debug.c

00001 /*
00002  *  Debugging routines
00003  *
00004  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00005  *  SPDX-License-Identifier: Apache-2.0
00006  *
00007  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00008  *  not use this file except in compliance with the License.
00009  *  You may obtain a copy of the License at
00010  *
00011  *  http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  *  Unless required by applicable law or agreed to in writing, software
00014  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00015  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  *  See the License for the specific language governing permissions and
00017  *  limitations under the License.
00018  *
00019  *  This file is part of mbed TLS (https://tls.mbed.org)
00020  */
00021 
00022 #if !defined(MBEDTLS_CONFIG_FILE)
00023 #include "mbedtls/config.h"
00024 #else
00025 #include MBEDTLS_CONFIG_FILE
00026 #endif
00027 
00028 #if defined(MBEDTLS_DEBUG_C)
00029 
00030 #if defined(MBEDTLS_PLATFORM_C)
00031 #include "mbedtls/platform.h"
00032 #else
00033 #include <stdlib.h>
00034 #define mbedtls_calloc      calloc
00035 #define mbedtls_free        free
00036 #define mbedtls_time_t      time_t
00037 #define mbedtls_snprintf    snprintf
00038 #endif
00039 
00040 #include "mbedtls/debug.h"
00041 
00042 #include <stdarg.h>
00043 #include <stdio.h>
00044 #include <string.h>
00045 
00046 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
00047     !defined(inline) && !defined(__cplusplus)
00048 #define inline __inline
00049 #endif
00050 
00051 #define DEBUG_BUF_SIZE      512
00052 
00053 static int debug_threshold = 0;
00054 
00055 void mbedtls_debug_set_threshold( int threshold )
00056 {
00057     debug_threshold = threshold;
00058 }
00059 
00060 /*
00061  * All calls to f_dbg must be made via this function
00062  */
00063 static inline void debug_send_line( const mbedtls_ssl_context *ssl, int level,
00064                                     const char *file, int line,
00065                                     const char *str )
00066 {
00067     /*
00068      * If in a threaded environment, we need a thread identifier.
00069      * Since there is no portable way to get one, use the address of the ssl
00070      * context instead, as it shouldn't be shared between threads.
00071      */
00072 #if defined(MBEDTLS_THREADING_C)
00073     char idstr[20 + DEBUG_BUF_SIZE]; /* 0x + 16 nibbles + ': ' */
00074     mbedtls_snprintf( idstr, sizeof( idstr ), "%p: %s", (void*)ssl, str );
00075     ssl->conf->f_dbg( ssl->conf->p_dbg, level, file, line, idstr );
00076 #else
00077     ssl->conf->f_dbg( ssl->conf->p_dbg, level, file, line, str );
00078 #endif
00079 }
00080 
00081 void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
00082                               const char *file, int line,
00083                               const char *format, ... )
00084 {
00085     va_list argp;
00086     char str[DEBUG_BUF_SIZE];
00087     int ret;
00088 
00089     if( NULL == ssl || NULL == ssl->conf || NULL == ssl->conf->f_dbg || level > debug_threshold )
00090         return;
00091 
00092     va_start( argp, format );
00093 #if defined(_WIN32)
00094 #if defined(_TRUNCATE)
00095     ret = _vsnprintf_s( str, DEBUG_BUF_SIZE, _TRUNCATE, format, argp );
00096 #else
00097     ret = _vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
00098     if( ret < 0 || (size_t) ret == DEBUG_BUF_SIZE )
00099     {
00100         str[DEBUG_BUF_SIZE-1] = '\0';
00101         ret = -1;
00102     }
00103 #endif
00104 #else
00105     ret = vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
00106 #endif
00107     va_end( argp );
00108 
00109     if( ret >= 0 && ret < DEBUG_BUF_SIZE - 1 )
00110     {
00111         str[ret]     = '\n';
00112         str[ret + 1] = '\0';
00113     }
00114 
00115     debug_send_line( ssl, level, file, line, str );
00116 }
00117 
00118 void mbedtls_debug_print_ret( const mbedtls_ssl_context *ssl, int level,
00119                       const char *file, int line,
00120                       const char *text, int ret )
00121 {
00122     char str[DEBUG_BUF_SIZE];
00123 
00124     if( ssl->conf == NULL || ssl->conf->f_dbg == NULL || level > debug_threshold )
00125         return;
00126 
00127     /*
00128      * With non-blocking I/O and examples that just retry immediately,
00129      * the logs would be quickly flooded with WANT_READ, so ignore that.
00130      * Don't ignore WANT_WRITE however, since is is usually rare.
00131      */
00132     if( ret == MBEDTLS_ERR_SSL_WANT_READ )
00133         return;
00134 
00135     mbedtls_snprintf( str, sizeof( str ), "%s() returned %d (-0x%04x)\n",
00136               text, ret, -ret );
00137 
00138     debug_send_line( ssl, level, file, line, str );
00139 }
00140 
00141 void mbedtls_debug_print_buf( const mbedtls_ssl_context *ssl, int level,
00142                       const char *file, int line, const char *text,
00143                       const unsigned char *buf, size_t len )
00144 {
00145     char str[DEBUG_BUF_SIZE];
00146     char txt[17];
00147     size_t i, idx = 0;
00148 
00149     if( ssl->conf == NULL || ssl->conf->f_dbg == NULL || level > debug_threshold )
00150         return;
00151 
00152     mbedtls_snprintf( str + idx, sizeof( str ) - idx, "dumping '%s' (%u bytes)\n",
00153               text, (unsigned int) len );
00154 
00155     debug_send_line( ssl, level, file, line, str );
00156 
00157     idx = 0;
00158     memset( txt, 0, sizeof( txt ) );
00159     for( i = 0; i < len; i++ )
00160     {
00161         if( i >= 4096 )
00162             break;
00163 
00164         if( i % 16 == 0 )
00165         {
00166             if( i > 0 )
00167             {
00168                 mbedtls_snprintf( str + idx, sizeof( str ) - idx, "  %s\n", txt );
00169                 debug_send_line( ssl, level, file, line, str );
00170 
00171                 idx = 0;
00172                 memset( txt, 0, sizeof( txt ) );
00173             }
00174 
00175             idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, "%04x: ",
00176                              (unsigned int) i );
00177 
00178         }
00179 
00180         idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x",
00181                          (unsigned int) buf[i] );
00182         txt[i % 16] = ( buf[i] > 31 && buf[i] < 127 ) ? buf[i] : '.' ;
00183     }
00184 
00185     if( len > 0 )
00186     {
00187         for( /* i = i */; i % 16 != 0; i++ )
00188             idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, "   " );
00189 
00190         mbedtls_snprintf( str + idx, sizeof( str ) - idx, "  %s\n", txt );
00191         debug_send_line( ssl, level, file, line, str );
00192     }
00193 }
00194 
00195 #if defined(MBEDTLS_ECP_C)
00196 void mbedtls_debug_print_ecp( const mbedtls_ssl_context *ssl, int level,
00197                       const char *file, int line,
00198                       const char *text, const mbedtls_ecp_point *X )
00199 {
00200     char str[DEBUG_BUF_SIZE];
00201 
00202     if( ssl->conf == NULL || ssl->conf->f_dbg == NULL || level > debug_threshold )
00203         return;
00204 
00205     mbedtls_snprintf( str, sizeof( str ), "%s(X)", text );
00206     mbedtls_debug_print_mpi( ssl, level, file, line, str, &X->X  );
00207 
00208     mbedtls_snprintf( str, sizeof( str ), "%s(Y)", text );
00209     mbedtls_debug_print_mpi( ssl, level, file, line, str, &X->Y  );
00210 }
00211 #endif /* MBEDTLS_ECP_C */
00212 
00213 #if defined(MBEDTLS_BIGNUM_C)
00214 void mbedtls_debug_print_mpi( const mbedtls_ssl_context *ssl, int level,
00215                       const char *file, int line,
00216                       const char *text, const mbedtls_mpi *X )
00217 {
00218     char str[DEBUG_BUF_SIZE];
00219     int j, k, zeros = 1;
00220     size_t i, n, idx = 0;
00221 
00222     if( ssl->conf == NULL || ssl->conf->f_dbg == NULL || X == NULL || level > debug_threshold )
00223         return;
00224 
00225     for( n = X->n  - 1; n > 0; n-- )
00226         if( X->p [n] != 0 )
00227             break;
00228 
00229     for( j = ( sizeof(mbedtls_mpi_uint) << 3 ) - 1; j >= 0; j-- )
00230         if( ( ( X->p [n] >> j ) & 1 ) != 0 )
00231             break;
00232 
00233     mbedtls_snprintf( str + idx, sizeof( str ) - idx, "value of '%s' (%d bits) is:\n",
00234               text, (int) ( ( n * ( sizeof(mbedtls_mpi_uint) << 3 ) ) + j + 1 ) );
00235 
00236     debug_send_line( ssl, level, file, line, str );
00237 
00238     idx = 0;
00239     for( i = n + 1, j = 0; i > 0; i-- )
00240     {
00241         if( zeros && X->p [i - 1] == 0 )
00242             continue;
00243 
00244         for( k = sizeof( mbedtls_mpi_uint ) - 1; k >= 0; k-- )
00245         {
00246             if( zeros && ( ( X->p [i - 1] >> ( k << 3 ) ) & 0xFF ) == 0 )
00247                 continue;
00248             else
00249                 zeros = 0;
00250 
00251             if( j % 16 == 0 )
00252             {
00253                 if( j > 0 )
00254                 {
00255                     mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
00256                     debug_send_line( ssl, level, file, line, str );
00257                     idx = 0;
00258                 }
00259             }
00260 
00261             idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x", (unsigned int)
00262                              ( X->p [i - 1] >> ( k << 3 ) ) & 0xFF );
00263 
00264             j++;
00265         }
00266 
00267     }
00268 
00269     if( zeros == 1 )
00270         idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " 00" );
00271 
00272     mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
00273     debug_send_line( ssl, level, file, line, str );
00274 }
00275 #endif /* MBEDTLS_BIGNUM_C */
00276 
00277 #if defined(MBEDTLS_X509_CRT_PARSE_C)
00278 static void debug_print_pk( const mbedtls_ssl_context *ssl, int level,
00279                             const char *file, int line,
00280                             const char *text, const mbedtls_pk_context *pk )
00281 {
00282     size_t i;
00283     mbedtls_pk_debug_item items[MBEDTLS_PK_DEBUG_MAX_ITEMS];
00284     char name[16];
00285 
00286     memset( items, 0, sizeof( items ) );
00287 
00288     if( mbedtls_pk_debug( pk, items ) != 0 )
00289     {
00290         debug_send_line( ssl, level, file, line,
00291                           "invalid PK context\n" );
00292         return;
00293     }
00294 
00295     for( i = 0; i < MBEDTLS_PK_DEBUG_MAX_ITEMS; i++ )
00296     {
00297         if( items[i].type == MBEDTLS_PK_DEBUG_NONE )
00298             return;
00299 
00300         mbedtls_snprintf( name, sizeof( name ), "%s%s", text, items[i].name );
00301         name[sizeof( name ) - 1] = '\0';
00302 
00303         if( items[i].type == MBEDTLS_PK_DEBUG_MPI )
00304             mbedtls_debug_print_mpi( ssl, level, file, line, name, items[i].value );
00305         else
00306 #if defined(MBEDTLS_ECP_C)
00307         if( items[i].type == MBEDTLS_PK_DEBUG_ECP )
00308             mbedtls_debug_print_ecp( ssl, level, file, line, name, items[i].value );
00309         else
00310 #endif
00311             debug_send_line( ssl, level, file, line,
00312                               "should not happen\n" );
00313     }
00314 }
00315 
00316 static void debug_print_line_by_line( const mbedtls_ssl_context *ssl, int level,
00317                                       const char *file, int line, const char *text )
00318 {
00319     char str[DEBUG_BUF_SIZE];
00320     const char *start, *cur;
00321 
00322     start = text;
00323     for( cur = text; *cur != '\0'; cur++ )
00324     {
00325         if( *cur == '\n' )
00326         {
00327             size_t len = cur - start + 1;
00328             if( len > DEBUG_BUF_SIZE - 1 )
00329                 len = DEBUG_BUF_SIZE - 1;
00330 
00331             memcpy( str, start, len );
00332             str[len] = '\0';
00333 
00334             debug_send_line( ssl, level, file, line, str );
00335 
00336             start = cur + 1;
00337         }
00338     }
00339 }
00340 
00341 void mbedtls_debug_print_crt( const mbedtls_ssl_context *ssl, int level,
00342                       const char *file, int line,
00343                       const char *text, const mbedtls_x509_crt *crt )
00344 {
00345     char str[DEBUG_BUF_SIZE];
00346     int i = 0;
00347 
00348     if( ssl->conf == NULL || ssl->conf->f_dbg == NULL || crt == NULL || level > debug_threshold )
00349         return;
00350 
00351     while( crt != NULL )
00352     {
00353         char buf[1024];
00354 
00355         mbedtls_snprintf( str, sizeof( str ), "%s #%d:\n", text, ++i );
00356         debug_send_line( ssl, level, file, line, str );
00357 
00358         mbedtls_x509_crt_info( buf, sizeof( buf ) - 1, "", crt );
00359         debug_print_line_by_line( ssl, level, file, line, buf );
00360 
00361         debug_print_pk( ssl, level, file, line, "crt->", &crt->pk );
00362 
00363         crt = crt->next;
00364     }
00365 }
00366 #endif /* MBEDTLS_X509_CRT_PARSE_C */
00367 
00368 #endif /* MBEDTLS_DEBUG_C */