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Diffstat (limited to 'thirdparty/mbedtls/library/rsa.c')
-rw-r--r--thirdparty/mbedtls/library/rsa.c70
1 files changed, 43 insertions, 27 deletions
diff --git a/thirdparty/mbedtls/library/rsa.c b/thirdparty/mbedtls/library/rsa.c
index c9f7ba91b6..88c1cf1007 100644
--- a/thirdparty/mbedtls/library/rsa.c
+++ b/thirdparty/mbedtls/library/rsa.c
@@ -48,6 +48,7 @@
#include "mbedtls/rsa.h"
#include "mbedtls/rsa_internal.h"
#include "mbedtls/oid.h"
+#include "mbedtls/platform_util.h"
#include <string.h>
@@ -70,11 +71,7 @@
#if !defined(MBEDTLS_RSA_ALT)
-/* Implementation that should never be optimized out by the compiler */
-static void mbedtls_zeroize( void *v, size_t n ) {
- volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
-}
-
+#if defined(MBEDTLS_PKCS1_V15)
/* constant-time buffer comparison */
static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
{
@@ -88,6 +85,7 @@ static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
return( diff );
}
+#endif /* MBEDTLS_PKCS1_V15 */
int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
const mbedtls_mpi *N,
@@ -493,6 +491,9 @@ size_t mbedtls_rsa_get_len( const mbedtls_rsa_context *ctx )
/*
* Generate an RSA keypair
+ *
+ * This generation method follows the RSA key pair generation procedure of
+ * FIPS 186-4 if 2^16 < exponent < 2^256 and nbits = 2048 or nbits = 3072.
*/
int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
@@ -500,7 +501,7 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
unsigned int nbits, int exponent )
{
int ret;
- mbedtls_mpi H, G;
+ mbedtls_mpi H, G, L;
if( f_rng == NULL || nbits < 128 || exponent < 3 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -510,10 +511,13 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
mbedtls_mpi_init( &H );
mbedtls_mpi_init( &G );
+ mbedtls_mpi_init( &L );
/*
* find primes P and Q with Q < P so that:
- * GCD( E, (P-1)*(Q-1) ) == 1
+ * 1. |P-Q| > 2^( nbits / 2 - 100 )
+ * 2. GCD( E, (P-1)*(Q-1) ) == 1
+ * 3. E^-1 mod LCM(P-1, Q-1) > 2^( nbits / 2 )
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) );
@@ -525,40 +529,51 @@ int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1, 0,
f_rng, p_rng ) );
- if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
+ /* make sure the difference between p and q is not too small (FIPS 186-4 §B.3.3 step 5.4) */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &H, &ctx->P, &ctx->Q ) );
+ if( mbedtls_mpi_bitlen( &H ) <= ( ( nbits >= 200 ) ? ( ( nbits >> 1 ) - 99 ) : 0 ) )
continue;
- MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
- if( mbedtls_mpi_bitlen( &ctx->N ) != nbits )
- continue;
-
- if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
+ /* not required by any standards, but some users rely on the fact that P > Q */
+ if( H.s < 0 )
mbedtls_mpi_swap( &ctx->P, &ctx->Q );
/* Temporarily replace P,Q by P-1, Q-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->P, &ctx->P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->Q, &ctx->Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &ctx->P, &ctx->Q ) );
+
+ /* check GCD( E, (P-1)*(Q-1) ) == 1 (FIPS 186-4 §B.3.1 criterion 2(a)) */
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) );
+ if( mbedtls_mpi_cmp_int( &G, 1 ) != 0 )
+ continue;
+
+ /* compute smallest possible D = E^-1 mod LCM(P-1, Q-1) (FIPS 186-4 §B.3.1 criterion 3(b)) */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->P, &ctx->Q ) );
+ MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &L, NULL, &H, &G ) );
+ MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D, &ctx->E, &L ) );
+
+ if( mbedtls_mpi_bitlen( &ctx->D ) <= ( ( nbits + 1 ) / 2 ) ) // (FIPS 186-4 §B.3.1 criterion 3(a))
+ continue;
+
+ break;
}
- while( mbedtls_mpi_cmp_int( &G, 1 ) != 0 );
+ while( 1 );
/* Restore P,Q */
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->P, &ctx->P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->Q, &ctx->Q, 1 ) );
+ MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
+
ctx->len = mbedtls_mpi_size( &ctx->N );
+#if !defined(MBEDTLS_RSA_NO_CRT)
/*
- * D = E^-1 mod ((P-1)*(Q-1))
* DP = D mod (P - 1)
* DQ = D mod (Q - 1)
* QP = Q^-1 mod P
*/
-
- MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D, &ctx->E, &H ) );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
MBEDTLS_MPI_CHK( mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
&ctx->DP, &ctx->DQ, &ctx->QP ) );
#endif /* MBEDTLS_RSA_NO_CRT */
@@ -570,6 +585,7 @@ cleanup:
mbedtls_mpi_free( &H );
mbedtls_mpi_free( &G );
+ mbedtls_mpi_free( &L );
if( ret != 0 )
{
@@ -1040,7 +1056,7 @@ static int mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src,
}
exit:
- mbedtls_zeroize( mask, sizeof( mask ) );
+ mbedtls_platform_zeroize( mask, sizeof( mask ) );
return( ret );
}
@@ -1354,8 +1370,8 @@ int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
ret = 0;
cleanup:
- mbedtls_zeroize( buf, sizeof( buf ) );
- mbedtls_zeroize( lhash, sizeof( lhash ) );
+ mbedtls_platform_zeroize( buf, sizeof( buf ) );
+ mbedtls_platform_zeroize( lhash, sizeof( lhash ) );
return( ret );
}
@@ -1452,7 +1468,7 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
ret = 0;
cleanup:
- mbedtls_zeroize( buf, sizeof( buf ) );
+ mbedtls_platform_zeroize( buf, sizeof( buf ) );
return( ret );
}
@@ -1583,7 +1599,7 @@ int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
p += hlen;
*p++ = 0xBC;
- mbedtls_zeroize( salt, sizeof( salt ) );
+ mbedtls_platform_zeroize( salt, sizeof( salt ) );
exit:
mbedtls_md_free( &md_ctx );
@@ -1725,7 +1741,7 @@ static int rsa_rsassa_pkcs1_v15_encode( mbedtls_md_type_t md_alg,
* after the initial bounds check. */
if( p != dst + dst_len )
{
- mbedtls_zeroize( dst, dst_len );
+ mbedtls_platform_zeroize( dst, dst_len );
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
@@ -2062,13 +2078,13 @@ cleanup:
if( encoded != NULL )
{
- mbedtls_zeroize( encoded, sig_len );
+ mbedtls_platform_zeroize( encoded, sig_len );
mbedtls_free( encoded );
}
if( encoded_expected != NULL )
{
- mbedtls_zeroize( encoded_expected, sig_len );
+ mbedtls_platform_zeroize( encoded_expected, sig_len );
mbedtls_free( encoded_expected );
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-22 01:20:42 +0000