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

Simon Glass sjg at chromium.org
Mon Dec 29 22:10:49 CET 2014


Hi Ruchika,

On 24 December 2014 at 03:28, Ruchika Gupta <ruchika.gupta at 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 at 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 at freescale.com>
>> > CC: Simon Glass <sjg at 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


More information about the U-Boot mailing list