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From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Sabrina Dubroca <sd@queasysnail.net>,
	"David S. Miller" <davem@davemloft.net>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12.y 1/2] selftests: tls: add rekey tests
Date: Wed, 19 Aug 2026 07:39:43 -0400	[thread overview]
Message-ID: <20260819113944.3620902-1-sashal@kernel.org> (raw)
In-Reply-To: <2026081717-verbalize-stylist-2627@gregkh>

From: Sabrina Dubroca <sd@queasysnail.net>

[ Upstream commit 555f0edb9ff043196655a5b7cc65f67dfd05b530 ]

Test the kernel's ability to:
 - update the key (but not the version or cipher), only for TLS1.3
 - pause decryption after receiving a KeyUpdate message, until a new
   RX key has been provided
 - reflect the pause/non-readable socket in poll()

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 1c8629651cb5 ("tls: rx: restore msg_iter before TLS 1.3 optimistic retry")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/net/tls.c | 458 ++++++++++++++++++++++++++++++
 1 file changed, 458 insertions(+)

diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index f27a12d2a2c9..1264a20c1a04 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -1649,6 +1649,464 @@ TEST_F(tls, recv_efault)
 		EXPECT_EQ(memcmp(rec2, recv_mem + 9, ret - 9), 0);
 }
 
+#define TLS_RECORD_TYPE_HANDSHAKE      0x16
+/* key_update, length 1, update_not_requested */
+static const char key_update_msg[] = "\x18\x00\x00\x01\x00";
+static void tls_send_keyupdate(struct __test_metadata *_metadata, int fd)
+{
+	size_t len = sizeof(key_update_msg);
+
+	EXPECT_EQ(tls_send_cmsg(fd, TLS_RECORD_TYPE_HANDSHAKE,
+				(char *)key_update_msg, len, 0),
+		  len);
+}
+
+static void tls_recv_keyupdate(struct __test_metadata *_metadata, int fd, int flags)
+{
+	char buf[100];
+
+	EXPECT_EQ(tls_recv_cmsg(_metadata, fd, TLS_RECORD_TYPE_HANDSHAKE, buf, sizeof(buf), flags),
+		  sizeof(key_update_msg));
+	EXPECT_EQ(memcmp(buf, key_update_msg, sizeof(key_update_msg)), 0);
+}
+
+/* set the key to 0 then 1 for RX, immediately to 1 for TX */
+TEST_F(tls_basic, rekey_rx)
+{
+	struct tls_crypto_info_keys tls12_0, tls12_1;
+	char const *test_str = "test_message";
+	int send_len = strlen(test_str) + 1;
+	char buf[20];
+	int ret;
+
+	if (self->notls)
+		return;
+
+	tls_crypto_info_init(TLS_1_3_VERSION, TLS_CIPHER_AES_GCM_128,
+			     &tls12_0, 0);
+	tls_crypto_info_init(TLS_1_3_VERSION, TLS_CIPHER_AES_GCM_128,
+			     &tls12_1, 1);
+
+	ret = setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12_1, tls12_1.len);
+	ASSERT_EQ(ret, 0);
+
+	ret = setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12_0, tls12_0.len);
+	ASSERT_EQ(ret, 0);
+
+	ret = setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12_1, tls12_1.len);
+	EXPECT_EQ(ret, 0);
+
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
+}
+
+/* set the key to 0 then 1 for TX, immediately to 1 for RX */
+TEST_F(tls_basic, rekey_tx)
+{
+	struct tls_crypto_info_keys tls12_0, tls12_1;
+	char const *test_str = "test_message";
+	int send_len = strlen(test_str) + 1;
+	char buf[20];
+	int ret;
+
+	if (self->notls)
+		return;
+
+	tls_crypto_info_init(TLS_1_3_VERSION, TLS_CIPHER_AES_GCM_128,
+			     &tls12_0, 0);
+	tls_crypto_info_init(TLS_1_3_VERSION, TLS_CIPHER_AES_GCM_128,
+			     &tls12_1, 1);
+
+	ret = setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12_0, tls12_0.len);
+	ASSERT_EQ(ret, 0);
+
+	ret = setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12_1, tls12_1.len);
+	ASSERT_EQ(ret, 0);
+
+	ret = setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12_1, tls12_1.len);
+	EXPECT_EQ(ret, 0);
+
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
+}
+
+TEST_F(tls, rekey)
+{
+	char const *test_str_1 = "test_message_before_rekey";
+	char const *test_str_2 = "test_message_after_rekey";
+	struct tls_crypto_info_keys tls12;
+	int send_len;
+	char buf[100];
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	/* initial send/recv */
+	send_len = strlen(test_str_1) + 1;
+	EXPECT_EQ(send(self->fd, test_str_1, send_len, 0), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	EXPECT_EQ(memcmp(buf, test_str_1, send_len), 0);
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	/* send after rekey */
+	send_len = strlen(test_str_2) + 1;
+	EXPECT_EQ(send(self->fd, test_str_2, send_len, 0), send_len);
+
+	/* can't receive the KeyUpdate without a control message */
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), -1);
+
+	/* get KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+
+	/* recv blocking -> -EKEYEXPIRED */
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), 0), -1);
+	EXPECT_EQ(errno, EKEYEXPIRED);
+
+	/* recv non-blocking -> -EKEYEXPIRED */
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), MSG_DONTWAIT), -1);
+	EXPECT_EQ(errno, EKEYEXPIRED);
+
+	/* update RX key */
+	EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+
+	/* recv after rekey */
+	EXPECT_NE(recv(self->cfd, buf, send_len, 0), -1);
+	EXPECT_EQ(memcmp(buf, test_str_2, send_len), 0);
+}
+
+TEST_F(tls, rekey_fail)
+{
+	char const *test_str_1 = "test_message_before_rekey";
+	char const *test_str_2 = "test_message_after_rekey";
+	struct tls_crypto_info_keys tls12;
+	int send_len;
+	char buf[100];
+
+	/* initial send/recv */
+	send_len = strlen(test_str_1) + 1;
+	EXPECT_EQ(send(self->fd, test_str_1, send_len, 0), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	EXPECT_EQ(memcmp(buf, test_str_1, send_len), 0);
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+
+	if (variant->tls_version != TLS_1_3_VERSION) {
+		/* just check that rekey is not supported and return */
+		tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+		EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), -1);
+		EXPECT_EQ(errno, EBUSY);
+		return;
+	}
+
+	/* successful update */
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	/* invalid update: change of version */
+	tls_crypto_info_init(TLS_1_2_VERSION, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	/* invalid update (RX socket): change of version */
+	tls_crypto_info_init(TLS_1_2_VERSION, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	/* invalid update: change of cipher */
+	if (variant->cipher_type == TLS_CIPHER_AES_GCM_256)
+		tls_crypto_info_init(variant->tls_version, TLS_CIPHER_CHACHA20_POLY1305, &tls12, 1);
+	else
+		tls_crypto_info_init(variant->tls_version, TLS_CIPHER_AES_GCM_256, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	/* send after rekey, the invalid updates shouldn't have an effect */
+	send_len = strlen(test_str_2) + 1;
+	EXPECT_EQ(send(self->fd, test_str_2, send_len, 0), send_len);
+
+	/* can't receive the KeyUpdate without a control message */
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), -1);
+
+	/* get KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+
+	/* recv blocking -> -EKEYEXPIRED */
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), 0), -1);
+	EXPECT_EQ(errno, EKEYEXPIRED);
+
+	/* recv non-blocking -> -EKEYEXPIRED */
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), MSG_DONTWAIT), -1);
+	EXPECT_EQ(errno, EKEYEXPIRED);
+
+	/* update RX key */
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+
+	/* recv after rekey */
+	EXPECT_NE(recv(self->cfd, buf, send_len, 0), -1);
+	EXPECT_EQ(memcmp(buf, test_str_2, send_len), 0);
+}
+
+TEST_F(tls, rekey_peek)
+{
+	char const *test_str_1 = "test_message_before_rekey";
+	struct tls_crypto_info_keys tls12;
+	int send_len;
+	char buf[100];
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	send_len = strlen(test_str_1) + 1;
+	EXPECT_EQ(send(self->fd, test_str_1, send_len, 0), send_len);
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), MSG_PEEK), send_len);
+	EXPECT_EQ(memcmp(buf, test_str_1, send_len), 0);
+
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	EXPECT_EQ(memcmp(buf, test_str_1, send_len), 0);
+
+	/* can't receive the KeyUpdate without a control message */
+	EXPECT_EQ(recv(self->cfd, buf, send_len, MSG_PEEK), -1);
+
+	/* peek KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, MSG_PEEK);
+
+	/* get KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+
+	/* update RX key */
+	EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+}
+
+TEST_F(tls, splice_rekey)
+{
+	int send_len = TLS_PAYLOAD_MAX_LEN / 2;
+	char mem_send[TLS_PAYLOAD_MAX_LEN];
+	char mem_recv[TLS_PAYLOAD_MAX_LEN];
+	struct tls_crypto_info_keys tls12;
+	int p[2];
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	memrnd(mem_send, sizeof(mem_send));
+
+	ASSERT_GE(pipe(p), 0);
+	EXPECT_EQ(send(self->fd, mem_send, send_len, 0), send_len);
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	EXPECT_EQ(send(self->fd, mem_send, send_len, 0), send_len);
+
+	EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, TLS_PAYLOAD_MAX_LEN, 0), send_len);
+	EXPECT_EQ(read(p[0], mem_recv, send_len), send_len);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+
+	/* can't splice the KeyUpdate */
+	EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, TLS_PAYLOAD_MAX_LEN, 0), -1);
+	EXPECT_EQ(errno, EINVAL);
+
+	/* peek KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, MSG_PEEK);
+
+	/* get KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+
+	/* can't splice before updating the key */
+	EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, TLS_PAYLOAD_MAX_LEN, 0), -1);
+	EXPECT_EQ(errno, EKEYEXPIRED);
+
+	/* update RX key */
+	EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+
+	EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, TLS_PAYLOAD_MAX_LEN, 0), send_len);
+	EXPECT_EQ(read(p[0], mem_recv, send_len), send_len);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+}
+
+TEST_F(tls, rekey_peek_splice)
+{
+	char const *test_str_1 = "test_message_before_rekey";
+	struct tls_crypto_info_keys tls12;
+	int send_len;
+	char buf[100];
+	char mem_recv[TLS_PAYLOAD_MAX_LEN];
+	int p[2];
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	ASSERT_GE(pipe(p), 0);
+
+	send_len = strlen(test_str_1) + 1;
+	EXPECT_EQ(send(self->fd, test_str_1, send_len, 0), send_len);
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), MSG_PEEK), send_len);
+	EXPECT_EQ(memcmp(buf, test_str_1, send_len), 0);
+
+	EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, TLS_PAYLOAD_MAX_LEN, 0), send_len);
+	EXPECT_EQ(read(p[0], mem_recv, send_len), send_len);
+	EXPECT_EQ(memcmp(mem_recv, test_str_1, send_len), 0);
+}
+
+TEST_F(tls, rekey_getsockopt)
+{
+	struct tls_crypto_info_keys tls12;
+	struct tls_crypto_info_keys tls12_get;
+	socklen_t len;
+
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 0);
+
+	len = tls12.len;
+	EXPECT_EQ(getsockopt(self->fd, SOL_TLS, TLS_TX, &tls12_get, &len), 0);
+	EXPECT_EQ(len, tls12.len);
+	EXPECT_EQ(memcmp(&tls12_get, &tls12, tls12.len), 0);
+
+	len = tls12.len;
+	EXPECT_EQ(getsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12_get, &len), 0);
+	EXPECT_EQ(len, tls12.len);
+	EXPECT_EQ(memcmp(&tls12_get, &tls12, tls12.len), 0);
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+	EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+
+	len = tls12.len;
+	EXPECT_EQ(getsockopt(self->fd, SOL_TLS, TLS_TX, &tls12_get, &len), 0);
+	EXPECT_EQ(len, tls12.len);
+	EXPECT_EQ(memcmp(&tls12_get, &tls12, tls12.len), 0);
+
+	len = tls12.len;
+	EXPECT_EQ(getsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12_get, &len), 0);
+	EXPECT_EQ(len, tls12.len);
+	EXPECT_EQ(memcmp(&tls12_get, &tls12, tls12.len), 0);
+}
+
+TEST_F(tls, rekey_poll_pending)
+{
+	char const *test_str = "test_message_after_rekey";
+	struct tls_crypto_info_keys tls12;
+	struct pollfd pfd = { };
+	int send_len;
+	int ret;
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	/* get KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+
+	/* send immediately after rekey */
+	send_len = strlen(test_str) + 1;
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+
+	/* key hasn't been updated, expect cfd to be non-readable */
+	pfd.fd = self->cfd;
+	pfd.events = POLLIN;
+	EXPECT_EQ(poll(&pfd, 1, 0), 0);
+
+	ret = fork();
+	ASSERT_GE(ret, 0);
+
+	if (ret) {
+		int pid2, status;
+
+		/* wait before installing the new key */
+		sleep(1);
+
+		/* update RX key while poll() is sleeping */
+		EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+
+		pid2 = wait(&status);
+		EXPECT_EQ(pid2, ret);
+		EXPECT_EQ(status, 0);
+	} else {
+		pfd.fd = self->cfd;
+		pfd.events = POLLIN;
+		EXPECT_EQ(poll(&pfd, 1, 5000), 1);
+
+		exit(!__test_passed(_metadata));
+	}
+}
+
+TEST_F(tls, rekey_poll_delay)
+{
+	char const *test_str = "test_message_after_rekey";
+	struct tls_crypto_info_keys tls12;
+	struct pollfd pfd = { };
+	int send_len;
+	int ret;
+
+	if (variant->tls_version != TLS_1_3_VERSION)
+		return;
+
+	/* update TX key */
+	tls_send_keyupdate(_metadata, self->fd);
+	tls_crypto_info_init(variant->tls_version, variant->cipher_type, &tls12, 1);
+	EXPECT_EQ(setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12, tls12.len), 0);
+
+	/* get KeyUpdate */
+	tls_recv_keyupdate(_metadata, self->cfd, 0);
+
+	ret = fork();
+	ASSERT_GE(ret, 0);
+
+	if (ret) {
+		int pid2, status;
+
+		/* wait before installing the new key */
+		sleep(1);
+
+		/* update RX key while poll() is sleeping */
+		EXPECT_EQ(setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12, tls12.len), 0);
+
+		sleep(1);
+		send_len = strlen(test_str) + 1;
+		EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+
+		pid2 = wait(&status);
+		EXPECT_EQ(pid2, ret);
+		EXPECT_EQ(status, 0);
+	} else {
+		pfd.fd = self->cfd;
+		pfd.events = POLLIN;
+		EXPECT_EQ(poll(&pfd, 1, 5000), 1);
+		exit(!__test_passed(_metadata));
+	}
+}
+
 FIXTURE(tls_err)
 {
 	int fd, cfd;
-- 
2.53.0


  reply	other threads:[~2026-08-19 11:39 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-17 12:48 FAILED: patch "[PATCH] tls: rx: restore msg_iter before TLS 1.3 optimistic retry" failed to apply to 6.12-stable tree gregkh
2026-08-19 11:39 ` Sasha Levin [this message]
2026-08-19 11:39   ` [PATCH 6.12.y 2/2] tls: rx: restore msg_iter before TLS 1.3 optimistic retry Sasha Levin
2026-08-19 15:19   ` [PATCH 6.12.y 1/2] selftests: tls: add rekey tests Sabrina Dubroca
2026-08-21 16:51     ` Sasha Levin
2026-08-21 20:10       ` Sabrina Dubroca

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