[U-Boot] [PATCH 5/9] [v3] lib/rsa: Modify rsa to use DM driver if available

Simon Glass
2014-12-29T21:10:49Z

Hi Ruchika,

On 24 December 2014 at 03:28, Ruchika Gupta <ruchika.gupta@freescale.com> wrote:
> Hi Simon,
>
>> -----Original Message-----
>> From: sjg at google.com [mailto:sjg at google.com] On Behalf Of Simon Glass
>> Sent: Wednesday, December 24, 2014 6:19 AM
>> To: Gupta Ruchika-R66431
>> Cc: U-Boot Mailing List; Sun York-R58495
>> Subject: Re: [PATCH 5/9] [v3] lib/rsa: Modify rsa to use DM driver if
>> available
>>
>> Hi Ruchika,
>>
>> On 23 December 2014 at 04:32, Ruchika Gupta <ruchika.gupta@freescale.com>
>> wrote:
>> > Modify rsa_verify to use the rsa driver of DM library available.The
>> > tools and the configurations which don't use Driver Model, will
>> > continue to use the same RSA sw library. The software implementation
>> > of RSA Modular Exponentation is now compiled if RSA_MOD_EXP_SW is selected.
>> >
>> > Kconfig options are also added for rsa library.
>> >
>> > Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
>> > CC: Simon Glass <sjg@chromium.org>
>> > ---
>> > Changes in v3:
>> > New patch
>> >
>> > include/configs/am335x_evm.h | 1 +
>> > lib/Kconfig | 6 +-----
>> > lib/rsa/Kconfig | 31 +++++++++++++++++++++++++++++++
>> > lib/rsa/Makefile | 3 ++-
>> > lib/rsa/rsa-verify.c | 18 ++++++++++++++++++
>> > 5 files changed, 53 insertions(+), 6 deletions(-) create mode 100644
>> > lib/rsa/Kconfig
>> >
>> > diff --git a/include/configs/am335x_evm.h
>> > b/include/configs/am335x_evm.h index cc36985..aa79841 100644
>> > --- a/include/configs/am335x_evm.h
>> > +++ b/include/configs/am335x_evm.h
>> > @@ -25,6 +25,7 @@
>> > # ifdef CONFIG_ENABLE_VBOOT
>> > # define CONFIG_FIT_SIGNATURE
>> > # define CONFIG_RSA
>> > +# define CONFIG_RSA_MOD_EXP_SW
>>
>> This should go in am335x_boneblack_vboot_defconfig I think.
> I didn?t move it in the defconfig as it was conditionally defined under CONFIG_ENABLE_VBOOT

Ah OK I see.

>
>>
>> > # endif
>> > #endif
>> >
>> > diff --git a/lib/Kconfig b/lib/Kconfig index 602dd37..a1f30a2 100644
>> > --- a/lib/Kconfig
>> > +++ b/lib/Kconfig
>> > @@ -27,10 +27,6 @@ config SYS_HZ
>> > get_timer() must operate in milliseconds and this option must be
>> > set to 1000.
>> >
>> > -config RSA
>> > - bool "Use RSA Library"
>> > - help
>> > - RSA support.This enables the RSA algorithm used for FIT image
>> > - verification in U-Boot.
>> > +source lib/rsa/Kconfig
>> >
>> > endmenu
>> > diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig new file mode 100644
>> > index 0000000..8f9aa44
>> > --- /dev/null
>> > +++ b/lib/rsa/Kconfig
>> > @@ -0,0 +1,31 @@
>> > +config RSA
>> > + bool "Use RSA Library"
>> > + select RSA_MOD_EXP_SW if !DM
>> > + select DM_RSA if DM
>> > + help
>> > + RSA support.This enables the RSA algorithm used for FIT image
>> > + verification in U-Boot.
>> > + See doc/uImage.FIT/signature.txt for more details.
>> > +
>> > +if RSA && DM_RSA
>> > +
>> > +config RSA_SW
>> > + bool "User driver Model for RSA Modular Exponentiation in software"
>> > + depends on DM && DM_RSA && RSA
>> > + select RSA_MOD_EXP_SW
>> > + default y
>> > + help
>> > + Enables driver for modular exponentiation in software. This is a
>> RSA
>> > + algorithm used in FIT image verification. It required RSA Key as
>> > + input.
>> > + See doc/uImage.FIT/signature.txt for more details.
>> > +
>> > +endif
>> > +
>> > +config RSA_MOD_EXP_SW
>> > + bool
>> > + default n
>> > + help
>> > + Library for SW implementation of RSA Modular Exponentiation. This
>> > + library is used by the mkimage tool(not selected through this
>> option)
>> > + as well as by the RSA driver model with SW implementation.
>> > diff --git a/lib/rsa/Makefile b/lib/rsa/Makefile index
>> > cc25b3c..ccc6060 100644
>> > --- a/lib/rsa/Makefile
>> > +++ b/lib/rsa/Makefile
>> > @@ -7,4 +7,5 @@
>> > # SPDX-License-Identifier: GPL-2.0+
>> > #
>> >
>> > -obj-$(CONFIG_FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o
>> > rsa-mod-exp.o
>> > +obj-$(CONFIG_FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o
>> > +obj-$(CONFIG_RSA_MOD_EXP_SW) += rsa-mod-exp.o
>> > diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c index
>> > f8bc086..27f10ef 100644
>> > --- a/lib/rsa/rsa-verify.c
>> > +++ b/lib/rsa/rsa-verify.c
>> > @@ -12,6 +12,7 @@
>> > #include <asm/errno.h>
>> > #include <asm/types.h>
>> > #include <asm/unaligned.h>
>> > +#include <dm.h>
>> > #else
>> > #include "fdt_host.h"
>> > #include "mkimage.h"
>> > @@ -43,6 +44,9 @@ static int rsa_verify_key(struct key_prop *prop, const
>> uint8_t *sig,
>> > const uint8_t *padding;
>> > int pad_len;
>> > int ret;
>> > +#if defined(CONFIG_DM_RSA) && !defined(USE_HOSTCC)
>> > + struct udevice *rsa_dev;
>> > +#endif
>> >
>> > if (!prop || !sig || !hash || !algo)
>> > return -EIO;
>> > @@ -63,11 +67,25 @@ static int rsa_verify_key(struct key_prop *prop,
>> > const uint8_t *sig,
>> >
>> > uint8_t buf[sig_len];
>> >
>> > +#if defined(CONFIG_DM_RSA) && !defined(USE_HOSTCC)
>> > + ret = uclass_get_device(UCLASS_RSA, 0, &rsa_dev);
>> > + if (!ret) {
>> > + ret = rsa_mod_exp(rsa_dev, sig, sig_len, prop, buf);
>> > + if (ret) {
>> > + debug("Error in Modular exponentation\n");
>> > + return ret;
>> > + }
>> > + } else {
>> > + printf("RSA: Can't find Mod Exp implemnetation\n");
>> > + return -EINVAL;
>> > + }
>> > +#else
>> > ret = rsa_mod_exp_sw(sig, sig_len, prop, buf);
>> > if (ret) {
>> > debug("Error in Modular exponentation\n");
>> > return ret;
>> > }
>> > +#endif
>>
>> This should use the uclass regardless I think. The software implementation
>> should just be a driver like the hardware implementation.
> I have already added software implementation as a driver in the previous patch. I have kept it here for the tools (mkimage) and the platforms which don?t use CONFIG_DM by default.

OK.
[ship]

Regards,
Simon