commit 487bbf68053143cdcb27cc60a91caf7738d86b68
author Gilles Peskine <Gilles.Peskine@arm.com> Thu May 27 22:17:07 2021 +0200
committer Gilles Peskine <Gilles.Peskine@arm.com> Tue Jun 15 00:12:37 2021 +0200
tree ecad368d220314fbe6134c3bf3cfc6664096a7bd
parent 85b1bc65a0f84aa6e453f316ce73e778b2cf8717

DHM: new functions to query the length of the modulus

Add two functions mbedtls_dhm_get_len() and mbedtls_dhm_get_bitlen() to
query the length of the modulus in bytes or bits.

Remove the len field: the cost of calling mbedtls_dhm_get_len() each time
it's needed is negligible, and this improves the abstraction of the DHM
module.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

library/ssl_srv.c

diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 4fe6b02..cf4b7c5 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -3049,7 +3049,7 @@
 
         if( ( ret = mbedtls_dhm_make_params(
                   &ssl->handshake->dhm_ctx,
-                  (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
+                  (int) mbedtls_dhm_get_len( &ssl->handshake->dhm_ctx ),
                   ssl->out_msg + ssl->out_msglen, &len,
                   ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
         {