--- /dev/null
+From 5f9017d4e28096b4589c4d5ee4f18cae086ba777 Mon Sep 17 00:00:00 2001
+Date: Fri, 31 May 2024 13:01:17 +0200
+Subject: [PATCH] mbedtls: v3.6.0 workarounds
+
+- add special sauce to disable unwanted peer verification by mbedtls
+ when negotiating TLS v1.3
+- add special sauce for MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET
+ return code on *writing* TLS data. We assume the data had not been
+ written and EAGAIN.
+- return correct Curl error code when peer verification failed.
+- disable test_08_05 with 50 HTTP/1.1 connections, as mbedtls reports a
+ memory allocation failed during handshake.
+- bump CI mbedtls version to 3.6.0
+
+Fixes #13653
+Closes #13838
+---
+ .github/workflows/linux.yml | 2 +-
+ lib/vtls/mbedtls.c | 52 +++++++++++++++++++++++++++++++----
+ tests/http/test_08_caddy.py | 3 ++
+ tests/http/test_17_ssl_use.py | 5 ++--
+ 4 files changed, 52 insertions(+), 10 deletions(-)
+
+--- a/lib/vtls/mbedtls.c
++++ b/lib/vtls/mbedtls.c
+@@ -482,6 +482,20 @@ mbed_set_selected_ciphers(struct Curl_ea
+ return CURLE_OK;
+ }
+
++#ifdef TLS13_SUPPORT
++static int mbed_no_verify(void *udata, mbedtls_x509_crt *crt,
++ int depth, uint32_t *flags)
++{
++ (void)udata;
++ (void)crt;
++ (void)depth;
++ /* we clear any faults the mbedtls' own verification found.
++ * See <https://github.com/Mbed-TLS/mbedtls/issues/9210> */
++ *flags = 0;
++ return 0;
++}
++#endif
++
+ static CURLcode
+ mbed_connect_step1(struct Curl_cfilter *cf, struct Curl_easy *data)
+ {
+@@ -737,6 +751,16 @@ mbed_connect_step1(struct Curl_cfilter *
+ failf(data, "mbedTLS: ssl_config failed");
+ return CURLE_SSL_CONNECT_ERROR;
+ }
++#ifdef TLS13_SUPPORT
++ if(!verifypeer) {
++ /* Default verify behaviour changed in mbedtls v3.6.0 with TLS v1.3.
++ * On 1.3 connections, the handshake fails by default without trust
++ * anchors. We override this questionable change by installing our
++ * own verify callback that clears all errors. */
++ mbedtls_ssl_conf_verify(&backend->config, mbed_no_verify, cf);
++ }
++#endif
++
+
+ mbedtls_ssl_init(&backend->ssl);
+
+@@ -924,10 +948,16 @@ mbed_connect_step2(struct Curl_cfilter *
+ connssl->connecting_state = ssl_connect_2_writing;
+ return CURLE_OK;
+ }
++ else if(ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED) {
++ failf(data, "peer certificate could not be verified");
++ return CURLE_PEER_FAILED_VERIFICATION;
++ }
+ else if(ret) {
+ char errorbuf[128];
++ CURL_TRC_CF(data, cf, "TLS version %04X",
++ mbedtls_ssl_get_version_number(&backend->ssl));
+ mbedtls_strerror(ret, errorbuf, sizeof(errorbuf));
+- failf(data, "ssl_handshake returned - mbedTLS: (-0x%04X) %s",
++ failf(data, "ssl_handshake returned: (-0x%04X) %s",
+ -ret, errorbuf);
+ return CURLE_SSL_CONNECT_ERROR;
+ }
+@@ -1141,8 +1171,13 @@ static ssize_t mbed_send(struct Curl_cfi
+ ret = mbedtls_ssl_write(&backend->ssl, (unsigned char *)mem, len);
+
+ if(ret < 0) {
+- *curlcode = (ret == MBEDTLS_ERR_SSL_WANT_WRITE) ?
+- CURLE_AGAIN : CURLE_SEND_ERROR;
++ CURL_TRC_CF(data, cf, "mbedtls_ssl_write(len=%zu) -> -0x%04X",
++ len, -ret);
++ *curlcode = ((ret == MBEDTLS_ERR_SSL_WANT_WRITE)
++#ifdef TLS13_SUPPORT
++ || (ret == MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET)
++#endif
++ )? CURLE_AGAIN : CURLE_SEND_ERROR;
+ ret = -1;
+ }
+
+@@ -1198,16 +1233,21 @@ static ssize_t mbed_recv(struct Curl_cfi
+
+ ret = mbedtls_ssl_read(&backend->ssl, (unsigned char *)buf,
+ buffersize);
+-
+ if(ret <= 0) {
++ CURL_TRC_CF(data, cf, "mbedtls_ssl_read(len=%zu) -> -0x%04X",
++ buffersize, -ret);
+ if(ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY)
+ return 0;
+-
+ *curlcode = ((ret == MBEDTLS_ERR_SSL_WANT_READ)
+ #ifdef TLS13_SUPPORT
+ || (ret == MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET)
+ #endif
+ ) ? CURLE_AGAIN : CURLE_RECV_ERROR;
++ if(*curlcode != CURLE_AGAIN) {
++ char errorbuf[128];
++ mbedtls_strerror(ret, errorbuf, sizeof(errorbuf));
++ failf(data, "ssl_read returned: (-0x%04X) %s", -ret, errorbuf);
++ }
+ return -1;
+ }
+
+--- a/tests/http/test_08_caddy.py
++++ b/tests/http/test_08_caddy.py
+@@ -151,6 +151,9 @@ class TestCaddy:
+ pytest.skip("h3 not supported in curl")
+ if proto == 'h3' and env.curl_uses_lib('msh3'):
+ pytest.skip("msh3 itself crashes")
++ if proto == 'http/1.1' and env.curl_uses_lib('mbedtls'):
++ pytest.skip("mbedtls 3.6.0 fails on 50 connections with: "\
++ "ssl_handshake returned: (-0x7F00) SSL - Memory allocation failed")
+ count = 50
+ curl = CurlClient(env=env)
+ urln = f'https://{env.domain1}:{caddy.port}/data10.data?[0-{count-1}]'