On 7/31/2019 8:33 AM, Ard Biesheuvel wrote:
> On Tue, 30 Jul 2019 at 13:33, Iuliana Prodan <iuliana.prodan@xxxxxxx> wrote:
>>
>> 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@xxxxxxx>
>> ---
>> include/crypto/aes.h | 17 +++++++++++++++++
>> lib/crypto/aes.c | 8 ++++----
>> 2 files changed, 21 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/crypto/aes.h b/include/crypto/aes.h
>> index 8e0f4cf..8ee07a8 100644
>> --- a/include/crypto/aes.h
>> +++ b/include/crypto/aes.h
>> @@ -31,6 +31,23 @@ struct crypto_aes_ctx {
>> extern const u32 crypto_ft_tab[4][256] ____cacheline_aligned;
>> extern const u32 crypto_it_tab[4][256] ____cacheline_aligned;
>>
>> +/*
>> + * validate key length for AES algorithms
>> + */
>> +static inline int crypto_aes_check_keylen(unsigned int keylen)
>
> Please rename this to aes_check_keylen()
>
I just renamed it to crypto_, the first version was check_aes_keylen
- see https://patchwork.kernel.org/patch/11058869/.
I think is better to keep the helper functions with crypto_, as most of
these type of functions, in crypto, have this prefix.
>> +{
>> + switch (keylen) {
>> + case AES_KEYSIZE_128:
>> + case AES_KEYSIZE_192:
>> + case AES_KEYSIZE_256:
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
>> unsigned int key_len);
>>
>> diff --git a/lib/crypto/aes.c b/lib/crypto/aes.c
>> index 4e100af..3407b01 100644
>> --- a/lib/crypto/aes.c
>> +++ b/lib/crypto/aes.c
>> @@ -187,11 +187,11 @@ int aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key,
>> {
>> u32 kwords = key_len / sizeof(u32);
>> u32 rc, i, j;
>> + int err;
>>
>> - if (key_len != AES_KEYSIZE_128 &&
>> - key_len != AES_KEYSIZE_192 &&
>> - key_len != AES_KEYSIZE_256)
>> - return -EINVAL;
>> + err = crypto_aes_check_keylen(key_len);
>> + if (err)
>> + return err;
>>
>> ctx->key_length = key_len;
>>
>> --
>> 2.1.0
>>
>
