Re: [PATCH v2 2/6] net: lwip: Update lwIP for mbedTLS > 3.0 support and enable https

On Wed, 6 Nov 2024 at 13:37, Jerome Forissier jerome.forissier@linaro.org wrote:

On 10/24/24 12:24, Ilias Apalodimas wrote:

...

From: Javier Tia javier.tia@linaro.org

The current code support mbedTLS 2.28. Since we are using a newer version in U-Boot, update the necessary accessors and the lwIP codebase to work with mbedTLS 3.6.0. It's worth noting that the patches are already sent to lwIP [0]

While at it enable LWIP_ALTCP_TLS and enable TLS support in lwIP

[0] https://github.com/lwip-tcpip/lwip/pull/47

Signed-off-by: Javier Tia javier.tia@linaro.org Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org

---

lib/lwip/Makefile | 3 ++ .../src/apps/altcp_tls/altcp_tls_mbedtls.c | 39 ++++++++++++------- lib/lwip/lwip/src/core/tcp_out.c | 10 +---- lib/lwip/u-boot/lwipopts.h | 6 +++ 4 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/lib/lwip/Makefile b/lib/lwip/Makefile index dfcd700ca474..19e5c6897f5a 100644 --- a/lib/lwip/Makefile +++ b/lib/lwip/Makefile @@ -53,3 +53,6 @@ obj-y += \ lwip/src/core/timeouts.o \ lwip/src/core/udp.o \ lwip/src/netif/ethernet.o

+obj-$(CONFIG_MBEDTLS_LIB_TLS) += lwip/src/apps/altcp_tls/altcp_tls_mbedtls.o \

• lwip/src/apps/altcp_tls/altcp_tls_mbedtls_mem.o
  

diff --git a/lib/lwip/lwip/src/apps/altcp_tls/altcp_tls_mbedtls.c b/lib/lwip/lwip/src/apps/altcp_tls/altcp_tls_mbedtls.c index a8c2fc2ee2cd..ef19821b89e0 100644 --- a/lib/lwip/lwip/src/apps/altcp_tls/altcp_tls_mbedtls.c +++ b/lib/lwip/lwip/src/apps/altcp_tls/altcp_tls_mbedtls.c @@ -3,7 +3,7 @@

• Application layered TCP/TLS connection API (to be used from TCPIP thread)
• This file provides a TLS layer using mbedTLS

Unrelated formatting change, do we want to do this in a separate patch maybe?

...

• This version is currently compatible with the 2.x.x branch (current LTS).

*/

@@ -70,7 +70,6 @@ /* @todo: which includes are really needed? */ #include "mbedtls/entropy.h" #include "mbedtls/ctr_drbg.h" -#include "mbedtls/certs.h" #include "mbedtls/x509.h" #include "mbedtls/ssl.h" #include "mbedtls/net_sockets.h" @@ -81,8 +80,6 @@ #include "mbedtls/ssl_cache.h" #include "mbedtls/ssl_ticket.h"

-#include "mbedtls/ssl_internal.h" /* to call mbedtls_flush_output after ERR_MEM */

#include <string.h>

#ifndef ALTCP_MBEDTLS_ENTROPY_PTR @@ -132,6 +129,16 @@ static err_t altcp_mbedtls_lower_recv_process(struct altcp_pcb *conn, altcp_mbed static err_t altcp_mbedtls_handle_rx_appldata(struct altcp_pcb *conn, altcp_mbedtls_state_t *state); static int altcp_mbedtls_bio_send(void *ctx, const unsigned char *dataptr, size_t size);

+static void +altcp_mbedtls_flush_output(altcp_mbedtls_state_t *state) +{

• if (state->ssl_context.MBEDTLS_PRIVATE(out_left) != 0) {
• int flushed = mbedtls_ssl_send_alert_message(&state->ssl_context, 0, 0);
• if (flushed) {

•  LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_ssl_send_alert_message failed: %d\n", flushed));
  

• }
• }

+}

/* callback functions from inner/lower connection: */

@@ -524,14 +531,14 @@ altcp_mbedtls_lower_sent(void *arg, struct altcp_pcb *inner_conn, u16_t len) LWIP_ASSERT("state", state != NULL); LWIP_ASSERT("pcb mismatch", conn->inner_conn == inner_conn); /* calculate TLS overhead part to not send it to application */

• overhead = state->overhead_bytes_adjust + state->ssl_context.out_left;

• overhead = state->overhead_bytes_adjust + state->ssl_context.MBEDTLS_PRIVATE(out_left); if ((unsigned)overhead > len) { overhead = len; } /* remove ACKed bytes from overhead adjust counter */ state->overhead_bytes_adjust -= len; /* try to send more if we failed before (may increase overhead adjust counter) */

• mbedtls_ssl_flush_output(&state->ssl_context);

• altcp_mbedtls_flush_output(state); /* remove calculated overhead from ACKed bytes len */ app_len = len - (u16_t)overhead; /* update application write counter and inform application */

@@ -559,7 +566,7 @@ altcp_mbedtls_lower_poll(void *arg, struct altcp_pcb *inner_conn) if (conn->state) { altcp_mbedtls_state_t *state = (altcp_mbedtls_state_t *)conn->state; /* try to send more if we failed before */

•  mbedtls_ssl_flush_output(&state->ssl_context);
  

•  altcp_mbedtls_flush_output(state);
   if (altcp_mbedtls_handle_rx_appldata(conn, state) == ERR_ABRT) {
     return ERR_ABRT;
   }
  

@@ -683,7 +690,7 @@ altcp_tls_set_session(struct altcp_pcb *conn, struct altcp_tls_session *session) if (session && conn && conn->state) { altcp_mbedtls_state_t *state = (altcp_mbedtls_state_t *)conn->state; int ret = -1;

• if (session->data.start)

• if (session->data.MBEDTLS_PRIVATE(start)) ret = mbedtls_ssl_set_session(&state->ssl_context, &session->data); return ret < 0 ? ERR_VAL : ERR_OK; }

@@ -776,7 +783,7 @@ altcp_tls_create_config(int is_server, u8_t cert_count, u8_t pkey_count, int hav struct altcp_tls_config *conf; mbedtls_x509_crt *mem;

• if (TCP_WND < MBEDTLS_SSL_MAX_CONTENT_LEN) {

• if (TCP_WND < MBEDTLS_SSL_IN_CONTENT_LEN || TCP_WND < MBEDTLS_SSL_OUT_CONTENT_LEN) { LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG|LWIP_DBG_LEVEL_SERIOUS, ("altcp_tls: TCP_WND is smaller than the RX decrypion buffer, connection RX might stall!\n")); }

@@ -900,7 +907,7 @@ err_t altcp_tls_config_server_add_privkey_cert(struct altcp_tls_config *config, return ERR_VAL; }

• ret = mbedtls_pk_parse_key(pkey, (const unsigned char *) privkey, privkey_len, privkey_pass, privkey_pass_len);

• ret = mbedtls_pk_parse_key(pkey, (const unsigned char *) privkey, privkey_len, privkey_pass, privkey_pass_len, mbedtls_ctr_drbg_random, &altcp_tls_entropy_rng->ctr_drbg); if (ret != 0) { LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_pk_parse_public_key failed: %d\n", ret)); mbedtls_x509_crt_free(srvcert);

@@ -1003,7 +1010,7 @@ altcp_tls_create_config_client_2wayauth(const u8_t *ca, size_t ca_len, const u8_ }

mbedtls_pk_init(conf->pkey);

• ret = mbedtls_pk_parse_key(conf->pkey, privkey, privkey_len, privkey_pass, privkey_pass_len);

• ret = mbedtls_pk_parse_key(conf->pkey, privkey, privkey_len, privkey_pass, privkey_pass_len, mbedtls_ctr_drbg_random, &altcp_tls_entropy_rng->ctr_drbg); if (ret != 0) { LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_pk_parse_key failed: %d 0x%x\n", ret, -1*ret)); altcp_tls_free_config(conf);

@@ -1189,7 +1196,7 @@ altcp_mbedtls_sndbuf(struct altcp_pcb *conn) size_t ret; #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) /* @todo: adjust ssl_added to real value related to negotiated cipher */

•      size_t max_frag_len = mbedtls_ssl_get_max_frag_len(&state->ssl_context);
  

•      size_t max_frag_len = mbedtls_ssl_get_max_in_record_payload(&state->ssl_context);
       max_len = LWIP_MIN(max_frag_len, max_len);
  

#endif /* Adjust sndbuf of inner_conn with what added by SSL */ @@ -1232,9 +1239,9 @@ altcp_mbedtls_write(struct altcp_pcb *conn, const void *dataptr, u16_t len, u8_t /* HACK: if there is something left to send, try to flush it and only allow sending more if this succeeded (this is a hack because neither returning 0 nor MBEDTLS_ERR_SSL_WANT_WRITE worked for me) */

• if (state->ssl_context.out_left) {
• mbedtls_ssl_flush_output(&state->ssl_context);
• if (state->ssl_context.out_left) {

• if (state->ssl_context.MBEDTLS_PRIVATE(out_left)) {
• altcp_mbedtls_flush_output(state);
• if (state->ssl_context.MBEDTLS_PRIVATE(out_left)) { return ERR_MEM; } }

@@ -1284,6 +1291,8 @@ altcp_mbedtls_bio_send(void *ctx, const unsigned char *dataptr, size_t size) while (size_left) { u16_t write_len = (u16_t)LWIP_MIN(size_left, 0xFFFF); err_t err = altcp_write(conn->inner_conn, (const void *)dataptr, write_len, apiflags);

• /* try to send data... */
• altcp_output(conn->inner_conn); if (err == ERR_OK) { written += write_len; size_left -= write_len;

diff --git a/lib/lwip/lwip/src/core/tcp_out.c b/lib/lwip/lwip/src/core/tcp_out.c index 64579ee5cbd8..b5d312137368 100644 --- a/lib/lwip/lwip/src/core/tcp_out.c +++ b/lib/lwip/lwip/src/core/tcp_out.c @@ -1255,14 +1255,6 @@ tcp_output(struct tcp_pcb *pcb) LWIP_ASSERT("don't call tcp_output for listen-pcbs", pcb->state != LISTEN);

• /* First, check if we are invoked by the TCP input processing

• code. If so, we do not output anything. Instead, we rely on the
  

• input processing code to call us when input processing is done
  

• with. */
  

• if (tcp_input_pcb == pcb) {

• return ERR_OK;

• }

• wnd = LWIP_MIN(pcb->snd_wnd, pcb->cwnd);

  seg = pcb->unsent;

@@ -2036,7 +2028,7 @@ tcp_rst(const struct tcp_pcb *pcb, u32_t seqno, u32_t ackno, u16_t local_port, u16_t remote_port) { struct pbuf *p;

Unrelated formatting change

...

p = tcp_rst_common(pcb, seqno, ackno, local_ip, remote_ip, local_port, remote_port); if (p != NULL) { tcp_output_control_segment(pcb, p, local_ip, remote_ip); diff --git a/lib/lwip/u-boot/lwipopts.h b/lib/lwip/u-boot/lwipopts.h index 9d618625facb..88d6faf327ae 100644 --- a/lib/lwip/u-boot/lwipopts.h +++ b/lib/lwip/u-boot/lwipopts.h @@ -154,4 +154,10 @@ #define MEMP_MEM_INIT 1 #define MEM_LIBC_MALLOC 1

+#if defined(CONFIG_MBEDTLS_LIB_TLS) +#define LWIP_ALTCP 1 +#define LWIP_ALTCP_TLS 1 +#define LWIP_ALTCP_TLS_MBEDTLS 1 +#endif

#endif /* LWIP_UBOOT_LWIPOPTS_H */

Acked-by: Jerome Forissier jerome.forissier@linaro.org

Thanks,

Thanks I'll get rid of the line changes in v3

-- Jerome