From 6dde596a03e4a8288d9d6134cd4656eae81826e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= <mpg@elzevir.fr>
Date: Mon, 11 May 2015 18:18:32 +0200
Subject: [PATCH] Remove ecp_sub()

---
 ChangeLog             |  1 +
 include/mbedtls/ecp.h | 17 -----------------
 library/ecp.c         | 28 ----------------------------
 3 files changed, 1 insertion(+), 45 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a3c46053b..28a3ef24a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -61,6 +61,7 @@ API Changes
 
 Removals
    * Removed mbedtls_ecp_group_read_string(). Only named groups are supported.
+   * Removed mbedtls_ecp_sub().
    * Removed individual mdX_hmac and shaX_hmac functions (use generic
      md_hmac functions from md.h)
    * Removed the PBKDF2 module (use PKCS5).
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 2d33c3853..901c23ed5 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -498,23 +498,6 @@ int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen,
 int mbedtls_ecp_add( const mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q );
 
-/**
- * \brief           Subtraction: R = P - Q
- *
- * \param grp       ECP group
- * \param R         Destination point
- * \param P         Left-hand point
- * \param Q         Right-hand point
- *
- * \return          0 if successful,
- *                  MBEDTLS_ERR_MPI_MALLOC_FAILED if memory allocation failed
- *
- * \note            This function does not support Montgomery curves, such as
- *                  Curve25519.
- */
-int mbedtls_ecp_sub( const mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
-             const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q );
-
 /**
  * \brief           Multiplication by an integer: R = m * P
  *                  (Not thread-safe to use same group in multiple threads)
diff --git a/library/ecp.c b/library/ecp.c
index e064c500a..f0fcc1f46 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -1066,34 +1066,6 @@ cleanup:
     return( ret );
 }
 
-/*
- * Subtraction: R = P - Q, result's coordinates normalized
- */
-int mbedtls_ecp_sub( const mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
-             const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q )
-{
-    int ret;
-    mbedtls_ecp_point mQ;
-
-    mbedtls_ecp_point_init( &mQ );
-
-    if( ecp_get_type( grp ) != ECP_TYPE_SHORT_WEIERSTRASS )
-        return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
-
-    /* mQ = - Q */
-    MBEDTLS_MPI_CHK( mbedtls_ecp_copy( &mQ, Q ) );
-    if( mbedtls_mpi_cmp_int( &mQ.Y, 0 ) != 0 )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &mQ.Y, &grp->P, &mQ.Y ) );
-
-    MBEDTLS_MPI_CHK( ecp_add_mixed( grp, R, P, &mQ ) );
-    MBEDTLS_MPI_CHK( ecp_normalize_jac( grp, R ) );
-
-cleanup:
-    mbedtls_ecp_point_free( &mQ );
-
-    return( ret );
-}
-
 /*
  * Randomize jacobian coordinates:
  * (X, Y, Z) -> (l^2 X, l^3 Y, l Z) for random l