem van Gulik <dirkx@xxxxxxxxxxxxxx> wrote:

I've got a very simple sequence of to integers that I am trying to convert to DER.

Bt I am getting an error or segfault in the final i2d step (lengt -1 for i2d_X9_62).

Any advice on what is going wrong here ?

With kind regards,

Dw.

#include <openssl/bn.h>

#include <openssl/ec.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <err.h>

#include <assert.h>

#include <stdio.h>

typedef struct X962_st {

ASN1_INTEGER *p;

ASN1_INTEGER *q;

} X962;

DECLARE_ASN1_FUNCTIONS(X962)

ASN1_SEQUENCE(X962) =

{

ASN1_SIMPLE(X962, p, ASN1_INTEGER),

ASN1_SIMPLE(X962, q, ASN1_INTEGER)

}ASN1_SEQUENCE_END(X962);

DECLARE_ASN1_ALLOC_FUNCTIONS(X962)

IMPLEMENT_ASN1_FUNCTIONS(X962)

int main(int argc, char **argv)

{

const unsigned char pbin[] = {1, 2, 3, 4, 5, 6, 7, 8, 

1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8};

const unsigned char qbin[] = {0, 0, 0, 0, 0, 0, 0, 0, 

1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8};

assert(sizeof(pbin) == 32);

assert(sizeof(qbin) == 32);

X962          *x962 = X962_new();

BIGNUM * p = BN_bin2bn(pbin, sizeof(pbin), NULL);

assert(p);

x962->p = BN_to_ASN1_INTEGER(p, NULL);

fprintf(stderr,"P: %s\n",BN_bn2hex(p));

assert(x962->p);

BIGNUM * q = BN_bin2bn(qbin, sizeof(qbin), NULL);

assert(q);

x962->q = BN_to_ASN1_INTEGER(q, NULL);

fprintf(stderr,"Q: %s\n",BN_bn2hex(q));

assert(x962->q);

int len = i2d_X962(x962, NULL);

assert(len>0 && len < 1000);

unsigned char buff[32 * 1024];

unsigned char           *outp = buff;

len = i2d_X962(x962, &outp );

for (size_t i = 0; i < len; i++)

putchar(buff[i]);

X962_free(x962);

return (0);

};