Move the AES-128-CBC encryption function implemented in tegra20-common/crypto.c into lib/aes.c . This is well re-usable common code. Moreover, clean the code up a bit and fix the kerneldoc-style annotations.
Signed-off-by: Marek Vasut marex@denx.de --- arch/arm/cpu/tegra20-common/crypto.c | 72 +----------------------------------- include/aes.h | 10 +++++ lib/aes.c | 52 ++++++++++++++++++++++++++ 3 files changed, 64 insertions(+), 70 deletions(-)
V2: Replace AES_AES_KEY_LENGTH with AES_KEY_LENGTH Use print_buffer() instead of ad-hoc implementation
diff --git a/arch/arm/cpu/tegra20-common/crypto.c b/arch/arm/cpu/tegra20-common/crypto.c index 8209f76..b18e67c 100644 --- a/arch/arm/cpu/tegra20-common/crypto.c +++ b/arch/arm/cpu/tegra20-common/crypto.c @@ -19,74 +19,6 @@ enum security_op { SECURITY_ENCRYPT = 1 << 1, /* Encrypt the data */ };
-static void debug_print_vector(char *name, u32 num_bytes, u8 *data) -{ - u32 i; - - debug("%s [%d] @0x%08x", name, num_bytes, (u32)data); - for (i = 0; i < num_bytes; i++) { - if (i % 16 == 0) - debug(" = "); - debug("%02x", data[i]); - if ((i+1) % 16 != 0) - debug(" "); - } - debug("\n"); -} - -/** - * Apply chain data to the destination using EOR - * - * Each array is of length AES_AES_KEY_LENGTH. - * - * \param cbc_chain_data Chain data - * \param src Source data - * \param dst Destination data, which is modified here - */ -static void apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst) -{ - int i; - - for (i = 0; i < 16; i++) - *dst++ = *src++ ^ *cbc_chain_data++; -} - -/** - * Encrypt some data with AES. - * - * \param key_schedule Expanded key to use - * \param src Source data to encrypt - * \param dst Destination buffer - * \param num_aes_blocks Number of AES blocks to encrypt - */ -static void encrypt_object(u8 *key_schedule, u8 *src, u8 *dst, - u32 num_aes_blocks) -{ - u8 tmp_data[AES_KEY_LENGTH]; - u8 *cbc_chain_data; - u32 i; - - cbc_chain_data = zero_key; /* Convenient array of 0's for IV */ - - for (i = 0; i < num_aes_blocks; i++) { - debug("encrypt_object: block %d of %d\n", i, num_aes_blocks); - debug_print_vector("AES Src", AES_KEY_LENGTH, src); - - /* Apply the chain data */ - apply_cbc_chain_data(cbc_chain_data, src, tmp_data); - debug_print_vector("AES Xor", AES_KEY_LENGTH, tmp_data); - - /* encrypt the AES block */ - aes_encrypt(tmp_data, key_schedule, dst); - debug_print_vector("AES Dst", AES_KEY_LENGTH, dst); - - /* Update pointers for next loop. */ - cbc_chain_data = dst; - src += AES_KEY_LENGTH; - dst += AES_KEY_LENGTH; - } -} - /** * Shift a vector left by one bit * @@ -129,7 +61,7 @@ static void sign_object(u8 *key, u8 *key_schedule, u8 *src, u8 *dst, for (i = 0; i < AES_KEY_LENGTH; i++) tmp_data[i] = 0;
- encrypt_object(key_schedule, tmp_data, left, 1); + aes_cbc_encrypt_blocks(key_schedule, tmp_data, left, 1); debug_print_vector("AES(key, nonce)", AES_KEY_LENGTH, left);
left_shift_vector(left, k1, sizeof(left)); @@ -193,7 +125,7 @@ static int encrypt_and_sign(u8 *key, enum security_op oper, u8 *src, if (oper & SECURITY_ENCRYPT) { /* Perform this in place, resulting in src being encrypted. */ debug("encrypt_and_sign: begin encryption\n"); - encrypt_object(key_schedule, src, src, num_aes_blocks); + aes_cbc_encrypt_blocks(key_schedule, src, src, num_aes_blocks); debug("encrypt_and_sign: end encryption\n"); }
diff --git a/include/aes.h b/include/aes.h index c70eda6..d9bb387 100644 --- a/include/aes.h +++ b/include/aes.h @@ -53,4 +53,14 @@ void aes_encrypt(u8 *in, u8 *expkey, u8 *out); */ void aes_decrypt(u8 *in, u8 *expkey, u8 *out);
+/** + * aes_cbc_encrypt_blocks() - Encrypt multiple blocks of data with AES CBC. + * + * @key_exp Expanded key to use + * @src Source data to encrypt + * @dst Destination buffer + * @num_aes_blocks Number of AES blocks to encrypt + */ +void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *src, u8 *dst, u32 num_aes_blocks); + #endif /* _AES_REF_H_ */ diff --git a/lib/aes.c b/lib/aes.c index e996b27..a6648f9 100644 --- a/lib/aes.c +++ b/lib/aes.c @@ -580,3 +580,55 @@ void aes_decrypt(u8 *in, u8 *expkey, u8 *out)
memcpy(out, state, sizeof(state)); } + +static void debug_print_vector(char *name, u32 num_bytes, u8 *data) +{ +#ifdef DEBUG + printf("%s [%d] @0x%08x", name, num_bytes, (u32)data); + print_buffer(0, data, 1, num_bytes, 16); +#endif +} + +/** + * Apply chain data to the destination using EOR + * + * Each array is of length AES_KEY_LENGTH. + * + * @cbc_chain_data Chain data + * @src Source data + * @dst Destination data, which is modified here + */ +static void apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst) +{ + int i; + + for (i = 0; i < AES_KEY_LENGTH; i++) + *dst++ = *src++ ^ *cbc_chain_data++; +} + +void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *src, u8 *dst, u32 num_aes_blocks) +{ + u8 zero_key[AES_KEY_LENGTH] = { 0 }; + u8 tmp_data[AES_KEY_LENGTH]; + /* Convenient array of 0's for IV */ + u8 *cbc_chain_data = zero_key; + u32 i; + + for (i = 0; i < num_aes_blocks; i++) { + debug("encrypt_object: block %d of %d\n", i, num_aes_blocks); + debug_print_vector("AES Src", AES_KEY_LENGTH, src); + + /* Apply the chain data */ + apply_cbc_chain_data(cbc_chain_data, src, tmp_data); + debug_print_vector("AES Xor", AES_KEY_LENGTH, tmp_data); + + /* Encrypt the AES block */ + aes_encrypt(tmp_data, key_exp, dst); + debug_print_vector("AES Dst", AES_KEY_LENGTH, dst); + + /* Update pointers for next loop. */ + cbc_chain_data = dst; + src += AES_KEY_LENGTH; + dst += AES_KEY_LENGTH; + } +}