Merge remote-tracking branch 'public/pr/1137' into mbedtls-2.1

ChangeLog

@@ -22,6 +22,8 @@ Bugfix
      introduced in Mbed TLS 2.12.0. Fixes #1954.
    * Fix undefined shifts with negative values in certificates parsing
      (found by Catena cyber using oss-fuzz)
+   * Fix memory leak and free without initialization in pk_encrypt
+     and pk_decrypt example programs. Reported by Brace Stout. Fixes #1128.
 
 = mbed TLS 2.1.14 branch released 2018-07-25
 

programs/pkey/pk_decrypt.c

@@ -69,7 +69,10 @@ int main( int argc, char *argv[] )
     const char *pers = "mbedtls_pk_decrypt";
     ((void) argv);
 
+    mbedtls_pk_init( &pk );
+    mbedtls_entropy_init( &entropy );
     mbedtls_ctr_drbg_init( &ctr_drbg );
+
     memset(result, 0, sizeof( result ) );
     ret = 1;
 
@@ -87,20 +90,18 @@ int main( int argc, char *argv[] )
     mbedtls_printf( "\n  . Seeding the random number generator..." );
     fflush( stdout );
 
-    mbedtls_entropy_init( &entropy );
+    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
-    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
+                                       &entropy, (const unsigned char *) pers,
-                               (const unsigned char *) pers,
+                                       strlen( pers ) ) ) != 0 )
-                               strlen( pers ) ) ) != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%04x\n",
+                        -ret );
         goto exit;
     }
 
     mbedtls_printf( "\n  . Reading private key from '%s'", argv[1] );
     fflush( stdout );
 
-    mbedtls_pk_init( &pk );
-
     if( ( ret = mbedtls_pk_parse_keyfile( &pk, argv[1], "" ) ) != 0 )
     {
         mbedtls_printf( " failed\n  ! mbedtls_pk_parse_keyfile returned -0x%04x\n", -ret );
@@ -115,14 +116,16 @@ int main( int argc, char *argv[] )
     if( ( f = fopen( "result-enc.txt", "rb" ) ) == NULL )
     {
         mbedtls_printf( "\n  ! Could not open %s\n\n", "result-enc.txt" );
+        ret = 1;
         goto exit;
     }
 
     i = 0;
-
     while( fscanf( f, "%02X", &c ) > 0 &&
            i < (int) sizeof( buf ) )
+    {
         buf[i++] = (unsigned char) c;
+    }
 
     fclose( f );
 
@@ -135,7 +138,8 @@ int main( int argc, char *argv[] )
     if( ( ret = mbedtls_pk_decrypt( &pk, buf, i, result, &olen, sizeof(result),
                             mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_pk_decrypt returned -0x%04x\n", -ret );
+        mbedtls_printf( " failed\n  ! mbedtls_pk_decrypt returned -0x%04x\n",
+                        -ret );
         goto exit;
     }
 
@@ -146,13 +150,15 @@ int main( int argc, char *argv[] )
     ret = 0;
 
 exit:
-    mbedtls_ctr_drbg_free( &ctr_drbg );
+
+    mbedtls_pk_free( &pk );
     mbedtls_entropy_free( &entropy );
+    mbedtls_ctr_drbg_free( &ctr_drbg );
 
 #if defined(MBEDTLS_ERROR_C)
     if( ret != 0 )
     {
-        mbedtls_strerror( ret, (char *) buf, sizeof(buf) );
+        mbedtls_strerror( ret, (char *) buf, sizeof( buf ) );
         mbedtls_printf( "  !  Last error was: %s\n", buf );
     }
 #endif

programs/pkey/pk_encrypt.c

@@ -70,6 +70,8 @@ int main( int argc, char *argv[] )
 
     ret = 1;
     mbedtls_ctr_drbg_init( &ctr_drbg );
+    mbedtls_entropy_init( &entropy );
+    mbedtls_pk_init( &pk );
 
     if( argc != 3 )
     {
@@ -85,20 +87,18 @@ int main( int argc, char *argv[] )
     mbedtls_printf( "\n  . Seeding the random number generator..." );
     fflush( stdout );
 
-    mbedtls_entropy_init( &entropy );
+    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
-    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
+                                       &entropy, (const unsigned char *) pers,
-                               (const unsigned char *) pers,
+                                       strlen( pers ) ) ) != 0 )
-                               strlen( pers ) ) ) != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%04x\n", -ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%04x\n",
+                        -ret );
         goto exit;
     }
 
     mbedtls_printf( "\n  . Reading public key from '%s'", argv[1] );
     fflush( stdout );
 
-    mbedtls_pk_init( &pk );
-
     if( ( ret = mbedtls_pk_parse_public_keyfile( &pk, argv[1] ) ) != 0 )
     {
         mbedtls_printf( " failed\n  ! mbedtls_pk_parse_public_keyfile returned -0x%04x\n", -ret );
@@ -123,7 +123,8 @@ int main( int argc, char *argv[] )
                             buf, &olen, sizeof(buf),
                             mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_pk_encrypt returned -0x%04x\n", -ret );
+        mbedtls_printf( " failed\n  ! mbedtls_pk_encrypt returned -0x%04x\n",
+                        -ret );
         goto exit;
     }
 
@@ -132,27 +133,32 @@ int main( int argc, char *argv[] )
      */
     if( ( f = fopen( "result-enc.txt", "wb+" ) ) == NULL )
     {
+        mbedtls_printf( " failed\n  ! Could not create %s\n\n",
+                        "result-enc.txt" );
         ret = 1;
-        mbedtls_printf( " failed\n  ! Could not create %s\n\n", "result-enc.txt" );
         goto exit;
     }
 
     for( i = 0; i < olen; i++ )
+    {
         mbedtls_fprintf( f, "%02X%s", buf[i],
                  ( i + 1 ) % 16 == 0 ? "\r\n" : " " );
+    }
 
     fclose( f );
 
     mbedtls_printf( "\n  . Done (created \"%s\")\n\n", "result-enc.txt" );
 
 exit:
-    mbedtls_ctr_drbg_free( &ctr_drbg );
+
+    mbedtls_pk_free( &pk );
     mbedtls_entropy_free( &entropy );
+    mbedtls_ctr_drbg_free( &ctr_drbg );
 
 #if defined(MBEDTLS_ERROR_C)
     if( ret != 0 )
     {
-        mbedtls_strerror( ret, (char *) buf, sizeof(buf) );
+        mbedtls_strerror( ret, (char *) buf, sizeof( buf ) );
         mbedtls_printf( "  !  Last error was: %s\n", buf );
     }
 #endif