linux/lib/crypto/Makefile

386 lines
13 KiB

lib/crypto: aes: Introduce improved AES library 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>
2026-01-12 11:20:00 -08:00
lib/crypto: powerpc/aes: Migrate POWER8 optimized code into library Move the POWER8 AES assembly code into lib/crypto/, wire the key expansion and single-block en/decryption functions up to the AES library API, and remove the superseded "p8_aes" crypto_cipher algorithm. The result is that both the AES library and crypto_cipher APIs are now optimized for POWER8, whereas previously only crypto_cipher was (and optimizations weren't enabled by default, which this commit fixes too). Note that many of the functions in the POWER8 assembly code are still used by the AES mode implementations in arch/powerpc/crypto/. For now, just export these functions. These exports will go away once the AES modes are migrated to the library as well. (Trying to split up the assembly file seemed like much more trouble than it would be worth.) Another challenge with this code is that the POWER8 assembly code uses a custom format for the expanded AES key. Since that code is imported from OpenSSL and is also targeted to POWER8 (rather than POWER9 which has better data movement and byteswap instructions), that is not easily changed. For now I've just kept the custom format. To maintain full correctness, this requires executing some slow fallback code in the case where the usability of VSX changes between key expansion and use. This should be tolerable, as this case shouldn't happen in practice. Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260112192035.10427-14-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-12 11:20:11 -08:00
lib/crypto: powerpc/aes: Migrate POWER8 optimized code into library Move the POWER8 AES assembly code into lib/crypto/, wire the key expansion and single-block en/decryption functions up to the AES library API, and remove the superseded "p8_aes" crypto_cipher algorithm. The result is that both the AES library and crypto_cipher APIs are now optimized for POWER8, whereas previously only crypto_cipher was (and optimizations weren't enabled by default, which this commit fixes too). Note that many of the functions in the POWER8 assembly code are still used by the AES mode implementations in arch/powerpc/crypto/. For now, just export these functions. These exports will go away once the AES modes are migrated to the library as well. (Trying to split up the assembly file seemed like much more trouble than it would be worth.) Another challenge with this code is that the POWER8 assembly code uses a custom format for the expanded AES key. Since that code is imported from OpenSSL and is also targeted to POWER8 (rather than POWER9 which has better data movement and byteswap instructions), that is not easily changed. For now I've just kept the custom format. To maintain full correctness, this requires executing some slow fallback code in the case where the usability of VSX changes between key expansion and use. This should be tolerable, as this case shouldn't happen in practice. Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260112192035.10427-14-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-12 11:20:11 -08:00
lib/crypto: aes: Introduce improved AES library 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>
2026-01-12 11:20:00 -08:00
lib/crypto: aes: Introduce improved AES library 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>
2026-01-12 11:20:00 -08:00
crypto: lib/aesgcm - Provide minimal library implementation Implement a minimal library version of AES-GCM based on the existing library implementations of AES and multiplication in GF(2^128). Using these primitives, GCM can be implemented in a straight-forward manner. GCM has a couple of sharp edges, i.e., the amount of input data processed with the same initialization vector (IV) should be capped to protect the counter from 32-bit rollover (or carry), and the size of the authentication tag should be fixed for a given key. [0] The former concern is addressed trivially, given that the function call API uses 32-bit signed types for the input lengths. It is still up to the caller to avoid IV reuse in general, but this is not something we can police at the implementation level. As for the latter concern, let's make the authentication tag size part of the key schedule, and only permit it to be configured as part of the key expansion routine. Note that table based AES implementations are susceptible to known plaintext timing attacks on the encryption key. The AES library already attempts to mitigate this to some extent, but given that the counter mode encryption used by GCM operates exclusively on known plaintext by construction (the IV and therefore the initial counter value are known to an attacker), let's take some extra care to mitigate this, by calling the AES library with interrupts disabled. [0] https://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-38d.pdf Link: https://lore.kernel.org/all/c6fb9b25-a4b6-2e4a-2dd1-63adda055a49@amd.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-11-03 20:22:59 +01:00
lib/crypto/curve25519-hacl64: Disable KASAN with clang-17 and older After commit 6f110a5e4f99 ("Disable SLUB_TINY for build testing"), which causes CONFIG_KASAN to be enabled in allmodconfig again, arm64 allmodconfig builds with clang-17 and older show an instance of -Wframe-larger-than (which breaks the build with CONFIG_WERROR=y): lib/crypto/curve25519-hacl64.c:757:6: error: stack frame size (2336) exceeds limit (2048) in 'curve25519_generic' [-Werror,-Wframe-larger-than] 757 | void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], | ^ When KASAN is disabled, the stack usage is roughly quartered: lib/crypto/curve25519-hacl64.c:757:6: error: stack frame size (608) exceeds limit (128) in 'curve25519_generic' [-Werror,-Wframe-larger-than] 757 | void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], | ^ Using '-Rpass-analysis=stack-frame-layout' shows the following variables and many, many 8-byte spills when KASAN is enabled: Offset: [SP-144], Type: Variable, Align: 8, Size: 40 Offset: [SP-464], Type: Variable, Align: 8, Size: 320 Offset: [SP-784], Type: Variable, Align: 8, Size: 320 Offset: [SP-864], Type: Variable, Align: 32, Size: 80 Offset: [SP-896], Type: Variable, Align: 32, Size: 32 Offset: [SP-1016], Type: Variable, Align: 8, Size: 120 When KASAN is disabled, there are still spills but not at many and the variables list is smaller: Offset: [SP-192], Type: Variable, Align: 32, Size: 80 Offset: [SP-224], Type: Variable, Align: 32, Size: 32 Offset: [SP-344], Type: Variable, Align: 8, Size: 120 Disable KASAN for this file when using clang-17 or older to avoid blowing out the stack, clearing up the warning. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250609-curve25519-hacl64-disable-kasan-clang-v1-1-08ea0ac5ccff@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-06-09 15:45:20 -07:00
lib/crypto/curve25519-hacl64: Disable KASAN with clang-17 and older After commit 6f110a5e4f99 ("Disable SLUB_TINY for build testing"), which causes CONFIG_KASAN to be enabled in allmodconfig again, arm64 allmodconfig builds with clang-17 and older show an instance of -Wframe-larger-than (which breaks the build with CONFIG_WERROR=y): lib/crypto/curve25519-hacl64.c:757:6: error: stack frame size (2336) exceeds limit (2048) in 'curve25519_generic' [-Werror,-Wframe-larger-than] 757 | void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], | ^ When KASAN is disabled, the stack usage is roughly quartered: lib/crypto/curve25519-hacl64.c:757:6: error: stack frame size (608) exceeds limit (128) in 'curve25519_generic' [-Werror,-Wframe-larger-than] 757 | void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], | ^ Using '-Rpass-analysis=stack-frame-layout' shows the following variables and many, many 8-byte spills when KASAN is enabled: Offset: [SP-144], Type: Variable, Align: 8, Size: 40 Offset: [SP-464], Type: Variable, Align: 8, Size: 320 Offset: [SP-784], Type: Variable, Align: 8, Size: 320 Offset: [SP-864], Type: Variable, Align: 32, Size: 80 Offset: [SP-896], Type: Variable, Align: 32, Size: 32 Offset: [SP-1016], Type: Variable, Align: 8, Size: 120 When KASAN is disabled, there are still spills but not at many and the variables list is smaller: Offset: [SP-192], Type: Variable, Align: 32, Size: 80 Offset: [SP-224], Type: Variable, Align: 32, Size: 32 Offset: [SP-344], Type: Variable, Align: 8, Size: 120 Disable KASAN for this file when using clang-17 or older to avoid blowing out the stack, clearing up the warning. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250609-curve25519-hacl64-disable-kasan-clang-v1-1-08ea0ac5ccff@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-06-09 15:45:20 -07:00
lib/crypto: md5: Add MD5 and HMAC-MD5 library functions Add library functions for MD5, including HMAC support. The MD5 implementation is derived from crypto/md5.c. This closely mirrors the corresponding SHA-1 and SHA-2 changes. Like SHA-1 and SHA-2, support for architecture-optimized MD5 implementations is included. I originally proposed dropping those, but unfortunately there is an AF_ALG user of the PowerPC MD5 code (https://lore.kernel.org/r/c4191597-341d-4fd7-bc3d-13daf7666c41@csgroup.eu/), and dropping that code would be viewed as a performance regression. We don't add new software algorithm implementations purely for AF_ALG, as escalating to kernel mode merely to do calculations that could be done in userspace is inefficient and is completely the wrong design. But since this one already existed, it gets grandfathered in for now. An objection was also raised to dropping the SPARC64 MD5 code because it utilizes the CPU's direct support for MD5, although it remains unclear that anyone is using that. Regardless, we'll keep these around for now. Note that while MD5 is a legacy algorithm that is vulnerable to practical collision attacks, it still has various in-kernel users that implement legacy protocols. Switching to a simple library API, which is the way the code should have been organized originally, will greatly simplify their code. For example: MD5: drivers/md/dm-crypt.c (for lmk IV generation) fs/nfsd/nfs4recover.c fs/ecryptfs/ fs/smb/client/ net/{ipv4,ipv6}/ (for TCP-MD5 signatures) HMAC-MD5: fs/smb/client/ fs/smb/server/ (Also net/sctp/ if it continues using HMAC-MD5 for cookie generation. However, that use case has the flexibility to upgrade to a more modern algorithm, which I'll be proposing instead.) As usual, the "md5" and "hmac(md5)" crypto_shash algorithms will also be reimplemented on top of these library functions. For "hmac(md5)" this will provide a faster, more streamlined implementation. Link: https://lore.kernel.org/r/20250805222855.10362-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-08-05 15:28:49 -07:00
lib/crypto: gf128hash: Rename polyval module to gf128hash Currently, the standalone GHASH code is coupled with crypto_shash. This has resulted in unnecessary complexity and overhead, as well as the code being unavailable to library code such as the AES-GCM library. Like was done with POLYVAL, it needs to find a new home in lib/crypto/. GHASH and POLYVAL are closely related and can each be implemented in terms of each other. Optimized code for one can be reused with the other. But also since GHASH tends to be difficult to implement directly due to its unnatural bit order, most modern GHASH implementations (including the existing arm, arm64, powerpc, and x86 optimized GHASH code, and the new generic GHASH code I'll be adding) actually reinterpret the GHASH computation as an equivalent POLYVAL computation, pre and post-processing the inputs and outputs to map to/from POLYVAL. Given this close relationship, it makes sense to group the GHASH and POLYVAL code together in the same module. This gives us a wide range of options for implementing them, reusing code between the two and properly utilizing whatever instructions each architecture provides. Thus, GHASH support will be added to the library module that is currently called "polyval". Rename it to an appropriate name: "gf128hash". Rename files, options, functions, etc. where appropriate to reflect the upcoming sharing with GHASH. (Note: polyval_kunit is not renamed, as ghash_kunit will be added alongside it instead.) Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260319061723.1140720-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-03-18 23:17:02 -07:00
lib/crypto: gf128hash: Rename polyval module to gf128hash Currently, the standalone GHASH code is coupled with crypto_shash. This has resulted in unnecessary complexity and overhead, as well as the code being unavailable to library code such as the AES-GCM library. Like was done with POLYVAL, it needs to find a new home in lib/crypto/. GHASH and POLYVAL are closely related and can each be implemented in terms of each other. Optimized code for one can be reused with the other. But also since GHASH tends to be difficult to implement directly due to its unnatural bit order, most modern GHASH implementations (including the existing arm, arm64, powerpc, and x86 optimized GHASH code, and the new generic GHASH code I'll be adding) actually reinterpret the GHASH computation as an equivalent POLYVAL computation, pre and post-processing the inputs and outputs to map to/from POLYVAL. Given this close relationship, it makes sense to group the GHASH and POLYVAL code together in the same module. This gives us a wide range of options for implementing them, reusing code between the two and properly utilizing whatever instructions each architecture provides. Thus, GHASH support will be added to the library module that is currently called "polyval". Rename it to an appropriate name: "gf128hash". Rename files, options, functions, etc. where appropriate to reflect the upcoming sharing with GHASH. (Note: polyval_kunit is not renamed, as ghash_kunit will be added alongside it instead.) Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260319061723.1140720-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-03-18 23:17:02 -07:00
lib/crypto: gf128hash: Rename polyval module to gf128hash Currently, the standalone GHASH code is coupled with crypto_shash. This has resulted in unnecessary complexity and overhead, as well as the code being unavailable to library code such as the AES-GCM library. Like was done with POLYVAL, it needs to find a new home in lib/crypto/. GHASH and POLYVAL are closely related and can each be implemented in terms of each other. Optimized code for one can be reused with the other. But also since GHASH tends to be difficult to implement directly due to its unnatural bit order, most modern GHASH implementations (including the existing arm, arm64, powerpc, and x86 optimized GHASH code, and the new generic GHASH code I'll be adding) actually reinterpret the GHASH computation as an equivalent POLYVAL computation, pre and post-processing the inputs and outputs to map to/from POLYVAL. Given this close relationship, it makes sense to group the GHASH and POLYVAL code together in the same module. This gives us a wide range of options for implementing them, reusing code between the two and properly utilizing whatever instructions each architecture provides. Thus, GHASH support will be added to the library module that is currently called "polyval". Rename it to an appropriate name: "gf128hash". Rename files, options, functions, etc. where appropriate to reflect the upcoming sharing with GHASH. (Note: polyval_kunit is not renamed, as ghash_kunit will be added alongside it instead.) Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260319061723.1140720-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-03-18 23:17:02 -07:00
lib/crypto: md5: Add MD5 and HMAC-MD5 library functions Add library functions for MD5, including HMAC support. The MD5 implementation is derived from crypto/md5.c. This closely mirrors the corresponding SHA-1 and SHA-2 changes. Like SHA-1 and SHA-2, support for architecture-optimized MD5 implementations is included. I originally proposed dropping those, but unfortunately there is an AF_ALG user of the PowerPC MD5 code (https://lore.kernel.org/r/c4191597-341d-4fd7-bc3d-13daf7666c41@csgroup.eu/), and dropping that code would be viewed as a performance regression. We don't add new software algorithm implementations purely for AF_ALG, as escalating to kernel mode merely to do calculations that could be done in userspace is inefficient and is completely the wrong design. But since this one already existed, it gets grandfathered in for now. An objection was also raised to dropping the SPARC64 MD5 code because it utilizes the CPU's direct support for MD5, although it remains unclear that anyone is using that. Regardless, we'll keep these around for now. Note that while MD5 is a legacy algorithm that is vulnerable to practical collision attacks, it still has various in-kernel users that implement legacy protocols. Switching to a simple library API, which is the way the code should have been organized originally, will greatly simplify their code. For example: MD5: drivers/md/dm-crypt.c (for lmk IV generation) fs/nfsd/nfs4recover.c fs/ecryptfs/ fs/smb/client/ net/{ipv4,ipv6}/ (for TCP-MD5 signatures) HMAC-MD5: fs/smb/client/ fs/smb/server/ (Also net/sctp/ if it continues using HMAC-MD5 for cookie generation. However, that use case has the flexibility to upgrade to a more modern algorithm, which I'll be proposing instead.) As usual, the "md5" and "hmac(md5)" crypto_shash algorithms will also be reimplemented on top of these library functions. For "hmac(md5)" this will provide a faster, more streamlined implementation. Link: https://lore.kernel.org/r/20250805222855.10362-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-08-05 15:28:49 -07:00
lib/crypto: Add ML-DSA verification support Add support for verifying ML-DSA signatures. ML-DSA (Module-Lattice-Based Digital Signature Algorithm) is specified in FIPS 204 and is the standard version of Dilithium. Unlike RSA and elliptic-curve cryptography, ML-DSA is believed to be secure even against adversaries in possession of a large-scale quantum computer. Compared to the earlier patch (https://lore.kernel.org/r/20251117145606.2155773-3-dhowells@redhat.com/) that was based on "leancrypto", this implementation: - Is about 700 lines of source code instead of 4800. - Generates about 4 KB of object code instead of 28 KB. - Uses 9-13 KB of memory to verify a signature instead of 31-84 KB. - Is at least about the same speed, with a microbenchmark showing 3-5% improvements on one x86_64 CPU and -1% to 1% changes on another. When memory is a bottleneck, it's likely much faster. - Correctly implements the RejNTTPoly step of the algorithm. The API just consists of a single function mldsa_verify(), supporting pure ML-DSA with any standard parameter set (ML-DSA-44, ML-DSA-65, or ML-DSA-87) as selected by an enum. That's all that's actually needed. The following four potential features are unneeded and aren't included. However, any that ever become needed could fairly easily be added later, as they only affect how the message representative mu is calculated: - Nonempty context strings - Incremental message hashing - HashML-DSA - External mu Signing support would, of course, be a larger and more complex addition. However, the kernel doesn't, and shouldn't, need ML-DSA signing support. Note that mldsa_verify() allocates memory, so it can sleep and can fail with ENOMEM. Unfortunately we don't have much choice about that, since ML-DSA needs a lot of memory. At least callers have to check for errors anyway, since the signature could be invalid. Note that verification doesn't require constant-time code, and in fact some steps are inherently variable-time. I've used constant-time patterns in some places anyway, but technically they're not needed. Reviewed-by: David Howells <dhowells@redhat.com> Tested-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20251214181712.29132-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-12-14 10:17:11 -08:00
lib/crypto: poly1305: Consolidate into single module Consolidate the Poly1305 code into a single module, similar to various other algorithms (SHA-1, SHA-256, SHA-512, etc.): - Each arch now provides a header file lib/crypto/$(SRCARCH)/poly1305.h, replacing lib/crypto/$(SRCARCH)/poly1305*.c. The header defines poly1305_block_init(), poly1305_blocks(), poly1305_emit(), and optionally poly1305_mod_init_arch(). It is included by lib/crypto/poly1305.c, and thus the code gets built into the single libpoly1305 module, with improved inlining in some cases. - Whether arch-optimized Poly1305 is buildable is now controlled centrally by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig. The conditions for enabling it remain the same as before, and it remains enabled by default. (The PPC64 one remains unconditionally disabled due to 'depends on BROKEN'.) - Any additional arch-specific translation units for the optimized Poly1305 code, such as assembly files, are now compiled by lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile. A special consideration is needed because the Adiantum code uses the poly1305_core_*() functions directly. For now, just carry forward that approach. This means retaining the CRYPTO_LIB_POLY1305_GENERIC kconfig symbol, and keeping the poly1305_core_*() functions in separate translation units. So it's not quite as streamlined I've done with the other hash functions, but we still get a single libpoly1305 module. Note: to see the diff from the arm, arm64, and x86 .c files to the new .h files, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250829152513.92459-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-08-29 08:25:12 -07:00
lib/crypto: poly1305: Consolidate into single module Consolidate the Poly1305 code into a single module, similar to various other algorithms (SHA-1, SHA-256, SHA-512, etc.): - Each arch now provides a header file lib/crypto/$(SRCARCH)/poly1305.h, replacing lib/crypto/$(SRCARCH)/poly1305*.c. The header defines poly1305_block_init(), poly1305_blocks(), poly1305_emit(), and optionally poly1305_mod_init_arch(). It is included by lib/crypto/poly1305.c, and thus the code gets built into the single libpoly1305 module, with improved inlining in some cases. - Whether arch-optimized Poly1305 is buildable is now controlled centrally by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig. The conditions for enabling it remain the same as before, and it remains enabled by default. (The PPC64 one remains unconditionally disabled due to 'depends on BROKEN'.) - Any additional arch-specific translation units for the optimized Poly1305 code, such as assembly files, are now compiled by lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile. A special consideration is needed because the Adiantum code uses the poly1305_core_*() functions directly. For now, just carry forward that approach. This means retaining the CRYPTO_LIB_POLY1305_GENERIC kconfig symbol, and keeping the poly1305_core_*() functions in separate translation units. So it's not quite as streamlined I've done with the other hash functions, but we still get a single libpoly1305 module. Note: to see the diff from the arm, arm64, and x86 .c files to the new .h files, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250829152513.92459-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-08-29 08:25:12 -07:00
lib/crypto: poly1305: Consolidate into single module Consolidate the Poly1305 code into a single module, similar to various other algorithms (SHA-1, SHA-256, SHA-512, etc.): - Each arch now provides a header file lib/crypto/$(SRCARCH)/poly1305.h, replacing lib/crypto/$(SRCARCH)/poly1305*.c. The header defines poly1305_block_init(), poly1305_blocks(), poly1305_emit(), and optionally poly1305_mod_init_arch(). It is included by lib/crypto/poly1305.c, and thus the code gets built into the single libpoly1305 module, with improved inlining in some cases. - Whether arch-optimized Poly1305 is buildable is now controlled centrally by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig. The conditions for enabling it remain the same as before, and it remains enabled by default. (The PPC64 one remains unconditionally disabled due to 'depends on BROKEN'.) - Any additional arch-specific translation units for the optimized Poly1305 code, such as assembly files, are now compiled by lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile. A special consideration is needed because the Adiantum code uses the poly1305_core_*() functions directly. For now, just carry forward that approach. This means retaining the CRYPTO_LIB_POLY1305_GENERIC kconfig symbol, and keeping the poly1305_core_*() functions in separate translation units. So it's not quite as streamlined I've done with the other hash functions, but we still get a single libpoly1305 module. Note: to see the diff from the arm, arm64, and x86 .c files to the new .h files, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250829152513.92459-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-08-29 08:25:12 -07:00
lib/crypto: poly1305: Consolidate into single module Consolidate the Poly1305 code into a single module, similar to various other algorithms (SHA-1, SHA-256, SHA-512, etc.): - Each arch now provides a header file lib/crypto/$(SRCARCH)/poly1305.h, replacing lib/crypto/$(SRCARCH)/poly1305*.c. The header defines poly1305_block_init(), poly1305_blocks(), poly1305_emit(), and optionally poly1305_mod_init_arch(). It is included by lib/crypto/poly1305.c, and thus the code gets built into the single libpoly1305 module, with improved inlining in some cases. - Whether arch-optimized Poly1305 is buildable is now controlled centrally by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig. The conditions for enabling it remain the same as before, and it remains enabled by default. (The PPC64 one remains unconditionally disabled due to 'depends on BROKEN'.) - Any additional arch-specific translation units for the optimized Poly1305 code, such as assembly files, are now compiled by lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile. A special consideration is needed because the Adiantum code uses the poly1305_core_*() functions directly. For now, just carry forward that approach. This means retaining the CRYPTO_LIB_POLY1305_GENERIC kconfig symbol, and keeping the poly1305_core_*() functions in separate translation units. So it's not quite as streamlined I've done with the other hash functions, but we still get a single libpoly1305 module. Note: to see the diff from the arm, arm64, and x86 .c files to the new .h files, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250829152513.92459-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-08-29 08:25:12 -07:00
crypto: testmgr - reinstate kconfig control over full self-tests Commit 698de822780f ("crypto: testmgr - make it easier to enable the full set of tests") removed support for building kernels that run only the "fast" set of crypto self-tests by default. This assumed that nearly everyone actually wanted the full set of tests, *if* they had already chosen to enable the tests at all. Unfortunately, it turns out that both Debian and Fedora intentionally have the crypto self-tests enabled in their production kernels. And for production kernels we do need to keep the testing time down, which implies just running the "fast" tests, not the full set of tests. For Fedora, a reason for enabling the tests in production is that they are being (mis)used to meet the FIPS 140-3 pre-operational testing requirement. However, the other reason for enabling the tests in production, which applies to both distros, is that they provide some value in protecting users from buggy drivers. Unfortunately, the crypto/ subsystem has many buggy and untested drivers for off-CPU hardware accelerators on rare platforms. These broken drivers get shipped to users, and there have been multiple examples of the tests preventing these buggy drivers from being used. So effectively, the tests are being relied on in production kernels. I think this is kind of crazy (untested drivers should just not be enabled at all), but that seems to be how things work currently. Thus, reintroduce a kconfig option that controls the level of testing. Call it CRYPTO_SELFTESTS_FULL instead of the original name CRYPTO_MANAGER_EXTRA_TESTS, which was slightly misleading. Moreover, given the "production kernel" use case, make CRYPTO_SELFTESTS depend on EXPERT instead of DEBUG_KERNEL. I also haven't reinstated all the #ifdefs in crypto/testmgr.c. Instead, just rely on the compiler to optimize out unused code. Fixes: 40b9969796bf ("crypto: testmgr - replace CRYPTO_MANAGER_DISABLE_TESTS with CRYPTO_SELFTESTS") Fixes: 698de822780f ("crypto: testmgr - make it easier to enable the full set of tests") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-06-12 10:47:09 -07:00