go-openssl/extension.c
Tiger 09d72588f7 - add custom extension support
- add support to retrive custom extension value
- add support to add custom protocol for protocol negotiation

Signed-off-by: Tiger <rbalajis25@gmail.com>
2020-05-23 17:24:57 +05:30

40 lines
1.2 KiB
C

#include <openssl/x509v3.h>
#include <string.h>
const unsigned char * get_extention(X509 *x, int NID, int *data_len){
int loc;
ASN1_OCTET_STRING *octet_str;
long xlen;
int tag, xclass;
loc = X509_get_ext_by_NID( x, NID, -1);
X509_EXTENSION *ex = X509_get_ext(x, loc);
octet_str = X509_EXTENSION_get_data(ex);
*data_len = octet_str->length;
return octet_str->data;
}
// Copied from https://github.com/libtor/openssl/blob/master/demos/x509/mkcert.c#L153
int add_custom_ext(X509 *cert, int nid,unsigned char *value, int len)
{
X509_EXTENSION *ex;
ASN1_OCTET_STRING *os = ASN1_OCTET_STRING_new();
ASN1_OCTET_STRING_set(os,value,len);
X509V3_CTX ctx;
/* This sets the 'context' of the extensions. */
/* No configuration database */
X509V3_set_ctx_nodb(&ctx);
/* Issuer and subject certs: both the target since it is self signed,
* no request and no CRL
*/
X509V3_set_ctx(&ctx, cert, cert, NULL, NULL, 0);
// ref http://openssl.6102.n7.nabble.com/Adding-a-custom-extension-to-a-CSR-td47446.html
ex = X509_EXTENSION_create_by_NID( NULL, nid, 0, os);
if (!X509_add_ext(cert,ex,-1))
return 0;
X509_EXTENSION_free(ex);
return 1;
}