gistfile1.c

#include "postgres.h"
#include "fmgr.h"

#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/bio.h>

#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

PG_FUNCTION_INFO_V1(openssl_x509_check_issued);

/* postgres fn to check whether DER encoded X.509 bytea [0] signed [1] */
Datum openssl_x509_check_issued(PG_FUNCTION_ARGS)
{
  uint8_t rs;
	bytea *parent, *child;
	uint64_t parent_len, child_len;
	X509 *parent_cert, *child_cert;

	if (PG_ARGISNULL(0) || PG_ARGISNULL(1)) {
		PG_RETURN_NULL();
	}
	parent = PG_GETARG_BYTEA_P(0);
	parent_len = VARSIZE(parent) - VARHDRSZ;
	child = PG_GETARG_BYTEA_P(1);
	child_len = VARSIZE(child) - VARHDRSZ;

	parent_cert = d2i_X509(NULL, (const unsigned char **) &parent, parent_len);
	if (!parent_cert) {
		PG_RETURN_NULL();
	}
	child_cert = d2i_X509(NULL, (const unsigned char **) &child, child_len);
	if (!child_cert) {
		OPENSSL_free(parent_cert);
		PG_RETURN_NULL();
	}

	if (X509_check_issued(parent_cert, child_cert) == X509_V_OK) {
			rs = 1;
	} else {
			rs = 0;
	}

	OPENSSL_free(parent_cert);
	OPENSSL_free(child_cert);
	PG_RETURN_BOOL(rs);
}