Merge remote-tracking branch 'restricted/pr/524' into mbedtls-2.1-restricted-proposed

This commit is contained in:
Simon Butcher 2018-11-07 00:07:03 +00:00
commit 6f682ee463
4 changed files with 128 additions and 24 deletions

View file

@ -60,6 +60,20 @@ Changes
* Improve documentation of mbedtls_ssl_get_verify_result().
Fixes #517 reported by github-monoculture.
Security
* Fix mbedtls_mpi_is_prime() to use more rounds of probabilistic testing. The
previous settings for the number of rounds made it practical for an
adversary to construct non-primes that would be erroneously accepted as
primes with high probability. This does not have an impact on the
security of TLS, but can matter in other contexts with potentially
adversarially-chosen numbers that should be prime and can be validated.
For example, the number of rounds was enough to securely generate RSA key
pairs or Diffie-Hellman parameters, but was insufficient to validate
Diffie-Hellman parameters properly.
See "Prime and Prejudice" by by Martin R. Albrecht and Jake Massimo and
Kenneth G. Paterson and Juraj Somorovsky.
= mbed TLS 2.1.15 branch released 2018-08-31
Security

View file

@ -2043,12 +2043,12 @@ cleanup:
/*
* Miller-Rabin pseudo-primality test (HAC 4.24)
*/
static int mpi_miller_rabin( const mbedtls_mpi *X,
static int mpi_miller_rabin( const mbedtls_mpi *X, size_t rounds,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int ret, count;
size_t i, j, k, n, s;
size_t i, j, k, s;
mbedtls_mpi W, R, T, A, RR;
mbedtls_mpi_init( &W ); mbedtls_mpi_init( &R ); mbedtls_mpi_init( &T ); mbedtls_mpi_init( &A );
@ -2064,27 +2064,12 @@ static int mpi_miller_rabin( const mbedtls_mpi *X,
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &R, s ) );
i = mbedtls_mpi_bitlen( X );
/*
* HAC, table 4.4
*/
n = ( ( i >= 1300 ) ? 2 : ( i >= 850 ) ? 3 :
( i >= 650 ) ? 4 : ( i >= 350 ) ? 8 :
( i >= 250 ) ? 12 : ( i >= 150 ) ? 18 : 27 );
for( i = 0; i < n; i++ )
for( i = 0; i < rounds; i++ )
{
/*
* pick a random A, 1 < A < |X| - 1
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &A, X->n * ciL, f_rng, p_rng ) );
if( mbedtls_mpi_cmp_mpi( &A, &W ) >= 0 )
{
j = mbedtls_mpi_bitlen( &A ) - mbedtls_mpi_bitlen( &W );
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &A, j + 1 ) );
}
A.p[0] |= 3;
count = 0;
do {
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &A, X->n * ciL, f_rng, p_rng ) );
@ -2092,7 +2077,7 @@ static int mpi_miller_rabin( const mbedtls_mpi *X,
j = mbedtls_mpi_bitlen( &A );
k = mbedtls_mpi_bitlen( &W );
if (j > k) {
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &A, j - k ) );
A.p[A.n - 1] &= ( (mbedtls_mpi_uint) 1 << ( k - ( A.n - 1 ) * biL - 1 ) ) - 1;
}
if (count++ > 30) {
@ -2147,7 +2132,7 @@ cleanup:
/*
* Pseudo-primality test: small factors, then Miller-Rabin
*/
int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
static int mpi_is_prime_internal( const mbedtls_mpi *X, int rounds,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
@ -2173,7 +2158,17 @@ int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
return( ret );
}
return( mpi_miller_rabin( &XX, f_rng, p_rng ) );
return( mpi_miller_rabin( &XX, rounds, f_rng, p_rng ) );
}
/*
* Pseudo-primality test, error probability 2^-80
*/
int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
return mpi_is_prime_internal( X, 40, f_rng, p_rng );
}
/*
@ -2185,6 +2180,7 @@ int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int dh_flag,
{
int ret;
size_t k, n;
int rounds;
mbedtls_mpi_uint r;
mbedtls_mpi Y;
@ -2195,6 +2191,13 @@ int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int dh_flag,
n = BITS_TO_LIMBS( nbits );
/*
* 2^-80 error probability, number of rounds chosen per HAC, table 4.4
*/
rounds = ( ( nbits >= 1300 ) ? 2 : ( nbits >= 850 ) ? 3 :
( nbits >= 650 ) ? 4 : ( nbits >= 350 ) ? 8 :
( nbits >= 250 ) ? 12 : ( nbits >= 150 ) ? 18 : 27 );
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( X, n * ciL, f_rng, p_rng ) );
k = mbedtls_mpi_bitlen( X );
@ -2206,7 +2209,7 @@ int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int dh_flag,
if( dh_flag == 0 )
{
while( ( ret = mbedtls_mpi_is_prime( X, f_rng, p_rng ) ) != 0 )
while( ( ret = mpi_is_prime_internal( X, rounds, f_rng, p_rng ) ) != 0 )
{
if( ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE )
goto cleanup;
@ -2242,8 +2245,10 @@ int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int dh_flag,
*/
if( ( ret = mpi_check_small_factors( X ) ) == 0 &&
( ret = mpi_check_small_factors( &Y ) ) == 0 &&
( ret = mpi_miller_rabin( X, f_rng, p_rng ) ) == 0 &&
( ret = mpi_miller_rabin( &Y, f_rng, p_rng ) ) == 0 )
( ret = mpi_miller_rabin( X, rounds, f_rng, p_rng ) )
== 0 &&
( ret = mpi_miller_rabin( &Y, rounds, f_rng, p_rng ) )
== 0 )
{
break;
}

View file

@ -680,6 +680,14 @@ Test mbedtls_mpi_is_prime #20
depends_on:MBEDTLS_GENPRIME
mbedtls_mpi_is_prime:10:"49979687":0
Test mbedtls_mpi_is_prime_det (4 non-witnesses)
depends_on:MBEDTLS_GENPRIME
mbedtls_mpi_is_prime_det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
Test mbedtls_mpi_is_prime_det (39 non-witnesses)
depends_on:MBEDTLS_GENPRIME
mbedtls_mpi_is_prime_det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
Test mbedtls_mpi_gen_prime (Too small)
depends_on:MBEDTLS_GENPRIME
mbedtls_mpi_gen_prime:2:0:MBEDTLS_ERR_MPI_BAD_INPUT_DATA

View file

@ -1,5 +1,49 @@
/* BEGIN_HEADER */
#include "mbedtls/bignum.h"
typedef struct mbedtls_test_mpi_random
{
uint8_t *data;
uint32_t data_len;
size_t pos;
size_t chunk_len;
} mbedtls_test_mpi_random;
/*
* This function is called by the Miller-Rabin primality test each time it
* chooses a random witness. The witnesses (or non-witnesses as provided by the
* test) are stored in the data member of the state structure. Each number is in
* the format that mbedtls_mpi_read_string understands and is chunk_len long.
*/
int mbedtls_test_mpi_miller_rabin_determinizer( void* state,
unsigned char* buf,
size_t len )
{
mbedtls_test_mpi_random *random = (mbedtls_test_mpi_random*) state;
if( random == NULL || random->data == NULL || buf == NULL )
return( -1 );
if( random->pos + random->chunk_len > random->data_len
|| random->chunk_len > len )
{
return( -1 );
}
memset( buf, 0, len );
/* The witness is written to the end of the buffer, since the buffer is
* used as big endian, unsigned binary data in mbedtls_mpi_read_binary.
* Writing the witness to the start of the buffer would result in the
* buffer being 'witness 000...000', which would be treated as
* witness * 2^n for some n. */
memcpy( buf + len - random->chunk_len, &random->data[random->pos],
random->chunk_len );
random->pos += random->chunk_len;
return( 0 );
}
/* END_HEADER */
/* BEGIN_DEPENDENCIES
@ -805,6 +849,39 @@ exit:
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_GENPRIME */
void mbedtls_mpi_is_prime_det( char *input_X, char *witnesses,
int chunk_len, int div_result )
{
mbedtls_mpi X;
int res;
mbedtls_test_mpi_random rand;
uint8_t *witness_buf = NULL;
uint8_t *input_buf = NULL;
size_t witness_len;
size_t input_len;
witness_buf = unhexify_alloc( witnesses, &witness_len );
input_buf = unhexify_alloc( input_X, &input_len );
mbedtls_mpi_init( &X );
rand.data = witness_buf;
rand.data_len = witness_len;
rand.pos = 0;
rand.chunk_len = chunk_len;
TEST_ASSERT( mbedtls_mpi_read_binary( &X, input_buf, input_len ) == 0 );
res = mbedtls_mpi_is_prime( &X, mbedtls_test_mpi_miller_rabin_determinizer,
&rand );
TEST_ASSERT( res == div_result );
exit:
mbedtls_mpi_free( &X );
mbedtls_free( witness_buf );
mbedtls_free( input_buf );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_GENPRIME */
void mbedtls_mpi_gen_prime( int bits, int safe, int ref_ret )
{