Keep the colleague's microbu-esp32c5 tree in this repository

obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but
that tree was gitignored, so a clone of this repository could not build the
firmware it ships. It is now committed here as ordinary files in its own
folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP
bridge's signature verification (--trust) used on the bench. Nothing is
fetched from or pushed to the colleague's repository; this repository and
its remotes carry everything. The folder's own .gitignore keeps build output,
downloaded components and private key material out, as it did there; the
committed file set is identical to that repository's tracked files.

The ESP32-C5 is still flashed from obu-firmware/, which only takes
vanetza-idf from microbu-esp32c5/, so the two stay separate folders.
FLASHING.md says how to take a newer version of the colleague's tree (copy
it over the folder, rebuild, test, commit).

microbu-esp32c5/external/vanetza-idf/vanetza/asn1/support/RELATIVE-OID_jer.c

@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2017 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include "asn_internal.h"
+#include "RELATIVE-OID.h"
+
+#define CQUOTE 0x22
+
+static enum jer_pbd_rval
+RELATIVE_OID__jer_body_decode(const asn_TYPE_descriptor_t *td,
+                              void *sptr, const void *chunk_buf,
+                              size_t chunk_size) {
+    RELATIVE_OID_t *st = (RELATIVE_OID_t *)sptr;
+    const char *chunk_end = (const char *)chunk_buf + chunk_size;
+    const char* p = (const char*)chunk_buf;
+    const char *endptr;
+    asn_oid_arc_t s_arcs[6];
+    asn_oid_arc_t *arcs = s_arcs;
+    ssize_t num_arcs;
+    int ret;
+
+    (void)td;
+
+    /* Strip quotes */
+    for (; p < chunk_end; ++p) {
+        if (*p == CQUOTE) {
+            ++p;
+            break;
+        }
+    }
+    --chunk_end;
+    for (; chunk_end >= p; --chunk_end) {
+        if (*chunk_end == CQUOTE)
+            break;
+    }
+    if (chunk_end - p < 0)
+        return JPBD_BROKEN_ENCODING;
+    chunk_size = chunk_end - p;
+    chunk_buf = p;
+
+    num_arcs = OBJECT_IDENTIFIER_parse_arcs(
+        (const char *)chunk_buf, chunk_size, arcs,
+        sizeof(s_arcs) / sizeof(s_arcs[0]), &endptr);
+    if(num_arcs < 0) {
+        /* Expecting at least one arc arcs */
+        return JPBD_BROKEN_ENCODING;
+    } else if(num_arcs == 0) {
+        return JPBD_NOT_BODY_IGNORE;
+    }
+    assert(endptr == chunk_end);
+
+    if((size_t)num_arcs > sizeof(s_arcs) / sizeof(s_arcs[0])) {
+        arcs = (asn_oid_arc_t *)MALLOC(num_arcs * sizeof(arcs[0]));
+        if(!arcs) return JPBD_SYSTEM_FAILURE;
+        ret = OBJECT_IDENTIFIER_parse_arcs((const char *)chunk_buf, chunk_size,
+                                           arcs, num_arcs, &endptr);
+        if(ret != num_arcs) {
+            return JPBD_SYSTEM_FAILURE;  /* assert?.. */
+        }
+    }
+
+    /*
+     * Convert arcs into BER representation.
+     */
+    ret = RELATIVE_OID_set_arcs(st, arcs, num_arcs);
+    if(arcs != s_arcs) FREEMEM(arcs);
+
+    return ret ? JPBD_SYSTEM_FAILURE : JPBD_BODY_CONSUMED;
+}
+
+asn_dec_rval_t
+RELATIVE_OID_decode_jer(const asn_codec_ctx_t *opt_codec_ctx,
+                        const asn_TYPE_descriptor_t *td,
+                        const asn_jer_constraints_t *constraints,
+                        void **sptr, const void *buf_ptr, size_t size) {
+    return jer_decode_primitive(opt_codec_ctx, td,
+                                sptr, sizeof(RELATIVE_OID_t),
+                                buf_ptr, size, RELATIVE_OID__jer_body_decode);
+}
+
+asn_enc_rval_t
+RELATIVE_OID_encode_jer(const asn_TYPE_descriptor_t *td,
+                        const asn_jer_constraints_t *constraints,
+                        const void *sptr, int ilevel,
+                        enum jer_encoder_flags_e flags,
+                        asn_app_consume_bytes_f *cb, void *app_key) {
+    const RELATIVE_OID_t *st = (const RELATIVE_OID_t *)sptr;
+    asn_enc_rval_t er = {0,0,0};
+    ssize_t ro_encoded = 0;
+
+    (void)ilevel;  /* Unused argument */
+    (void)flags;  /* Unused argument */
+
+    if(!st || !st->buf)
+        ASN__ENCODE_FAILED;
+
+    ASN__CALLBACK("\"", 1);
+    ro_encoded = RELATIVE_OID__dump_body(st, cb, app_key);
+    if(ro_encoded < 0) goto cb_failed;
+    er.encoded += ro_encoded;
+    ASN__CALLBACK("\"", 1);
+
+    ASN__ENCODED_OK(er);
+
+cb_failed:
+    ASN__ENCODE_FAILED;
+}