kernel/linux.git/crypto/sig.c, branch v7.2-rc1

crypto: api - use designated initializers for report structs

2026-05-15T10:08:48+00:00

Use designated initializers for the report structs instead of clearing the struct with memset() and then copying fixed strings with strscpy() at runtime. This keeps the structs zero-initialized, lets the compiler diagnose oversized string literals, and makes the code easier to read. Signed-off-by: Thorsten Blum Signed-off-by: Herbert Xu

crypto: api - Add support for duplicating algorithms before registration

2025-04-16T07:36:24+00:00

If the bit CRYPTO_ALG_DUP_FIRST is set, an algorithm will be duplicated by kmemdup before registration. This is inteded for hardware-based algorithms that may be unplugged at will. Do not use this if the algorithm data structure is embedded in a bigger data structure. Perform the duplication in the driver instead. Signed-off-by: Herbert Xu

crypto: ecdsa - Fix NIST P521 key size reported by KEYCTL_PKEY_QUERY

2025-04-16T07:16:21+00:00

When user space issues a KEYCTL_PKEY_QUERY system call for a NIST P521 key, the key_size is incorrectly reported as 528 bits instead of 521. That's because the key size obtained through crypto_sig_keysize() is in bytes and software_key_query() multiplies by 8 to yield the size in bits. The underlying assumption is that the key size is always a multiple of 8. With the recent addition of NIST P521, that's no longer the case. Fix by returning the key_size in bits from crypto_sig_keysize() and adjusting the calculations in software_key_query(). The ->key_size() callbacks of sig_alg algorithms now return the size in bits, whereas the ->digest_size() and ->max_size() callbacks return the size in bytes. This matches with the units in struct keyctl_pkey_query. Fixes: a7d45ba77d3d ("crypto: ecdsa - Register NIST P521 and extend test suite") Signed-off-by: Lukas Wunner Reviewed-by: Stefan Berger Reviewed-by: Ignat Korchagin Signed-off-by: Herbert Xu

crypto: sig - Set maskset to CRYPTO_ALG_TYPE_MASK

2024-12-10T05:44:21+00:00

As sig is now a standalone type, it no longer needs to have a wide mask that includes akcipher. Signed-off-by: Herbert Xu

crypto: sig - Fix oops on KEYCTL_PKEY_QUERY for RSA keys

2024-10-26T06:41:59+00:00

Commit a2471684dae2 ("crypto: ecdsa - Move X9.62 signature size calculation into template") introduced ->max_size() and ->digest_size() callbacks to struct sig_alg. They return an algorithm's maximum signature size and digest size, respectively. For algorithms which lack these callbacks, crypto_register_sig() was amended to use the ->key_size() callback instead. However the commit neglected to also amend sig_register_instance(). As a result, the ->max_size() and ->digest_size() callbacks remain NULL pointers if instances do not define them. A KEYCTL_PKEY_QUERY system call results in an oops for such instances: BUG: kernel NULL pointer dereference, address: 0000000000000000 Call Trace: software_key_query+0x169/0x370 query_asymmetric_key+0x67/0x90 keyctl_pkey_query+0x86/0x120 __do_sys_keyctl+0x428/0x480 do_syscall_64+0x4b/0x110 The only instances affected by this are "pkcs1(rsa, ...)". Fix by moving the callback checks from crypto_register_sig() to sig_prepare_alg(), which is also invoked by sig_register_instance(). Change the return type of sig_prepare_alg() from void to int to be able to return errors. This matches other algorithm types, see e.g. aead_prepare_alg() or ahash_prepare_alg(). Fixes: a2471684dae2 ("crypto: ecdsa - Move X9.62 signature size calculation into template") Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu

crypto: ecdsa - Move X9.62 signature size calculation into template

2024-10-05T05:22:04+00:00

software_key_query() returns the maximum signature and digest size for a given key to user space. When it only supported RSA keys, calculating those sizes was trivial as they were always equivalent to the key size. However when ECDSA was added, the function grew somewhat complicated calculations which take the ASN.1 encoding and curve into account. This doesn't scale well and adjusting the calculations is easily forgotten when adding support for new encodings or curves. In fact, when NIST P521 support was recently added, the function was initially not amended: https://lore.kernel.org/all/b749d5ee-c3b8-4cbd-b252-7773e4536e07@linux.ibm.com/ Introduce a ->max_size() callback to struct sig_alg and take advantage of it to move the signature size calculations to ecdsa-x962.c. Introduce a ->digest_size() callback to struct sig_alg and move the maximum ECDSA digest size to ecdsa.c. It is common across ecdsa-x962.c and the upcoming ecdsa-p1363.c and thus inherited by both of them. For all other algorithms, continue using the key size as maximum signature and digest size. Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu

crypto: sig - Rename crypto_sig_maxsize() to crypto_sig_keysize()

2024-10-05T05:22:04+00:00

crypto_sig_maxsize() is a bit of a misnomer as it doesn't return the maximum signature size, but rather the key size. Rename it as well as all implementations of the ->max_size callback. A subsequent commit introduces a crypto_sig_maxsize() function which returns the actual maximum signature size. While at it, change the return type of crypto_sig_keysize() from int to unsigned int for consistency with crypto_akcipher_maxsize(). None of the callers checks for a negative return value and an error condition can always be indicated by returning zero. Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu

crypto: sig - Move crypto_sig_*() API calls to include file

2024-10-05T05:22:04+00:00

The crypto_sig_*() API calls lived in sig.c so far because they needed access to struct crypto_sig_type: This was necessary to differentiate between signature algorithms that had already been migrated from crypto_akcipher to crypto_sig and those that hadn't yet. Now that all algorithms have been migrated, the API calls can become static inlines in to mimic what is doing. Signed-off-by: Lukas Wunner Reviewed-by: Stefan Berger Signed-off-by: Herbert Xu

crypto: akcipher - Drop sign/verify operations

2024-10-05T05:22:04+00:00

A sig_alg backend has just been introduced and all asymmetric sign/verify algorithms have been migrated to it. The sign/verify operations can thus be dropped from akcipher_alg. It is now purely for asymmetric encrypt/decrypt. Move struct crypto_akcipher_sync_data from internal.h to akcipher.c and unexport crypto_akcipher_sync_{prep,post}(): They're no longer used by sig.c but only locally in akcipher.c. In crypto_akcipher_sync_{prep,post}(), drop various NULL pointer checks for data->dst as they were only necessary for the verify operation. In the crypto_sig_*() API calls, remove the forks that were necessary while algorithms were converted from crypto_akcipher to crypto_sig one by one. In struct akcipher_testvec, remove the "params", "param_len" and "algo" elements as they were only needed for the ecrdsa verify operation. Remove corresponding dead code from test_akcipher_one() as well. Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu

crypto: sig - Introduce sig_alg backend

2024-10-05T05:22:04+00:00

Commit 6cb8815f41a9 ("crypto: sig - Add interface for sign/verify") began a transition of asymmetric sign/verify operations from crypto_akcipher to a new crypto_sig frontend. Internally, the crypto_sig frontend still uses akcipher_alg as backend, however: "The link between sig and akcipher is meant to be temporary. The plan is to create a new low-level API for sig and then migrate the signature code over to that from akcipher." https://lore.kernel.org/r/ZrG6w9wsb-iiLZIF@gondor.apana.org.au/ "having a separate alg for sig is definitely where we want to be since there is very little that the two types actually share." https://lore.kernel.org/r/ZrHlpz4qnre0zWJO@gondor.apana.org.au/ Take the next step of that migration and augment the crypto_sig frontend with a sig_alg backend to which all algorithms can be moved. During the migration, there will briefly be signature algorithms that are still based on crypto_akcipher, whilst others are already based on crypto_sig. Allow for that by building a fork into crypto_sig_*() API calls (i.e. crypto_sig_maxsize() and friends) such that one of the two backends is selected based on the transform's cra_type. Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu