Fix possible mutex lock/unlock mismatch

fixes #257
This commit is contained in:
Manuel Pégourié-Gonnard 2015-08-27 11:30:58 +02:00
parent 3dce9ec3af
commit 1385a289f4
2 changed files with 19 additions and 49 deletions

View file

@ -26,6 +26,9 @@ Bugfix
* Fix error when loading libmbedtls.so.
* Fix bug in mbedtls_ssl_conf_default() that caused the default preset to
be always used (found by dcb314) (#235)
* Fix bug in mbedtls_rsa_public() and mbedtls_rsa_private() that could
result trying to unlock an unlocked mutex on invalid input (found by
Fredrik Axelsson) (#257)
Changes
* The PEM parser now accepts a trailing space at end of lines (#226).

View file

@ -274,6 +274,11 @@ int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
mbedtls_mpi_init( &T );
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
return( ret );
#endif
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
@ -282,11 +287,6 @@ int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
return( ret );
#endif
olen = ctx->len;
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
@ -311,16 +311,11 @@ cleanup:
* DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
* Berlin Heidelberg, 1996. p. 104-113.
*/
static int rsa_prepare_blinding( mbedtls_rsa_context *ctx, mbedtls_mpi *Vi, mbedtls_mpi *Vf,
static int rsa_prepare_blinding( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
int ret, count = 0;
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
return( ret );
#endif
if( ctx->Vf.p != NULL )
{
/* We already have blinding values, just update them by squaring */
@ -329,7 +324,7 @@ static int rsa_prepare_blinding( mbedtls_rsa_context *ctx, mbedtls_mpi *Vi, mbed
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->N ) );
goto done;
goto cleanup;
}
/* Unblinding value: Vf = random number, invertible mod N */
@ -345,19 +340,8 @@ static int rsa_prepare_blinding( mbedtls_rsa_context *ctx, mbedtls_mpi *Vi, mbed
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vf, &ctx->N ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) );
done:
if( Vi != &ctx->Vi )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( Vi, &ctx->Vi ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( Vf, &ctx->Vf ) );
}
cleanup:
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_unlock( &ctx->mutex ) ) != 0 )
return( ret );
#endif
return( ret );
}
@ -373,26 +357,14 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
int ret;
size_t olen;
mbedtls_mpi T, T1, T2;
mbedtls_mpi *Vi, *Vf;
/*
* When using the Chinese Remainder Theorem, we use blinding values.
* Without threading, we just read them directly from the context,
* otherwise we make a local copy in order to reduce locking contention.
*/
#if defined(MBEDTLS_THREADING_C)
mbedtls_mpi Vi_copy, Vf_copy;
mbedtls_mpi_init( &Vi_copy ); mbedtls_mpi_init( &Vf_copy );
Vi = &Vi_copy;
Vf = &Vf_copy;
#else
Vi = &ctx->Vi;
Vf = &ctx->Vf;
#endif
mbedtls_mpi_init( &T ); mbedtls_mpi_init( &T1 ); mbedtls_mpi_init( &T2 );
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
return( ret );
#endif
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
{
@ -406,16 +378,11 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
* Blinding
* T = T * Vi mod N
*/
MBEDTLS_MPI_CHK( rsa_prepare_blinding( ctx, Vi, Vf, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, Vi ) );
MBEDTLS_MPI_CHK( rsa_prepare_blinding( ctx, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vi ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
}
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
return( ret );
#endif
#if defined(MBEDTLS_RSA_NO_CRT)
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->D, &ctx->N, &ctx->RN ) );
#else
@ -448,7 +415,7 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
* Unblind
* T = T * Vf mod N
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, Vf ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vf ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
}
@ -459,8 +426,8 @@ cleanup:
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_unlock( &ctx->mutex ) ) != 0 )
return( ret );
mbedtls_mpi_free( &Vi_copy ); mbedtls_mpi_free( &Vf_copy );
#endif
mbedtls_mpi_free( &T ); mbedtls_mpi_free( &T1 ); mbedtls_mpi_free( &T2 );
if( ret != 0 )