dm: crypto: Create AES uclass

Create a basic framework for a group of devices that perform AES
cryptographic operations.

Signed-off-by: Ion Agorria <ion@agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>

drivers/crypto/Kconfig

@@ -2,6 +2,8 @@ menu "Hardware crypto devices"
 
 source "drivers/crypto/hash/Kconfig"
 
+source "drivers/crypto/aes/Kconfig"
+
 source "drivers/crypto/fsl/Kconfig"
 
 source "drivers/crypto/aspeed/Kconfig"

drivers/crypto/Makefile

@@ -4,6 +4,7 @@
 #	http://www.samsung.com
 
 obj-$(CONFIG_EXYNOS_ACE_SHA)	+= ace_sha.o
+obj-y += aes/
 obj-y += rsa_mod_exp/
 obj-y += fsl/
 obj-y += hash/

drivers/crypto/aes/Kconfig

@@ -0,0 +1,5 @@
+config DM_AES
+	bool "Enable Driver Model for AES crypto operations"
+	depends on DM
+	help
+	  If you want to use driver model for AES crypto operations, say Y.

drivers/crypto/aes/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-$(CONFIG_$(PHASE_)DM_AES) += aes-uclass.o

drivers/crypto/aes/aes-uclass.c

@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#define LOG_CATEGORY UCLASS_AES
+
+#include <dm.h>
+#include <malloc.h>
+#include <log.h>
+#include <uboot_aes.h>
+#include <linux/string.h>
+
+int dm_aes_get_available_key_slots(struct udevice *dev)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->available_key_slots)
+		return -ENOSYS;
+
+	return ops->available_key_slots(dev);
+}
+
+int dm_aes_select_key_slot(struct udevice *dev, u32 key_size, u8 slot)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->select_key_slot)
+		return -ENOSYS;
+
+	return ops->select_key_slot(dev, key_size, slot);
+}
+
+int dm_aes_set_key_for_key_slot(struct udevice *dev, u32 key_size, u8 *key, u8 slot)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->set_key_for_key_slot)
+		return -ENOSYS;
+
+	return ops->set_key_for_key_slot(dev, key_size, key, slot);
+}
+
+int dm_aes_ecb_encrypt(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->aes_ecb_encrypt)
+		return -ENOSYS;
+
+	return ops->aes_ecb_encrypt(dev, src, dst, num_aes_blocks);
+}
+
+int dm_aes_ecb_decrypt(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->aes_ecb_decrypt)
+		return -ENOSYS;
+
+	return ops->aes_ecb_decrypt(dev, src, dst, num_aes_blocks);
+}
+
+int dm_aes_cbc_encrypt(struct udevice *dev, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->aes_cbc_encrypt)
+		return -ENOSYS;
+
+	return ops->aes_cbc_encrypt(dev, iv, src, dst, num_aes_blocks);
+}
+
+int dm_aes_cbc_decrypt(struct udevice *dev, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks)
+{
+	const struct aes_ops *ops;
+
+	if (!dev)
+		return -ENODEV;
+
+	ops = aes_get_ops(dev);
+
+	if (!ops->aes_cbc_decrypt)
+		return -ENOSYS;
+
+	return ops->aes_cbc_decrypt(dev, iv, src, dst, num_aes_blocks);
+}
+
+static void left_shift_vector(u8 *in, u8 *out, int size)
+{
+	int carry = 0;
+	int i;
+
+	for (i = size - 1; i >= 0; i--) {
+		out[i] = (in[i] << 1) | carry;
+		carry = in[i] >> 7;	/* get most significant bit */
+	}
+}
+
+int dm_aes_cmac(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks)
+{
+	const u8 AES_CMAC_CONST_RB = 0x87; /* from RFC 4493, Figure 2.2 */
+	const u32 TMP_BUFFER_LEN = 128;
+	u8 tmp_block[AES128_KEY_LENGTH] = { };
+	u8 k1[AES128_KEY_LENGTH];
+	u8 *tmp_buffer;
+	int ret;
+
+	log_debug("%s: 0x%p -> %p blocks %d\n", __func__, src, dst, num_aes_blocks);
+
+	if (!num_aes_blocks) {
+		log_debug("%s: called with 0 blocks!\n", __func__);
+		return -1;
+	}
+
+	/* Compute K1 constant needed by AES-CMAC calculation */
+	ret = dm_aes_cbc_encrypt(dev, (u8 *)AES_ZERO_BLOCK, (u8 *)AES_ZERO_BLOCK, tmp_block, 1);
+	if (ret)
+		return -1;
+
+	left_shift_vector(tmp_block, k1, AES_BLOCK_LENGTH);
+
+	if ((tmp_block[0] >> 7) != 0) /* get MSB of L */
+		k1[AES128_KEY_LENGTH - 1] ^= AES_CMAC_CONST_RB;
+
+	/* Set what will be the initial IV as zero */
+	memset(tmp_block, 0, AES_BLOCK_LENGTH);
+
+	/* Process all blocks except last by calling engine several times per dma buffer size */
+	if (num_aes_blocks > 1) {
+		tmp_buffer = malloc(AES_BLOCK_LENGTH * min(num_aes_blocks - 1, TMP_BUFFER_LEN));
+		while (num_aes_blocks > 1) {
+			u32 blocks = min(num_aes_blocks - 1, TMP_BUFFER_LEN);
+
+			/* Encrypt the current remaining set of blocks that fits in tmp buffer */
+			ret = dm_aes_cbc_encrypt(dev, tmp_block, src, tmp_buffer, blocks);
+			if (ret)
+				return -1;
+
+			num_aes_blocks -= blocks;
+			src += blocks * AES_BLOCK_LENGTH;
+
+			/* Copy the last encrypted block to tmp_block as IV */
+			memcpy(tmp_block, tmp_buffer + ((blocks - 1) * AES_BLOCK_LENGTH),
+			       AES_BLOCK_LENGTH);
+		}
+		free(tmp_buffer);
+	}
+
+	if (num_aes_blocks != 1) {
+		log_debug("%s: left with %d blocks! must be 1\n", __func__, num_aes_blocks);
+		return -1;
+	}
+
+	/* XOR last IV with K1 */
+	aes_apply_cbc_chain_data(tmp_block, k1, tmp_block);
+
+	/* Encrypt the last src block already with tmp_block as IV and output to dst */
+	return dm_aes_cbc_encrypt(dev, tmp_block, src, dst, 1);
+}
+
+UCLASS_DRIVER(aes) = {
+	.id	= UCLASS_AES,
+	.name	= "aes",
+};

include/dm/uclass-id.h

@@ -38,6 +38,7 @@ enum uclass_id {
 	/* U-Boot uclasses start here - in alphabetical order */
 	UCLASS_ACPI_PMC,	/* (x86) Power-management controller (PMC) */
 	UCLASS_ADC,		/* Analog-to-digital converter */
+	UCLASS_AES,		/* AES cryptographic engine */
 	UCLASS_AHCI,		/* SATA disk controller */
 	UCLASS_AUDIO_CODEC,	/* Audio codec with control and data path */
 	UCLASS_AXI,		/* AXI bus */

include/uboot_aes.h

@@ -7,6 +7,8 @@
 #ifndef _AES_REF_H_
 #define _AES_REF_H_
 
+#include <errno.h>
+
 #ifdef USE_HOSTCC
 /* Define compat stuff for use in fw_* tools. */
 typedef unsigned char u8;
@@ -107,4 +109,253 @@ void aes_cbc_encrypt_blocks(u32 key_size, u8 *key_exp, u8 *iv, u8 *src, u8 *dst,
 void aes_cbc_decrypt_blocks(u32 key_size, u8 *key_exp, u8 *iv, u8 *src, u8 *dst,
 			    u32 num_aes_blocks);
 
+/* An AES block filled with zeros */
+static const u8 AES_ZERO_BLOCK[AES_BLOCK_LENGTH] = { 0 };
+struct udevice;
+
+/**
+ * struct struct aes_ops - Driver model for AES related operations
+ *
+ * The uclass interface is implemented by AES crypto devices which use driver model.
+ *
+ * Some AES crypto devices use key slots to store the key for the encrypt/decrypt
+ * operations, while others may simply pass the key on each operation.
+ *
+ * In case the device does not implement hardware slots, driver can emulate or simply
+ * store one active key slot at 0 in the driver state and pass it on each underlying
+ * hw calls for AES operations.
+ *
+ * Note that some devices like Tegra AES engine may contain preloaded keys by bootrom,
+ * thus in those cases the set_key_for_key_slot() may be skipped.
+ *
+ * Sequence for a series of AES CBC encryption, one decryption and a CMAC hash example
+ * with 128bits key at slot 0 would be as follow:
+ *
+ * set_key_for_key_slot(DEV, 128, KEY, 0);
+ * select_key_slot(DEV, 128, 0);
+ * aes_cbc_encrypt(DEV, IV1, SRC1, DST1, LEN1);
+ * aes_cbc_encrypt(DEV, IV2, SRC2, DST2, LEN2);
+ * aes_cbc_decrypt(DEV, IV3, SRC3, DST3, LEN3);
+ */
+struct aes_ops {
+	/**
+	 * available_key_slots() - How many key slots this AES device has
+	 *
+	 * @dev			The AES udevice
+	 * @return		Available slots to use, 0 for none
+	 */
+	int (*available_key_slots)(struct udevice *dev);
+
+	/**
+	 * select_key_slot() - Selects the AES key slot to use for following operations
+	 *
+	 * @dev			The AES udevice
+	 * @key_size		Size of the aes key (in bits)
+	 * @slot		The key slot to set as selected
+	 * @return		0 on success, negative value on failure
+	 */
+	int (*select_key_slot)(struct udevice *dev, u32 key_size, u8 slot);
+
+	/**
+	 * set_key_for_key_slot() - Sets the AES key to use for specified key slot
+	 *
+	 * @dev			The AES udevice
+	 * @key_size		Size of the aes key (in bits)
+	 * @key			An AES key to set
+	 * @slot		The slot to load the key at
+	 * @return		0 on success, negative value on failure
+	 */
+	int (*set_key_for_key_slot)(struct udevice *dev, u32 key_size, u8 *key,
+				    u8 slot);
+
+	/**
+	 * aes_ecb_encrypt() - Encrypt multiple blocks of data with AES ECB.
+	 *
+	 * @dev			The AES udevice
+	 * @src			Source data of length 'num_aes_blocks' blocks
+	 * @dst			Destination data of length 'num_aes_blocks' blocks
+	 * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+	 * @return		0 on success, negative value on failure
+	 */
+	int (*aes_ecb_encrypt)(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+	/**
+	 * aes_ecb_decrypt() - Decrypt multiple blocks of data with AES ECB.
+	 *
+	 * @dev			The AES udevice
+	 * @src			Source data of length 'num_aes_blocks' blocks
+	 * @dst			Destination data of length 'num_aes_blocks' blocks
+	 * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+	 * @return		0 on success, negative value on failure
+	 */
+	int (*aes_ecb_decrypt)(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+	/**
+	 * aes_cbc_encrypt() - Encrypt multiple blocks of data with AES CBC.
+	 *
+	 * @dev			The AES udevice
+	 * @iv			Initialization vector
+	 * @src			Source data of length 'num_aes_blocks' blocks
+	 * @dst			Destination data of length 'num_aes_blocks' blocks
+	 * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+	 * @return		0 on success, negative value on failure
+	 */
+	int (*aes_cbc_encrypt)(struct udevice *dev, u8 *iv,
+			       u8 *src, u8 *dst, u32 num_aes_blocks);
+
+	/**
+	 * aes_cbc_decrypt() - Decrypt multiple blocks of data with AES CBC.
+	 *
+	 * @dev			The AES udevice
+	 * @iv			Initialization vector
+	 * @src			Source data of length 'num_aes_blocks' blocks
+	 * @dst			Destination data of length 'num_aes_blocks' blocks
+	 * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+	 * @return		0 on success, negative value on failure
+	 */
+	int (*aes_cbc_decrypt)(struct udevice *dev, u8 *iv,
+			       u8 *src, u8 *dst, u32 num_aes_blocks);
+};
+
+#define aes_get_ops(dev)	((struct aes_ops *)(dev)->driver->ops)
+
+#if CONFIG_IS_ENABLED(DM_AES)
+
+/**
+ * dm_aes_get_available_key_slots - How many key slots this AES device has
+ *
+ * @dev			The AES udevice
+ * Return:		Available slots to use, 0 for none, -ve on failure
+ */
+int dm_aes_get_available_key_slots(struct udevice *dev);
+
+/**
+ * dm_aes_select_key_slot - Selects the AES key slot to use for following operations
+ *
+ * @dev			The AES udevice
+ * @key_size		Size of the aes key (in bits)
+ * @slot		The key slot to set as selected
+ * Return:		0 on success, -ve on failure
+ */
+int dm_aes_select_key_slot(struct udevice *dev, u32 key_size, u8 slot);
+
+/**
+ * dm_aes_set_key_for_key_slot - Sets the AES key to use for specified key slot
+ *
+ * @dev			The AES udevice
+ * @key_size		Size of the aes key (in bits)
+ * @key			An AES key to set
+ * @slot		The slot to load the key at
+ * Return:		0 on success, negative value on failure
+ */
+int dm_aes_set_key_for_key_slot(struct udevice *dev, u32 key_size, u8 *key, u8 slot);
+
+/**
+ * dm_aes_ecb_encrypt - Encrypt multiple blocks of data with AES ECB.
+ *
+ * @dev			The AES udevice
+ * @src			Source data of length 'num_aes_blocks' blocks
+ * @dst			Destination data of length 'num_aes_blocks' blocks
+ * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+ * Return:		0 on success, negative value on failure
+ */
+int dm_aes_ecb_encrypt(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+/**
+ * dm_aes_ecb_decrypt - Decrypt multiple blocks of data with AES ECB.
+ *
+ * @dev			The AES udevice
+ * @src			Source data of length 'num_aes_blocks' blocks
+ * @dst			Destination data of length 'num_aes_blocks' blocks
+ * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+ * Return:		0 on success, negative value on failure
+ */
+int dm_aes_ecb_decrypt(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+/**
+ * dm_aes_cbc_encrypt - Encrypt multiple blocks of data with AES CBC.
+ *
+ * @dev			The AES udevice
+ * @iv			Initialization vector
+ * @src			Source data of length 'num_aes_blocks' blocks
+ * @dst			Destination data of length 'num_aes_blocks' blocks
+ * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+ * Return:		0 on success, negative value on failure
+ */
+int dm_aes_cbc_encrypt(struct udevice *dev, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+/**
+ * dm_aes_cbc_decrypt - Decrypt multiple blocks of data with AES CBC.
+ *
+ * @dev			The AES udevice
+ * @iv			Initialization vector
+ * @src			Source data of length 'num_aes_blocks' blocks
+ * @dst			Destination data of length 'num_aes_blocks' blocks
+ * @num_aes_blocks	Number of AES blocks to encrypt/decrypt
+ * Return:		0 on success, negative value on failure
+ */
+int dm_aes_cbc_decrypt(struct udevice *dev, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+/**
+ * dm_aes_cmac - Hashes the input data with AES-CMAC, putting the result into dst.
+ * The key slot must be selected already.
+ *
+ * @dev			The AES udevice
+ * @key_size		Size of the aes key (in bits)
+ * @src			Source data of length 'num_aes_blocks' blocks
+ * @dst			Destination for hash result
+ * @num_aes_blocks	Number of AES blocks to encrypt
+ * Return:		0 on success, negative value on failure.
+ */
+int dm_aes_cmac(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks);
+
+#else
+
+static inline int dm_aes_get_available_key_slots(struct udevice *dev)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_select_key_slot(struct udevice *dev, u32 key_size, u8 slot)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_set_key_for_key_slot(struct udevice *dev, u32 key_size, u8 *key,
+					      u8 slot)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_ecb_encrypt(struct udevice *dev, u8 *src, u8 *dst,
+				     u32 num_aes_blocks)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_ecb_decrypt(struct udevice *dev, u8 *src, u8 *dst,
+				     u32 num_aes_blocks)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_cbc_encrypt(struct udevice *dev, u8 *iv, u8 *src,
+				     u8 *dst, u32 num_aes_blocks)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_cbc_decrypt(struct udevice *dev, u8 *iv, u8 *src,
+				     u8 *dst, u32 num_aes_blocks)
+{
+	return -ENOSYS;
+}
+
+static inline int dm_aes_cmac(struct udevice *dev, u8 *src, u8 *dst, u32 num_aes_blocks)
+{
+	return -ENOSYS;
+}
+
+#endif /* CONFIG_DM_AES */
+
 #endif /* _AES_REF_H_ */