tls13: srv: Simplify mbedtls_ssl_read_early_data() API

Do not progress the handshake in the API, just
read early data if some has been detected by
a previous call to mbedtls_ssl_handshake(),
mbedtls_ssl_handshake_step(),
mbedtls_ssl_read() or mbedtls_ssl_write().

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
This commit is contained in:
Ronald Cron 2024-01-31 07:55:19 +01:00
parent 44d70a5f23
commit ed7d4bfda5
3 changed files with 18 additions and 72 deletions

View File

@ -5141,49 +5141,25 @@ int mbedtls_ssl_close_notify(mbedtls_ssl_context *ssl);
* same warnings apply to any use of the
* early_exporter_master_secret.
*
* \note This function behaves mainly as mbedtls_ssl_read(). The
* specification of mbedtls_ssl_read() relevant to TLS 1.3
* (thus not the parts specific to (D)TLS 1.2) applies to this
* function and the present documentation is restricted to the
* differences with mbedtls_ssl_read().
*
* \note This function can be used in conjunction with
* \note This function is used in conjunction with
* mbedtls_ssl_handshake(), mbedtls_ssl_handshake_step(),
* mbedtls_ssl_read() and mbedtls_ssl_write() to read early
* data when these functions return
* #MBEDTLS_ERR_SSL_RECEIVED_EARLY_DATA.
*
* \param ssl SSL context
* \param ssl SSL context, it must have been initialized and set up.
* \param buf buffer that will hold the data
* \param len maximum number of bytes to read
*
* \note Unlike mbedtls_ssl_read(), this function does not return
* \return The (positive) number of bytes read if successful.
* \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if input data is invalid.
* \return #MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA if it is not
* possible to read early data for the SSL context \p ssl. Note
* that this function is intended to be called for an SSL
* context \p ssl only after a call to mbedtls_ssl_handshake(),
* mbedtls_ssl_handshake_step(), mbedtls_ssl_read() or
* mbedtls_ssl_write() for \p ssl that has returned
* #MBEDTLS_ERR_SSL_RECEIVED_EARLY_DATA.
*
* \return One additional specific return value:
* #MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA.
*
* #MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA is returned when it
* is not possible to read early data for the SSL context
* \p ssl.
*
* It may have been possible and it is not possible
* anymore because the server received the End of Early Data
* message or the maximum number of allowed early data for the
* PSK in use has been reached.
*
* It may never have been possible and will never be possible
* for the SSL context \p ssl because the use of early data
* is disabled for that context or more generally the context
* is not suitably configured to enable early data or the
* client does not use early data or the first call to the
* function was done while the handshake was already too
* advanced to gather and accept early data.
*
* It is not possible to read early data for the SSL context
* \p ssl but this does not preclude for using it with
* mbedtls_ssl_write(), mbedtls_ssl_read() or
* mbedtls_ssl_handshake().
*/
int mbedtls_ssl_read_early_data(mbedtls_ssl_context *ssl,
unsigned char *buf, size_t len);

View File

@ -5865,54 +5865,20 @@ int mbedtls_ssl_read(mbedtls_ssl_context *ssl, unsigned char *buf, size_t len)
return ret;
}
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_EARLY_DATA)
int mbedtls_ssl_read_early_data(mbedtls_ssl_context *ssl,
unsigned char *buf, size_t len)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const struct mbedtls_ssl_config *conf;
unsigned char *p = buf;
if (ssl == NULL || ((conf = ssl->conf) == NULL)) {
if (ssl == NULL || (ssl->conf == NULL)) {
return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
}
if ((!mbedtls_ssl_conf_is_tls13_enabled(conf)) ||
(conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) ||
(conf->early_data_enabled != MBEDTLS_SSL_EARLY_DATA_ENABLED)) {
if ((ssl->state != MBEDTLS_SSL_END_OF_EARLY_DATA) ||
(ssl->in_offt == NULL)) {
return MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA;
}
if (ssl->tls_version != MBEDTLS_SSL_VERSION_TLS1_3) {
return MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA;
}
if ((ssl->early_data_state.srv !=
MBEDTLS_SSL_SRV_EARLY_DATA_STATE_WAITING_CH) &&
(ssl->early_data_state.srv !=
MBEDTLS_SSL_SRV_EARLY_DATA_STATE_ACCEPTING)) {
return MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA;
}
ret = mbedtls_ssl_handshake(ssl);
if (ret == MBEDTLS_ERR_SSL_RECEIVED_EARLY_DATA) {
if (ssl->in_offt == NULL) {
/* Set the reading pointer */
ssl->in_offt = ssl->in_msg;
}
ret = ssl_read_application_data(ssl, p, len);
} else if (ret == 0) {
/*
* If the handshake is completed, return immediately that early data
* cannot be read anymore. This potentially saves another call to this
* API and when the function returns 0, it only means that zero byte
* of early data has been received.
*/
return MBEDTLS_ERR_SSL_CANNOT_READ_EARLY_DATA;
}
return ret;
return ssl_read_application_data(ssl, buf, len);
}
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_EARLY_DATA */

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@ -2929,6 +2929,10 @@ static int ssl_tls13_end_of_early_data_coordinate(mbedtls_ssl_context *ssl)
*
* TODO: Add received data size check here.
*/
if (ssl->in_offt == NULL) {
/* Set the reading pointer */
ssl->in_offt = ssl->in_msg;
}
return SSL_GOT_EARLY_DATA;
}