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

29 Dec 2014

Hi Ruchika,
On 24 December 2014 at 03:28, Ruchika Gupta ruchika.gupta@freescale.com wrote:
...
Hi Simon,
...
-----Original Message-----
From: sjg@google.com [mailto:sjg@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

    

Simon Glass

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