commit c16ec6be85003519c15034bc3a6bbbe98741245d
author Janos Follath <janos.follath@arm.com> Thu Jun 24 14:24:13 2021 +0100
committer Janos Follath <janos.follath@arm.com> Mon Jun 28 10:05:31 2021 +0100
tree c0e50f8f379e522564c22e6cc7350390ff43939a
parent 9f12b11be0b882b4fdef2287f990fb871adda4eb

Prevent memory leak in ecp_check_pubkey_x25519()

Signed-off-by: Janos Follath <janos.follath@arm.com>

library/ecp.c

diff --git a/library/ecp.c b/library/ecp.c
index 5927abc..a8cbfc7 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -3032,18 +3032,30 @@
     /* Check against the known bad values that are less than P in the
      * following list: https://cr.yp.to/ecdh.html#validate */
     if( mbedtls_mpi_cmp_int( &XmP, 1 ) <= 0 ) /* takes care of 0 and 1 */
-        return( MBEDTLS_ERR_ECP_INVALID_KEY );
+    {
+        ret = MBEDTLS_ERR_ECP_INVALID_KEY;
+        goto cleanup;
+    }
 
     if( mbedtls_mpi_cmp_mpi( &XmP, &ecp_x25519_bad_point_1 ) == 0 )
-        return( MBEDTLS_ERR_ECP_INVALID_KEY );
+    {
+        ret = MBEDTLS_ERR_ECP_INVALID_KEY;
+        goto cleanup;
+    }
 
     if( mbedtls_mpi_cmp_mpi( &XmP, &ecp_x25519_bad_point_2 ) == 0 )
-        return( MBEDTLS_ERR_ECP_INVALID_KEY );
+    {
+        ret = MBEDTLS_ERR_ECP_INVALID_KEY;
+        goto cleanup;
+    }
 
     /* Final check: check if XmP + 1 is P (final because it changes XmP!) */
     MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &XmP, &XmP, 1 ) );
     if( mbedtls_mpi_cmp_mpi( &XmP, P ) == 0 )
-        return( MBEDTLS_ERR_ECP_INVALID_KEY );
+    {
+        ret = MBEDTLS_ERR_ECP_INVALID_KEY;
+        goto cleanup;
+    }
 
     ret = 0;