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Upstream-Status: Backport
Index: gnupg-1.4.7/cipher/dsa.c
===================================================================
--- gnupg-1.4.7.orig/cipher/dsa.c 2006-12-12 02:27:21.000000000 +0800
+++ gnupg-1.4.7/cipher/dsa.c 2014-01-23 11:30:17.300915919 +0800
@@ -287,6 +287,8 @@
MPI kinv;
MPI tmp;
+ mpi_normalize (hash);
+
/* select a random k with 0 < k < q */
k = gen_k( skey->q );
Index: gnupg-1.4.7/cipher/elgamal.c
===================================================================
--- gnupg-1.4.7.orig/cipher/elgamal.c 2006-12-12 03:08:05.000000000 +0800
+++ gnupg-1.4.7/cipher/elgamal.c 2014-01-23 11:30:17.300915919 +0800
@@ -376,6 +376,9 @@
{
MPI t1 = mpi_alloc_secure( mpi_get_nlimbs( skey->p ) );
+ mpi_normalize (a);
+ mpi_normalize (b);
+
/* output = b/(a^x) mod p */
mpi_powm( t1, a, skey->x, skey->p );
mpi_invm( t1, t1, skey->p );
Index: gnupg-1.4.7/cipher/random.c
===================================================================
--- gnupg-1.4.7.orig/cipher/random.c 2006-11-03 18:09:39.000000000 +0800
+++ gnupg-1.4.7/cipher/random.c 2014-01-23 11:31:53.993495462 +0800
@@ -273,6 +273,18 @@
}
+/* Randomize the MPI */
+void
+randomize_mpi (MPI mpi, size_t nbits, int level)
+{
+ unsigned char *buffer;
+
+ buffer = get_random_bits (nbits, level, mpi_is_secure (mpi));
+ mpi_set_buffer (mpi, buffer, (nbits+7)/8, 0);
+ xfree (buffer);
+}
+
+
int
random_is_faked()
{
Index: gnupg-1.4.7/cipher/random.h
===================================================================
--- gnupg-1.4.7.orig/cipher/random.h 2006-02-09 19:29:29.000000000 +0800
+++ gnupg-1.4.7/cipher/random.h 2014-01-23 11:30:17.300915919 +0800
@@ -32,6 +32,7 @@
int random_is_faked(void);
void random_disable_locking (void);
void randomize_buffer( byte *buffer, size_t length, int level );
+void randomize_mpi (MPI mpi, size_t nbits, int level);
byte *get_random_bits( size_t nbits, int level, int secure );
void fast_random_poll( void );
Index: gnupg-1.4.7/cipher/rsa.c
===================================================================
--- gnupg-1.4.7.orig/cipher/rsa.c 2006-12-12 03:09:00.000000000 +0800
+++ gnupg-1.4.7/cipher/rsa.c 2014-01-23 11:35:04.330639125 +0800
@@ -301,9 +301,26 @@
#if 0
mpi_powm( output, input, skey->d, skey->n );
#else
- MPI m1 = mpi_alloc_secure( mpi_get_nlimbs(skey->n)+1 );
- MPI m2 = mpi_alloc_secure( mpi_get_nlimbs(skey->n)+1 );
- MPI h = mpi_alloc_secure( mpi_get_nlimbs(skey->n)+1 );
+ int nlimbs = mpi_get_nlimbs (skey->n)+1;
+ MPI m1 = mpi_alloc_secure (nlimbs);
+ MPI m2 = mpi_alloc_secure (nlimbs);
+ MPI h = mpi_alloc_secure (nlimbs);
+# if 1
+ MPI bdata= mpi_alloc_secure (nlimbs);
+ MPI r = mpi_alloc_secure (nlimbs);
+# endif
+
+ /* Remove superfluous leading zeroes from INPUT. */
+ mpi_normalize (input);
+
+# if 1
+ /* Blind: bdata = (data * r^e) mod n */
+ randomize_mpi (r, mpi_get_nbits (skey->n), 0);
+ mpi_fdiv_r (r, r, skey->n);
+ mpi_powm (bdata, r, skey->e, skey->n);
+ mpi_mulm (bdata, bdata, input, skey->n);
+ input = bdata;
+# endif
/* m1 = c ^ (d mod (p-1)) mod p */
mpi_sub_ui( h, skey->p, 1 );
@@ -321,8 +338,15 @@
/* m = m2 + h * p */
mpi_mul ( h, h, skey->p );
mpi_add ( output, m1, h );
- /* ready */
-
+
+# if 1
+ mpi_free (bdata);
+ /* Unblind: output = (output * r^(-1)) mod n */
+ mpi_invm (r, r, skey->n);
+ mpi_mulm (output, output, r, skey->n);
+ mpi_free (r);
+# endif
+
mpi_free ( h );
mpi_free ( m1 );
mpi_free ( m2 );
@@ -397,6 +421,7 @@
rsa_decrypt( int algo, MPI *result, MPI *data, MPI *skey )
{
RSA_secret_key sk;
+ MPI input;
if( algo != 1 && algo != 2 )
return G10ERR_PUBKEY_ALGO;
@@ -407,8 +432,14 @@
sk.p = skey[3];
sk.q = skey[4];
sk.u = skey[5];
- *result = mpi_alloc_secure( mpi_get_nlimbs( sk.n ) );
- secret( *result, data[0], &sk );
+
+ /* Mitigates side-channel attacks (CVE-2013-4576). */
+ input = mpi_alloc (0);
+ mpi_normalize (data[0]);
+ mpi_fdiv_r (input, data[0], sk.n);
+ *result = mpi_alloc_secure (mpi_get_nlimbs (sk.n));
+ secret (*result, input, &sk);
+ mpi_free (input);
return 0;
}
Index: gnupg-1.4.7/g10/gpgv.c
===================================================================
--- gnupg-1.4.7.orig/g10/gpgv.c 2006-12-13 19:25:04.000000000 +0800
+++ gnupg-1.4.7/g10/gpgv.c 2014-01-23 11:30:17.300915919 +0800
@@ -390,6 +390,7 @@
void random_dump_stats(void) {}
int quick_random_gen( int onoff ) { return -1;}
void randomize_buffer( byte *buffer, size_t length, int level ) {}
+void randomize_mpi (MPI mpi, size_t nbits, int level) {}
int random_is_faked() { return -1;}
byte *get_random_bits( size_t nbits, int level, int secure ) { return NULL;}
void set_random_seed_file( const char *name ) {}
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