Commit graph

14 commits

Author SHA1 Message Date
Eric Biggers
1c9b0a7665 crypto: chacha20poly1305 - fix atomic sleep when using async algorithm
commit 7545b6c2087f4ef0287c8c9b7eba6a728c67ff8e upstream.

Clear the CRYPTO_TFM_REQ_MAY_SLEEP flag when the chacha20poly1305
operation is being continued from an async completion callback, since
sleeping may not be allowed in that context.

This is basically the same bug that was recently fixed in the xts and
lrw templates.  But, it's always been broken in chacha20poly1305 too.
This was found using syzkaller in combination with the updated crypto
self-tests which actually test the MAY_SLEEP flag now.

Reproducer:

    python -c 'import socket; socket.socket(socket.AF_ALG, 5, 0).bind(
    	       ("aead", "rfc7539(cryptd(chacha20-generic),poly1305-generic)"))'

Kernel output:

    BUG: sleeping function called from invalid context at include/crypto/algapi.h:426
    in_atomic(): 1, irqs_disabled(): 0, pid: 1001, name: kworker/2:2
    [...]
    CPU: 2 PID: 1001 Comm: kworker/2:2 Not tainted 5.2.0-rc2 #5
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
    Workqueue: crypto cryptd_queue_worker
    Call Trace:
     __dump_stack lib/dump_stack.c:77 [inline]
     dump_stack+0x4d/0x6a lib/dump_stack.c:113
     ___might_sleep kernel/sched/core.c:6138 [inline]
     ___might_sleep.cold.19+0x8e/0x9f kernel/sched/core.c:6095
     crypto_yield include/crypto/algapi.h:426 [inline]
     crypto_hash_walk_done+0xd6/0x100 crypto/ahash.c:113
     shash_ahash_update+0x41/0x60 crypto/shash.c:251
     shash_async_update+0xd/0x10 crypto/shash.c:260
     crypto_ahash_update include/crypto/hash.h:539 [inline]
     poly_setkey+0xf6/0x130 crypto/chacha20poly1305.c:337
     poly_init+0x51/0x60 crypto/chacha20poly1305.c:364
     async_done_continue crypto/chacha20poly1305.c:78 [inline]
     poly_genkey_done+0x15/0x30 crypto/chacha20poly1305.c:369
     cryptd_skcipher_complete+0x29/0x70 crypto/cryptd.c:279
     cryptd_skcipher_decrypt+0xcd/0x110 crypto/cryptd.c:339
     cryptd_queue_worker+0x70/0xa0 crypto/cryptd.c:184
     process_one_work+0x1ed/0x420 kernel/workqueue.c:2269
     worker_thread+0x3e/0x3a0 kernel/workqueue.c:2415
     kthread+0x11f/0x140 kernel/kthread.c:255
     ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Fixes: 71ebc4d1b2 ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Cc: <stable@vger.kernel.org> # v4.2+
Cc: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26 09:14:19 +02:00
Eric Biggers
fe632ee5ad crypto: chacha20poly1305 - set cra_name correctly
commit 5e27f38f1f3f45a0c938299c3a34a2d2db77165a upstream.

If the rfc7539 template is instantiated with specific implementations,
e.g. "rfc7539(chacha20-generic,poly1305-generic)" rather than
"rfc7539(chacha20,poly1305)", then the implementation names end up
included in the instance's cra_name.  This is incorrect because it then
prevents all users from allocating "rfc7539(chacha20,poly1305)", if the
highest priority implementations of chacha20 and poly1305 were selected.
Also, the self-tests aren't run on an instance allocated in this way.

Fix it by setting the instance's cra_name from the underlying
algorithms' actual cra_names, rather than from the requested names.
This matches what other templates do.

Fixes: 71ebc4d1b2 ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Cc: <stable@vger.kernel.org> # v4.2+
Cc: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22 07:37:36 +02:00
Eric Biggers
e57121d08c crypto: chacha20poly1305 - validate the digest size
If the rfc7539 template was instantiated with a hash algorithm with
digest size larger than 16 bytes (POLY1305_DIGEST_SIZE), then the digest
overran the 'tag' buffer in 'struct chachapoly_req_ctx', corrupting the
subsequent memory, including 'cryptlen'.  This caused a crash during
crypto_skcipher_decrypt().

Fix it by, when instantiating the template, requiring that the
underlying hash algorithm has the digest size expected for Poly1305.

Reproducer:

    #include <linux/if_alg.h>
    #include <sys/socket.h>
    #include <unistd.h>

    int main()
    {
            int algfd, reqfd;
            struct sockaddr_alg addr = {
                    .salg_type = "aead",
                    .salg_name = "rfc7539(chacha20,sha256)",
            };
            unsigned char buf[32] = { 0 };

            algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(algfd, (void *)&addr, sizeof(addr));
            setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, sizeof(buf));
            reqfd = accept(algfd, 0, 0);
            write(reqfd, buf, 16);
            read(reqfd, buf, 16);
    }

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 71ebc4d1b2 ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-12-22 19:02:33 +11:00
Eric Biggers
60425a8bad crypto: skcipher - Get rid of crypto_spawn_skcipher2()
Since commit 3a01d0ee2b ("crypto: skcipher - Remove top-level
givcipher interface"), crypto_spawn_skcipher2() and
crypto_spawn_skcipher() are equivalent.  So switch callers of
crypto_spawn_skcipher2() to crypto_spawn_skcipher() and remove it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-11-01 08:37:17 +08:00
Eric Biggers
a35528eca0 crypto: skcipher - Get rid of crypto_grab_skcipher2()
Since commit 3a01d0ee2b ("crypto: skcipher - Remove top-level
givcipher interface"), crypto_grab_skcipher2() and
crypto_grab_skcipher() are equivalent.  So switch callers of
crypto_grab_skcipher2() to crypto_grab_skcipher() and remove it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-11-01 08:37:16 +08:00
Herbert Xu
1e1f006112 crypto: chacha20poly1305 - Use skcipher
This patch converts chacha20poly1305 to use the new skcipher
interface as opposed to ablkcipher.

It also fixes a buglet where we may end up with an async poly1305
when the user asks for a async algorithm.  This shouldn't be a
problem yet as there aren't any async implementations of poly1305
out there.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-18 17:35:41 +08:00
Jason A. Donenfeld
161151d79f crypto: chacha20poly1305 - Skip encryption/decryption for 0-len
If the length of the plaintext is zero, there's no need to waste cycles
on encryption and decryption. Using the chacha20poly1305 construction
for zero-length plaintexts is a common way of using a shared encryption
key for AAD authentication.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-12-09 20:16:04 +08:00
Herbert Xu
5e4b8c1fcc crypto: aead - Remove CRYPTO_ALG_AEAD_NEW flag
This patch removes the CRYPTO_ALG_AEAD_NEW flag now that everyone
has been converted.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-08-17 16:53:53 +08:00
Martin Willi
2546f811ef crypto: poly1305 - Export common Poly1305 helpers
As architecture specific drivers need a software fallback, export Poly1305
init/update/final functions together with some helpers in a header file.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-07-17 21:20:26 +08:00
Martin Willi
31d7247da5 crypto: chacha20 - Export common ChaCha20 helpers
As architecture specific drivers need a software fallback, export a
ChaCha20 en-/decryption function together with some helpers in a header
file.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-07-17 21:20:21 +08:00
Herbert Xu
7479092233 crypto: chacha20poly1305 - Convert to new AEAD interface
This patch converts rfc7539 and rfc7539esp to the new AEAD interface.
The test vectors for rfc7539esp have also been updated to include
the IV.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Martin Willi <martin@strongswan.org>
2015-07-17 21:20:19 +08:00
Martin Willi
c2b7b20aed crypto: poly1305 - Pass key as first two message blocks to each desc_ctx
The Poly1305 authenticator requires a unique key for each generated tag. This
implies that we can't set the key per tfm, as multiple users set individual
keys. Instead we pass a desc specific key as the first two blocks of the
message to authenticate in update().

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-17 15:35:11 +08:00
Martin Willi
4db4ad2609 crypto: chacha20poly1305 - Add an IPsec variant for RFC7539 AEAD
draft-ietf-ipsecme-chacha20-poly1305 defines the use of ChaCha20/Poly1305 in
ESP. It uses additional four byte key material as a salt, which is then used
with an 8 byte IV to form the ChaCha20 nonce as defined in the RFC7539.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-04 15:04:53 +08:00
Martin Willi
71ebc4d1b2 crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539
This AEAD uses a chacha20 ablkcipher and a poly1305 ahash to construct the
ChaCha20-Poly1305 AEAD as defined in RFC7539. It supports both synchronous and
asynchronous operations, even if we currently have no async chacha20 or poly1305
drivers.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-04 15:04:52 +08:00