Remove the duplicated boilerplate help text and add a bit of explanation about the nature of the various AES implementations that exist for ARM and x86. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- arch/arm/crypto/Kconfig | 4 +- arch/arm64/crypto/Kconfig | 7 ++ crypto/Kconfig | 68 +++----------------- 3 files changed, 18 insertions(+), 61 deletions(-) diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig index 3a6994ada2d1..24d70d74ae51 100644 --- a/arch/arm/crypto/Kconfig +++ b/arch/arm/crypto/Kconfig @@ -66,7 +66,9 @@ config CRYPTO_AES_ARM select CRYPTO_ALGAPI select CRYPTO_AES_GENERIC help - Use optimized AES assembler routines for ARM platforms. + Use optimized AES assembler routines for ARM platforms. This + implementation is table based, and thus not time invariant. + It reuses the tables exposed by the generic AES driver. config CRYPTO_AES_ARM_BS tristate "Bit sliced AES using NEON instructions" diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig index 7ffe88267943..48404ae2a11a 100644 --- a/arch/arm64/crypto/Kconfig +++ b/arch/arm64/crypto/Kconfig @@ -44,11 +44,18 @@ config CRYPTO_CRC32_ARM64_CE config CRYPTO_AES_ARM64 tristate "AES core cipher using scalar instructions" select CRYPTO_AES_GENERIC + help + Use optimized AES assembler routines for ARM platforms. This + implementation is table based, and thus not time invariant. + It reuses the tables exposed by the generic AES driver. config CRYPTO_AES_ARM64_CE tristate "AES core cipher using ARMv8 Crypto Extensions" depends on ARM64 && KERNEL_MODE_NEON select CRYPTO_ALGAPI + help + Assembler implementation for arm64 of AES using special dedicated + instructions. This implementation is time invariant. config CRYPTO_AES_ARM64_CE_CCM tristate "AES in CCM mode using ARMv8 Crypto Extensions" diff --git a/crypto/Kconfig b/crypto/Kconfig index 9ae3dade4b2b..f33c0d9136cf 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -906,21 +906,10 @@ config CRYPTO_AES_GENERIC select CRYPTO_ALGAPI select CRYPTO_AES_CORE help - AES cipher algorithms (FIPS-197). AES uses the Rijndael - algorithm. - - Rijndael appears to be consistently a very good performer in - both hardware and software across a wide range of computing - environments regardless of its use in feedback or non-feedback - modes. Its key setup time is excellent, and its key agility is - good. Rijndael's very low memory requirements make it very well - suited for restricted-space environments, in which it also - demonstrates excellent performance. Rijndael's operations are - among the easiest to defend against power and timing attacks. - - The AES specifies three key sizes: 128, 192 and 256 bits - - See <http://csrc.nist.gov/CryptoToolkit/aes/> for more information. + Generic table based implementation of AES. This is the fastest + implementation in C, but may be susceptible to known plaintext + attacks on the key due to the correlation between the processing + time and the input of the first round. config CRYPTO_AES_TI tristate "Fixed time AES cipher" @@ -946,44 +935,18 @@ config CRYPTO_AES_586 select CRYPTO_ALGAPI select CRYPTO_AES_GENERIC help - AES cipher algorithms (FIPS-197). AES uses the Rijndael + Assembler implementation for 32-bit x86 of the table based AES algorithm. - Rijndael appears to be consistently a very good performer in - both hardware and software across a wide range of computing - environments regardless of its use in feedback or non-feedback - modes. Its key setup time is excellent, and its key agility is - good. Rijndael's very low memory requirements make it very well - suited for restricted-space environments, in which it also - demonstrates excellent performance. Rijndael's operations are - among the easiest to defend against power and timing attacks. - - The AES specifies three key sizes: 128, 192 and 256 bits - - See <http://csrc.nist.gov/encryption/aes/> for more information. - config CRYPTO_AES_X86_64 tristate "AES cipher algorithms (x86_64)" depends on (X86 || UML_X86) && 64BIT select CRYPTO_ALGAPI select CRYPTO_AES_GENERIC help - AES cipher algorithms (FIPS-197). AES uses the Rijndael + Assembler implementation for 64-bit x86 of the table based AES algorithm. - Rijndael appears to be consistently a very good performer in - both hardware and software across a wide range of computing - environments regardless of its use in feedback or non-feedback - modes. Its key setup time is excellent, and its key agility is - good. Rijndael's very low memory requirements make it very well - suited for restricted-space environments, in which it also - demonstrates excellent performance. Rijndael's operations are - among the easiest to defend against power and timing attacks. - - The AES specifies three key sizes: 128, 192 and 256 bits - - See <http://csrc.nist.gov/encryption/aes/> for more information. - config CRYPTO_AES_NI_INTEL tristate "AES cipher algorithms (AES-NI)" depends on X86 @@ -994,23 +957,8 @@ config CRYPTO_AES_NI_INTEL select CRYPTO_GLUE_HELPER_X86 if 64BIT select CRYPTO_SIMD help - Use Intel AES-NI instructions for AES algorithm. - - AES cipher algorithms (FIPS-197). AES uses the Rijndael - algorithm. - - Rijndael appears to be consistently a very good performer in - both hardware and software across a wide range of computing - environments regardless of its use in feedback or non-feedback - modes. Its key setup time is excellent, and its key agility is - good. Rijndael's very low memory requirements make it very well - suited for restricted-space environments, in which it also - demonstrates excellent performance. Rijndael's operations are - among the easiest to defend against power and timing attacks. - - The AES specifies three key sizes: 128, 192 and 256 bits - - See <http://csrc.nist.gov/encryption/aes/> for more information. + Assembler implementation for x86 of AES using special dedicated + instructions. This implementation is time invariant. In addition to AES cipher algorithm support, the acceleration for some popular block cipher mode is supported too, including -- 2.7.4
