crypto: GnuPG based MPI lib - header files (part 2)
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 <dmitry.kasatkin@intel.com>
diff --git a/lib/mpi/mpi-inline.h b/lib/mpi/mpi-inline.h
new file mode 100644
index 0000000..e2b3985
--- /dev/null
+++ b/lib/mpi/mpi-inline.h
@@ -0,0 +1,122 @@
+/* mpi-inline.h - Internal to the Multi Precision Integers
+ * Copyright (C) 1994, 1996, 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#ifndef G10_MPI_INLINE_H
+#define G10_MPI_INLINE_H
+
+#ifndef G10_MPI_INLINE_DECL
+#define G10_MPI_INLINE_DECL extern inline
+#endif
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+ mpi_limb_t x;
+
+ x = *s1_ptr++;
+ s2_limb += x;
+ *res_ptr++ = s2_limb;
+ if (s2_limb < x) { /* sum is less than the left operand: handle carry */
+ while (--s1_size) {
+ x = *s1_ptr++ + 1; /* add carry */
+ *res_ptr++ = x; /* and store */
+ if (x) /* not 0 (no overflow): we can stop */
+ goto leave;
+ }
+ return 1; /* return carry (size of s1 to small) */
+ }
+
+leave:
+ if (res_ptr != s1_ptr) { /* not the same variable */
+ mpi_size_t i; /* copy the rest */
+ for (i = 0; i < s1_size - 1; i++)
+ res_ptr[i] = s1_ptr[i];
+ }
+ return 0; /* no carry */
+}
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+ mpi_ptr_t s2_ptr, mpi_size_t s2_size)
+{
+ mpi_limb_t cy = 0;
+
+ if (s2_size)
+ cy = mpihelp_add_n(res_ptr, s1_ptr, s2_ptr, s2_size);
+
+ if (s1_size - s2_size)
+ cy = mpihelp_add_1(res_ptr + s2_size, s1_ptr + s2_size,
+ s1_size - s2_size, cy);
+ return cy;
+}
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+ mpi_limb_t x;
+
+ x = *s1_ptr++;
+ s2_limb = x - s2_limb;
+ *res_ptr++ = s2_limb;
+ if (s2_limb > x) {
+ while (--s1_size) {
+ x = *s1_ptr++;
+ *res_ptr++ = x - 1;
+ if (x)
+ goto leave;
+ }
+ return 1;
+ }
+
+leave:
+ if (res_ptr != s1_ptr) {
+ mpi_size_t i;
+ for (i = 0; i < s1_size - 1; i++)
+ res_ptr[i] = s1_ptr[i];
+ }
+ return 0;
+}
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+ mpi_ptr_t s2_ptr, mpi_size_t s2_size)
+{
+ mpi_limb_t cy = 0;
+
+ if (s2_size)
+ cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size);
+
+ if (s1_size - s2_size)
+ cy = mpihelp_sub_1(res_ptr + s2_size, s1_ptr + s2_size,
+ s1_size - s2_size, cy);
+ return cy;
+}
+
+#endif /*G10_MPI_INLINE_H */