linux-stable.git/lib/mpi/mpicoder.c, branch v3.16.78

lib/mpi: mpi_read_raw_data(): fix nbits calculation

2016-11-20T01:16:38+00:00

commit eef0df6a59537032ab6b708f30b28d9530f8760e upstream.

The number of bits, nbits, is calculated in mpi_read_raw_data() as follows:

  nbits = nbytes * 8;

Afterwards, the number of leading zero bits of the first byte get
subtracted:

  nbits -= count_leading_zeros(buffer[0]);

However, count_leading_zeros() takes an unsigned long and thus,
the u8 gets promoted to an unsigned long.

Thus, the above doesn't subtract the number of leading zeros in the most
significant nonzero input byte from nbits, but the number of leading
zeros of the most significant nonzero input byte promoted to unsigned long,
i.e. BITS_PER_LONG - 8 too many.

Fix this by subtracting

  count_leading_zeros(...) - (BITS_PER_LONG - 8)

from nbits only.

Fixes: e1045992949 ("MPILIB: Provide a function to read raw data into an
                     MPI")
Signed-off-by: Nicolai Stange 
Signed-off-by: Herbert Xu 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

lib/mpi/mpicoder.c: looping issue, need stop when equal to zero, found by 'EXTRA_FLAGS=-W'.

2013-06-12T23:29:44+00:00

For 'while' looping, need stop when 'nbytes == 0', or will cause issue.
('nbytes' is size_t which is always bigger or equal than zero).

The related warning: (with EXTRA_CFLAGS=-W)

  lib/mpi/mpicoder.c:40:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]

Signed-off-by: Chen Gang 
Cc: Rusty Russell 
Cc: David Howells 
Cc: James Morris 
Cc: Andy Shevchenko 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mpilib: use DIV_ROUND_UP and remove unused macros

2013-02-01T05:28:32+00:00

Remove MIN, MAX and ABS macros that are duplicates kernel's native
implementation.

Signed-off-by: Andy Shevchenko 
Signed-off-by: James Morris

MPILIB: Provide a function to read raw data into an MPI

2012-10-08T03:20:21+00:00

Provide a function to read raw data of a predetermined size into an MPI rather
than expecting the size to be encoded within the data.  The data is assumed to
represent an unsigned integer, and the resulting MPI will be positive.

The function looks like this:

	MPI mpi_read_raw_data(const void *, size_t);

This is useful for reading ASN.1 integer primitives where the length is encoded
in the ASN.1 metadata.

Signed-off-by: David Howells 
Signed-off-by: Rusty Russell

Remove unused code from MPI library

2012-05-26T01:51:03+00:00

MPI library is used by RSA verification implementation.
Few files contains functions which are never called.

James Morris has asked to remove all of them.

Signed-off-by: Dmitry Kasatkin 
Requested-by: James Morris 
Signed-off-by: James Morris

lib/mpi: removed unused functions

2012-02-01T13:23:14+00:00

do_encode_md() and mpi_get_keyid() are not parts of mpi library.
They were used early versions of gnupg and in digsig project,
but they are not used neither here nor there anymore.

Signed-off-by: Dmitry Kasatkin 
Reviewed-by: Tetsuo Handa 
Signed-off-by: James Morris

lib/mpi: replaced MPI_NULL with normal NULL

2012-02-01T13:23:14+00:00

MPI_NULL is replaced with normal NULL.

Signed-off-by: Dmitry Kasatkin 
Reviewed-by: Tetsuo Handa 
Signed-off-by: James Morris

lib/mpi: added missing NULL check

2012-02-01T13:23:13+00:00

Added missing NULL check after mpi_alloc().

Signed-off-by: Dmitry Kasatkin 
Reviewed-by: Tetsuo Handa 
Signed-off-by: James Morris

MPILIB: Add a missing ENOMEM check

2012-01-19T02:45:51+00:00

Add a missing ENOMEM check.

Signed-off-by: David Howells 
Acked-by: Mimi Zohar 
Signed-off-by: James Morris

crypto: GnuPG based MPI lib - source files (part 1)

2011-11-09T09:45:22+00:00

Adds the multi-precision-integer maths library which was originally taken
from GnuPG and ported to the kernel by (among others) David Howells.
This version is taken from Fedora kernel 2.6.32-71.14.1.el6.
The difference is that checkpatch reported errors and warnings have been fixed.

This library is used to implemenet RSA digital signature verification
used in IMA/EVM integrity protection subsystem.

Due to patch size limitation, the patch is divided into 4 parts.

Signed-off-by: Dmitry Kasatkin