[U-Boot] [PATCH 3/9] [v3] DM: crypto/rsa: Add rsa Modular Exponentiation DM driver

Simon Glass
2014-12-24T00:48:43Z

Hi Ruchika,

On 23 December 2014 at 04:32, Ruchika Gupta <ruchika.gupta@freescale.com> wrote:
> Add a new rsa uclass for performing modular exponentiation and implement
> the software driver basing on this uclass.
>
> Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
> CC: Simon Glass <sjg@chromium.org>
> ---
> Changes in v3:
> New patch with driver model for RSA UCLASS
>
> drivers/crypto/Kconfig | 1 +
> drivers/crypto/Makefile | 1 +
> drivers/crypto/rsa/Kconfig | 5 +++++
> drivers/crypto/rsa/Makefile | 8 ++++++++
> drivers/crypto/rsa/rsa_sw.c | 39 +++++++++++++++++++++++++++++++++++++++
> drivers/crypto/rsa/rsa_uclass.c | 31 +++++++++++++++++++++++++++++++
> include/dm/uclass-id.h | 1 +
> include/u-boot/rsa-mod-exp.h | 40 ++++++++++++++++++++++++++++++++++++++++
> 8 files changed, 126 insertions(+)
> create mode 100644 drivers/crypto/rsa/Kconfig
> create mode 100644 drivers/crypto/rsa/Makefile
> create mode 100644 drivers/crypto/rsa/rsa_sw.c
> create mode 100644 drivers/crypto/rsa/rsa_uclass.c
>
> diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
> index e69de29..75f3479 100644
> --- a/drivers/crypto/Kconfig
> +++ b/drivers/crypto/Kconfig
> @@ -0,0 +1 @@
> +source drivers/crypto/rsa/Kconfig
> diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
> index 7b79237..a2f30fc 100644
> --- a/drivers/crypto/Makefile
> +++ b/drivers/crypto/Makefile
> @@ -6,4 +6,5 @@
> #
>
> obj-$(CONFIG_EXYNOS_ACE_SHA) += ace_sha.o
> +obj-y += rsa/
> obj-y += fsl/
> diff --git a/drivers/crypto/rsa/Kconfig b/drivers/crypto/rsa/Kconfig
> new file mode 100644
> index 0000000..7eb90a1
> --- /dev/null
> +++ b/drivers/crypto/rsa/Kconfig
> @@ -0,0 +1,5 @@
> +config DM_RSA
> + bool "Enable Driver Model for RSA "
> + depends on DM
> + help
> + If you want to use driver model for RSA Modular Exponentiation, say Y.

Can you send a new patch (later if you prefer) which removes this
option altogether? It should be the default. In other words, RSA
should always use driver model.

> diff --git a/drivers/crypto/rsa/Makefile b/drivers/crypto/rsa/Makefile
> new file mode 100644
> index 0000000..fae4f8c
> --- /dev/null
> +++ b/drivers/crypto/rsa/Makefile
> @@ -0,0 +1,8 @@
> +#
> +# (C) Copyright 2014 Freescale Semiconductor, Inc.
> +#
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +
> +obj-$(CONFIG_DM_RSA) += rsa_uclass.o
> +obj-$(CONFIG_RSA_SW) += rsa_sw.o
> diff --git a/drivers/crypto/rsa/rsa_sw.c b/drivers/crypto/rsa/rsa_sw.c
> new file mode 100644
> index 0000000..5d94754
> --- /dev/null
> +++ b/drivers/crypto/rsa/rsa_sw.c
> @@ -0,0 +1,39 @@
> +/*
> + * (C) Copyright 2014 Freescale Semiconductor, Inc.
> + * Author: Ruchika Gupta <ruchika.gupta@freescale.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <config.h>
> +#include <common.h>
> +#include <dm.h>
> +#include <u-boot/rsa-mod-exp.h>
> +
> +int mod_exp_sw(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
> + struct key_prop *prop, uint8_t *out)
> +{
> + int ret = 0;
> +
> + ret = rsa_mod_exp_sw(sig, sig_len, prop, out);
> +
> + if (ret) {
> + debug("%s: RSA failed to verify: %d\n", __func__, ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static const struct rsa_ops rsa_ops_sw = {
> + .get_mod_exp = mod_exp_sw,
> +};
> +
> +U_BOOT_DRIVER(fsl_rsa) = {
> + .name = "rsa_sw",
> + .id = UCLASS_RSA,
> + .ops = &rsa_ops_sw,
> +};
> +
> +U_BOOT_DEVICE(rsa_sw) = {
> + .name = "rsa_sw",
> +};
> diff --git a/drivers/crypto/rsa/rsa_uclass.c b/drivers/crypto/rsa/rsa_uclass.c
> new file mode 100644
> index 0000000..f4f4f39
> --- /dev/null
> +++ b/drivers/crypto/rsa/rsa_uclass.c
> @@ -0,0 +1,31 @@
> +/*
> + * (C) Copyright 2014 Freescale Semiconductor, Inc
> + * Author: Ruchika Gupta <ruchika.gupta@freescale.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <u-boot/rsa-mod-exp.h>
> +#include <errno.h>
> +#include <fdtdec.h>
> +#include <malloc.h>
> +#include <asm/io.h>
> +#include <linux/list.h>
> +
> +int rsa_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
> + struct key_prop *node, uint8_t *out)
> +{
> + const struct rsa_ops *ops = device_get_ops(dev);
> +
> + if (!ops->get_mod_exp)
> + return -ENOSYS;
> +
> + return ops->get_mod_exp(dev, sig, sig_len, node, out);
> +}
> +
> +UCLASS_DRIVER(rsa) = {
> + .id = UCLASS_RSA,
> + .name = "rsa",
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index f17c3c2..659369e 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -33,6 +33,7 @@ enum uclass_id {
> UCLASS_I2C, /* I2C bus */
> UCLASS_I2C_GENERIC, /* Generic I2C device */
> UCLASS_I2C_EEPROM, /* I2C EEPROM device */
> + UCLASS_RSA , /* RSA Mod Exp device */

Funny spacing here.

>
> UCLASS_COUNT,
> UCLASS_INVALID = -1,
> diff --git a/include/u-boot/rsa-mod-exp.h b/include/u-boot/rsa-mod-exp.h
> index 59cd9ea..7f7e196 100644
> --- a/include/u-boot/rsa-mod-exp.h
> +++ b/include/u-boot/rsa-mod-exp.h
> @@ -40,4 +40,44 @@ struct key_prop {
> int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len,
> struct key_prop *node, uint8_t *out);
>
> +/**
> + * rsa_mod_exp - Perform RSA Modular Exponentiation
> + *
> + * Operation: out[] = sig ^ exponent % modulus
> + *
> + * @udev: RSA Device
> + * @sig: RSA PKCS1.5 signature
> + * @sig_len: Length of signature in number of bytes
> + * @node: Node with RSA key elements like modulus, exponent, R^2, n0inv
> + * @out: Result in form of byte array

How big is this array?

> + */
> +int rsa_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
> + struct key_prop *node, uint8_t *out);
> +
> +/**
> + * struct struct rsa_ops - Driver model for RSA operations
> + *
> + * The uclass interface is implemented by all crypto devices which use
> + * driver model.
> + */
> +struct rsa_ops {
> + /**
> + * Perform Modular Exponentiation
> + *
> + * Operation: out[] = sig ^ exponent % modulus
> + *
> + * @dev: RSA Device
> + * @sig: RSA PKCS1.5 signature
> + * @sig_len: Length of signature in number of bytes
> + * @node: Node with RSA key elements like modulus, exponent,
> + * R^2, n0inv
> + * @out: Result in form of byte array

How big is this array?

> + * Returns: 0 if exponentiation is succesful, or a negative value

successful

> + * if it wasn't.
> + */
> + int (*get_mod_exp)(struct udevice *dev, const uint8_t *sig,

mod_exp() is better I think, since it matches your function above.

> + uint32_t sig_len, struct key_prop *node,
> + uint8_t *out);
> +};
> +
> #endif
> --
> 1.8.1.4
>

Regards,
Simon