Hi Ruchika, On 6 January 2015 at 02:37, Ruchika Gupta <ruchika.gu...@freescale.com> wrote:
> Hi Simon, > > > -----Original Message----- > > From: s...@google.com [mailto:s...@google.com] On Behalf Of Simon Glass > > Sent: Saturday, January 03, 2015 3:54 AM > > To: Gupta Ruchika-R66431 > > Cc: U-Boot Mailing List; Sun York-R58495 > > Subject: Re: [PATCH 3/9] [v4] DM: crypto/rsa: Add rsa Modular > Exponentiation > > DM driver > > > > Hi Ruchika, > > > > On 30 December 2014 at 02:30, Ruchika Gupta <ruchika.gu...@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.gu...@freescale.com> > > > CC: Simon Glass <s...@chromium.org> > > > --- > > > Changes in v4: > > > Removed Kconfig option for DM_RSA > > > Corrected driver name for sw rsa driver Updated the rsa_mod_exp > > > operation to have output length > > > > > > Changes in v3: > > > New patch with driver model for RSA UCLASS > > > > > > drivers/crypto/Makefile | 1 + > > > drivers/crypto/rsa/Makefile | 7 +++++++ > > > 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 | 37 > +++++++++++++++++++++++++++++++++++++ > > > 6 files changed, 116 insertions(+) > > > 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 > > > > Again I'm a bit worried we are going off into the weeds. > > > > Is this an RSA driver or a modular exponentiation driver? It seems like > the > > latter to me. If so, the uclass should be UCLASS_MOD_EXP, not > UCLASS_RSA, and > > the files and directories should be renames also. Some hardware will > > implement the entire RSA algorithm, which would be a true RSA uclass. > Here I > > think you are only doing part of it. > I did this to introduce a generic class for RSA which has mod_exp > implementation for now and can be extended to have sign or any other algo > added later.For now I will change it to UCLASS_MOD_EXP as you have > suggested. > >From what I understand the RSA API consists of two functions: rsa_sign() rsa_verify() These are defined in rsa.h. So if you are planning to implement an RSA uclass it should support these two. In your case it seems like you are implementing a part of RSA, i.e. lower-level functionality. That's why I'm saying it doesn't look like an RSA uclass to me. > > > > > Other than that rename the code looks fine. > > > > Minor point: again I don't see the value of returning the same value as > > sig_len, so you may as well drop those last two args to mod_exp() - > unless I > > am missing something. > I will do that and revert back to earlier implementation with uint8_t *out. > > > > > > > > > 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-$(CONFIG_EXYNOS_ACE_SHA) += ace_sha.o > > > +obj-y += rsa/ > > > obj-y += fsl/ > > > diff --git a/drivers/crypto/rsa/Makefile b/drivers/crypto/rsa/Makefile > > > new file mode 100644 index 0000000..927c5bd > > > --- /dev/null > > > +++ b/drivers/crypto/rsa/Makefile > > > @@ -0,0 +1,7 @@ > > > +# > > > +# (C) Copyright 2014 Freescale Semiconductor, Inc. > > > +# > > > +# SPDX-License-Identifier: GPL-2.0+ > > > +# > > > + > > > +obj-$(CONFIG_RSA) += rsa_uclass.o 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..3dcd512 > > > --- /dev/null > > > +++ b/drivers/crypto/rsa/rsa_sw.c > > > @@ -0,0 +1,39 @@ > > > +/* > > > + * (C) Copyright 2014 Freescale Semiconductor, Inc. > > > + * Author: Ruchika Gupta <ruchika.gu...@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 **outp, uint32_t > > > +*out_len) { > > > + int ret = 0; > > > + > > > + ret = rsa_mod_exp_sw(sig, sig_len, prop, outp, out_len); > > > + if (ret) { > > > + debug("%s: RSA failed to verify: %d\n", __func__, ret); > > > + return ret; > > > + } > > > + > > > + return 0; > > > +} > > > + > > > +static const struct rsa_ops rsa_ops_sw = { > > > + .mod_exp = mod_exp_sw, > > > +}; > > > + > > > +U_BOOT_DRIVER(rsa_sw) = { > > > + .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..4d52dcc > > > --- /dev/null > > > +++ b/drivers/crypto/rsa/rsa_uclass.c > > > @@ -0,0 +1,31 @@ > > > +/* > > > + * (C) Copyright 2014 Freescale Semiconductor, Inc > > > + * Author: Ruchika Gupta <ruchika.gu...@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, uint32_t > > > +*out_len) { > > > + const struct rsa_ops *ops = device_get_ops(dev); > > > + > > > + if (!ops->mod_exp) > > > + return -ENOSYS; > > > + > > > + return ops->mod_exp(dev, sig, sig_len, node, out, out_len); } > > > + > > > +UCLASS_DRIVER(rsa) = { > > > + .id = UCLASS_RSA, > > > + .name = "rsa", > > > +}; > > > diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index > > > f17c3c2..823e43c 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 */ > > > > > > UCLASS_COUNT, > > > UCLASS_INVALID = -1, > > > diff --git a/include/u-boot/rsa-mod-exp.h > > > b/include/u-boot/rsa-mod-exp.h index 7b74f3c..417e468 100644 > > > --- a/include/u-boot/rsa-mod-exp.h > > > +++ b/include/u-boot/rsa-mod-exp.h > > > @@ -46,4 +46,41 @@ struct key_prop { > > > int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len, > > > struct key_prop *node, uint8_t **outp, uint32_t > > > *out_len); > > > > > > +int rsa_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t > sig_len, > > > + struct key_prop *node, uint8_t **outp, uint32_t > > > +*out_len); > > > + > > > +/** > > > + * 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 > > > + * @outp: Set to an allocated buffer holding the output > hash > > > + * @out_len: Set to length of hash(outp) calculated after > > > + * exponentiation. > > > + * > > > + * This computes exponentiation over the signature. Resulting > > > + * hash value is placed in an allocated buffer, the pointer is > > > + * returned as *outp. The length of calulated hash is returned > via > > > + * the out_len pointer argument. The caller should free *outp > > > + * > > > + * Returns: 0 if exponentiation is successful, or a negative > value > > > + * if it wasn't. > > > + */ > > > + int (*mod_exp)(struct udevice *dev, const uint8_t *sig, > > > + uint32_t sig_len, struct key_prop *node, > > > + uint8_t **outp, uint32_t *len); }; > > > + > > > #endif > > > -- > > > 1.8.1.4 > > > > > Regards, > Ruchika Regards, Simon
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