+/*-
+ * Get critical flag and decoded version of extension from a NID.
+ * The "idx" variable returns the last found extension and can
+ * be used to retrieve multiple extensions of the same NID.
+ * However multiple extensions with the same NID is usually
+ * due to a badly encoded certificate so if idx is NULL we
+ * choke if multiple extensions exist.
+ * The "crit" variable is set to the critical value.
+ * The return value is the decoded extension or NULL on
+ * error. The actual error can have several different causes,
+ * the value of *crit reflects the cause:
+ * >= 0, extension found but not decoded (reflects critical value).
+ * -1 extension not found.
+ * -2 extension occurs more than once.
+ */
+
+void *X509V3_get_d2i(STACK_OF(X509_EXTENSION) *x, int nid, int *crit,
+ int *idx)
+{
+ int lastpos, i;
+ X509_EXTENSION *ex, *found_ex = NULL;
+ if (!x) {
+ if (idx)
+ *idx = -1;
+ if (crit)
+ *crit = -1;
+ return NULL;
+ }
+ if (idx)
+ lastpos = *idx + 1;
+ else
+ lastpos = 0;
+ if (lastpos < 0)
+ lastpos = 0;
+ for (i = lastpos; i < sk_X509_EXTENSION_num(x); i++) {
+ ex = sk_X509_EXTENSION_value(x, i);
+ if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == nid) {
+ if (idx) {
+ *idx = i;
+ found_ex = ex;
+ break;
+ } else if (found_ex) {
+ /* Found more than one */
+ if (crit)
+ *crit = -2;
+ return NULL;
+ }
+ found_ex = ex;
+ }
+ }
+ if (found_ex) {
+ /* Found it */
+ if (crit)
+ *crit = X509_EXTENSION_get_critical(found_ex);
+ return X509V3_EXT_d2i(found_ex);
+ }
+
+ /* Extension not found */
+ if (idx)
+ *idx = -1;
+ if (crit)
+ *crit = -1;
+ return NULL;
+}
+
+/*
+ * This function is a general extension append, replace and delete utility.
+ * The precise operation is governed by the 'flags' value. The 'crit' and
+ * 'value' arguments (if relevant) are the extensions internal structure.
+ */
+
+int X509V3_add1_i2d(STACK_OF(X509_EXTENSION) **x, int nid, void *value,
+ int crit, unsigned long flags)
+{
+ int extidx = -1;
+ int errcode;
+ X509_EXTENSION *ext, *extmp;
+ unsigned long ext_op = flags & X509V3_ADD_OP_MASK;
+
+ /*
+ * If appending we don't care if it exists, otherwise look for existing
+ * extension.
+ */
+ if (ext_op != X509V3_ADD_APPEND)
+ extidx = X509v3_get_ext_by_NID(*x, nid, -1);
+
+ /* See if extension exists */
+ if (extidx >= 0) {
+ /* If keep existing, nothing to do */
+ if (ext_op == X509V3_ADD_KEEP_EXISTING)
+ return 1;
+ /* If default then its an error */
+ if (ext_op == X509V3_ADD_DEFAULT) {
+ errcode = X509V3_R_EXTENSION_EXISTS;
+ goto err;
+ }
+ /* If delete, just delete it */
+ if (ext_op == X509V3_ADD_DELETE) {
+ if (!sk_X509_EXTENSION_delete(*x, extidx))
+ return -1;
+ return 1;
+ }
+ } else {
+ /*
+ * If replace existing or delete, error since extension must exist
+ */
+ if ((ext_op == X509V3_ADD_REPLACE_EXISTING) ||
+ (ext_op == X509V3_ADD_DELETE)) {
+ errcode = X509V3_R_EXTENSION_NOT_FOUND;
+ goto err;
+ }
+ }
+
+ /*
+ * If we get this far then we have to create an extension: could have
+ * some flags for alternative encoding schemes...
+ */
+
+ ext = X509V3_EXT_i2d(nid, crit, value);
+
+ if (!ext) {
+ X509V3err(X509V3_F_X509V3_ADD1_I2D,
+ X509V3_R_ERROR_CREATING_EXTENSION);
+ return 0;
+ }
+
+ /* If extension exists replace it.. */
+ if (extidx >= 0) {
+ extmp = sk_X509_EXTENSION_value(*x, extidx);
+ X509_EXTENSION_free(extmp);
+ if (!sk_X509_EXTENSION_set(*x, extidx, ext))
+ return -1;
+ return 1;
+ }
+
+ if (*x == NULL
+ && (*x = sk_X509_EXTENSION_new_null()) == NULL)
+ return -1;
+ if (!sk_X509_EXTENSION_push(*x, ext))
+ return -1;
+
+ return 1;
+
+ err:
+ if (!(flags & X509V3_ADD_SILENT))
+ X509V3err(X509V3_F_X509V3_ADD1_I2D, errcode);
+ return 0;
+}