[git] GCRYPT - branch, master, updated. libgcrypt-1.6.0-248-gce74693

[by NIIBE Yutaka]

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      from  0e17f7a05bba309a87811992aa47a77af9935b99 (commit)

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- Log -----------------------------------------------------------------
commit ce746936b6c210e602d106cfbf45cf60b408d871
Author: NIIBE Yutaka <gniibe at fsij.org>
Date:   Mon Aug 10 19:09:16 2015 +0900

    ecc: fix Montgomery curve bugs.
    
    * cipher/ecc.c (check_secret_key): Y1 should not be NULL when check.
    (ecc_check_secret_key): Support Montgomery curve.
    * mpi/ec.c (_gcry_mpi_ec_curve_point): Fix condition.

diff --git a/cipher/ecc-curves.c b/cipher/ecc-curves.c
index 51d9e39..a74501d 100644
--- a/cipher/ecc-curves.c
+++ b/cipher/ecc-curves.c
@@ -108,7 +108,7 @@ typedef struct
   const char *p;              /* The prime defining the field.  */
   const char *a, *b;          /* The coefficients.  For Twisted Edwards
                                  Curves b is used for d.  For Montgomery
-                                 Curves a has (A-2)/4.  */
+                                 Curves (a,b) has ((A-2)/4,B^-1).  */
   const char *n;              /* The order of the base point.  */
   const char *g_x, *g_y;      /* Base point.  */
   const char *h;              /* Cofactor.  */
diff --git a/cipher/ecc.c b/cipher/ecc.c
index cc617f8..4958fbb 100644
--- a/cipher/ecc.c
+++ b/cipher/ecc.c
@@ -450,7 +450,7 @@ check_secret_key (ECC_secret_key *sk, mpi_ec_t ec, int flags)
   else if (!mpi_cmp_ui (sk->Q.z, 1))
     {
       /* Fast path if Q is already in affine coordinates.  */
-      if (mpi_cmp (x1, sk->Q.x) || (!y1 && mpi_cmp (y1, sk->Q.y)))
+      if (mpi_cmp (x1, sk->Q.x) || (y1 && mpi_cmp (y1, sk->Q.y)))
         {
           if (DBG_CIPHER)
             log_debug
@@ -825,6 +825,8 @@ ecc_check_secret_key (gcry_sexp_t keyparms)
       point_init (&sk.Q);
       if (ec->dialect == ECC_DIALECT_ED25519)
         rc = _gcry_ecc_eddsa_decodepoint (mpi_q, ec, &sk.Q, NULL, NULL);
+      else if (ec->model == MPI_EC_MONTGOMERY)
+        rc = _gcry_ecc_mont_decodepoint (mpi_q, ec, &sk.Q);
       else
         rc = _gcry_ecc_os2ec (&sk.Q, mpi_q);
       if (rc)
diff --git a/mpi/ec.c b/mpi/ec.c
index 0b7c7a7..7266f2a 100644
--- a/mpi/ec.c
+++ b/mpi/ec.c
@@ -1470,7 +1470,7 @@ _gcry_mpi_ec_curve_point (gcry_mpi_point_t point, mpi_ec_t ctx)
         mpi_rshift (p_minus1, p_minus1, 1);
         ec_powm (w, w, p_minus1, ctx);
 
-        res = mpi_cmp_ui (w, 1);
+        res = !mpi_cmp_ui (w, 1);
 #undef p_minus1
       }
       break;

-----------------------------------------------------------------------

Summary of changes:
 cipher/ecc-curves.c | 2 +-
 cipher/ecc.c        | 4 +++-
 mpi/ec.c            | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)


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