Commit 6e7b9f4f authored by Marek Vasut's avatar Marek Vasut Committed by Tom Rini

aes: Move the AES-128-CBC encryption function to common code

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: default avatarMarek Vasut <marex@denx.de>
parent 957ba85c
......@@ -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");
}
......
......@@ -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_ */
......@@ -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;
}
}
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