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FLASHING.md says how to take a newer version of the colleague's tree (copy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/uper_decoder.h

@@ -0,0 +1,98 @@
+/*-
+ * Copyright (c) 2005-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	_UPER_DECODER_H_
+#define	_UPER_DECODER_H_
+
+#include "asn_application.h"
+#include "uper_support.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct asn_TYPE_descriptor_s;	/* Forward declaration */
+
+/* Flags used by the uper_decode() functions */
+enum uper_decoder_flags_e {
+	/* Mode of decoding */
+	UPER_F_BASIC      = 0x00,	/* BASIC-UPER (default, lenient) */
+	UPER_F_CANONICAL  = 0x01	/* CANONICAL-UPER (strict rules) */
+};
+
+/*
+ * Unaligned PER decoder of a "complete encoding" as per X.691 (08/2015) #11.1.
+ * On success, this call always returns (.consumed >= 1), as per #11.1.3.
+ */
+asn_dec_rval_t uper_decode_complete(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size         /* Size of data buffer */
+);
+
+/*
+ * Unaligned PER decoder of any ASN.1 type. May be invoked by the application.
+ * WARNING: This call returns the number of BITS read from the stream. Beware.
+ */
+asn_dec_rval_t uper_decode(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size,        /* Size of the input data buffer, in bytes */
+    int skip_bits,      /* Number of unused leading bits, 0..7 */
+    int unused_bits     /* Number of unused tailing bits, 0..7 */
+);
+
+/*
+ * Canonical Unaligned PER decoder variants that enforce strict X.691 rules.
+ */
+asn_dec_rval_t uper_decode_complete_canonical(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size         /* Size of data buffer */
+);
+
+asn_dec_rval_t uper_decode_canonical(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size,        /* Size of the input data buffer, in bytes */
+    int skip_bits,      /* Number of unused leading bits, 0..7 */
+    int unused_bits     /* Number of unused tailing bits, 0..7 */
+);
+
+/*
+ * Lenient Canonical UPER decoder variants for interoperability.
+ * These perform canonical validation but allow non-canonical encodings
+ * from other implementations to decode successfully with warnings.
+ */
+asn_dec_rval_t uper_decode_complete_canonical_lenient(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size         /* Size of data buffer */
+);
+
+asn_dec_rval_t uper_decode_canonical_lenient(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size,        /* Size of the input data buffer, in bytes */
+    int skip_bits,      /* Number of unused leading bits, 0..7 */
+    int unused_bits     /* Number of unused tailing bits, 0..7 */
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _UPER_DECODER_H_ */