api: New function gcry_mpi_point_copy.

* src/gcrypt.h.in (gcry_mpi_point_copy): New.
(mpi_point_copy): New macro.
* src/visibility.c (gcry_mpi_point_copy): New.
* src/libgcrypt.def, src/libgcrypt.vers: Add function.
* mpi/ec.c (_gcry_mpi_point_copy): New.
* tests/t-mpi-point.c (set_get_point): Add test.

Signed-off-by: Werner Koch <wk@gnupg.org>

10 files changed, 56 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index b29bb899..17c9a422 100644
--- a/NEWS
+++ b/NEWS
@@ -72,6 +72,7 @@ Noteworthy changes in version 1.8.0 (unreleased)  [C21/A1/R_]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    GCRYCTL_REINIT_SYSCALL_CLAMP    NEW macro.
    gcry_get_config                 NEW function.
+   gcry_mpi_point_copy             NEW function.
    gcry_md_info                    DEPRECATED.
 
 
diff --git a/doc/gcrypt.texi b/doc/gcrypt.texi
index cab1318d..649332b4 100644
--- a/doc/gcrypt.texi
+++ b/doc/gcrypt.texi
@@ -4876,6 +4876,13 @@ Release @var{point} and free all associated resources.  Passing
 @code{NULL} is allowed and ignored.
 @end deftypefun
 
+@deftypefun gcry_mpi_point_t gcry_mpi_point_copy (@w{gcry_mpi_point_t @var{point}})
+
+Allocate and return a new point object and initialize it with
+@var{point}.  If @var{point} is NULL the function is identical to
+@code{gcry_mpi_point_new(0)}.
+@end deftypefun
+
 @deftypefun void gcry_mpi_point_get (@w{gcry_mpi_t @var{x}}, @
  @w{gcry_mpi_t @var{y}}, @w{gcry_mpi_t @var{z}}, @
  @w{gcry_mpi_point_t @var{point}})
diff --git a/mpi/ec.c b/mpi/ec.c
index 8a6a656c..a0f73575 100644
--- a/mpi/ec.c
+++ b/mpi/ec.c
@@ -139,6 +139,20 @@ point_set (mpi_point_t d, mpi_point_t s)
 }
 
 
+/* Return a copy of POINT. */
+gcry_mpi_point_t
+_gcry_mpi_point_copy (gcry_mpi_point_t point)
+{
+  mpi_point_t newpoint;
+
+  newpoint = _gcry_mpi_point_new (0);
+  if (point)
+    point_set (newpoint, point);
+
+  return newpoint;
+}
+
+
 static void
 point_resize (mpi_point_t p, mpi_ec_t ctx)
 {
diff --git a/src/gcrypt-int.h b/src/gcrypt-int.h
index ef5337bb..ddcafa54 100644
--- a/src/gcrypt-int.h
+++ b/src/gcrypt-int.h
@@ -400,6 +400,7 @@ int _gcry_mpi_gcd (gcry_mpi_t g, gcry_mpi_t a, gcry_mpi_t b);
 int _gcry_mpi_invm (gcry_mpi_t x, gcry_mpi_t a, gcry_mpi_t m);
 gcry_mpi_point_t _gcry_mpi_point_new (unsigned int nbits);
 void _gcry_mpi_point_release (gcry_mpi_point_t point);
+gcry_mpi_point_t _gcry_mpi_point_copy (gcry_mpi_point_t point);
 void _gcry_mpi_point_get (gcry_mpi_t x, gcry_mpi_t y, gcry_mpi_t z,
                          gcry_mpi_point_t point);
 void _gcry_mpi_point_snatch_get (gcry_mpi_t x, gcry_mpi_t y, gcry_mpi_t z,
@@ -498,6 +499,8 @@ int _gcry_mpi_get_flag (gcry_mpi_t a, enum gcry_mpi_flag flag);
     }                                            \
   while (0)
 
+#define mpi_point_copy(p)      _gcry_mpi_point_copy((p))
+
 #define mpi_point_get(x,y,z,p)        _gcry_mpi_point_get((x),(y),(z),(p))
 #define mpi_point_snatch_get(x,y,z,p) _gcry_mpi_point_snatch_get((x),(y), \
                                                                  (z),(p))
diff --git a/src/gcrypt.h.in b/src/gcrypt.h.in
index 9a9acc4b..68c1f9e4 100644
--- a/src/gcrypt.h.in
+++ b/src/gcrypt.h.in
@@ -698,6 +698,9 @@ gcry_mpi_point_t gcry_mpi_point_new (unsigned int nbits);
 /* Release the object POINT.  POINT may be NULL. */
 void gcry_mpi_point_release (gcry_mpi_point_t point);
 
+/* Return a copy of POINT. */
+gcry_mpi_point_t gcry_mpi_point_copy (gcry_mpi_point_t point);
+
 /* Store the projective coordinates from POINT into X, Y, and Z.  */
 void gcry_mpi_point_get (gcry_mpi_t x, gcry_mpi_t y, gcry_mpi_t z,
                          gcry_mpi_point_t point);
@@ -868,6 +871,7 @@ gcry_mpi_t _gcry_mpi_get_const (int no);
       (p) = NULL;                               \
     }                                           \
   while (0)
+#define mpi_point_copy(p)             gcry_mpi_point_copy((p))
 #define mpi_point_get(x,y,z,p)        gcry_mpi_point_get((x),(y),(z),(p))
 #define mpi_point_snatch_get(x,y,z,p) gcry_mpi_point_snatch_get((x),(y),(z),(p))
 #define mpi_point_set(p,x,y,z)        gcry_mpi_point_set((p),(x),(y),(z))
diff --git a/src/libgcrypt.def b/src/libgcrypt.def
index c4a9eacc..a76b3775 100644
--- a/src/libgcrypt.def
+++ b/src/libgcrypt.def
@@ -284,4 +284,6 @@ EXPORTS
 
       gcry_get_config           @247
 
+      gcry_mpi_point_copy       @248
+
 ;; end of file with public symbols for Windows.
diff --git a/src/libgcrypt.vers b/src/libgcrypt.vers
index 1d2d150a..1aa830f9 100644
--- a/src/libgcrypt.vers
+++ b/src/libgcrypt.vers
@@ -107,6 +107,7 @@ GCRYPT_1.6 {
     gcry_mpi_ec_get_affine;
     gcry_mpi_ec_dup; gcry_mpi_ec_add; gcry_mpi_ec_sub; gcry_mpi_ec_mul;
     gcry_mpi_ec_curve_point; gcry_mpi_ec_decode_point;
+    gcry_mpi_point_copy;
 
     gcry_log_debug;
     gcry_log_debughex; gcry_log_debugmpi; gcry_log_debugpnt; gcry_log_debugsxp;
diff --git a/src/visibility.c b/src/visibility.c
index fe46c82a..104c70d5 100644
--- a/src/visibility.c
+++ b/src/visibility.c
@@ -484,6 +484,12 @@ gcry_mpi_point_release (gcry_mpi_point_t point)
   _gcry_mpi_point_release (point);
 }
 
+gcry_mpi_point_t
+gcry_mpi_point_copy (gcry_mpi_point_t point)
+{
+  return _gcry_mpi_point_copy (point);
+}
+
 void
 gcry_mpi_point_get (gcry_mpi_t x, gcry_mpi_t y, gcry_mpi_t z,
                     gcry_mpi_point_t point)
diff --git a/src/visibility.h b/src/visibility.h
index d28993a8..df2caf6f 100644
--- a/src/visibility.h
+++ b/src/visibility.h
@@ -246,6 +246,7 @@ MARK_VISIBLEX (gcry_mpi_new)
 MARK_VISIBLEX (gcry_mpi_point_get)
 MARK_VISIBLEX (gcry_mpi_point_new)
 MARK_VISIBLEX (gcry_mpi_point_release)
+MARK_VISIBLEX (gcry_mpi_point_copy)
 MARK_VISIBLEX (gcry_mpi_point_set)
 MARK_VISIBLEX (gcry_mpi_point_snatch_get)
 MARK_VISIBLEX (gcry_mpi_point_snatch_set)
@@ -466,6 +467,7 @@ MARK_VISIBLEX (_gcry_mpi_get_const)
 #define gcry_mpi_point_get          _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_mpi_point_new          _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_mpi_point_release      _gcry_USE_THE_UNDERSCORED_FUNCTION
+#define gcry_mpi_point_copy         _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_mpi_point_set          _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_mpi_point_snatch_get   _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_mpi_point_snatch_set   _gcry_USE_THE_UNDERSCORED_FUNCTION
diff --git a/tests/t-mpi-point.c b/tests/t-mpi-point.c
index 9919932c..1eaa08a5 100644
--- a/tests/t-mpi-point.c
+++ b/tests/t-mpi-point.c
@@ -306,7 +306,7 @@ ec_p_new (gcry_ctx_t *r_ctx, gcry_mpi_t p, gcry_mpi_t a)
 static void
 set_get_point (void)
 {
-  gcry_mpi_point_t point;
+  gcry_mpi_point_t point, point2;
   gcry_mpi_t x, y, z;
 
   wherestr = "set_get_point";
@@ -350,7 +350,22 @@ set_get_point (void)
       || gcry_mpi_cmp_ui (y, 42) || gcry_mpi_cmp_ui (z, 11371))
     fail ("point_snatch_set/point_get failed\n");
 
+  point2 = gcry_mpi_point_copy (point);
+
+  gcry_mpi_point_get (x, y, z, point2);
+  if (gcry_mpi_cmp_ui (x, 17)
+      || gcry_mpi_cmp_ui (y, 42) || gcry_mpi_cmp_ui (z, 11371))
+    fail ("point_copy failed (1)\n");
+
   gcry_mpi_point_release (point);
+
+  gcry_mpi_point_get (x, y, z, point2);
+  if (gcry_mpi_cmp_ui (x, 17)
+      || gcry_mpi_cmp_ui (y, 42) || gcry_mpi_cmp_ui (z, 11371))
+    fail ("point_copy failed (2)\n");
+
+  gcry_mpi_point_release (point2);
+
   gcry_mpi_release (x);
   gcry_mpi_release (y);
   gcry_mpi_release (z);