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FLASHING.md says how to take a newer version of the colleague's tree (copy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

@@ -0,0 +1,185 @@
+/*-
+ * Copyright (c) 2004, 2005, 2006 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+/*
+ * Read the NativeInteger.h for the explanation wrt. differences between
+ * INTEGER and NativeInteger.
+ * Basically, both are decoders and encoders of ASN.1 INTEGER type, but this
+ * implementation deals with the standard (machine-specific) representation
+ * of them instead of using the platform-independent buffer.
+ */
+#include "asn_internal.h"
+#include "NativeInteger.h"
+
+/*
+ * NativeInteger basic type description.
+ */
+static const ber_tlv_tag_t asn_DEF_NativeInteger_tags[] = {
+    (ASN_TAG_CLASS_UNIVERSAL | (2 << 2))
+};
+asn_TYPE_operation_t asn_OP_NativeInteger = {
+    NativeInteger_free,
+#if !defined(ASN_DISABLE_PRINT_SUPPORT)
+    NativeInteger_print,
+#else
+    0,
+#endif  /* !defined(ASN_DISABLE_PRINT_SUPPORT) */
+    NativeInteger_compare,
+    NativeInteger_copy,
+#if !defined(ASN_DISABLE_BER_SUPPORT)
+    NativeInteger_decode_ber,
+    NativeInteger_encode_der,
+#else
+    0,
+    0,
+#endif  /* !defined(ASN_DISABLE_BER_SUPPORT) */
+#if !defined(ASN_DISABLE_XER_SUPPORT)
+    NativeInteger_decode_xer,
+    NativeInteger_encode_xer,
+#else
+    0,
+    0,
+#endif  /* !defined(ASN_DISABLE_XER_SUPPORT) */
+#if !defined(ASN_DISABLE_JER_SUPPORT)
+    NativeInteger_decode_jer,
+    NativeInteger_encode_jer,
+#else
+    0,
+    0,
+#endif  /* !defined(ASN_DISABLE_JER_SUPPORT) */
+#if !defined(ASN_DISABLE_OER_SUPPORT)
+    NativeInteger_decode_oer,  /* OER decoder */
+    NativeInteger_encode_oer,  /* Canonical OER encoder */
+#else
+    0,
+    0,
+#endif  /* !defined(ASN_DISABLE_OER_SUPPORT) */
+#if !defined(ASN_DISABLE_UPER_SUPPORT)
+    NativeInteger_decode_uper,  /* Unaligned PER decoder */
+    NativeInteger_encode_uper,  /* Unaligned PER encoder */
+#else
+    0,
+    0,
+#endif  /* !defined(ASN_DISABLE_UPER_SUPPORT) */
+#if !defined(ASN_DISABLE_APER_SUPPORT)
+    NativeInteger_decode_aper,  /* Aligned PER decoder */
+    NativeInteger_encode_aper,  /* Aligned PER encoder */
+#else
+    0,
+    0,
+#endif  /* !defined(ASN_DISABLE_APER_SUPPORT) */
+#if !defined(ASN_DISABLE_RFILL_SUPPORT)
+    NativeInteger_random_fill,
+#else
+    0,
+#endif  /* !defined(ASN_DISABLE_RFILL_SUPPORT) */
+    0  /* Use generic outmost tag fetcher */
+};
+asn_TYPE_descriptor_t asn_DEF_NativeInteger = {
+    "INTEGER",  /* The ASN.1 type is still INTEGER */
+    "INTEGER",
+    &asn_OP_NativeInteger,
+    asn_DEF_NativeInteger_tags,
+    sizeof(asn_DEF_NativeInteger_tags) / sizeof(asn_DEF_NativeInteger_tags[0]),
+    asn_DEF_NativeInteger_tags,  /* Same as above */
+    sizeof(asn_DEF_NativeInteger_tags) / sizeof(asn_DEF_NativeInteger_tags[0]),
+    {
+#if !defined(ASN_DISABLE_OER_SUPPORT)
+        0,
+#endif  /* !defined(ASN_DISABLE_OER_SUPPORT) */
+#if !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT)
+        0,
+#endif  /* !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT) */
+#if !defined(ASN_DISABLE_JER_SUPPORT)
+        0,
+#endif  /* !defined(ASN_DISABLE_JER_SUPPORT) */
+        asn_generic_no_constraint
+    },
+    0, 0,  /* No members */
+    0  /* No specifics */
+};
+
+void
+NativeInteger_free(const asn_TYPE_descriptor_t *td, void *ptr,
+                   enum asn_struct_free_method method) {
+    if(!td || !ptr)
+		return;
+
+	ASN_DEBUG("Freeing %s as INTEGER (%d, %p, Native)",
+		td->name, method, ptr);
+
+    switch(method) {
+    case ASFM_FREE_EVERYTHING:
+        FREEMEM(ptr);
+        break;
+    case ASFM_FREE_UNDERLYING:
+        break;
+    case ASFM_FREE_UNDERLYING_AND_RESET:
+        memset(ptr, 0, sizeof(long));
+        break;
+    }
+}
+
+int
+NativeInteger_compare(const asn_TYPE_descriptor_t *td, const void *aptr, const void *bptr) {
+    (void)td;
+
+    if(aptr && bptr) {
+        const asn_INTEGER_specifics_t *specs =
+            (const asn_INTEGER_specifics_t *)td->specifics;
+        if(specs && specs->field_unsigned) {
+            const unsigned long *a = aptr;
+            const unsigned long *b = bptr;
+            if(*a < *b) {
+                return -1;
+            } else if(*a > *b) {
+                return 1;
+            } else {
+                return 0;
+            }
+        } else {
+            const long *a = aptr;
+            const long *b = bptr;
+            if(*a < *b) {
+                return -1;
+            } else if(*a > *b) {
+                return 1;
+            } else {
+                return 0;
+            }
+        }
+    } else if(!aptr) {
+        return -1;
+    } else {
+        return 1;
+    }
+}
+
+int
+NativeInteger_copy(const asn_TYPE_descriptor_t *td, void **aptr, const void *bptr) {
+    unsigned long *a = *aptr;
+    const unsigned long *b = bptr;
+
+    (void)td;
+
+    /* Check if source has data */
+    if(!b) {
+        /* Clear destination */
+        if(a) {
+            FREEMEM(a);
+            *aptr = 0;
+        }
+        return 0;
+    }
+
+    if(!a) {
+        a = *aptr = MALLOC(sizeof(*a));
+        if(!a) return -1;
+    }
+
+    *a = *b;
+
+    return 0;
+}