tor-browser

certv3.c (5737B)

---

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
* Code for dealing with X509.V3 extensions.
*/

#include "cert.h"
#include "secitem.h"
#include "secoid.h"
#include "secder.h"
#include "secasn1.h"
#include "certxutl.h"
#include "secerr.h"

SECStatus
CERT_FindCertExtensionByOID(CERTCertificate *cert, SECItem *oid, SECItem *value)
{
   return (cert_FindExtensionByOID(cert->extensions, oid, value));
}

SECStatus
CERT_FindCertExtension(const CERTCertificate *cert, int tag, SECItem *value)
{
   return (cert_FindExtension(cert->extensions, tag, value));
}

static void
SetExts(void *object, CERTCertExtension **exts)
{
   CERTCertificate *cert = (CERTCertificate *)object;

   cert->extensions = exts;
   DER_SetUInteger(cert->arena, &(cert->version), SEC_CERTIFICATE_VERSION_3);
}

void *
CERT_StartCertExtensions(CERTCertificate *cert)
{
   return (cert_StartExtensions((void *)cert, cert->arena, SetExts));
}

/*
* get the value of the Netscape Certificate Type Extension
*/
SECStatus
CERT_FindNSCertTypeExtension(CERTCertificate *cert, SECItem *retItem)
{

   return (CERT_FindBitStringExtension(
       cert->extensions, SEC_OID_NS_CERT_EXT_CERT_TYPE, retItem));
}

/*
* get the value of a string type extension
*/
char *
CERT_FindNSStringExtension(CERTCertificate *cert, int oidtag)
{
   SECItem wrapperItem, tmpItem = { siBuffer, 0 };
   SECStatus rv;
   PLArenaPool *arena = NULL;
   char *retstring = NULL;

   wrapperItem.data = NULL;
   tmpItem.data = NULL;

   arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);

   if (!arena) {
       goto loser;
   }

   rv = cert_FindExtension(cert->extensions, oidtag, &wrapperItem);
   if (rv != SECSuccess) {
       goto loser;
   }

   rv = SEC_QuickDERDecodeItem(
       arena, &tmpItem, SEC_ASN1_GET(SEC_IA5StringTemplate), &wrapperItem);

   if (rv != SECSuccess) {
       goto loser;
   }

   retstring = (char *)PORT_Alloc(tmpItem.len + 1);
   if (retstring == NULL) {
       goto loser;
   }

   PORT_Memcpy(retstring, tmpItem.data, tmpItem.len);
   retstring[tmpItem.len] = '\0';

loser:
   if (arena) {
       PORT_FreeArena(arena, PR_FALSE);
   }

   if (wrapperItem.data) {
       PORT_Free(wrapperItem.data);
   }

   return (retstring);
}

/*
* get the value of the X.509 v3 Key Usage Extension
*/
SECStatus
CERT_FindKeyUsageExtension(CERTCertificate *cert, SECItem *retItem)
{

   return (CERT_FindBitStringExtension(cert->extensions,
                                       SEC_OID_X509_KEY_USAGE, retItem));
}

/*
* get the value of the X.509 v3 Key Usage Extension
*/
SECStatus
CERT_FindSubjectKeyIDExtension(CERTCertificate *cert, SECItem *retItem)
{

   SECStatus rv;
   SECItem encodedValue = { siBuffer, NULL, 0 };
   SECItem decodedValue = { siBuffer, NULL, 0 };

   rv = cert_FindExtension(cert->extensions, SEC_OID_X509_SUBJECT_KEY_ID,
                           &encodedValue);
   if (rv == SECSuccess) {
       PORTCheapArenaPool tmpArena;
       PORT_InitCheapArena(&tmpArena, DER_DEFAULT_CHUNKSIZE);
       rv = SEC_QuickDERDecodeItem(&tmpArena.arena, &decodedValue,
                                   SEC_ASN1_GET(SEC_OctetStringTemplate),
                                   &encodedValue);
       if (rv == SECSuccess) {
           rv = SECITEM_CopyItem(NULL, retItem, &decodedValue);
       }
       PORT_DestroyCheapArena(&tmpArena);
   }
   SECITEM_FreeItem(&encodedValue, PR_FALSE);
   return rv;
}

SECStatus
CERT_FindBasicConstraintExten(CERTCertificate *cert,
                             CERTBasicConstraints *value)
{
   SECItem encodedExtenValue;
   SECStatus rv;

   encodedExtenValue.data = NULL;
   encodedExtenValue.len = 0;

   rv = cert_FindExtension(cert->extensions, SEC_OID_X509_BASIC_CONSTRAINTS,
                           &encodedExtenValue);
   if (rv != SECSuccess) {
       return (rv);
   }

   rv = CERT_DecodeBasicConstraintValue(value, &encodedExtenValue);

   /* free the raw extension data */
   PORT_Free(encodedExtenValue.data);
   encodedExtenValue.data = NULL;

   return (rv);
}

CERTAuthKeyID *
CERT_FindAuthKeyIDExten(PLArenaPool *arena, CERTCertificate *cert)
{
   SECItem encodedExtenValue;
   SECStatus rv;
   CERTAuthKeyID *ret;

   encodedExtenValue.data = NULL;
   encodedExtenValue.len = 0;

   rv = cert_FindExtension(cert->extensions, SEC_OID_X509_AUTH_KEY_ID,
                           &encodedExtenValue);
   if (rv != SECSuccess) {
       return (NULL);
   }

   ret = CERT_DecodeAuthKeyID(arena, &encodedExtenValue);

   PORT_Free(encodedExtenValue.data);
   encodedExtenValue.data = NULL;

   return (ret);
}

SECStatus
CERT_CheckCertUsage(CERTCertificate *cert, unsigned char usage)
{
   SECItem keyUsage;
   SECStatus rv;

   /* There is no extension, v1 or v2 certificate */
   if (cert->extensions == NULL) {
       return (SECSuccess);
   }

   keyUsage.data = NULL;

   /* This code formerly ignored the Key Usage extension if it was
   ** marked non-critical.  That was wrong.  Since we do understand it,
   ** we are obligated to honor it, whether or not it is critical.
   */
   rv = CERT_FindKeyUsageExtension(cert, &keyUsage);
   if (rv == SECFailure) {
       rv = (PORT_GetError() == SEC_ERROR_EXTENSION_NOT_FOUND) ? SECSuccess
                                                               : SECFailure;
   } else if (!keyUsage.data || !keyUsage.len || !(keyUsage.data[0] & usage)) {
       PORT_SetError(SEC_ERROR_CERT_USAGES_INVALID);
       rv = SECFailure;
   }
   PORT_Free(keyUsage.data);
   return (rv);
}