1/*
2 * Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License").  You may not use
5 * this file except in compliance with the License.  You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#ifndef OPENSSL_TRACE_H
11# define OPENSSL_TRACE_H
12# pragma once
13
14# include <stdarg.h>
15
16# include <openssl/bio.h>
17
18# ifdef  __cplusplus
19extern "C" {
20# endif
21
22/*
23 * TRACE CATEGORIES
24 */
25
26/*
27 * The trace messages of the OpenSSL libraries are organized into different
28 * categories. For every trace category, the application can register a separate
29 * tracer callback. When a callback is registered, a so called trace channel is
30 * created for this category. This channel consists essentially of an internal
31 * BIO which sends all trace output it receives to the registered application
32 * callback.
33 *
34 * The ALL category can be used as a fallback category to register a single
35 * channel which receives the output from all categories. However, if the
36 * application intends to print the trace channel name in the line prefix,
37 * it is better to register channels for all categories separately.
38 * (This is how the openssl application does it.)
39 */
40# define OSSL_TRACE_CATEGORY_ALL                 0 /* The fallback */
41# define OSSL_TRACE_CATEGORY_TRACE               1
42# define OSSL_TRACE_CATEGORY_INIT                2
43# define OSSL_TRACE_CATEGORY_TLS                 3
44# define OSSL_TRACE_CATEGORY_TLS_CIPHER          4
45# define OSSL_TRACE_CATEGORY_CONF                5
46# define OSSL_TRACE_CATEGORY_ENGINE_TABLE        6
47# define OSSL_TRACE_CATEGORY_ENGINE_REF_COUNT    7
48# define OSSL_TRACE_CATEGORY_PKCS5V2             8
49# define OSSL_TRACE_CATEGORY_PKCS12_KEYGEN       9
50# define OSSL_TRACE_CATEGORY_PKCS12_DECRYPT     10
51# define OSSL_TRACE_CATEGORY_X509V3_POLICY      11
52# define OSSL_TRACE_CATEGORY_BN_CTX             12
53# define OSSL_TRACE_CATEGORY_CMP                13
54# define OSSL_TRACE_CATEGORY_STORE              14
55# define OSSL_TRACE_CATEGORY_DECODER            15
56# define OSSL_TRACE_CATEGORY_ENCODER            16
57# define OSSL_TRACE_CATEGORY_REF_COUNT          17
58/* Count of available categories. */
59# define OSSL_TRACE_CATEGORY_NUM                18
60
61/* Returns the trace category number for the given |name| */
62int OSSL_trace_get_category_num(const char *name);
63
64/* Returns the trace category name for the given |num| */
65const char *OSSL_trace_get_category_name(int num);
66
67/*
68 * TRACE CONSUMERS
69 */
70
71/*
72 * Enables tracing for the given |category| by providing a BIO sink
73 * as |channel|. If a null pointer is passed as |channel|, an existing
74 * trace channel is removed and tracing for the category is disabled.
75 *
76 * Returns 1 on success and 0 on failure
77 */
78int OSSL_trace_set_channel(int category, BIO* channel);
79
80/*
81 * Attach a prefix and a suffix to the given |category|, to be printed at the
82 * beginning and at the end of each trace output group, i.e. when
83 * OSSL_trace_begin() and OSSL_trace_end() are called.
84 * If a null pointer is passed as argument, the existing prefix or suffix is
85 * removed.
86 *
87 * They return 1 on success and 0 on failure
88 */
89int OSSL_trace_set_prefix(int category, const char *prefix);
90int OSSL_trace_set_suffix(int category, const char *suffix);
91
92/*
93 * OSSL_trace_cb is the type tracing callback provided by the application.
94 * It MUST return the number of bytes written, or 0 on error (in other words,
95 * it can never write zero bytes).
96 *
97 * The |buffer| will always contain text, which may consist of several lines.
98 * The |data| argument points to whatever data was provided by the application
99 * when registering the tracer function.
100 *
101 * The |category| number is given, as well as a |cmd| number, described below.
102 */
103typedef size_t (*OSSL_trace_cb)(const char *buffer, size_t count,
104                                int category, int cmd, void *data);
105/*
106 * Possible |cmd| numbers.
107 */
108# define OSSL_TRACE_CTRL_BEGIN  0
109# define OSSL_TRACE_CTRL_WRITE  1
110# define OSSL_TRACE_CTRL_END    2
111
112/*
113 * Enables tracing for the given |category| by creating an internal
114 * trace channel which sends the output to the given |callback|.
115 * If a null pointer is passed as callback, an existing trace channel
116 * is removed and tracing for the category is disabled.
117 *
118 * NOTE: OSSL_trace_set_channel() and OSSL_trace_set_callback() are mutually
119 *       exclusive.
120 *
121 * Returns 1 on success and 0 on failure
122 */
123int OSSL_trace_set_callback(int category, OSSL_trace_cb callback, void *data);
124
125/*
126 * TRACE PRODUCERS
127 */
128
129/*
130 * Returns 1 if tracing for the specified category is enabled, otherwise 0
131 */
132int OSSL_trace_enabled(int category);
133
134/*
135 * Wrap a group of tracing output calls.  OSSL_trace_begin() locks tracing and
136 * returns the trace channel associated with the given category, or NULL if no
137 * channel is associated with the category.  OSSL_trace_end() unlocks tracing.
138 *
139 * Usage:
140 *
141 *    BIO *out;
142 *    if ((out = OSSL_trace_begin(category)) != NULL) {
143 *        ...
144 *        BIO_fprintf(out, ...);
145 *        ...
146 *        OSSL_trace_end(category, out);
147 *    }
148 *
149 * See also the convenience macros OSSL_TRACE_BEGIN and OSSL_TRACE_END below.
150 */
151BIO *OSSL_trace_begin(int category);
152void OSSL_trace_end(int category, BIO *channel);
153
154/*
155 * OSSL_TRACE* Convenience Macros
156 */
157
158/*
159 * When the tracing feature is disabled, these macros are defined to
160 * produce dead code, which a good compiler should eliminate.
161 */
162
163/*
164 * OSSL_TRACE_BEGIN, OSSL_TRACE_END - Define a Trace Group
165 *
166 * These two macros can be used to create a block which is executed only
167 * if the corresponding trace category is enabled. Inside this block, a
168 * local variable named |trc_out| is defined, which points to the channel
169 * associated with the given trace category.
170 *
171 * Usage: (using 'TLS' as an example category)
172 *
173 *     OSSL_TRACE_BEGIN(TLS) {
174 *
175 *         BIO_fprintf(trc_out, ... );
176 *
177 *     } OSSL_TRACE_END(TLS);
178 *
179 *
180 * This expands to the following code
181 *
182 *     do {
183 *         BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_TLS);
184 *         if (trc_out != NULL) {
185 *             ...
186 *             BIO_fprintf(trc_out, ...);
187 *         }
188 *         OSSL_trace_end(OSSL_TRACE_CATEGORY_TLS, trc_out);
189 *     } while (0);
190 *
191 * The use of the inner '{...}' group and the trailing ';' is enforced
192 * by the definition of the macros in order to make the code look as much
193 * like C code as possible.
194 *
195 * Before returning from inside the trace block, it is necessary to
196 * call OSSL_TRACE_CANCEL(category).
197 */
198
199# if !defined OPENSSL_NO_TRACE && !defined FIPS_MODULE
200
201#  define OSSL_TRACE_BEGIN(category) \
202    do { \
203        BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_##category); \
204 \
205        if (trc_out != NULL)
206
207#  define OSSL_TRACE_END(category) \
208        OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out); \
209    } while (0)
210
211#  define OSSL_TRACE_CANCEL(category) \
212        OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out) \
213
214# else
215
216#  define OSSL_TRACE_BEGIN(category)           \
217    do {                                        \
218        BIO *trc_out = NULL;                    \
219        if (0)
220
221#  define OSSL_TRACE_END(category)             \
222    } while(0)
223
224#  define OSSL_TRACE_CANCEL(category)          \
225    ((void)0)
226
227# endif
228
229/*
230 * OSSL_TRACE_ENABLED() - Check whether tracing is enabled for |category|
231 *
232 * Usage:
233 *
234 *     if (OSSL_TRACE_ENABLED(TLS)) {
235 *         ...
236 *     }
237 */
238# if !defined OPENSSL_NO_TRACE && !defined FIPS_MODULE
239
240#  define OSSL_TRACE_ENABLED(category) \
241    OSSL_trace_enabled(OSSL_TRACE_CATEGORY_##category)
242
243# else
244
245#  define OSSL_TRACE_ENABLED(category) (0)
246
247# endif
248
249/*
250 * OSSL_TRACE*() - OneShot Trace Macros
251 *
252 * These macros are intended to produce a simple printf-style trace output.
253 * Unfortunately, C90 macros don't support variable arguments, so the
254 * "vararg" OSSL_TRACEV() macro has a rather weird usage pattern:
255 *
256 *    OSSL_TRACEV(category, (trc_out, "format string", ...args...));
257 *
258 * Where 'channel' is the literal symbol of this name, not a variable.
259 * For that reason, it is currently not intended to be used directly,
260 * but only as helper macro for the other oneshot trace macros
261 * OSSL_TRACE(), OSSL_TRACE1(), OSSL_TRACE2(), ...
262 *
263 * Usage:
264 *
265 *    OSSL_TRACE(INIT, "Hello world!\n");
266 *    OSSL_TRACE1(TLS, "The answer is %d\n", 42);
267 *    OSSL_TRACE2(TLS, "The ultimate question to answer %d is '%s'\n",
268 *                42, "What do you get when you multiply six by nine?");
269 */
270
271# if !defined OPENSSL_NO_TRACE && !defined FIPS_MODULE
272
273#  define OSSL_TRACEV(category, args) \
274    OSSL_TRACE_BEGIN(category) \
275        BIO_printf args; \
276    OSSL_TRACE_END(category)
277
278# else
279
280#  define OSSL_TRACEV(category, args) ((void)0)
281
282# endif
283
284# define OSSL_TRACE(category, text) \
285    OSSL_TRACEV(category, (trc_out, "%s", text))
286
287# define OSSL_TRACE1(category, format, arg1) \
288    OSSL_TRACEV(category, (trc_out, format, arg1))
289# define OSSL_TRACE2(category, format, arg1, arg2) \
290    OSSL_TRACEV(category, (trc_out, format, arg1, arg2))
291# define OSSL_TRACE3(category, format, arg1, arg2, arg3) \
292    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3))
293# define OSSL_TRACE4(category, format, arg1, arg2, arg3, arg4) \
294    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4))
295# define OSSL_TRACE5(category, format, arg1, arg2, arg3, arg4, arg5) \
296    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5))
297# define OSSL_TRACE6(category, format, arg1, arg2, arg3, arg4, arg5, arg6) \
298    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6))
299# define OSSL_TRACE7(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
300    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7))
301# define OSSL_TRACE8(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
302    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8))
303# define OSSL_TRACE9(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \
304    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9))
305
306# ifdef  __cplusplus
307}
308# endif
309
310#endif
311