1 /*
2 * Debugging routines
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 #include "common.h"
21
22 #if defined(MBEDTLS_DEBUG_C)
23
24 #include "mbedtls/platform.h"
25
26 #include "mbedtls/debug.h"
27 #include "mbedtls/error.h"
28
29 #include <stdarg.h>
30 #include <stdio.h>
31 #include <string.h>
32
33 #define DEBUG_BUF_SIZE 512
34
35 static int debug_threshold = 0;
36
mbedtls_debug_set_threshold(int threshold)37 void mbedtls_debug_set_threshold(int threshold)
38 {
39 debug_threshold = threshold;
40 }
41
42 /*
43 * All calls to f_dbg must be made via this function
44 */
debug_send_line(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * str)45 static inline void debug_send_line(const mbedtls_ssl_context *ssl, int level,
46 const char *file, int line,
47 const char *str)
48 {
49 /*
50 * If in a threaded environment, we need a thread identifier.
51 * Since there is no portable way to get one, use the address of the ssl
52 * context instead, as it shouldn't be shared between threads.
53 */
54 #if defined(MBEDTLS_THREADING_C)
55 char idstr[20 + DEBUG_BUF_SIZE]; /* 0x + 16 nibbles + ': ' */
56 mbedtls_snprintf(idstr, sizeof(idstr), "%p: %s", (void *) ssl, str);
57 ssl->conf->f_dbg(ssl->conf->p_dbg, level, file, line, idstr);
58 #else
59 ssl->conf->f_dbg(ssl->conf->p_dbg, level, file, line, str);
60 #endif
61 }
62
63 MBEDTLS_PRINTF_ATTRIBUTE(5, 6)
mbedtls_debug_print_msg(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * format,...)64 void mbedtls_debug_print_msg(const mbedtls_ssl_context *ssl, int level,
65 const char *file, int line,
66 const char *format, ...)
67 {
68 va_list argp;
69 char str[DEBUG_BUF_SIZE];
70 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
71
72 if (NULL == ssl ||
73 NULL == ssl->conf ||
74 NULL == ssl->conf->f_dbg ||
75 level > debug_threshold) {
76 return;
77 }
78
79 va_start(argp, format);
80 ret = mbedtls_vsnprintf(str, DEBUG_BUF_SIZE, format, argp);
81 va_end(argp);
82
83 if (ret >= 0 && ret < DEBUG_BUF_SIZE - 1) {
84 str[ret] = '\n';
85 str[ret + 1] = '\0';
86 }
87
88 debug_send_line(ssl, level, file, line, str);
89 }
90
mbedtls_debug_print_ret(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text,int ret)91 void mbedtls_debug_print_ret(const mbedtls_ssl_context *ssl, int level,
92 const char *file, int line,
93 const char *text, int ret)
94 {
95 char str[DEBUG_BUF_SIZE];
96
97 if (NULL == ssl ||
98 NULL == ssl->conf ||
99 NULL == ssl->conf->f_dbg ||
100 level > debug_threshold) {
101 return;
102 }
103
104 /*
105 * With non-blocking I/O and examples that just retry immediately,
106 * the logs would be quickly flooded with WANT_READ, so ignore that.
107 * Don't ignore WANT_WRITE however, since it is usually rare.
108 */
109 if (ret == MBEDTLS_ERR_SSL_WANT_READ) {
110 return;
111 }
112
113 mbedtls_snprintf(str, sizeof(str), "%s() returned %d (-0x%04x)\n",
114 text, ret, (unsigned int) -ret);
115
116 debug_send_line(ssl, level, file, line, str);
117 }
118
mbedtls_debug_print_buf(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text,const unsigned char * buf,size_t len)119 void mbedtls_debug_print_buf(const mbedtls_ssl_context *ssl, int level,
120 const char *file, int line, const char *text,
121 const unsigned char *buf, size_t len)
122 {
123 char str[DEBUG_BUF_SIZE];
124 char txt[17];
125 size_t i, idx = 0;
126
127 if (NULL == ssl ||
128 NULL == ssl->conf ||
129 NULL == ssl->conf->f_dbg ||
130 level > debug_threshold) {
131 return;
132 }
133
134 mbedtls_snprintf(str + idx, sizeof(str) - idx, "dumping '%s' (%u bytes)\n",
135 text, (unsigned int) len);
136
137 debug_send_line(ssl, level, file, line, str);
138
139 idx = 0;
140 memset(txt, 0, sizeof(txt));
141 for (i = 0; i < len; i++) {
142 if (i >= 4096) {
143 break;
144 }
145
146 if (i % 16 == 0) {
147 if (i > 0) {
148 mbedtls_snprintf(str + idx, sizeof(str) - idx, " %s\n", txt);
149 debug_send_line(ssl, level, file, line, str);
150
151 idx = 0;
152 memset(txt, 0, sizeof(txt));
153 }
154
155 idx += mbedtls_snprintf(str + idx, sizeof(str) - idx, "%04x: ",
156 (unsigned int) i);
157
158 }
159
160 idx += mbedtls_snprintf(str + idx, sizeof(str) - idx, " %02x",
161 (unsigned int) buf[i]);
162 txt[i % 16] = (buf[i] > 31 && buf[i] < 127) ? buf[i] : '.';
163 }
164
165 if (len > 0) {
166 for (/* i = i */; i % 16 != 0; i++) {
167 idx += mbedtls_snprintf(str + idx, sizeof(str) - idx, " ");
168 }
169
170 mbedtls_snprintf(str + idx, sizeof(str) - idx, " %s\n", txt);
171 debug_send_line(ssl, level, file, line, str);
172 }
173 }
174
175 #if defined(MBEDTLS_ECP_C)
mbedtls_debug_print_ecp(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text,const mbedtls_ecp_point * X)176 void mbedtls_debug_print_ecp(const mbedtls_ssl_context *ssl, int level,
177 const char *file, int line,
178 const char *text, const mbedtls_ecp_point *X)
179 {
180 char str[DEBUG_BUF_SIZE];
181
182 if (NULL == ssl ||
183 NULL == ssl->conf ||
184 NULL == ssl->conf->f_dbg ||
185 level > debug_threshold) {
186 return;
187 }
188
189 mbedtls_snprintf(str, sizeof(str), "%s(X)", text);
190 mbedtls_debug_print_mpi(ssl, level, file, line, str, &X->X);
191
192 mbedtls_snprintf(str, sizeof(str), "%s(Y)", text);
193 mbedtls_debug_print_mpi(ssl, level, file, line, str, &X->Y);
194 }
195 #endif /* MBEDTLS_ECP_C */
196
197 #if defined(MBEDTLS_BIGNUM_C)
mbedtls_debug_print_mpi(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text,const mbedtls_mpi * X)198 void mbedtls_debug_print_mpi(const mbedtls_ssl_context *ssl, int level,
199 const char *file, int line,
200 const char *text, const mbedtls_mpi *X)
201 {
202 char str[DEBUG_BUF_SIZE];
203 size_t bitlen;
204 size_t idx = 0;
205
206 if (NULL == ssl ||
207 NULL == ssl->conf ||
208 NULL == ssl->conf->f_dbg ||
209 NULL == X ||
210 level > debug_threshold) {
211 return;
212 }
213
214 bitlen = mbedtls_mpi_bitlen(X);
215
216 mbedtls_snprintf(str, sizeof(str), "value of '%s' (%u bits) is:\n",
217 text, (unsigned) bitlen);
218 debug_send_line(ssl, level, file, line, str);
219
220 if (bitlen == 0) {
221 str[0] = ' '; str[1] = '0'; str[2] = '0';
222 idx = 3;
223 } else {
224 int n;
225 for (n = (int) ((bitlen - 1) / 8); n >= 0; n--) {
226 size_t limb_offset = n / sizeof(mbedtls_mpi_uint);
227 size_t offset_in_limb = n % sizeof(mbedtls_mpi_uint);
228 unsigned char octet =
229 (X->p[limb_offset] >> (offset_in_limb * 8)) & 0xff;
230 mbedtls_snprintf(str + idx, sizeof(str) - idx, " %02x", octet);
231 idx += 3;
232 /* Wrap lines after 16 octets that each take 3 columns */
233 if (idx >= 3 * 16) {
234 mbedtls_snprintf(str + idx, sizeof(str) - idx, "\n");
235 debug_send_line(ssl, level, file, line, str);
236 idx = 0;
237 }
238 }
239 }
240
241 if (idx != 0) {
242 mbedtls_snprintf(str + idx, sizeof(str) - idx, "\n");
243 debug_send_line(ssl, level, file, line, str);
244 }
245 }
246 #endif /* MBEDTLS_BIGNUM_C */
247
248 #if defined(MBEDTLS_X509_CRT_PARSE_C) && !defined(MBEDTLS_X509_REMOVE_INFO)
debug_print_pk(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text,const mbedtls_pk_context * pk)249 static void debug_print_pk(const mbedtls_ssl_context *ssl, int level,
250 const char *file, int line,
251 const char *text, const mbedtls_pk_context *pk)
252 {
253 size_t i;
254 mbedtls_pk_debug_item items[MBEDTLS_PK_DEBUG_MAX_ITEMS];
255 char name[16];
256
257 memset(items, 0, sizeof(items));
258
259 if (mbedtls_pk_debug(pk, items) != 0) {
260 debug_send_line(ssl, level, file, line,
261 "invalid PK context\n");
262 return;
263 }
264
265 for (i = 0; i < MBEDTLS_PK_DEBUG_MAX_ITEMS; i++) {
266 if (items[i].type == MBEDTLS_PK_DEBUG_NONE) {
267 return;
268 }
269
270 mbedtls_snprintf(name, sizeof(name), "%s%s", text, items[i].name);
271 name[sizeof(name) - 1] = '\0';
272
273 if (items[i].type == MBEDTLS_PK_DEBUG_MPI) {
274 mbedtls_debug_print_mpi(ssl, level, file, line, name, items[i].value);
275 } else
276 #if defined(MBEDTLS_ECP_C)
277 if (items[i].type == MBEDTLS_PK_DEBUG_ECP) {
278 mbedtls_debug_print_ecp(ssl, level, file, line, name, items[i].value);
279 } else
280 #endif
281 { debug_send_line(ssl, level, file, line,
282 "should not happen\n"); }
283 }
284 }
285
debug_print_line_by_line(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text)286 static void debug_print_line_by_line(const mbedtls_ssl_context *ssl, int level,
287 const char *file, int line, const char *text)
288 {
289 char str[DEBUG_BUF_SIZE];
290 const char *start, *cur;
291
292 start = text;
293 for (cur = text; *cur != '\0'; cur++) {
294 if (*cur == '\n') {
295 size_t len = cur - start + 1;
296 if (len > DEBUG_BUF_SIZE - 1) {
297 len = DEBUG_BUF_SIZE - 1;
298 }
299
300 memcpy(str, start, len);
301 str[len] = '\0';
302
303 debug_send_line(ssl, level, file, line, str);
304
305 start = cur + 1;
306 }
307 }
308 }
309
mbedtls_debug_print_crt(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const char * text,const mbedtls_x509_crt * crt)310 void mbedtls_debug_print_crt(const mbedtls_ssl_context *ssl, int level,
311 const char *file, int line,
312 const char *text, const mbedtls_x509_crt *crt)
313 {
314 char str[DEBUG_BUF_SIZE];
315 int i = 0;
316
317 if (NULL == ssl ||
318 NULL == ssl->conf ||
319 NULL == ssl->conf->f_dbg ||
320 NULL == crt ||
321 level > debug_threshold) {
322 return;
323 }
324
325 while (crt != NULL) {
326 char buf[1024];
327
328 mbedtls_snprintf(str, sizeof(str), "%s #%d:\n", text, ++i);
329 debug_send_line(ssl, level, file, line, str);
330
331 mbedtls_x509_crt_info(buf, sizeof(buf) - 1, "", crt);
332 debug_print_line_by_line(ssl, level, file, line, buf);
333
334 debug_print_pk(ssl, level, file, line, "crt->", &crt->pk);
335
336 crt = crt->next;
337 }
338 }
339 #endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_X509_REMOVE_INFO */
340
341 #if defined(MBEDTLS_ECDH_C)
mbedtls_debug_printf_ecdh_internal(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const mbedtls_ecdh_context * ecdh,mbedtls_debug_ecdh_attr attr)342 static void mbedtls_debug_printf_ecdh_internal(const mbedtls_ssl_context *ssl,
343 int level, const char *file,
344 int line,
345 const mbedtls_ecdh_context *ecdh,
346 mbedtls_debug_ecdh_attr attr)
347 {
348 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
349 const mbedtls_ecdh_context *ctx = ecdh;
350 #else
351 const mbedtls_ecdh_context_mbed *ctx = &ecdh->ctx.mbed_ecdh;
352 #endif
353
354 switch (attr) {
355 case MBEDTLS_DEBUG_ECDH_Q:
356 mbedtls_debug_print_ecp(ssl, level, file, line, "ECDH: Q",
357 &ctx->Q);
358 break;
359 case MBEDTLS_DEBUG_ECDH_QP:
360 mbedtls_debug_print_ecp(ssl, level, file, line, "ECDH: Qp",
361 &ctx->Qp);
362 break;
363 case MBEDTLS_DEBUG_ECDH_Z:
364 mbedtls_debug_print_mpi(ssl, level, file, line, "ECDH: z",
365 &ctx->z);
366 break;
367 default:
368 break;
369 }
370 }
371
mbedtls_debug_printf_ecdh(const mbedtls_ssl_context * ssl,int level,const char * file,int line,const mbedtls_ecdh_context * ecdh,mbedtls_debug_ecdh_attr attr)372 void mbedtls_debug_printf_ecdh(const mbedtls_ssl_context *ssl, int level,
373 const char *file, int line,
374 const mbedtls_ecdh_context *ecdh,
375 mbedtls_debug_ecdh_attr attr)
376 {
377 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
378 mbedtls_debug_printf_ecdh_internal(ssl, level, file, line, ecdh, attr);
379 #else
380 switch (ecdh->var) {
381 default:
382 mbedtls_debug_printf_ecdh_internal(ssl, level, file, line, ecdh,
383 attr);
384 }
385 #endif
386 }
387 #endif /* MBEDTLS_ECDH_C */
388
389 #endif /* MBEDTLS_DEBUG_C */
390