[U-Boot] [PATCH 2/4] aes: Move the AES-128-CBC encryption function to common code
Marek Vasut
marex at denx.de
Thu Feb 6 04:44:38 CET 2014
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 at denx.de>
---
arch/arm/cpu/tegra20-common/crypto.c | 72 +-----------------------------------
include/aes.h | 10 +++++
lib/aes.c | 59 +++++++++++++++++++++++++++++
3 files changed, 71 insertions(+), 70 deletions(-)
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..4df5dae 100644
--- a/lib/aes.c
+++ b/lib/aes.c
@@ -580,3 +580,62 @@ 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)
+{
+ 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.
+ *
+ * @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 < 16; 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;
+ }
+}
--
1.8.5.3
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