crypto: GnuPG based MPI lib - source files (part 1)
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/mpiutil.c b/lib/mpi/mpiutil.c
new file mode 100644
index 0000000..eefc55d
--- /dev/null
+++ b/lib/mpi/mpiutil.c
@@ -0,0 +1,208 @@
+/* mpiutil.ac - Utility functions for MPI
+ * Copyright (C) 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
+ */
+
+#include "mpi-internal.h"
+
+/****************
+ * Note: It was a bad idea to use the number of limbs to allocate
+ * because on a alpha the limbs are large but we normally need
+ * integers of n bits - So we should chnage this to bits (or bytes).
+ *
+ * But mpi_alloc is used in a lot of places :-)
+ */
+MPI mpi_alloc(unsigned nlimbs)
+{
+ MPI a;
+
+ a = kmalloc(sizeof *a, GFP_KERNEL);
+ if (!a)
+ return a;
+
+ if (nlimbs) {
+ a->d = mpi_alloc_limb_space(nlimbs);
+ if (!a->d) {
+ kfree(a);
+ return NULL;
+ }
+ } else {
+ a->d = NULL;
+ }
+
+ a->alloced = nlimbs;
+ a->nlimbs = 0;
+ a->sign = 0;
+ a->flags = 0;
+ a->nbits = 0;
+ return a;
+}
+EXPORT_SYMBOL_GPL(mpi_alloc);
+
+mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
+{
+ size_t len = nlimbs * sizeof(mpi_limb_t);
+
+ return kmalloc(len, GFP_KERNEL);
+}
+
+void mpi_free_limb_space(mpi_ptr_t a)
+{
+ if (!a)
+ return;
+
+ kfree(a);
+}
+
+void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
+{
+ mpi_free_limb_space(a->d);
+ a->d = ap;
+ a->alloced = nlimbs;
+}
+
+/****************
+ * Resize the array of A to NLIMBS. the additional space is cleared
+ * (set to 0) [done by m_realloc()]
+ */
+int mpi_resize(MPI a, unsigned nlimbs)
+{
+ void *p;
+
+ if (nlimbs <= a->alloced)
+ return 0; /* no need to do it */
+
+ if (a->d) {
+ p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
+ kfree(a->d);
+ a->d = p;
+ } else {
+ a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
+ if (!a->d)
+ return -ENOMEM;
+ }
+ a->alloced = nlimbs;
+ return 0;
+}
+
+void mpi_clear(MPI a)
+{
+ a->nlimbs = 0;
+ a->nbits = 0;
+ a->flags = 0;
+}
+
+void mpi_free(MPI a)
+{
+ if (!a)
+ return;
+
+ if (a->flags & 4)
+ kfree(a->d);
+ else
+ mpi_free_limb_space(a->d);
+
+ if (a->flags & ~7)
+ pr_info("invalid flag value in mpi\n");
+ kfree(a);
+}
+EXPORT_SYMBOL_GPL(mpi_free);
+
+/****************
+ * Note: This copy function should not interpret the MPI
+ * but copy it transparently.
+ */
+int mpi_copy(MPI *copied, const MPI a)
+{
+ size_t i;
+ MPI b;
+
+ *copied = MPI_NULL;
+
+ if (a) {
+ b = mpi_alloc(a->nlimbs);
+ if (!b)
+ return -ENOMEM;
+
+ b->nlimbs = a->nlimbs;
+ b->sign = a->sign;
+ b->flags = a->flags;
+ b->nbits = a->nbits;
+
+ for (i = 0; i < b->nlimbs; i++)
+ b->d[i] = a->d[i];
+
+ *copied = b;
+ }
+
+ return 0;
+}
+
+int mpi_set(MPI w, const MPI u)
+{
+ mpi_ptr_t wp, up;
+ mpi_size_t usize = u->nlimbs;
+ int usign = u->sign;
+
+ if (RESIZE_IF_NEEDED(w, (size_t) usize) < 0)
+ return -ENOMEM;
+
+ wp = w->d;
+ up = u->d;
+ MPN_COPY(wp, up, usize);
+ w->nlimbs = usize;
+ w->nbits = u->nbits;
+ w->flags = u->flags;
+ w->sign = usign;
+ return 0;
+}
+
+int mpi_set_ui(MPI w, unsigned long u)
+{
+ if (RESIZE_IF_NEEDED(w, 1) < 0)
+ return -ENOMEM;
+ w->d[0] = u;
+ w->nlimbs = u ? 1 : 0;
+ w->sign = 0;
+ w->nbits = 0;
+ w->flags = 0;
+ return 0;
+}
+
+MPI mpi_alloc_set_ui(unsigned long u)
+{
+ MPI w = mpi_alloc(1);
+ if (!w)
+ return w;
+ w->d[0] = u;
+ w->nlimbs = u ? 1 : 0;
+ w->sign = 0;
+ return w;
+}
+
+void mpi_swap(MPI a, MPI b)
+{
+ struct gcry_mpi tmp;
+
+ tmp = *a;
+ *a = *b;
+ *b = tmp;
+}