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Commit 0f74fbf7 authored by Tadeusz Struk's avatar Tadeusz Struk Committed by Herbert Xu
Browse files

MPI: Fix mpi_read_buffer 



Change mpi_read_buffer to return a number without leading zeros
so that mpi_read_buffer and mpi_get_buffer return the same thing.

Signed-off-by: default avatarTadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 55e8dba1

lib/mpi/mpicoder.c

+25 −13
Original line number Diff line number Diff line
@@ -146,18 +146,25 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, 
	uint8_t *p;

	mpi_limb_t alimb;

	unsigned int n = mpi_get_size(a);

	int i;

	int i, lzeros = 0;



	if (buf_len < n || !buf)

	if (buf_len < n || !buf || !nbytes)

		return -EINVAL;



	if (sign)

		*sign = a->sign;



	if (nbytes)

		*nbytes = n;

	p = (void *)&a->d[a->nlimbs] - 1;



	for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) {

		if (!*p)

			lzeros++;

		else

			break;

	}



	p = buf;

	*nbytes = n - lzeros;



	for (i = a->nlimbs - 1; i >= 0; i--) {

		alimb = a->d[i];
@@ -178,6 +185,19 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, 
#else

#error please implement for this limb size.

#endif



		if (lzeros > 0) {

			if (lzeros >= sizeof(alimb)) {

				p -= sizeof(alimb);

			} else {

				mpi_limb_t *limb1 = (void *)p - sizeof(alimb);

				mpi_limb_t *limb2 = (void *)p - sizeof(alimb)

							+ lzeros;

				*limb1 = *limb2;

				p -= lzeros;

			}

			lzeros -= sizeof(alimb);

		}

	}

	return 0;

}
@@ -197,7 +217,7 @@ EXPORT_SYMBOL_GPL(mpi_read_buffer); 
 */

void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign)

{

	uint8_t *buf, *p;

	uint8_t *buf;

	unsigned int n;

	int ret;
@@ -220,14 +240,6 @@ void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) 
		kfree(buf);

		return NULL;

	}



	/* this is sub-optimal but we need to do the shift operation

	 * because the caller has to free the returned buffer */

	for (p = buf; !*p && *nbytes; p++, --*nbytes)

		;

	if (p != buf)

		memmove(buf, p, *nbytes);



	return buf;

}

EXPORT_SYMBOL_GPL(mpi_get_buffer);