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2026-08-10lib/crypto: aes-cmac: Use __cleanup() instead of memzero_explicit()Thomas Huth
By using __cleanup(aes_cmac_zeroize_key) for clearing the key data, we can save one line of code here. Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260807125845.1477067-6-thuth@redhat.com Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-08-10lib/crypto: aes: Add FIPS self-tests for GCM and CCMEric Biggers
Upcoming changes will wire up architecture-optimized implementations of GCM and CCM. FIPS labs can consider such designs to meet the threshold for separate self-tests to be needed. Therefore, add FIPS self-tests for encryption and decryption in these modes. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://patch.msgid.link/20260802222408.91757-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-08-10lib/crypto: aes: Add FIPS self-tests for unauthenticated modesEric Biggers
Upcoming changes will wire up architecture-optimized implementations of ECB, CBC, CBC-CTS, CTR, and XTS. FIPS labs can consider such designs to meet the threshold for separate self-tests to be needed. The inverse direction of the block cipher also needs to be exercised, which the existing CMAC self-test doesn't do. Therefore, add FIPS self-tests for encryption and decryption in these modes as well as the "bare" AES. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://patch.msgid.link/20260802222408.91757-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-08-10lib/crypto: fips: Split fips.h into fips-aes.h and fips-sha.hEric Biggers
In preparation for adding FIPS self-tests for AES encryption modes, split fips.h into separate files for the AES and SHA test vectors. They are still generated by the same script, but this keeps things a bit more organized. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://patch.msgid.link/20260802222408.91757-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-22lib/crypto: aes: Add CCM supportEric Biggers
Add support for AES-CCM to the crypto library. This will be used to provide a streamlined implementation of the "ccm(aes)" crypto_aead algorithm. Most users of "ccm(aes)" will also be able to switch to the library, which as usual will be faster and simpler, e.g.: - fs/smb/client/ - fs/smb/server/ - net/mac80211/ - net/mac802154/ (I've already written proof-of-concept patches for all the above, and they helped inform the API design.) As in the AES-GCM API, incremental operation is supported. It has to be used carefully, especially when decrypting, but it makes the API general enough to work well for all users. The AES-CCM library code calls aes_cbcmac_blocks() directly, bypassing the higher-level aes_cbcmac_init(), aes_cbcmac_update(), and aes_cbcmac_final(). The latter set of functions is useful only for AES-CCM, so they don't make sense to keep around and will be removed once the "ccm(aes)" crypto_aead starts using the AES-CCM library. Initial test coverage is provided by the crypto_aead support added in a later commit. I'm planning a KUnit test suite as well. Link: https://patch.msgid.link/20260715221153.246410-8-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-22lib/crypto: aes: Add GCM supportEric Biggers
Add support for AES-GCM to the crypto library. This will be used to provide streamlined implementations of the "gcm(aes)" and "rfc4106(gcm(aes))" crypto_aead algorithms. Most users of these will also be able to switch to the library, which as usual will be faster and simpler, e.g.: - drivers/net/macsec.c - fs/smb/client/ - fs/smb/server/ - net/ceph/messenger_v2.c - net/mac80211/ (for both GMAC and GCMP) - net/tipc/crypto.c - security/keys/trusted-keys/trusted_dcp.c (I've already written proof-of-concept patches for all the above, and they helped inform the API design.) As usual, the architecture-optimized AES-GCM code will be migrated into the library as well (using the hooks provided in this commit as well as the GHASH ones), eliminating lots of repetitive boilerplate code. Incremental en/decryption is supported. Incremental operation is a bit controversial in AEAD APIs because users have to be careful not to consume any decrypted data that hasn't been authenticated yet. But I do think it's the right choice here. It's not fundamentally different from the existing incremental MAC APIs, and it's the only approach that's general enough to work well for all users in the kernel: - An array of virtually-addressed buffers (like that used by BoringSSL's EVP_AEAD_CTX_sealv() and EVP_AEAD_CTX_openv()) doesn't work in the kernel in general, since in some cases the data for a single AES-GCM message is contained in a large number of highmem pages that each need to be mapped into memory individually. That can be done efficiently only by using CPU-local mappings, but there is a limited number of those. Ceph messenger v2 is a great example, as it can send or receive up to 32 MiB in a single AES-GCM message. And it needs the en/decrypted data to go into a (potentially large) number of bvecs provided by a custom iterator, as well as into four virtually-addressed buffers, two of which can be large buffers in the vmalloc region. Even just allocating an array big enough to store all the pointers can be problematic in the kernel. There are cases in which decryption runs in GFP_NOIO context or even in softirq context, where memory allocations are not as reliable as they normally are. - Meanwhile, 'struct scatterlist' (the choice of crypto_aead) has turned out to be really inconvenient for anyone who *does* just have virtually-addressed buffers. This is especially true if they can be in the vmalloc region, including the stack, as in that case the conversion to a scatterlist has to be done page-by-page. And even for users who have all of their data in bare 'struct page', none of them actually use 'struct scatterlist' as their native data structure anyway. They actually use skbs, bvecs, or other formats. - iov_iter is attractive, but ultimately not general enough either (considering the Ceph case for example), but also too general in some ways (like having support for userspace addresses). Additional iter types like ITER_SKB would help a bit, but bloating iov_iter with more types would reduce performance elsewhere in the kernel. Initial test coverage is provided by the crypto_aead support added in a later commit. I'm planning a KUnit test suite as well. Link: https://patch.msgid.link/20260715221153.246410-7-ebiggers@kernel.org Link: https://patch.msgid.link/20260722021730.16897-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-19lib/crypto: aes: Add XTS supportEric Biggers
Add support for AES-XTS to the crypto library. This will be used to provide a streamlined implementation of the "xts(aes)" crypto_skcipher algorithm. I'm also planning to use this directly in fscrypt and blk-crypto-fallback. As usual, the architecture-optimized AES-XTS code will be migrated into the library as well (using the hooks provided in this commit), eliminating lots of repetitive boilerplate code. Compared to direct implementation of "xts(aes)", I've also eliminated the requirement for architectures to implement ciphertext stealing, as the library just handles it portably instead. That will simplify things considerably. Initial test coverage is provided by the crypto_skcipher support added in a later commit. I'm planning a KUnit test suite as well. Link: https://patch.msgid.link/20260715221153.246410-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-19lib/crypto: aes: Add CTR and XCTR supportEric Biggers
Add support for AES-CTR and AES-XCTR to the crypto library. These will be used to provide streamlined implementations of the "ctr(aes)" and "xctr(aes)" crypto_skcipher algorithms. Most users of "ctr(aes)" will also be able to switch to the library, which as usual will be simpler and faster, e.g.: - net/mac80211/fils_aead.c - net/mac802154/llsec.c As usual, the architecture-optimized AES-CTR and AES-XCTR code will be migrated into the library as well (using the hooks provided in this commit), eliminating lots of repetitive boilerplate code. This is also a prerequisite for supporting AES-GCM, AES-CCM, and AES-HCTR2 in the crypto library. Initial test coverage is provided by the crypto_skcipher support added in a later commit. I'm planning a KUnit test suite as well. Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260715221153.246410-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-19lib/crypto: aes: Add CBC and CBC-CTS supportEric Biggers
Add support for AES-CBC and AES-CBC-CTS to the crypto library. These will be used to provide streamlined implementations of the "cbc(aes)" and "cts(cbc(aes))" crypto_skcipher algorithms. Most users of these crypto_skcipher algorithms will also be able to switch to the library, which as usual will be simpler and faster, e.g.: - block/blk-crypto-fallback.c (for AES-128-CBC-ESSIV) - fs/crypto/crypto.c (for AES-128-CBC-ESSIV) - fs/crypto/fname.c (for AES-256-CTS and AES-128-CBC) - kernel/bpf/crypto.c - net/ceph/crypto.c - security/keys/encrypted-keys/encrypted.c As usual, the architecture-optimized AES-CBC and AES-CBC-CTS code will be migrated into the library as well (using the hooks provided in this commit), eliminating lots of repetitive boilerplate code. Initial test coverage is provided by the crypto_skcipher support added in a later commit. I'm planning a KUnit test suite as well. Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260715221153.246410-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-19lib/crypto: aes: Add ECB supportEric Biggers
Add support for AES-ECB to the crypto library. This will be used to provide a streamlined implementation of the "ecb(aes)" crypto_skcipher algorithm. fs/crypto/keysetup_v1.c will also use aes_ecb_encrypt() directly. As usual, the architecture-optimized AES-ECB code will be migrated into the library as well (using the hooks provided in this commit), eliminating lots of repetitive boilerplate code. ECB is obsolete of course, but we need this for parity with the traditional API and to support some odd users of ECB in the kernel. Initial test coverage is provided by the crypto_skcipher support added in a later commit. I'm planning a KUnit test suite as well. Create a documentation file libcrypto-unauth-encryption.rst to hold the documentation for this and other unauthenticated encryption modes. Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260715221153.246410-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-03-09lib/crypto: aes: Add FIPS self-test for CMACEric Biggers
Add a FIPS cryptographic algorithm self-test for AES-CMAC to fulfill the self-test requirement when this code is built into a FIPS 140 cryptographic module. This provides parity with the traditional crypto API, which uses crypto/testmgr.c to meet the FIPS self-test requirement. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260218213501.136844-8-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-03-09lib/crypto: aes: Add support for CBC-based MACsEric Biggers
Add support for CBC-based MACs to the AES library, specifically AES-CMAC, AES-XCBC-MAC, and AES-CBC-MAC. Of these three algorithms, AES-CMAC is the most modern and the most commonly used. Use cases for the AES-CMAC library include the kernel's SMB client and server, and the bluetooth and mac80211 drivers. Support for AES-XCBC-MAC and AES-CBC-MAC is included so that there will be no performance regression in the "xcbc(aes)" and "ccm(aes)" support in the traditional crypto API once the arm64-optimized code is migrated into the library. AES-XCBC-MAC is given its own key preparation function but is otherwise identical to AES-CMAC and just reuses the AES-CMAC structs and functions. The implementation automatically uses the optimized AES key expansion and single block en/decryption functions. It also allows architectures to provide an optimized implementation of aes_cbcmac_blocks(), which allows the existing arm64-optimized code for these modes to be used. Just put the code for these modes directly in the libaes module rather than in a separate module. This is simpler, it makes it easier to share code between AES modes, and it increases the amount of inlining that is possible. (Indeed, for these reasons, most of the architecture-optimized AES code already provides multiple modes per module. x86 for example has only a single aesni-intel module. So to a large extent, this design choice just reflects the status quo.) However, since there are a lot of AES modes, there's still some value in omitting modes that are not needed at all in a given kernel. Therefore, make these modes an optional feature of libaes, controlled by CONFIG_CRYPTO_LIB_AES_CBC_MACS. This seems like a good middle ground. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260218213501.136844-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15lib/crypto: aes: Drop 'volatile' from aes_sbox and aes_inv_sboxEric Biggers
The volatile keyword is no longer necessary or useful on aes_sbox and aes_inv_sbox, since the table prefetching is now done using a helper function that casts to volatile itself and also includes an optimization barrier. Since it prevents some compiler optimizations, remove it. Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260112192035.10427-36-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15lib/crypto: aes: Remove old AES en/decryption functionsEric Biggers
Now that all callers of the aes_encrypt() and aes_decrypt() type-generic macros are using the new types, remove the old functions. Then, replace the macro with direct calls to the new functions, dropping the "_new" suffix from them. This completes the change in the type of the key struct that is passed to aes_encrypt() and aes_decrypt(). Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260112192035.10427-35-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-12lib/crypto: aes: Introduce improved AES libraryEric Biggers
The kernel's AES library currently has the following issues: - It doesn't take advantage of the architecture-optimized AES code, including the implementations using AES instructions. - It's much slower than even the other software AES implementations: 2-4 times slower than "aes-generic", "aes-arm", and "aes-arm64". - It requires that both the encryption and decryption round keys be computed and cached. This is wasteful for users that need only the forward (encryption) direction of the cipher: the key struct is 484 bytes when only 244 are actually needed. This missed optimization is very common, as many AES modes (e.g. GCM, CFB, CTR, CMAC, and even the tweak key in XTS) use the cipher only in the forward (encryption) direction even when doing decryption. - It doesn't provide the flexibility to customize the prepared key format. The API is defined to do key expansion, and several callers in drivers/crypto/ use it specifically to expand the key. This is an issue when integrating the existing powerpc, s390, and sparc code, which is necessary to provide full parity with the traditional API. To resolve these issues, I'm proposing the following changes: 1. New structs 'aes_key' and 'aes_enckey' are introduced, with corresponding functions aes_preparekey() and aes_prepareenckey(). Generally these structs will include the encryption+decryption round keys and the encryption round keys, respectively. However, the exact format will be under control of the architecture-specific AES code. (The verb "prepare" is chosen over "expand" since key expansion isn't necessarily done. It's also consistent with hmac*_preparekey().) 2. aes_encrypt() and aes_decrypt() will be changed to operate on the new structs instead of struct crypto_aes_ctx. 3. aes_encrypt() and aes_decrypt() will use architecture-optimized code when available, or else fall back to a new generic AES implementation that unifies the existing two fragmented generic AES implementations. The new generic AES implementation uses tables for both SubBytes and MixColumns, making it almost as fast as "aes-generic". However, instead of aes-generic's huge 8192-byte tables per direction, it uses only 1024 bytes for encryption and 1280 bytes for decryption (similar to "aes-arm"). The cost is just some extra rotations. The new generic AES implementation also includes table prefetching, making it have some "constant-time hardening". That's an improvement from aes-generic which has no constant-time hardening. It does slightly regress in constant-time hardening vs. the old lib/crypto/aes.c which had smaller tables, and from aes-fixed-time which disabled IRQs on top of that. But I think this is tolerable. The real solutions for constant-time AES are AES instructions or bit-slicing. The table-based code remains a best-effort fallback for the increasingly-rare case where a real solution is unavailable. 4. crypto_aes_ctx and aes_expandkey() will remain for now, but only for callers that are using them specifically for the AES key expansion (as opposed to en/decrypting data with the AES library). This commit begins the migration process by introducing the new structs and functions, backed by the new generic AES implementation. To allow callers to be incrementally converted, aes_encrypt() and aes_decrypt() are temporarily changed into macros that use a _Generic expression to call either the old functions (which take crypto_aes_ctx) or the new functions (which take the new types). Once all callers have been updated, these macros will go away, the old functions will be removed, and the "_new" suffix will be dropped from the new functions. Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260112192035.10427-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-08lib/crypto: aes: Fix missing MMU protection for AES S-boxEric Biggers
__cacheline_aligned puts the data in the ".data..cacheline_aligned" section, which isn't marked read-only i.e. it doesn't receive MMU protection. Replace it with ____cacheline_aligned which does the right thing and just aligns the data while keeping it in ".rodata". Fixes: b5e0b032b6c3 ("crypto: aes - add generic time invariant AES cipher") Cc: stable@vger.kernel.org Reported-by: Qingfang Deng <dqfext@gmail.com> Closes: https://lore.kernel.org/r/20260105074712.498-1-dqfext@gmail.com/ Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260107052023.174620-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-30lib/crypto: Explicitly include <linux/export.h>Eric Biggers
Fix build warnings with W=1 that started appearing after commit a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1"). While at it, also sort the include lists alphabetically. (Keep asm/irqflags.h last, as otherwise it doesn't build on alpha.) This handles all of lib/crypto/, but not arch/*/lib/crypto/. The exports in arch/*/lib/crypto/ will go away when the code is properly integrated into lib/crypto/ as planned. Link: https://lore.kernel.org/r/20250613184814.50173-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2019-08-09crypto: aes - helper function to validate key length for AES algorithmsIuliana Prodan
Add inline helper function to check key length for AES algorithms. The key can be 128, 192 or 256 bits size. This function is used in the generic aes implementation. Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-07-26crypto: lib/aes - export sbox and inverse sboxArd Biesheuvel
There are a few copies of the AES S-boxes floating around, so export the ones from the AES library so that we can reuse them in other modules. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-07-26crypto: aes - create AES library based on the fixed time AES codeArd Biesheuvel
Take the existing small footprint and mostly time invariant C code and turn it into a AES library that can be used for non-performance critical, casual use of AES, and as a fallback for, e.g., SIMD code that needs a secondary path that can be taken in contexts where the SIMD unit is off limits (e.g., in hard interrupts taken from kernel context) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>