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

Jerome Forissier jerome.forissier at linaro.org
Wed Nov 6 14:37:16 CET 2024



On 10/24/24 12:24, Ilias Apalodimas wrote:
> From: Javier Tia <javier.tia at 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 at linaro.org>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at 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 at linaro.org>

Thanks,
-- 
Jerome


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