COSE dissector from dtn-wireshark project

1 files changed, 295 insertions, 0 deletions

diff --git a/epan/wscbor.h b/epan/wscbor.h
new file mode 100644
index 0000000000..0687afaff5
--- /dev/null
+++ b/epan/wscbor.h
@@ -0,0 +1,295 @@
+/* wscbor.h
+ * Definitions for the Wireshark CBOR item decoding API.
+ * References:
+ *     RFC 8949: https://tools.ietf.org/html/rfc8949
+ *
+ * Copyright 2019-2021, Brian Sipos <brian.sipos@gmail.com>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef __WSCBOR_H__
+#define __WSCBOR_H__
+
+#include <ws_symbol_export.h>
+#include <epan/tvbuff.h>
+#include <epan/proto.h>
+#include <epan/expert.h>
+#include <wsutil/wmem/wmem_list.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Register expert info and other wireshark data.
+ */
+WS_DLL_PUBLIC
+void wscbor_init(void);
+
+/// The same enumeration from libcbor-0.5
+typedef enum cbor_type {
+    CBOR_TYPE_UINT = 0, ///< positive integers
+    CBOR_TYPE_NEGINT = 1, ///< negative integers
+    CBOR_TYPE_BYTESTRING = 2, ///< byte strings
+    CBOR_TYPE_STRING = 3, ///< text strings
+    CBOR_TYPE_ARRAY = 4, ///< arrays
+    CBOR_TYPE_MAP = 5, ///< maps
+    CBOR_TYPE_TAG = 6, ///< tags
+    CBOR_TYPE_FLOAT_CTRL = 7, ///< decimals and special values (true, false, nil, ...)
+} cbor_type;
+
+/// The same enumeration from libcbor-0.5
+typedef enum {
+    CBOR_CTRL_NONE = 0,
+    CBOR_CTRL_FALSE = 20,
+    CBOR_CTRL_TRUE = 21,
+    CBOR_CTRL_NULL = 22,
+    CBOR_CTRL_UNDEF = 23
+} _cbor_ctrl;
+
+/// Decoding or require_* error
+typedef struct {
+    /// The associated expert info
+    expert_field *ei;
+    /// Optional specific text
+    const char *msg;
+} wscbor_error_t;
+
+/** Construct a new error object.
+ *
+ * @param alloc The allocator to use.
+ * @param ei The specific error type.
+ * @param format If non-NULL, a message format string.
+ * @return The new object.
+ */
+WS_DLL_PUBLIC
+wscbor_error_t * wscbor_error_new(wmem_allocator_t *alloc, expert_field *ei, const char *format, ...);
+
+/// Tag metadata and value
+typedef struct {
+    /// The start offset of this tag head
+    gint start;
+    /// The length of just this tag head
+    gint length;
+    /// The tag value
+    guint64 value;
+} wscbor_tag_t;
+
+/// A data-containing, optionally-tagged chunk of CBOR
+typedef struct {
+    /// The allocator used for #errors and #tags
+    wmem_allocator_t *_alloc;
+
+    /// The start offset of this chunk
+    gint start;
+    /// The length of just this header any any preceding tags
+    gint head_length;
+    /// The length of this chunk and its immediate definite data (i.e. strings)
+    gint data_length;
+    /// Errors processing this chunk (type wscbor_error_t*)
+    wmem_list_t *errors;
+    /// Tags on this chunk, in encoded order (type wscbor_tag_t*)
+    wmem_list_t *tags;
+
+    /// Major type of this block.
+    /// This will be one of the cbor_type values.
+    cbor_type type_major;
+    /// Minor type of this item
+    guint8 type_minor;
+    /// The header-encoded value
+    guint64 head_value;
+} wscbor_chunk_t;
+
+/** Scan for a tagged chunk of headers.
+ * The chunk of byte string and text string items includes the data content
+ * in its @c offset.
+ *
+ * @param alloc The allocator to use.
+ * @param tvb The TVB to read from.
+ * @param[in,out] offset The offset with in @c tvb.
+ * @return The chunk of data found, including any errors.
+ * This never returns NULL.
+ * @post This can throw ReportedBoundsError if the read itself ran out of data.
+ */
+WS_DLL_PUBLIC
+wscbor_chunk_t * wscbor_chunk_read(wmem_allocator_t *alloc, tvbuff_t *tvb, gint *offset);
+
+/** Free a chunk and its lists.
+ */
+WS_DLL_PUBLIC
+void wscbor_chunk_free(wscbor_chunk_t *chunk);
+
+/** After both reading and decoding a chunk, report on any errors found.
+ * @param pinfo The associated packet.
+ * @param item The associated tree item.
+ * @param chunk The chunk with possible errors.
+ * @return The error count.
+ */
+WS_DLL_PUBLIC
+guint64 wscbor_chunk_mark_errors(packet_info *pinfo, proto_item *item, const wscbor_chunk_t *chunk);
+
+/** Determine if a chunk has errors.
+ * @param chunk The chunk with possible errors.
+ * @return The error count.
+ */
+WS_DLL_PUBLIC
+guint wscbor_has_errors(const wscbor_chunk_t *chunk);
+
+/** Determine if an indefinite break is present.
+ *
+ * @param chunk The chunk to check.
+ * @return True if it's an indefinite break.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_is_indefinite_break(const wscbor_chunk_t *chunk);
+
+/** Recursively skip items from a stream.
+ *
+ * @param alloc The allocator to use.
+ * @param tvb The data buffer.
+ * @param[in,out] offset The initial offset to read and skip over.
+ * @return True if the skipped item was an indefinite break.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_skip_next_item(wmem_allocator_t *alloc, tvbuff_t *tvb, gint *offset);
+
+/** Skip over an item if a chunk has errors.
+ * This allows skipping an entire array or map if the major type or size is
+ * not as expected.
+ *
+ * @param alloc The allocator to use.
+ * @param tvb The data buffer.
+ * @param[in,out] offset The initial offset to read and skip over.
+ * @param chunk The chunk with possible errors.
+ * @return True if there were errors and the item skipped.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_skip_if_errors(wmem_allocator_t *alloc, tvbuff_t *tvb, gint *offset, const wscbor_chunk_t *chunk);
+
+
+/** Require a specific item major type.
+ *
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @param major The required major type.
+ * @return True if the item is that type.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_require_major_type(wscbor_chunk_t *chunk, cbor_type major);
+
+/** Require an array item.
+ *
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return True if the item is an array.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_require_array(wscbor_chunk_t *chunk);
+
+/** Require an array have a specific ranged size.
+ *
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @param count_min The minimum acceptable size.
+ * @param count_max The maximum acceptable size.
+ * @return True if the size is acceptable.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_require_array_size(wscbor_chunk_t *chunk, guint64 count_min, guint64 count_max);
+
+/** Require a map item.
+ *
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return True if the item is a map.
+ */
+WS_DLL_PUBLIC
+gboolean wscbor_require_map(wscbor_chunk_t *chunk);
+
+/** Require a CBOR item to have a boolean value.
+ *
+ * @param alloc The allocator to use.
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return Pointer to the boolean value, if the item was boolean.
+ * The value can be deleted with wscbor_require_delete().
+ */
+WS_DLL_PUBLIC
+gboolean * wscbor_require_boolean(wmem_allocator_t *alloc, wscbor_chunk_t *chunk);
+
+/** Require a CBOR item to have an unsigned-integer value.
+ * @note This reader will clip the most significant bit of the value.
+ *
+ * @param alloc The allocator to use.
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return Pointer to the boolean value, if the item was an integer.
+ * The value can be deleted with wscbor_require_delete().
+ */
+WS_DLL_PUBLIC
+guint64 * wscbor_require_uint64(wmem_allocator_t *alloc, wscbor_chunk_t *chunk);
+
+/** Require a CBOR item to have an signed- or unsigned-integer value.
+ * @note This reader will clip the most significant bit of the value.
+ *
+ * @param alloc The allocator to use.
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return Pointer to the value, if the item was an integer.
+ * The value can be deleted with wscbor_require_delete().
+ */
+WS_DLL_PUBLIC
+gint64 * wscbor_require_int64(wmem_allocator_t *alloc, wscbor_chunk_t *chunk);
+
+/** Require a CBOR item to have a text-string value.
+ *
+ * @param alloc The allocator to use.
+ * @param parent The containing buffer.
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return Pointer to the null-terminated UTF-8, if the item was a tstr.
+ */
+WS_DLL_PUBLIC
+char * wscbor_require_tstr(wmem_allocator_t *alloc, tvbuff_t *parent, wscbor_chunk_t *chunk);
+
+/** Require a CBOR item to have a byte-string value.
+ *
+ * @param parent The containing buffer.
+ * @param[in,out] chunk The chunk to read from and write errors on.
+ * @return Pointer to the value, if the item was an string.
+ * The value is memory managed by wireshark.
+ */
+WS_DLL_PUBLIC
+tvbuff_t * wscbor_require_bstr(tvbuff_t *parent, wscbor_chunk_t *chunk);
+
+/** Add an item representing an array or map container.
+ * If the item is type FT_UINT* or FT_INT* the count of (array) items
+ * or map (pairs) is used as the iterm value.
+ */
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_container(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk);
+
+/** Add an item representing a non-boolean, non-float control value.
+ */
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_ctrl(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk);
+
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_boolean(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk, const gboolean *value);
+
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_uint64(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk, const guint64 *value);
+
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_int64(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk, const gint64 *value);
+
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_bitmask(proto_tree *tree, int hfindex, const gint ett, int *const *fields, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk, const guint64 *value);
+
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_tstr(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk);
+
+WS_DLL_PUBLIC
+proto_item * proto_tree_add_cbor_bstr(proto_tree *tree, int hfindex, packet_info *pinfo, tvbuff_t *tvb, const wscbor_chunk_t *chunk);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __WSCBOR_H__ */