Externals: Update mbedtls to 2.28.0

This commit is contained in:
OatmealDome
2022-04-02 19:30:22 -04:00
parent c9896e1c4b
commit d8a5a8827e
256 changed files with 67343 additions and 15595 deletions

View File

@ -1,7 +1,7 @@
/*
* The RSA public-key cryptosystem
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
@ -15,8 +15,6 @@
* 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)
*/
/*
@ -37,11 +35,7 @@
*
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "common.h"
#if defined(MBEDTLS_RSA_C)
@ -49,6 +43,9 @@
#include "mbedtls/rsa_internal.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "constant_time_internal.h"
#include "mbedtls/constant_time.h"
#include <string.h>
@ -56,7 +53,7 @@
#include "mbedtls/md.h"
#endif
#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__)
#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) && !defined(__NetBSD__)
#include <stdlib.h>
#endif
@ -77,28 +74,12 @@
#define RSA_VALIDATE( cond ) \
MBEDTLS_INTERNAL_VALIDATE( cond )
#if defined(MBEDTLS_PKCS1_V15)
/* constant-time buffer comparison */
static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
{
size_t i;
const unsigned char *A = (const unsigned char *) a;
const unsigned char *B = (const unsigned char *) b;
unsigned char diff = 0;
for( i = 0; i < n; i++ )
diff |= A[i] ^ B[i];
return( diff );
}
#endif /* MBEDTLS_PKCS1_V15 */
int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
const mbedtls_mpi *N,
const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, const mbedtls_mpi *E )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
RSA_VALIDATE_RET( ctx != NULL );
if( ( N != NULL && ( ret = mbedtls_mpi_copy( &ctx->N, N ) ) != 0 ) ||
@ -107,7 +88,7 @@ int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
( D != NULL && ( ret = mbedtls_mpi_copy( &ctx->D, D ) ) != 0 ) ||
( E != NULL && ( ret = mbedtls_mpi_copy( &ctx->E, E ) ) != 0 ) )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
if( N != NULL )
@ -147,7 +128,7 @@ int mbedtls_rsa_import_raw( mbedtls_rsa_context *ctx,
cleanup:
if( ret != 0 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
return( 0 );
}
@ -249,6 +230,9 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
{
int ret = 0;
int have_N, have_P, have_Q, have_D, have_E;
#if !defined(MBEDTLS_RSA_NO_CRT)
int have_DP, have_DQ, have_QP;
#endif
int n_missing, pq_missing, d_missing, is_pub, is_priv;
RSA_VALIDATE_RET( ctx != NULL );
@ -259,6 +243,12 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
#if !defined(MBEDTLS_RSA_NO_CRT)
have_DP = ( mbedtls_mpi_cmp_int( &ctx->DP, 0 ) != 0 );
have_DQ = ( mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) != 0 );
have_QP = ( mbedtls_mpi_cmp_int( &ctx->QP, 0 ) != 0 );
#endif
/*
* Check whether provided parameters are enough
* to deduce all others. The following incomplete
@ -289,7 +279,7 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
if( ( ret = mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P,
&ctx->Q ) ) != 0 )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
ctx->len = mbedtls_mpi_size( &ctx->N );
@ -304,7 +294,7 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
ret = mbedtls_rsa_deduce_primes( &ctx->N, &ctx->E, &ctx->D,
&ctx->P, &ctx->Q );
if( ret != 0 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
else if( d_missing )
@ -314,7 +304,7 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
&ctx->E,
&ctx->D ) ) != 0 )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
}
@ -324,12 +314,12 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
*/
#if !defined(MBEDTLS_RSA_NO_CRT)
if( is_priv )
if( is_priv && ! ( have_DP && have_DQ && have_QP ) )
{
ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
&ctx->DP, &ctx->DQ, &ctx->QP );
if( ret != 0 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
#endif /* MBEDTLS_RSA_NO_CRT */
@ -392,7 +382,7 @@ int mbedtls_rsa_export( const mbedtls_rsa_context *ctx,
mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q,
mbedtls_mpi *D, mbedtls_mpi *E )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
int is_priv;
RSA_VALIDATE_RET( ctx != NULL );
@ -436,7 +426,7 @@ int mbedtls_rsa_export( const mbedtls_rsa_context *ctx,
int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx,
mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
int is_priv;
RSA_VALIDATE_RET( ctx != NULL );
@ -457,13 +447,13 @@ int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx,
( DQ != NULL && ( ret = mbedtls_mpi_copy( DQ, &ctx->DQ ) ) != 0 ) ||
( QP != NULL && ( ret = mbedtls_mpi_copy( QP, &ctx->QP ) ) != 0 ) )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
#else
if( ( ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
DP, DQ, QP ) ) != 0 )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
}
#endif
@ -486,6 +476,9 @@ void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
mbedtls_rsa_set_padding( ctx, padding, hash_id );
#if defined(MBEDTLS_THREADING_C)
/* Set ctx->ver to nonzero to indicate that the mutex has been
* initialized and will need to be freed. */
ctx->ver = 1;
mbedtls_mutex_init( &ctx->mutex );
#endif
}
@ -527,15 +520,12 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
void *p_rng,
unsigned int nbits, int exponent )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_mpi H, G, L;
int prime_quality = 0;
RSA_VALIDATE_RET( ctx != NULL );
RSA_VALIDATE_RET( f_rng != NULL );
if( nbits < 128 || exponent < 3 || nbits % 2 != 0 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
/*
* If the modulus is 1024 bit long or shorter, then the security strength of
* the RSA algorithm is less than or equal to 80 bits and therefore an error
@ -548,6 +538,12 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
mbedtls_mpi_init( &G );
mbedtls_mpi_init( &L );
if( nbits < 128 || exponent < 3 || nbits % 2 != 0 )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
/*
* find primes P and Q with Q < P so that:
* 1. |P-Q| > 2^( nbits / 2 - 100 )
@ -625,7 +621,10 @@ cleanup:
if( ret != 0 )
{
mbedtls_rsa_free( ctx );
return( MBEDTLS_ERR_RSA_KEY_GEN_FAILED + ret );
if( ( -ret & ~0x7f ) == 0 )
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_KEY_GEN_FAILED, ret );
return( ret );
}
return( 0 );
@ -719,7 +718,7 @@ int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
const unsigned char *input,
unsigned char *output )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t olen;
mbedtls_mpi T;
RSA_VALIDATE_RET( ctx != NULL );
@ -757,7 +756,7 @@ cleanup:
mbedtls_mpi_free( &T );
if( ret != 0 )
return( MBEDTLS_ERR_RSA_PUBLIC_FAILED + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_PUBLIC_FAILED, ret ) );
return( 0 );
}
@ -772,6 +771,9 @@ static int rsa_prepare_blinding( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
int ret, count = 0;
mbedtls_mpi R;
mbedtls_mpi_init( &R );
if( ctx->Vf.p != NULL )
{
@ -787,18 +789,40 @@ static int rsa_prepare_blinding( mbedtls_rsa_context *ctx,
/* Unblinding value: Vf = random number, invertible mod N */
do {
if( count++ > 10 )
return( MBEDTLS_ERR_RSA_RNG_FAILED );
{
ret = MBEDTLS_ERR_RSA_RNG_FAILED;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vf, ctx->len - 1, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &ctx->Vi, &ctx->Vf, &ctx->N ) );
} while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 );
/* Blinding value: Vi = Vf^(-e) mod N */
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vf, &ctx->N ) );
/* Compute Vf^-1 as R * (R Vf)^-1 to avoid leaks from inv_mod. */
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, ctx->len - 1, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vf, &R ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
/* At this point, Vi is invertible mod N if and only if both Vf and R
* are invertible mod N. If one of them isn't, we don't need to know
* which one, we just loop and choose new values for both of them.
* (Each iteration succeeds with overwhelming probability.) */
ret = mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vi, &ctx->N );
if( ret != 0 && ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE )
goto cleanup;
} while( ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
/* Finish the computation of Vf^-1 = R * (R Vf)^-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &R ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
/* Blinding value: Vi = Vf^(-e) mod N
* (Vi already contains Vf^-1 at this point) */
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) );
cleanup:
mbedtls_mpi_free( &R );
return( ret );
}
@ -832,7 +856,7 @@ int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
const unsigned char *input,
unsigned char *output )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t olen;
/* Temporary holding the result */
@ -1047,10 +1071,10 @@ cleanup:
mbedtls_mpi_free( &C );
mbedtls_mpi_free( &I );
if( ret != 0 )
return( MBEDTLS_ERR_RSA_PRIVATE_FAILED + ret );
if( ret != 0 && ret >= -0x007f )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_PRIVATE_FAILED, ret ) );
return( 0 );
return( ret );
}
#if defined(MBEDTLS_PKCS1_V21)
@ -1125,7 +1149,7 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
unsigned char *output )
{
size_t olen;
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *p = output;
unsigned int hlen;
const mbedtls_md_info_t *md_info;
@ -1135,7 +1159,7 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
mode == MBEDTLS_RSA_PUBLIC );
RSA_VALIDATE_RET( output != NULL );
RSA_VALIDATE_RET( input != NULL );
RSA_VALIDATE_RET( ilen == 0 || input != NULL );
RSA_VALIDATE_RET( label_len == 0 || label != NULL );
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
@ -1161,7 +1185,7 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
/* Generate a random octet string seed */
if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 )
return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_RNG_FAILED, ret ) );
p += hlen;
@ -1171,7 +1195,8 @@ int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
p += hlen;
p += olen - 2 * hlen - 2 - ilen;
*p++ = 1;
memcpy( p, input, ilen );
if( ilen != 0 )
memcpy( p, input, ilen );
mbedtls_md_init( &md_ctx );
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
@ -1211,14 +1236,14 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
unsigned char *output )
{
size_t nb_pad, olen;
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *p = output;
RSA_VALIDATE_RET( ctx != NULL );
RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
mode == MBEDTLS_RSA_PUBLIC );
RSA_VALIDATE_RET( output != NULL );
RSA_VALIDATE_RET( input != NULL );
RSA_VALIDATE_RET( ilen == 0 || input != NULL );
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@ -1249,7 +1274,7 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
/* Check if RNG failed to generate data */
if( rng_dl == 0 || ret != 0 )
return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_RNG_FAILED, ret ) );
p++;
}
@ -1263,7 +1288,8 @@ int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
}
*p++ = 0;
memcpy( p, input, ilen );
if( ilen != 0 )
memcpy( p, input, ilen );
return( ( mode == MBEDTLS_RSA_PUBLIC )
? mbedtls_rsa_public( ctx, output, output )
@ -1285,7 +1311,7 @@ int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
mode == MBEDTLS_RSA_PUBLIC );
RSA_VALIDATE_RET( output != NULL );
RSA_VALIDATE_RET( input != NULL );
RSA_VALIDATE_RET( ilen == 0 || input != NULL );
switch( ctx->padding )
{
@ -1320,7 +1346,7 @@ int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
unsigned char *output,
size_t output_max_len )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t ilen, i, pad_len;
unsigned char *p, bad, pad_done;
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
@ -1441,7 +1467,8 @@ int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
}
*olen = ilen - (p - buf);
memcpy( output, p, *olen );
if( *olen != 0 )
memcpy( output, p, *olen );
ret = 0;
cleanup:
@ -1453,126 +1480,21 @@ cleanup:
#endif /* MBEDTLS_PKCS1_V21 */
#if defined(MBEDTLS_PKCS1_V15)
/** Turn zero-or-nonzero into zero-or-all-bits-one, without branches.
*
* \param value The value to analyze.
* \return Zero if \p value is zero, otherwise all-bits-one.
*/
static unsigned all_or_nothing_int( unsigned value )
{
/* MSVC has a warning about unary minus on unsigned, but this is
* well-defined and precisely what we want to do here */
#if defined(_MSC_VER)
#pragma warning( push )
#pragma warning( disable : 4146 )
#endif
return( - ( ( value | - value ) >> ( sizeof( value ) * 8 - 1 ) ) );
#if defined(_MSC_VER)
#pragma warning( pop )
#endif
}
/** Check whether a size is out of bounds, without branches.
*
* This is equivalent to `size > max`, but is likely to be compiled to
* to code using bitwise operation rather than a branch.
*
* \param size Size to check.
* \param max Maximum desired value for \p size.
* \return \c 0 if `size <= max`.
* \return \c 1 if `size > max`.
*/
static unsigned size_greater_than( size_t size, size_t max )
{
/* Return the sign bit (1 for negative) of (max - size). */
return( ( max - size ) >> ( sizeof( size_t ) * 8 - 1 ) );
}
/** Choose between two integer values, without branches.
*
* This is equivalent to `cond ? if1 : if0`, but is likely to be compiled
* to code using bitwise operation rather than a branch.
*
* \param cond Condition to test.
* \param if1 Value to use if \p cond is nonzero.
* \param if0 Value to use if \p cond is zero.
* \return \c if1 if \p cond is nonzero, otherwise \c if0.
*/
static unsigned if_int( unsigned cond, unsigned if1, unsigned if0 )
{
unsigned mask = all_or_nothing_int( cond );
return( ( mask & if1 ) | (~mask & if0 ) );
}
/** Shift some data towards the left inside a buffer without leaking
* the length of the data through side channels.
*
* `mem_move_to_left(start, total, offset)` is functionally equivalent to
* ```
* memmove(start, start + offset, total - offset);
* memset(start + offset, 0, total - offset);
* ```
* but it strives to use a memory access pattern (and thus total timing)
* that does not depend on \p offset. This timing independence comes at
* the expense of performance.
*
* \param start Pointer to the start of the buffer.
* \param total Total size of the buffer.
* \param offset Offset from which to copy \p total - \p offset bytes.
*/
static void mem_move_to_left( void *start,
size_t total,
size_t offset )
{
volatile unsigned char *buf = start;
size_t i, n;
if( total == 0 )
return;
for( i = 0; i < total; i++ )
{
unsigned no_op = size_greater_than( total - offset, i );
/* The first `total - offset` passes are a no-op. The last
* `offset` passes shift the data one byte to the left and
* zero out the last byte. */
for( n = 0; n < total - 1; n++ )
{
unsigned char current = buf[n];
unsigned char next = buf[n+1];
buf[n] = if_int( no_op, current, next );
}
buf[total-1] = if_int( no_op, buf[total-1], 0 );
}
}
/*
* Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
*/
int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode, size_t *olen,
int mode,
size_t *olen,
const unsigned char *input,
unsigned char *output,
size_t output_max_len )
{
int ret;
size_t ilen, i, plaintext_max_size;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t ilen;
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
/* The following variables take sensitive values: their value must
* not leak into the observable behavior of the function other than
* the designated outputs (output, olen, return value). Otherwise
* this would open the execution of the function to
* side-channel-based variants of the Bleichenbacher padding oracle
* attack. Potential side channels include overall timing, memory
* access patterns (especially visible to an adversary who has access
* to a shared memory cache), and branches (especially visible to
* an adversary who has access to a shared code cache or to a shared
* branch predictor). */
size_t pad_count = 0;
unsigned bad = 0;
unsigned char pad_done = 0;
size_t plaintext_size = 0;
unsigned output_too_large;
RSA_VALIDATE_RET( ctx != NULL );
RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
@ -1582,9 +1504,6 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
RSA_VALIDATE_RET( olen != NULL );
ilen = ctx->len;
plaintext_max_size = ( output_max_len > ilen - 11 ?
ilen - 11 :
output_max_len );
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@ -1599,109 +1518,8 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
if( ret != 0 )
goto cleanup;
/* Check and get padding length in constant time and constant
* memory trace. The first byte must be 0. */
bad |= buf[0];
if( mode == MBEDTLS_RSA_PRIVATE )
{
/* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
* where PS must be at least 8 nonzero bytes. */
bad |= buf[1] ^ MBEDTLS_RSA_CRYPT;
/* Read the whole buffer. Set pad_done to nonzero if we find
* the 0x00 byte and remember the padding length in pad_count. */
for( i = 2; i < ilen; i++ )
{
pad_done |= ((buf[i] | (unsigned char)-buf[i]) >> 7) ^ 1;
pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
}
}
else
{
/* Decode EMSA-PKCS1-v1_5 padding: 0x00 || 0x01 || PS || 0x00
* where PS must be at least 8 bytes with the value 0xFF. */
bad |= buf[1] ^ MBEDTLS_RSA_SIGN;
/* Read the whole buffer. Set pad_done to nonzero if we find
* the 0x00 byte and remember the padding length in pad_count.
* If there's a non-0xff byte in the padding, the padding is bad. */
for( i = 2; i < ilen; i++ )
{
pad_done |= if_int( buf[i], 0, 1 );
pad_count += if_int( pad_done, 0, 1 );
bad |= if_int( pad_done, 0, buf[i] ^ 0xFF );
}
}
/* If pad_done is still zero, there's no data, only unfinished padding. */
bad |= if_int( pad_done, 0, 1 );
/* There must be at least 8 bytes of padding. */
bad |= size_greater_than( 8, pad_count );
/* If the padding is valid, set plaintext_size to the number of
* remaining bytes after stripping the padding. If the padding
* is invalid, avoid leaking this fact through the size of the
* output: use the maximum message size that fits in the output
* buffer. Do it without branches to avoid leaking the padding
* validity through timing. RSA keys are small enough that all the
* size_t values involved fit in unsigned int. */
plaintext_size = if_int( bad,
(unsigned) plaintext_max_size,
(unsigned) ( ilen - pad_count - 3 ) );
/* Set output_too_large to 0 if the plaintext fits in the output
* buffer and to 1 otherwise. */
output_too_large = size_greater_than( plaintext_size,
plaintext_max_size );
/* Set ret without branches to avoid timing attacks. Return:
* - INVALID_PADDING if the padding is bad (bad != 0).
* - OUTPUT_TOO_LARGE if the padding is good but the decrypted
* plaintext does not fit in the output buffer.
* - 0 if the padding is correct. */
ret = - (int) if_int( bad, - MBEDTLS_ERR_RSA_INVALID_PADDING,
if_int( output_too_large, - MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE,
0 ) );
/* If the padding is bad or the plaintext is too large, zero the
* data that we're about to copy to the output buffer.
* We need to copy the same amount of data
* from the same buffer whether the padding is good or not to
* avoid leaking the padding validity through overall timing or
* through memory or cache access patterns. */
bad = all_or_nothing_int( bad | output_too_large );
for( i = 11; i < ilen; i++ )
buf[i] &= ~bad;
/* If the plaintext is too large, truncate it to the buffer size.
* Copy anyway to avoid revealing the length through timing, because
* revealing the length is as bad as revealing the padding validity
* for a Bleichenbacher attack. */
plaintext_size = if_int( output_too_large,
(unsigned) plaintext_max_size,
(unsigned) plaintext_size );
/* Move the plaintext to the leftmost position where it can start in
* the working buffer, i.e. make it start plaintext_max_size from
* the end of the buffer. Do this with a memory access trace that
* does not depend on the plaintext size. After this move, the
* starting location of the plaintext is no longer sensitive
* information. */
mem_move_to_left( buf + ilen - plaintext_max_size,
plaintext_max_size,
plaintext_max_size - plaintext_size );
/* Finally copy the decrypted plaintext plus trailing zeros
* into the output buffer. */
memcpy( output, buf + ilen - plaintext_max_size, plaintext_max_size );
/* Report the amount of data we copied to the output buffer. In case
* of errors (bad padding or output too large), the value of *olen
* when this function returns is not specified. Making it equivalent
* to the good case limits the risks of leaking the padding validity. */
*olen = plaintext_size;
ret = mbedtls_ct_rsaes_pkcs1_v15_unpadding( mode, buf, ilen,
output, output_max_len, olen );
cleanup:
mbedtls_platform_zeroize( buf, sizeof( buf ) );
@ -1749,23 +1567,21 @@ int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
}
#if defined(MBEDTLS_PKCS1_V21)
/*
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
*/
int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
static int rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode,
mbedtls_md_type_t md_alg,
unsigned int hashlen,
const unsigned char *hash,
int saltlen,
unsigned char *sig )
{
size_t olen;
unsigned char *p = sig;
unsigned char salt[MBEDTLS_MD_MAX_SIZE];
unsigned char *salt = NULL;
size_t slen, min_slen, hlen, offset = 0;
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t msb;
const mbedtls_md_info_t *md_info;
mbedtls_md_context_t md_ctx;
@ -1801,31 +1617,44 @@ int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
hlen = mbedtls_md_get_size( md_info );
/* Calculate the largest possible salt length. Normally this is the hash
* length, which is the maximum length the salt can have. If there is not
* enough room, use the maximum salt length that fits. The constraint is
* that the hash length plus the salt length plus 2 bytes must be at most
* the key length. This complies with FIPS 186-4 §5.5 (e) and RFC 8017
* (PKCS#1 v2.2) §9.1.1 step 3. */
min_slen = hlen - 2;
if( olen < hlen + min_slen + 2 )
if (saltlen == MBEDTLS_RSA_SALT_LEN_ANY)
{
/* Calculate the largest possible salt length, up to the hash size.
* Normally this is the hash length, which is the maximum salt length
* according to FIPS 185-4 §5.5 (e) and common practice. If there is not
* enough room, use the maximum salt length that fits. The constraint is
* that the hash length plus the salt length plus 2 bytes must be at most
* the key length. This complies with FIPS 186-4 §5.5 (e) and RFC 8017
* (PKCS#1 v2.2) §9.1.1 step 3. */
min_slen = hlen - 2;
if( olen < hlen + min_slen + 2 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
else if( olen >= hlen + hlen + 2 )
slen = hlen;
else
slen = olen - hlen - 2;
}
else if ( (saltlen < 0) || (saltlen + hlen + 2 > olen) )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
else if( olen >= hlen + hlen + 2 )
slen = hlen;
}
else
slen = olen - hlen - 2;
{
slen = (size_t) saltlen;
}
memset( sig, 0, olen );
/* Generate salt of length slen */
if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
/* Note: EMSA-PSS encoding is over the length of N - 1 bits */
msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
p += olen - hlen - slen - 2;
*p++ = 0x01;
memcpy( p, salt, slen );
/* Generate salt of length slen in place in the encoded message */
salt = p;
if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_RNG_FAILED, ret ) );
p += slen;
mbedtls_md_init( &md_ctx );
@ -1859,8 +1688,6 @@ int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
p += hlen;
*p++ = 0xBC;
mbedtls_platform_zeroize( salt, sizeof( salt ) );
exit:
mbedtls_md_free( &md_ctx );
@ -1871,6 +1698,40 @@ exit:
? mbedtls_rsa_public( ctx, sig, sig )
: mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig ) );
}
/*
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function with
* the option to pass in the salt length.
*/
int mbedtls_rsa_rsassa_pss_sign_ext( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_md_type_t md_alg,
unsigned int hashlen,
const unsigned char *hash,
int saltlen,
unsigned char *sig )
{
return rsa_rsassa_pss_sign( ctx, f_rng, p_rng, MBEDTLS_RSA_PRIVATE, md_alg,
hashlen, hash, saltlen, sig );
}
/*
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
*/
int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode,
mbedtls_md_type_t md_alg,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig )
{
return rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg,
hashlen, hash, MBEDTLS_RSA_SALT_LEN_ANY, sig );
}
#endif /* MBEDTLS_PKCS1_V21 */
#if defined(MBEDTLS_PKCS1_V15)
@ -2020,7 +1881,7 @@ int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
const unsigned char *hash,
unsigned char *sig )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *sig_try = NULL, *verif = NULL;
RSA_VALIDATE_RET( ctx != NULL );
@ -2072,7 +1933,7 @@ int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
MBEDTLS_MPI_CHK( mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig_try ) );
MBEDTLS_MPI_CHK( mbedtls_rsa_public( ctx, sig_try, verif ) );
if( mbedtls_safer_memcmp( verif, sig, ctx->len ) != 0 )
if( mbedtls_ct_memcmp( verif, sig, ctx->len ) != 0 )
{
ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
goto cleanup;
@ -2081,9 +1942,13 @@ int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
memcpy( sig, sig_try, ctx->len );
cleanup:
mbedtls_platform_zeroize( sig_try, ctx->len );
mbedtls_platform_zeroize( verif, ctx->len );
mbedtls_free( sig_try );
mbedtls_free( verif );
if( ret != 0 )
memset( sig, '!', ctx->len );
return( ret );
}
#endif /* MBEDTLS_PKCS1_V15 */
@ -2142,7 +2007,7 @@ int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
int expected_salt_len,
const unsigned char *sig )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t siglen;
unsigned char *p;
unsigned char *hash_start;
@ -2370,8 +2235,8 @@ int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
* Compare
*/
if( ( ret = mbedtls_safer_memcmp( encoded, encoded_expected,
sig_len ) ) != 0 )
if( ( ret = mbedtls_ct_memcmp( encoded, encoded_expected,
sig_len ) ) != 0 )
{
ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
goto cleanup;
@ -2439,11 +2304,10 @@ int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
*/
int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
{
int ret;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
RSA_VALIDATE_RET( dst != NULL );
RSA_VALIDATE_RET( src != NULL );
dst->ver = src->ver;
dst->len = src->len;
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->N, &src->N ) );
@ -2502,7 +2366,12 @@ void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
#endif /* MBEDTLS_RSA_NO_CRT */
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_free( &ctx->mutex );
/* Free the mutex, but only if it hasn't been freed already. */
if( ctx->ver != 0 )
{
mbedtls_mutex_free( &ctx->mutex );
ctx->ver = 0;
}
#endif
}
@ -2554,7 +2423,7 @@ void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
#if defined(MBEDTLS_PKCS1_V15)
static int myrand( void *rng_state, unsigned char *output, size_t len )
{
#if !defined(__OpenBSD__)
#if !defined(__OpenBSD__) && !defined(__NetBSD__)
size_t i;
if( rng_state != NULL )
@ -2567,7 +2436,7 @@ static int myrand( void *rng_state, unsigned char *output, size_t len )
rng_state = NULL;
arc4random_buf( output, len );
#endif /* !OpenBSD */
#endif /* !OpenBSD && !NetBSD */
return( 0 );
}