[PATCH RFC net-next 5/5] selftests/tls: add KeyUpdate tests
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COOLING5d
SUPERSEDED
From: Martin Belanger via B4 Relay <devnull+martin.nvme.dev.gmail.com@kernel.org>
Date: 2026-10-26 00:36:54
Also in:
b4-sent, linux-doc, linux-kselftest, linux-nvme, lkml
Subsystem:
kernel selftest framework, networking [general], networking [tls], the rest · Maintainers:
Shuah Khan, Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, John Fastabend, Sabrina Dubroca, Linus Torvalds
Status: Superseded by v3 (posted 2026-10-30). [go to v3]
Revision rfc (3 revisions archived).
Revisions (3)
- rfc current
- v2 [diff against previous]
- v3 [diff against previous]
From: Martin Belanger <redacted>
Test the in-kernel KeyUpdate on a bidirectional connection with both
traffic secrets registered on each socket:
- registration errors: wrong length, missing key, TLS 1.2, SM4, and
the RX secret before the TX secret;
- KeyUpdates in both directions with data around them;
- a data record, a KeyUpdate and another data record queued before
the first read;
- update_requested: the peer answers before its next data, and a
second request waits for the answer;
- splice() across a KeyUpdate;
- a key installed with TLS_TX removes the registered secrets;
- more than 8 KeyUpdates in one second, and an invalid
request_update value, end the connection.
Assisted-by: LLM
Signed-off-by: Martin Belanger <redacted>
---
tools/testing/selftests/net/tls.c | 249 ++++++++++++++++++++++++++++++++++++++
1 file changed, 249 insertions(+)
diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index 9d3cd4fff062..838030d09cd3 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c@@ -2390,6 +2390,255 @@ TEST_F(tls, rekey_poll_delay) } } +/* In-kernel KeyUpdate: fd and cfd both register the TX and RX traffic + * secrets of a bidirectional connection. Returns false if the variant + * does not support it. + */ +static bool keyupdate_setup(struct __test_metadata *_metadata, + FIXTURE_DATA(tls) *self, + const FIXTURE_VARIANT(tls) *variant) +{ + struct tls_crypto_info_keys tls12; + unsigned char secret_a[48], secret_b[48]; + int len; + + if (self->notls || variant->tls_version != TLS_1_3_VERSION) + return false; + + switch (variant->cipher_type) { + case TLS_CIPHER_AES_GCM_128: + case TLS_CIPHER_AES_CCM_128: + case TLS_CIPHER_CHACHA20_POLY1305: + len = 32; + break; + case TLS_CIPHER_AES_GCM_256: + len = 48; + break; + default: + return false; + } + + /* cfd -> fd */ + tls_crypto_info_init(variant->tls_version, variant->cipher_type, + &tls12, 1); + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0); + EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0); + + memset(secret_a, 0xa5, sizeof(secret_a)); + memset(secret_b, 0x5a, sizeof(secret_b)); + + /* the RX secret needs the TX secret first */ + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_RX_TRAFFIC_SECRET, + secret_b, len), -1); + EXPECT_EQ(errno, EINVAL); + + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_TRAFFIC_SECRET, + secret_a, len), 0); + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_RX_TRAFFIC_SECRET, + secret_b, len), 0); + EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_TX_TRAFFIC_SECRET, + secret_b, len), 0); + EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX_TRAFFIC_SECRET, + secret_a, len), 0); + + return true; +} + +static void keyupdate_send(struct __test_metadata *_metadata, int fd, + int request) +{ + EXPECT_EQ(setsockopt(fd, SOL_TLS, TLS_TX_KEY_UPDATE, + &request, sizeof(request)), 0); +} + +static void send_recv_str(struct __test_metadata *_metadata, int from, int to, + const char *str) +{ + int len = strlen(str) + 1; + char buf[64]; + + EXPECT_EQ(send(from, str, len, 0), len); + EXPECT_EQ(recv(to, buf, sizeof(buf), 0), len); + EXPECT_EQ(memcmp(buf, str, len), 0); +} + +TEST_F(tls, keyupdate_secret_errors) +{ + unsigned char secret[48] = {}; + int one = 1; + + if (self->notls) + SKIP(return, "no TLS support"); + + /* no secret registered */ + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_KEY_UPDATE, + &one, sizeof(one)), -1); + EXPECT_EQ(errno, EINVAL); + + if (variant->tls_version != TLS_1_3_VERSION) { + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_TRAFFIC_SECRET, + secret, 32), -1); + EXPECT_EQ(errno, EINVAL); + return; + } + + if (variant->cipher_type == TLS_CIPHER_SM4_GCM || + variant->cipher_type == TLS_CIPHER_SM4_CCM) { + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_TRAFFIC_SECRET, + secret, 32), -1); + EXPECT_EQ(errno, EOPNOTSUPP); + return; + } + + /* the RX key is not installed on fd */ + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_RX_TRAFFIC_SECRET, + secret, 32), -1); + EXPECT_EQ(errno, EINVAL); + + /* wrong length */ + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_TRAFFIC_SECRET, + secret, 16), -1); + EXPECT_EQ(errno, EINVAL); +} + +TEST_F(tls, keyupdate) +{ + int i; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + send_recv_str(_metadata, self->fd, self->cfd, "before"); + + /* stay below the limit of 8 received KeyUpdates per second */ + for (i = 0; i < 4; i++) { + keyupdate_send(_metadata, self->fd, 0); + send_recv_str(_metadata, self->fd, self->cfd, "after"); + keyupdate_send(_metadata, self->cfd, 0); + send_recv_str(_metadata, self->cfd, self->fd, "reverse"); + } +} + +TEST_F(tls, keyupdate_queued) +{ + const char *str = "queued behind a KeyUpdate"; + int len = strlen(str) + 1; + char buf[64]; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + /* the record before the KeyUpdate, the KeyUpdate and the record + * after it are all queued before the first read + */ + EXPECT_EQ(send(self->fd, str, len, MSG_MORE), len); + keyupdate_send(_metadata, self->fd, 0); + EXPECT_EQ(send(self->fd, str, len, 0), len); + + EXPECT_EQ(recv(self->cfd, buf, len, MSG_WAITALL), len); + EXPECT_EQ(memcmp(buf, str, len), 0); + EXPECT_EQ(recv(self->cfd, buf, len, MSG_WAITALL), len); + EXPECT_EQ(memcmp(buf, str, len), 0); +} + +TEST_F(tls, keyupdate_request) +{ + int one = 1; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + keyupdate_send(_metadata, self->fd, 1); + + /* no answer yet */ + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_KEY_UPDATE, + &one, sizeof(one)), -1); + EXPECT_EQ(errno, EBUSY); + + /* cfd processes the request, then answers ahead of its data */ + send_recv_str(_metadata, self->fd, self->cfd, "request"); + send_recv_str(_metadata, self->cfd, self->fd, "answer"); + + /* answered */ + keyupdate_send(_metadata, self->fd, 1); + send_recv_str(_metadata, self->fd, self->cfd, "request"); + send_recv_str(_metadata, self->cfd, self->fd, "answer"); +} + +TEST_F(tls, keyupdate_splice) +{ + const char *str = "spliced after a KeyUpdate"; + int len = strlen(str) + 1; + char buf[64]; + int p[2]; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + ASSERT_GE(pipe(p), 0); + + keyupdate_send(_metadata, self->fd, 0); + EXPECT_EQ(send(self->fd, str, len, 0), len); + + EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, len, 0), len); + EXPECT_EQ(read(p[0], buf, len), len); + EXPECT_EQ(memcmp(buf, str, len), 0); + + close(p[0]); + close(p[1]); +} + +TEST_F(tls, keyupdate_manual_rekey) +{ + struct tls_crypto_info_keys tls12; + int zero = 0; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + /* a key installed by the user removes the registered secrets */ + tls_crypto_info_init(variant->tls_version, variant->cipher_type, + &tls12, 2); + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0); + + EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX_KEY_UPDATE, + &zero, sizeof(zero)), -1); + EXPECT_EQ(errno, EINVAL); +} + +TEST_F(tls, keyupdate_rate_limit) +{ + char buf[64]; + int i; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + /* the ninth KeyUpdate in one second ends the connection */ + for (i = 0; i < 9; i++) + keyupdate_send(_metadata, self->fd, 0); + EXPECT_EQ(send(self->fd, "x", 1, 0), 1); + + EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), 0), -1); + EXPECT_EQ(errno, EBADMSG); +} + +TEST_F(tls, keyupdate_invalid) +{ + /* key_update, length 1, request_update 2 */ + static const char bad[] = "\x18\x00\x00\x01\x02"; + char buf[64]; + + if (!keyupdate_setup(_metadata, self, variant)) + SKIP(return, "no in-kernel KeyUpdate for this variant"); + + EXPECT_EQ(tls_send_cmsg(self->fd, TLS_RECORD_TYPE_HANDSHAKE, + (char *)bad, 5, 0), 5); + + EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), 0), -1); + EXPECT_EQ(errno, EBADMSG); +} + struct raw_rec { unsigned int plain_len; unsigned char plain_data[100];
--
2.53.0