Merge pull request #7312 from valeriosetti/issue7254
driver-only ECDH: enable TLS 1.3 key exchanges
diff --git a/ChangeLog.d/driver-only-ecdh.txt b/ChangeLog.d/driver-only-ecdh.txt
new file mode 100644
index 0000000..1aeed64
--- /dev/null
+++ b/ChangeLog.d/driver-only-ecdh.txt
@@ -0,0 +1,7 @@
+Features
+ * When a PSA driver for ECDH is present, it is now possible to disable
+ MBEDTLS_ECDH_C in the build in order to save code size. For TLS 1.2
+ key exchanges based on ECDH(E) to work, this requires
+ MBEDTLS_USE_PSA_CRYPTO. Restartable/interruptible ECDHE operations in
+ TLS 1.2 (ECDHE-ECDSA key exchange) are not supported in those builds yet,
+ as PSA does not have an API for restartable ECDH yet.
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 1293f43..ff4eef7 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -802,14 +802,14 @@
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
-#if !( defined(MBEDTLS_ECDH_C) && defined(MBEDTLS_X509_CRT_PARSE_C) && \
+#if !( defined(MBEDTLS_PK_HAVE_ECDH) && defined(MBEDTLS_X509_CRT_PARSE_C) && \
( defined(MBEDTLS_PK_HAVE_ECDSA) || defined(MBEDTLS_PKCS1_V21) ) )
#error "MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED defined, but not all prerequisites"
#endif
#endif
#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED)
-#if !( defined(MBEDTLS_ECDH_C) )
+#if !( defined(MBEDTLS_PK_HAVE_ECDH) )
#error "MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED defined, but not all prerequisites"
#endif
#endif
diff --git a/include/mbedtls/pk.h b/include/mbedtls/pk.h
index f029265..3de7a8f 100644
--- a/include/mbedtls/pk.h
+++ b/include/mbedtls/pk.h
@@ -193,12 +193,6 @@
#endif /* PSA_WANT_ALG_ECDSA */
#endif /* MBEDTLS_USE_PSA_CRYPTO */
-/* Symbol for ECDH capabilities, no matter how it is provided */
-#if (defined(MBEDTLS_USE_PSA_CRYPTO) && defined(PSA_HAVE_FULL_ECDH)) || \
- (!defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_ECDH_C))
-#define MBEDTLS_PK_CAN_ECDH
-#endif
-
#if defined(MBEDTLS_PK_CAN_ECDSA_VERIFY) || defined(MBEDTLS_PK_CAN_ECDSA_SIGN)
#define MBEDTLS_PK_CAN_ECDSA_SOME
#endif
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index f53e9ec..9dc4021 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -760,16 +760,18 @@
#if !defined(MBEDTLS_USE_PSA_CRYPTO)
mbedtls_ecdh_context ecdh_ctx; /*!< ECDH key exchange */
#endif /* !MBEDTLS_USE_PSA_CRYPTO */
+#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
-#if defined(MBEDTLS_USE_PSA_CRYPTO) || defined(MBEDTLS_SSL_PROTO_TLS1_3)
+#if defined(PSA_WANT_ALG_ECDH) && \
+ (defined(MBEDTLS_USE_PSA_CRYPTO) || defined(MBEDTLS_SSL_PROTO_TLS1_3))
psa_key_type_t ecdh_psa_type;
size_t ecdh_bits;
mbedtls_svc_key_id_t ecdh_psa_privkey;
uint8_t ecdh_psa_privkey_is_external;
unsigned char ecdh_psa_peerkey[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
size_t ecdh_psa_peerkey_len;
-#endif /* MBEDTLS_USE_PSA_CRYPTO || MBEDTLS_SSL_PROTO_TLS1_3 */
-#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
+#endif /* PSA_WANT_ALG_ECDH &&
+ (MBEDTLS_USE_PSA_CRYPTO || MBEDTLS_SSL_PROTO_TLS1_3) */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
#if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -2089,7 +2091,7 @@
MBEDTLS_CHECK_RETURN_CRITICAL
int mbedtls_ssl_reset_transcript_for_hrr(mbedtls_ssl_context *ssl);
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
MBEDTLS_CHECK_RETURN_CRITICAL
int mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange(
mbedtls_ssl_context *ssl,
@@ -2097,7 +2099,7 @@
unsigned char *buf,
unsigned char *end,
size_t *out_len);
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
#if defined(MBEDTLS_SSL_EARLY_DATA)
int mbedtls_ssl_tls13_write_early_data_ext(mbedtls_ssl_context *ssl,
@@ -2215,7 +2217,7 @@
static inline int mbedtls_ssl_named_group_is_supported(uint16_t named_group)
{
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
if (mbedtls_ssl_tls13_named_group_is_ecdhe(named_group)) {
if (mbedtls_ssl_get_ecp_group_id_from_tls_id(named_group) !=
MBEDTLS_ECP_DP_NONE) {
@@ -2224,7 +2226,7 @@
}
#else
((void) named_group);
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
return 0;
}
@@ -2617,14 +2619,14 @@
const mbedtls_ssl_ciphersuite_t *suite);
#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM */
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
MBEDTLS_CHECK_RETURN_CRITICAL
int mbedtls_ssl_tls13_read_public_ecdhe_share(mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t buf_len);
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
static inline int mbedtls_ssl_tls13_cipher_suite_is_offered(
mbedtls_ssl_context *ssl, int cipher_suite)
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index a9c7005..ad019b1 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4219,12 +4219,12 @@
mbedtls_ssl_buffering_free(ssl);
#endif /* MBEDTLS_SSL_PROTO_DTLS */
-#if defined(MBEDTLS_PK_CAN_ECDH) && \
+#if defined(PSA_WANT_ALG_ECDH) && \
(defined(MBEDTLS_USE_PSA_CRYPTO) || defined(MBEDTLS_SSL_PROTO_TLS1_3))
if (handshake->ecdh_psa_privkey_is_external == 0) {
psa_destroy_key(handshake->ecdh_psa_privkey);
}
-#endif /* MBEDTLS_ECDH_C && MBEDTLS_USE_PSA_CRYPTO */
+#endif /* PSA_WANT_ALG_ECDH && (MBEDTLS_USE_PSA_CRYPTO || MBEDTLS_SSL_PROTO_TLS1_3) */
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
mbedtls_ssl_transform_free(handshake->transform_handshake);
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index a7feced..d10fbeb 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -184,7 +184,7 @@
return MBEDTLS_ERR_SSL_INTERNAL_ERROR;
}
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
if (mbedtls_ssl_tls13_named_group_is_ecdhe(group_id)) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
@@ -200,7 +200,7 @@
ssl->handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
return 0;
} else
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
if (0 /* other KEMs? */) {
/* Do something */
}
@@ -219,7 +219,7 @@
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
const uint16_t *group_list = mbedtls_ssl_get_groups(ssl);
/* Pick first available ECDHE group compatible with TLS 1.3 */
if (group_list == NULL) {
@@ -237,7 +237,7 @@
#else
((void) ssl);
((void) group_id);
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
/*
* Add DHE named groups here.
@@ -301,7 +301,7 @@
* only one key share entry is allowed.
*/
client_shares = p;
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
if (mbedtls_ssl_tls13_named_group_is_ecdhe(group_id)) {
/* Pointer to group */
unsigned char *group = p;
@@ -326,7 +326,7 @@
/* Write key_exchange_length */
MBEDTLS_PUT_UINT16_BE(key_exchange_len, group, 2);
} else
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
if (0 /* other KEMs? */) {
/* Do something */
} else {
@@ -375,7 +375,7 @@
const unsigned char *buf,
const unsigned char *end)
{
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
const unsigned char *p = buf;
int selected_group;
int found = 0;
@@ -480,7 +480,7 @@
return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE;
}
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
if (mbedtls_ssl_tls13_named_group_is_ecdhe(group)) {
if (mbedtls_ssl_get_psa_curve_info_from_tls_id(group, NULL, NULL)
== PSA_ERROR_NOT_SUPPORTED) {
@@ -496,7 +496,7 @@
return ret;
}
} else
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
if (0 /* other KEMs? */) {
/* Do something */
} else {
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 669a90a..38077dd 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -1428,7 +1428,7 @@
return ret;
}
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
int mbedtls_ssl_tls13_read_public_ecdhe_share(mbedtls_ssl_context *ssl,
const unsigned char *buf,
@@ -1510,7 +1510,7 @@
return 0;
}
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
/* RFC 8446 section 4.2
*
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 6edce50..8ec3570 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -1463,7 +1463,7 @@
*/
if (mbedtls_ssl_tls13_key_exchange_mode_with_ephemeral(ssl)) {
if (mbedtls_ssl_tls13_named_group_is_ecdhe(handshake->offered_group_id)) {
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
/* Compute ECDH shared secret. */
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
psa_key_attributes_t key_attributes = PSA_KEY_ATTRIBUTES_INIT;
@@ -1499,7 +1499,7 @@
}
handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
} else {
MBEDTLS_SSL_DEBUG_MSG(1, ("Group not supported."));
return MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index bccf9ab..4cfb20b 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -762,7 +762,7 @@
return 0;
}
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
/*
*
* From RFC 8446:
@@ -818,11 +818,11 @@
return 0;
}
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
#define SSL_TLS1_3_PARSE_KEY_SHARES_EXT_NO_MATCH 1
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
/*
* ssl_tls13_parse_key_shares_ext() verifies whether the information in the
* extension is correct and stores the first acceptable key share and its associated group.
@@ -923,7 +923,7 @@
}
return 0;
}
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
MBEDTLS_CHECK_RETURN_CRITICAL
static int ssl_tls13_client_hello_has_exts(mbedtls_ssl_context *ssl,
@@ -1462,7 +1462,7 @@
break;
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS:
MBEDTLS_SSL_DEBUG_MSG(3, ("found supported group extension"));
@@ -1481,9 +1481,9 @@
}
break;
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
case MBEDTLS_TLS_EXT_KEY_SHARE:
MBEDTLS_SSL_DEBUG_MSG(3, ("found key share extension"));
@@ -1508,7 +1508,7 @@
}
break;
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS:
MBEDTLS_SSL_DEBUG_MSG(3, ("found supported versions extension"));
@@ -1826,7 +1826,7 @@
*out_len = 0;
-#if defined(MBEDTLS_ECDH_C)
+#if defined(PSA_WANT_ALG_ECDH)
if (mbedtls_ssl_tls13_named_group_is_ecdhe(named_group)) {
ret = mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange(
ssl, named_group, buf, end, out_len);
@@ -1837,7 +1837,7 @@
return ret;
}
} else
-#endif /* MBEDTLS_ECDH_C */
+#endif /* PSA_WANT_ALG_ECDH */
if (0 /* Other kinds of KEMs */) {
} else {
((void) ssl);
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 2801214..0973216 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2258,14 +2258,6 @@
scripts/config.py unset MBEDTLS_ECDH_C
fi
- scripts/config.py unset MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
- scripts/config.py unset MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
- # Note: the above two lines should be enough, but currently there's a bug
- # that prevents tests from passing TLS 1.3 with only PSK (no ephemeral)
- # when TLS 1.2 is also enabled, see #6848.
- # So, as a temporary measure disable all of TLS 1.3.
- scripts/config.py unset MBEDTLS_SSL_PROTO_TLS1_3
-
# Restartable feature is not yet supported by PSA. Once it will in
# the future, the following line could be removed (see issues
# 6061, 6332 and following ones)