From 33dc46b080a254d6639f6c5cf07a864a32f05c78 Mon Sep 17 00:00:00 2001 From: Paul Bakker Date: Wed, 30 Apr 2014 16:11:39 +0200 Subject: [PATCH] Fix bug with mpi_fill_random() on big-endian --- ChangeLog | 2 ++ library/bignum.c | 14 +++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index 2f5be94a9..5598467e3 100644 --- a/ChangeLog +++ b/ChangeLog @@ -25,6 +25,8 @@ Bugfix ServerHello when no extensions are present (found by Matthew Page) * rsa_check_pubkey() now allows an E up to N * On OpenBSD, use arc4random_buf() instead of rand() to prevent warnings + * mpi_fill_random() was creating numbers larger than requested on + big-endian platform when size was not an integer number of limbs = PolarSSL 1.3.6 released on 2014-04-11 diff --git a/library/bignum.c b/library/bignum.c index 012e9e3e4..5fbb7d354 100644 --- a/library/bignum.c +++ b/library/bignum.c @@ -1773,16 +1773,28 @@ cleanup: return( ret ); } +/* + * Fill X with size bytes of random. + * + * Use a temporary bytes representation to make sure the result is the same + * regardless of the platform endianness (usefull when f_rng is actually + * deterministic, eg for tests). + */ int mpi_fill_random( mpi *X, size_t size, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) { int ret; + unsigned char buf[POLARSSL_MPI_MAX_SIZE]; + + if( size > POLARSSL_MPI_MAX_SIZE ) + return( POLARSSL_ERR_MPI_BAD_INPUT_DATA ); MPI_CHK( mpi_grow( X, CHARS_TO_LIMBS( size ) ) ); MPI_CHK( mpi_lset( X, 0 ) ); - MPI_CHK( f_rng( p_rng, (unsigned char *) X->p, size ) ); + MPI_CHK( f_rng( p_rng, buf, size ) ); + MPI_CHK( mpi_read_binary( X, buf, size ) ); cleanup: return( ret );