BIT STRING decode for OER
diff --git a/skeletons/BIT_STRING_oer.c b/skeletons/BIT_STRING_oer.c
new file mode 100644
index 0000000..55cee4a
--- /dev/null
+++ b/skeletons/BIT_STRING_oer.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2017 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef ASN_DISABLE_OER_SUPPORT
+
+#include <asn_internal.h>
+#include <BIT_STRING.h>
+#include <errno.h>
+
+asn_dec_rval_t
+BIT_STRING_decode_oer(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+ const asn_oer_constraints_t *constraints, void **sptr,
+ const void *ptr, size_t size) {
+ BIT_STRING_t *st = (BIT_STRING_t *)*sptr;
+ const asn_oer_constraints_t *cts =
+ constraints ? constraints : td->oer_constraints;
+ ssize_t ct_size = cts ? cts->size : -1;
+ asn_dec_rval_t rval = {RC_OK, 0};
+ size_t expected_length = 0;
+
+ (void)opt_codec_ctx;
+
+ if(!st) {
+ st = (BIT_STRING_t *)(*sptr = CALLOC(1, sizeof(*st)));
+ if(!st) ASN__DECODE_FAILED;
+ }
+
+ if(ct_size >= 0) {
+ expected_length = (ct_size + 7) >> 3;
+ st->bits_unused = (8 - (ct_size & 7)) & 7;
+ } else {
+ /*
+ * X.696 (08/2015) #13.3.1
+ * Encode length determinant as _number of octets_, but only
+ * if upper bound is not equal to lower bound.
+ */
+ ssize_t len_len = oer_fetch_length(ptr, size, &expected_length);
+ if(len_len > 0) {
+ ptr = (const char *)ptr + len_len;
+ size -= len_len;
+ } else if(len_len == 0) {
+ ASN__DECODE_STARVED;
+ } else if(len_len < 0) {
+ ASN__DECODE_FAILED;
+ }
+
+ if(expected_length < 1) {
+ ASN__DECODE_STARVED;
+ }
+
+ st->bits_unused = ((const uint8_t *)ptr)[0];
+ if(st->bits_unused & ~7) {
+ ASN_DEBUG("%s: unused bits outside of 0..7 range", td->name);
+ ASN__DECODE_FAILED;
+ }
+ ptr = (const char *)ptr + 1;
+ size--;
+ expected_length--;
+ rval.consumed = len_len + 1;
+ }
+
+ if(size < expected_length) {
+ ASN__DECODE_STARVED;
+ } else {
+ uint8_t *buf = MALLOC(expected_length + 1);
+ if(buf == NULL) {
+ ASN__DECODE_FAILED;
+ } else {
+ memcpy(buf, ptr, expected_length);
+ buf[expected_length] = '\0';
+ }
+ FREEMEM(st->buf);
+ st->buf = buf;
+ st->size = expected_length;
+ if(expected_length > 0) {
+ buf[expected_length - 1] &= (0xff << st->bits_unused);
+ }
+
+ rval.consumed += expected_length;
+ return rval;
+ }
+}
+
+/*
+ * Encode as Canonical OER.
+ */
+asn_enc_rval_t
+BIT_STRING_encode_oer(asn_TYPE_descriptor_t *td,
+ const asn_oer_constraints_t *constraints, void *sptr,
+ asn_app_consume_bytes_f *cb, void *app_key) {
+ asn_enc_rval_t er = {-1,td,sptr};
+ (void)constraints;
+ (void)cb;
+ (void)app_key;
+ return er;
+}
+
+
+#endif /* ASN_DISABLE_OER_SUPPORT */