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authorDavid Howells <dhowells@redhat.com>2012-09-21 23:25:22 +0100
committerRusty Russell <rusty@rustcorp.com.au>2012-10-08 13:50:15 +1030
commit12f008b6dc5ff1c822fdb2198d20e3dbdc92f3f5 (patch)
treee8b2281155d6f962f6f4296efcd3dd02ebe02f6d /lib
parent4ae71c1dce1e3d2270a0755988033e236b8e45d6 (diff)
downloadvexpress-lsk-12f008b6dc5ff1c822fdb2198d20e3dbdc92f3f5.tar.gz
MPILIB: Reinstate mpi_cmp[_ui]() and export for RSA signature verification
Reinstate and export mpi_cmp() and mpi_cmp_ui() from the MPI library for use by RSA signature verification as per RFC3447 section 5.2.2 step 1. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'lib')
-rw-r--r--lib/mpi/Makefile1
-rw-r--r--lib/mpi/mpi-cmp.c70
2 files changed, 71 insertions, 0 deletions
diff --git a/lib/mpi/Makefile b/lib/mpi/Makefile
index 45ca90a8639..019a68c9014 100644
--- a/lib/mpi/Makefile
+++ b/lib/mpi/Makefile
@@ -14,6 +14,7 @@ mpi-y = \
generic_mpih-add1.o \
mpicoder.o \
mpi-bit.o \
+ mpi-cmp.o \
mpih-cmp.o \
mpih-div.o \
mpih-mul.o \
diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c
new file mode 100644
index 00000000000..1871e7b61ca
--- /dev/null
+++ b/lib/mpi/mpi-cmp.c
@@ -0,0 +1,70 @@
+/* mpi-cmp.c - MPI functions
+ * 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"
+
+int mpi_cmp_ui(MPI u, unsigned long v)
+{
+ mpi_limb_t limb = v;
+
+ mpi_normalize(u);
+ if (!u->nlimbs && !limb)
+ return 0;
+ if (u->sign)
+ return -1;
+ if (u->nlimbs > 1)
+ return 1;
+
+ if (u->d[0] == limb)
+ return 0;
+ else if (u->d[0] > limb)
+ return 1;
+ else
+ return -1;
+}
+EXPORT_SYMBOL_GPL(mpi_cmp_ui);
+
+int mpi_cmp(MPI u, MPI v)
+{
+ mpi_size_t usize, vsize;
+ int cmp;
+
+ mpi_normalize(u);
+ mpi_normalize(v);
+ usize = u->nlimbs;
+ vsize = v->nlimbs;
+ if (!u->sign && v->sign)
+ return 1;
+ if (u->sign && !v->sign)
+ return -1;
+ if (usize != vsize && !u->sign && !v->sign)
+ return usize - vsize;
+ if (usize != vsize && u->sign && v->sign)
+ return vsize + usize;
+ if (!usize)
+ return 0;
+ cmp = mpihelp_cmp(u->d, v->d, usize);
+ if (!cmp)
+ return 0;
+ if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
+ return 1;
+ return -1;
+}
+EXPORT_SYMBOL_GPL(mpi_cmp);