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: Marek Vasut <marex@denx.de>

diff --git a/arch/arm/cpu/tegra20-common/crypto.c b/arch/arm/cpu/tegra20-common/crypto.c
index 8209f7661ad76c631edb8450aa3c489d642cdbde..b18e67c3463e0a3989b8e55d864b0b0bda96be01 100644 (file)
--- 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 c70eda6f981578e3fd42ca97bedcf5b9ea6f0cf5..d9bb3876140649fd343bc11e67f671c6736e6fac 100644 (file)
--- 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 e996b273ac8633adfaea3d8ee3e2eb63e81c06b8..a6648f90db29f714ef52bab78eafecf0bcadbcaa 100644 (file)
--- 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;
+       }
+}