[U-Boot] [PATCH v1 3/3] lib: rsa: add rsa_verify_with_pkey()

Heinrich Schuchardt xypron.glpk at gmx.de
Sat Oct 12 12:47:33 UTC 2019


On 10/10/19 3:04 AM, AKASHI Takahiro wrote:
> On Wed, Oct 09, 2019 at 07:56:04PM +0200, Heinrich Schuchardt wrote:
>> On 10/9/19 7:30 AM, AKASHI Takahiro wrote:
>>> This function, and hence rsa_verify(), will perform RSA verification
>>> with two essential parameters for a RSA public key in contract of
>>> rsa_verify_with_keynode(), which requires additional three parameters
>>> stored in FIT image.
>>>
>>> It will be used in implementing UEFI secure boot, i.e. image authentication
>>> and variable authentication.
>>>
>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
>>
>> Is this code tested by test/py/tests/test_vboot.py? Or is there another
>> unit test?
>
> I haven't run vboot test yet.

I would have assumed that you to through Travis CI before submitting.

> For rsa_verify_with_pkey(), as with vtest for FIT signature,
> we can test it with my "UEFI secure boot" pytest.

I can't see such a test in this patch series. So how I can test the
changes before merging?

Best regards

Heinrich

>
>>> ---
>>>   lib/rsa/Kconfig      |  7 -----
>>>   lib/rsa/Makefile     |  1 -
>>>   lib/rsa/rsa-verify.c | 63 ++++++++++++++++++++++++++++++++++++++------
>>>   3 files changed, 55 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig
>>> index d1743d7a4c47..62b7ab9c5e5c 100644
>>> --- a/lib/rsa/Kconfig
>>> +++ b/lib/rsa/Kconfig
>>> @@ -30,13 +30,6 @@ config RSA_VERIFY
>>>   	help
>>>   	  Add RSA signature verification support.
>>>
>>> -config RSA_VERIFY_WITH_PKEY
>>> -	bool "Execute RSA verification without key parameters from FDT"
>>> -	depends on RSA
>>> -	help
>>> -	  This options enables RSA signature verification without
>>> -	  using public key parameters which is embedded control FDT.
>>> -
>>>   config RSA_SOFTWARE_EXP
>>>   	bool "Enable driver for RSA Modular Exponentiation in software"
>>>   	depends on DM
>>> diff --git a/lib/rsa/Makefile b/lib/rsa/Makefile
>>> index 14ed3cb4012b..c07305188e0c 100644
>>> --- a/lib/rsa/Makefile
>>> +++ b/lib/rsa/Makefile
>>> @@ -6,5 +6,4 @@
>>>   # Wolfgang Denk, DENX Software Engineering, wd at denx.de.
>>>
>>>   obj-$(CONFIG_$(SPL_)RSA_VERIFY) += rsa-verify.o rsa-checksum.o
>>> -obj-$(CONFIG_RSA_VERIFY_WITH_PKEY) += rsa-keyprop.o
>>>   obj-$(CONFIG_RSA_SOFTWARE_EXP) += rsa-mod-exp.o
>>> diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
>>> index 1df42f28c64a..ce79984b30f9 100644
>>> --- a/lib/rsa/rsa-verify.c
>>> +++ b/lib/rsa/rsa-verify.c
>>> @@ -17,9 +17,14 @@
>>>   #include "mkimage.h"
>>>   #include <fdt_support.h>
>>>   #endif
>>> +#include <linux/kconfig.h>
>>>   #include <u-boot/rsa-mod-exp.h>
>>>   #include <u-boot/rsa.h>
>>>
>>> +#ifndef __UBOOT__ /* for host tools */
>>> +#undef CONFIG_RSA_VERIFY_WITH_PKEY
>>
>> Where should it have been defined?
>
> defined in patch#2
>
>>> +#endif
>>> +
>>>   /* Default public exponent for backward compatibility */
>>>   #define RSA_DEFAULT_PUBEXP	65537
>>>
>>> @@ -344,6 +349,34 @@ static int rsa_verify_key(struct image_sign_info *info,
>>>   }
>>>   #endif
>>>
>>> +#ifdef CONFIG_RSA_VERIFY_WITH_PKEY
>>
>> Where would CONFIG_RSA_VERIFY_WITH_PKEY be defined? You just a removed
>> it from Kconfig.
>
> Because rsa-keyprop.c be compiled only under CONFIG_RSA_VERIFY_WITH_PKEY
> per Simon's comment.
>
>>> +/**
>>> + * rsa_verify_with_pkey()
>>
>> The short text for the function is missing.
>>
>>> + *
>>
>> Please, describe the parameters.
>
> Sure.
>
> -Takahiro Akashi
>
>>> + */
>>> +static int rsa_verify_with_pkey(struct image_sign_info *info,
>>> +				const void *hash, uint8_t *sig, uint sig_len)
>>> +{
>>> +	struct key_prop *prop;
>>> +	int ret;
>>> +
>>> +	/* Public key is self-described to fill key_prop */
>>> +	prop = rsa_gen_key_prop(info->key, info->keylen);
>>> +	if (!prop) {
>>> +		debug("Generating necessary parameter for decoding failed\n");
>>> +		return -EACCES;
>>> +	}
>>> +
>>> +	ret = rsa_verify_key(info, prop, sig, sig_len, hash,
>>> +			     info->crypto->key_len);
>>> +
>>> +	rsa_free_key_prop(prop);
>>> +
>>> +	return ret;
>>> +}
>>> +#endif
>>> +
>>> +#if CONFIG_IS_ENABLED(FIT_SIGNATURE)
>>>   /**
>>>    * rsa_verify_with_keynode() - Verify a signature against some data using
>>>    * information in node with prperties of RSA Key like modulus, exponent etc.
>>> @@ -397,18 +430,21 @@ static int rsa_verify_with_keynode(struct image_sign_info *info,
>>>
>>>   	return ret;
>>>   }
>>> +#endif
>>>
>>>   int rsa_verify(struct image_sign_info *info,
>>>   	       const struct image_region region[], int region_count,
>>>   	       uint8_t *sig, uint sig_len)
>>>   {
>>> -	const void *blob = info->fdt_blob;
>>>   	/* Reserve memory for maximum checksum-length */
>>>   	uint8_t hash[info->crypto->key_len];
>>> +	int ret = -EACCES;
>>> +#if CONFIG_IS_ENABLED(FIT_SIGNATURE)
>>> +	const void *blob = info->fdt_blob;
>>>   	int ndepth, noffset;
>>>   	int sig_node, node;
>>>   	char name[100];
>>> -	int ret;
>>> +#endif
>>>
>>>   	/*
>>>   	 * Verify that the checksum-length does not exceed the
>>> @@ -421,12 +457,6 @@ int rsa_verify(struct image_sign_info *info,
>>>   		return -EINVAL;
>>>   	}
>>>
>>> -	sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME);
>>> -	if (sig_node < 0) {
>>> -		debug("%s: No signature node found\n", __func__);
>>> -		return -ENOENT;
>>> -	}
>>> -
>>>   	/* Calculate checksum with checksum-algorithm */
>>>   	ret = info->checksum->calculate(info->checksum->name,
>>>   					region, region_count, hash);
>>> @@ -435,6 +465,22 @@ int rsa_verify(struct image_sign_info *info,
>>>   		return -EINVAL;
>>>   	}
>>>
>>> +#ifdef CONFIG_RSA_VERIFY_WITH_PKEY
>>
>> Where should this have been defined?
>>
>> Best regards
>>
>> Heinrich
>>
>>> +	if (!info->fdt_blob) {
>>> +		/* don't rely on fdt properties */
>>> +		ret = rsa_verify_with_pkey(info, hash, sig, sig_len);
>>> +
>>> +		return ret;
>>> +	}
>>> +#endif
>>> +
>>> +#if CONFIG_IS_ENABLED(FIT_SIGNATURE)
>>> +	sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME);
>>> +	if (sig_node < 0) {
>>> +		debug("%s: No signature node found\n", __func__);
>>> +		return -ENOENT;
>>> +	}
>>> +
>>>   	/* See if we must use a particular key */
>>>   	if (info->required_keynode != -1) {
>>>   		ret = rsa_verify_with_keynode(info, hash, sig, sig_len,
>>> @@ -461,6 +507,7 @@ int rsa_verify(struct image_sign_info *info,
>>>   				break;
>>>   		}
>>>   	}
>>> +#endif
>>>
>>>   	return ret;
>>>   }
>>>
>>
>



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