mbedtls_ssl_prepare_handshake_record(): refactor first fragment prep

Minor refactoring of the initial checks and preparation when receiving the
first fragment. Use `ssl->in_hsfraglen` to determine whether there is a
pending handshake fragment, for consistency, and possibly for more
robustness in case handshake fragments are mixed with non-handshake
records (although this is not currently supported anyway).

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2025-02-28 21:59:12 +01:00
parent 07027722cb
commit 7a17696c34

View File

@ -2962,16 +2962,19 @@ static uint32_t ssl_get_hs_total_len(mbedtls_ssl_context const *ssl)
int mbedtls_ssl_prepare_handshake_record(mbedtls_ssl_context *ssl)
{
/* First handshake fragment must at least include the header. */
if (ssl->in_msglen < mbedtls_ssl_hs_hdr_len(ssl) && ssl->in_hslen == 0) {
MBEDTLS_SSL_DEBUG_MSG(1, ("handshake message too short: %" MBEDTLS_PRINTF_SIZET,
ssl->in_msglen));
return MBEDTLS_ERR_SSL_INVALID_RECORD;
}
if (ssl->in_hsfraglen == 0) {
/* The handshake message must at least include the header.
* We may not have the full message yet in case of fragmentation.
* To simplify the code, we insist on having the header (and in
* particular the handshake message length) in the first
* fragment. */
if (ssl->in_msglen < mbedtls_ssl_hs_hdr_len(ssl)) {
MBEDTLS_SSL_DEBUG_MSG(1, ("handshake message too short: %" MBEDTLS_PRINTF_SIZET,
ssl->in_msglen));
return MBEDTLS_ERR_SSL_INVALID_RECORD;
}
if (ssl->in_hslen == 0) {
ssl->in_hslen = mbedtls_ssl_hs_hdr_len(ssl) + ssl_get_hs_total_len(ssl);
ssl->in_hsfraglen = 0;
}
MBEDTLS_SSL_DEBUG_MSG(3, ("handshake message: msglen ="