mbedtls/library/debug.c
Hanno Becker 99f3916e31 Return from debugging functions if SSL context is unset
The debugging functions
- mbedtls_debug_print_ret,
- mbedtls_debug_print_buf,
- mbedtls_debug_print_mpi, and
- mbedtls_debug_print_crt
return immediately if the SSL configuration bound to the
passed SSL context is NULL, has no debugging functions
configured, or if the debug threshold is below the debugging
level.
However, they do not check whether the provided SSL context
is not NULL before accessing the SSL configuration bound to it,
therefore leading to a segmentation fault if it is.
In contrast, the debugging function
- mbedtls_debug_print_msg
does check for ssl != NULL before accessing ssl->conf.

This commit unifies the checks by always returning immediately
if ssl == NULL.
2018-08-23 14:57:39 +01:00

401 lines
11 KiB
C

/*
* Debugging routines
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_DEBUG_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#define mbedtls_time_t time_t
#define mbedtls_snprintf snprintf
#endif
#include "mbedtls/debug.h"
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
!defined(inline) && !defined(__cplusplus)
#define inline __inline
#endif
#define DEBUG_BUF_SIZE 512
static int debug_threshold = 0;
void mbedtls_debug_set_threshold( int threshold )
{
debug_threshold = threshold;
}
/*
* All calls to f_dbg must be made via this function
*/
static inline void debug_send_line( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *str )
{
/*
* If in a threaded environment, we need a thread identifier.
* Since there is no portable way to get one, use the address of the ssl
* context instead, as it shouldn't be shared between threads.
*/
#if defined(MBEDTLS_THREADING_C)
char idstr[20 + DEBUG_BUF_SIZE]; /* 0x + 16 nibbles + ': ' */
mbedtls_snprintf( idstr, sizeof( idstr ), "%p: %s", (void*)ssl, str );
ssl->conf->f_dbg( ssl->conf->p_dbg, level, file, line, idstr );
#else
ssl->conf->f_dbg( ssl->conf->p_dbg, level, file, line, str );
#endif
}
void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *format, ... )
{
va_list argp;
char str[DEBUG_BUF_SIZE];
int ret;
if( NULL == ssl ||
NULL == ssl->conf ||
NULL == ssl->conf->f_dbg ||
level > debug_threshold )
{
return;
}
va_start( argp, format );
#if defined(_WIN32)
#if defined(_TRUNCATE) && !defined(__MINGW32__)
ret = _vsnprintf_s( str, DEBUG_BUF_SIZE, _TRUNCATE, format, argp );
#else
ret = _vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
if( ret < 0 || (size_t) ret == DEBUG_BUF_SIZE )
{
str[DEBUG_BUF_SIZE-1] = '\0';
ret = -1;
}
#endif
#else
ret = vsnprintf( str, DEBUG_BUF_SIZE, format, argp );
#endif
va_end( argp );
if( ret >= 0 && ret < DEBUG_BUF_SIZE - 1 )
{
str[ret] = '\n';
str[ret + 1] = '\0';
}
debug_send_line( ssl, level, file, line, str );
}
void mbedtls_debug_print_ret( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *text, int ret )
{
char str[DEBUG_BUF_SIZE];
if( NULL == ssl ||
NULL == ssl->conf ||
NULL == ssl->conf->f_dbg ||
level > debug_threshold )
{
return;
}
/*
* With non-blocking I/O and examples that just retry immediately,
* the logs would be quickly flooded with WANT_READ, so ignore that.
* Don't ignore WANT_WRITE however, since is is usually rare.
*/
if( ret == MBEDTLS_ERR_SSL_WANT_READ )
return;
mbedtls_snprintf( str, sizeof( str ), "%s() returned %d (-0x%04x)\n",
text, ret, -ret );
debug_send_line( ssl, level, file, line, str );
}
void 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 )
{
char str[DEBUG_BUF_SIZE];
char txt[17];
size_t i, idx = 0;
if( NULL == ssl ||
NULL == ssl->conf ||
NULL == ssl->conf->f_dbg ||
level > debug_threshold )
{
return;
}
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "dumping '%s' (%u bytes)\n",
text, (unsigned int) len );
debug_send_line( ssl, level, file, line, str );
idx = 0;
memset( txt, 0, sizeof( txt ) );
for( i = 0; i < len; i++ )
{
if( i >= 4096 )
break;
if( i % 16 == 0 )
{
if( i > 0 )
{
mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %s\n", txt );
debug_send_line( ssl, level, file, line, str );
idx = 0;
memset( txt, 0, sizeof( txt ) );
}
idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, "%04x: ",
(unsigned int) i );
}
idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x",
(unsigned int) buf[i] );
txt[i % 16] = ( buf[i] > 31 && buf[i] < 127 ) ? buf[i] : '.' ;
}
if( len > 0 )
{
for( /* i = i */; i % 16 != 0; i++ )
idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " " );
mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %s\n", txt );
debug_send_line( ssl, level, file, line, str );
}
}
#if defined(MBEDTLS_ECP_C)
void mbedtls_debug_print_ecp( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *text, const mbedtls_ecp_point *X )
{
char str[DEBUG_BUF_SIZE];
if( NULL == ssl ||
NULL == ssl->conf ||
NULL == ssl->conf->f_dbg ||
level > debug_threshold )
{
return;
}
mbedtls_snprintf( str, sizeof( str ), "%s(X)", text );
mbedtls_debug_print_mpi( ssl, level, file, line, str, &X->X );
mbedtls_snprintf( str, sizeof( str ), "%s(Y)", text );
mbedtls_debug_print_mpi( ssl, level, file, line, str, &X->Y );
}
#endif /* MBEDTLS_ECP_C */
#if defined(MBEDTLS_BIGNUM_C)
void mbedtls_debug_print_mpi( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *text, const mbedtls_mpi *X )
{
char str[DEBUG_BUF_SIZE];
int j, k, zeros = 1;
size_t i, n, idx = 0;
if( NULL == ssl ||
NULL == ssl->conf ||
NULL == ssl->conf->f_dbg ||
NULL == X ||
level > debug_threshold )
{
return;
}
for( n = X->n - 1; n > 0; n-- )
if( X->p[n] != 0 )
break;
for( j = ( sizeof(mbedtls_mpi_uint) << 3 ) - 1; j >= 0; j-- )
if( ( ( X->p[n] >> j ) & 1 ) != 0 )
break;
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "value of '%s' (%d bits) is:\n",
text, (int) ( ( n * ( sizeof(mbedtls_mpi_uint) << 3 ) ) + j + 1 ) );
debug_send_line( ssl, level, file, line, str );
idx = 0;
for( i = n + 1, j = 0; i > 0; i-- )
{
if( zeros && X->p[i - 1] == 0 )
continue;
for( k = sizeof( mbedtls_mpi_uint ) - 1; k >= 0; k-- )
{
if( zeros && ( ( X->p[i - 1] >> ( k << 3 ) ) & 0xFF ) == 0 )
continue;
else
zeros = 0;
if( j % 16 == 0 )
{
if( j > 0 )
{
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
debug_send_line( ssl, level, file, line, str );
idx = 0;
}
}
idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x", (unsigned int)
( X->p[i - 1] >> ( k << 3 ) ) & 0xFF );
j++;
}
}
if( zeros == 1 )
idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " 00" );
mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
debug_send_line( ssl, level, file, line, str );
}
#endif /* MBEDTLS_BIGNUM_C */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
static void debug_print_pk( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *text, const mbedtls_pk_context *pk )
{
size_t i;
mbedtls_pk_debug_item items[MBEDTLS_PK_DEBUG_MAX_ITEMS];
char name[16];
memset( items, 0, sizeof( items ) );
if( mbedtls_pk_debug( pk, items ) != 0 )
{
debug_send_line( ssl, level, file, line,
"invalid PK context\n" );
return;
}
for( i = 0; i < MBEDTLS_PK_DEBUG_MAX_ITEMS; i++ )
{
if( items[i].type == MBEDTLS_PK_DEBUG_NONE )
return;
mbedtls_snprintf( name, sizeof( name ), "%s%s", text, items[i].name );
name[sizeof( name ) - 1] = '\0';
if( items[i].type == MBEDTLS_PK_DEBUG_MPI )
mbedtls_debug_print_mpi( ssl, level, file, line, name, items[i].value );
else
#if defined(MBEDTLS_ECP_C)
if( items[i].type == MBEDTLS_PK_DEBUG_ECP )
mbedtls_debug_print_ecp( ssl, level, file, line, name, items[i].value );
else
#endif
debug_send_line( ssl, level, file, line,
"should not happen\n" );
}
}
static void debug_print_line_by_line( const mbedtls_ssl_context *ssl, int level,
const char *file, int line, const char *text )
{
char str[DEBUG_BUF_SIZE];
const char *start, *cur;
start = text;
for( cur = text; *cur != '\0'; cur++ )
{
if( *cur == '\n' )
{
size_t len = cur - start + 1;
if( len > DEBUG_BUF_SIZE - 1 )
len = DEBUG_BUF_SIZE - 1;
memcpy( str, start, len );
str[len] = '\0';
debug_send_line( ssl, level, file, line, str );
start = cur + 1;
}
}
}
void mbedtls_debug_print_crt( const mbedtls_ssl_context *ssl, int level,
const char *file, int line,
const char *text, const mbedtls_x509_crt *crt )
{
char str[DEBUG_BUF_SIZE];
int i = 0;
if( NULL == ssl ||
NULL == ssl->conf ||
NULL == ssl->conf->f_dbg ||
NULL == crt ||
level > debug_threshold )
{
return;
}
while( crt != NULL )
{
char buf[1024];
mbedtls_snprintf( str, sizeof( str ), "%s #%d:\n", text, ++i );
debug_send_line( ssl, level, file, line, str );
mbedtls_x509_crt_info( buf, sizeof( buf ) - 1, "", crt );
debug_print_line_by_line( ssl, level, file, line, buf );
debug_print_pk( ssl, level, file, line, "crt->", &crt->pk );
crt = crt->next;
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#endif /* MBEDTLS_DEBUG_C */