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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2019-07-02 22:41:22 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-07-26 07:55:33 +0300 |
| commit | e59c1c98745637796df824c0177f279b6e9cad94 (patch) | |
| tree | 7cd4e284c1634defc73581c5ac879cb17bb2c907 /include | |
| parent | b158fcbba857c71ffb05ab254aff3b32b5e3cfc3 (diff) | |
| download | linux-e59c1c98745637796df824c0177f279b6e9cad94.tar.xz | |
crypto: aes - create AES library based on the fixed time AES code
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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/crypto/aes.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/include/crypto/aes.h b/include/crypto/aes.h index 0fdb542c70cd..d0067fca0cd0 100644 --- a/include/crypto/aes.h +++ b/include/crypto/aes.h @@ -37,4 +37,38 @@ int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len); int crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key, unsigned int key_len); + +/** + * aes_expandkey - Expands the AES key as described in FIPS-197 + * @ctx: The location where the computed key will be stored. + * @in_key: The supplied key. + * @key_len: The length of the supplied key. + * + * Returns 0 on success. The function fails only if an invalid key size (or + * pointer) is supplied. + * The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes + * key schedule plus a 16 bytes key which is used before the first round). + * The decryption key is prepared for the "Equivalent Inverse Cipher" as + * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is + * for the initial combination, the second slot for the first round and so on. + */ +int aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, + unsigned int key_len); + +/** + * aes_encrypt - Encrypt a single AES block + * @ctx: Context struct containing the key schedule + * @out: Buffer to store the ciphertext + * @in: Buffer containing the plaintext + */ +void aes_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); + +/** + * aes_decrypt - Decrypt a single AES block + * @ctx: Context struct containing the key schedule + * @out: Buffer to store the plaintext + * @in: Buffer containing the ciphertext + */ +void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); + #endif |