adjusting size of sliding window array to correct size.
Probably the `W[2 << MBEDTLS_MPI_WINDOW_SIZE]` notation is based on a transcription of 2**MBEDTLS_MPI_WINDOW_SIZE.
Signed-off-by: Daniel Otte <d.otte@wut.de>
diff --git a/library/bignum.c b/library/bignum.c
index 3135ec4..0e39e3a 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1850,7 +1850,7 @@
size_t i, j, nblimbs;
size_t bufsize, nbits;
mbedtls_mpi_uint ei, mm, state;
- mbedtls_mpi RR, T, W[ 2 << MBEDTLS_MPI_WINDOW_SIZE ], Apos;
+ mbedtls_mpi RR, T, W[ 1 << MBEDTLS_MPI_WINDOW_SIZE ], Apos;
int neg;
if( mbedtls_mpi_cmp_int( N, 0 ) <= 0 || ( N->p[0] & 1 ) == 0 )