From a77fc2756e9fd0b1bfdbc0259b4fe77fbf1f6d6d Mon Sep 17 00:00:00 2001 From: Ronald Cron Date: Wed, 30 Mar 2022 17:20:47 +0200 Subject: [PATCH] ssl_tls13_client.c: versions ext writing : Fix available space check Signed-off-by: Ronald Cron --- library/ssl_tls13_client.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c index 58aac471e..7c1f95e5c 100644 --- a/library/ssl_tls13_client.c +++ b/library/ssl_tls13_client.c @@ -60,10 +60,9 @@ static int ssl_tls13_write_supported_versions_ext( mbedtls_ssl_context *ssl, * - extension_type (2 bytes) * - extension_data_length (2 bytes) * - versions_length (1 byte ) - * - versions (2 to 4 bytes) + * - versions (2 or 4 bytes) */ - - MBEDTLS_SSL_CHK_BUF_PTR( p, end, 9 ); + MBEDTLS_SSL_CHK_BUF_PTR( p, end, 5 + versions_len ); MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS, p, 0 ); MBEDTLS_PUT_UINT16_BE( versions_len + 1, p, 2 );