[PATCH v7 02/11] lib: uuid: add UUID v5 support
Ilias Apalodimas
ilias.apalodimas at linaro.org
Mon Aug 26 17:46:04 CEST 2024
On Fri, 9 Aug 2024 at 03:56, Caleb Connolly <caleb.connolly at linaro.org> wrote:
>
> Add support for generating version 5 UUIDs, these are determistic and work
> by hashing a "namespace" UUID together with some unique data. One intended
> usecase is to allow for dynamically generate payload UUIDs for UEFI
> capsule updates, so that supported boards can have their own UUIDs
> without needing to hardcode them.
>
> In addition, move the common bit twiddling code from gen_ran_uuid into a
> separate function and rewrite it not to use clrsetbits (which is not
> available when building as part of host tools).
>
> Tests for this are added in an upcoming patch.
>
> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
> ---
> include/uuid.h | 17 +++++++++++++++--
> lib/Kconfig | 1 +
> lib/uuid.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++-------
> 3 files changed, 67 insertions(+), 9 deletions(-)
>
> diff --git a/include/uuid.h b/include/uuid.h
> index f5a941250f48..1f4fa103b5e9 100644
> --- a/include/uuid.h
> +++ b/include/uuid.h
> @@ -10,8 +10,9 @@
> #ifndef __UUID_H__
> #define __UUID_H__
>
> #include <linux/bitops.h>
> +#include <linux/kconfig.h>
>
> /*
> * UUID - Universally Unique IDentifier - 128 bits unique number.
> * There are 5 versions and one variant of UUID defined by RFC4122
> @@ -45,10 +46,10 @@
> * where x is a hexadecimal character. Fields are separated by '-'s.
> * When converting to a binary UUID, le means the field should be converted
> * to little endian and be means it should be converted to big endian.
> *
> - * UUID is also used as GUID (Globally Unique Identifier) with the same binary
> - * format but it differs in string format like below.
> + * UUID is also used as GUID (Globally Unique Identifier) with the same format
> + * but with some fields stored in little endian.
> *
> * GUID:
> * 0 9 14 19 24
> * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
> @@ -142,8 +143,20 @@ void gen_rand_uuid(unsigned char *uuid_bin);
> * @param - uuid output type: UUID - 0, GUID - 1
> */
> void gen_rand_uuid_str(char *uuid_str, int str_format);
>
> +struct efi_guid;
> +
> +/**
> + * gen_v5_guid() - generate little endian v5 GUID from namespace and other seed data.
> + *
> + * @namespace: pointer to UUID namespace salt
> + * @guid: pointer to allocated GUID output
> + * @...: NULL terminated list of seed data as pairs of pointers
> + * to data and their lengths
> + */
> +void gen_v5_guid(const struct uuid *namespace, struct efi_guid *guid, ...);
> +
> /**
> * uuid_str_to_le_bin() - Convert string UUID to little endian binary data.
> * @uuid_str: pointer to UUID string
> * @uuid_bin: pointer to allocated array for little endian output [16B]
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 2059219a1207..5a48c016d2c5 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -72,8 +72,9 @@ config HAVE_PRIVATE_LIBGCC
> bool
>
> config LIB_UUID
> bool
> + select SHA1
>
> config RANDOM_UUID
> bool "GPT Random UUID generation"
> select LIB_UUID
> diff --git a/lib/uuid.c b/lib/uuid.c
> index dfa2320ba267..24b5881600fd 100644
> --- a/lib/uuid.c
> +++ b/lib/uuid.c
> @@ -21,8 +21,9 @@
> #include <part_efi.h>
> #include <malloc.h>
> #include <dm/uclass.h>
> #include <rng.h>
> +#include <u-boot/sha1.h>
>
> int uuid_str_valid(const char *uuid)
> {
> int i, valid;
> @@ -368,8 +369,57 @@ void uuid_bin_to_str(const unsigned char *uuid_bin, char *uuid_str,
> }
> }
> }
>
> +static void configure_uuid(struct uuid *uuid, unsigned char version)
> +{
> + uint16_t tmp;
> +
> + /* Configure variant/version bits */
> + tmp = be16_to_cpu(uuid->time_hi_and_version);
> + tmp = (tmp & ~UUID_VERSION_MASK) | (version << UUID_VERSION_SHIFT);
> + uuid->time_hi_and_version = cpu_to_be16(tmp);
> +
> + uuid->clock_seq_hi_and_reserved &= ~UUID_VARIANT_MASK;
> + uuid->clock_seq_hi_and_reserved |= (UUID_VARIANT << UUID_VARIANT_SHIFT);
> +}
> +
> +void gen_v5_guid(const struct uuid *namespace, struct efi_guid *guid, ...)
> +{
> + sha1_context ctx;
> + va_list args;
> + const uint8_t *data;
> + uint32_t *tmp32;
> + uint16_t *tmp16;
> + uint8_t hash[SHA1_SUM_LEN];
> +
> + sha1_starts(&ctx);
> + /* Hash the namespace UUID as salt */
> + sha1_update(&ctx, (unsigned char *)namespace, UUID_BIN_LEN);
> + va_start(args, guid);
> +
> + while ((data = va_arg(args, const uint8_t *))) {
> + unsigned int len = va_arg(args, size_t);
> + sha1_update(&ctx, data, len);
> + }
> +
> + va_end(args);
> + sha1_finish(&ctx, hash);
> +
> + /* Truncate the hash into output UUID, it is already big endian */
> + memcpy(guid, hash, sizeof(*guid));
> +
> + configure_uuid((struct uuid *)guid, 5);
> +
> + /* Make little endian */
> + tmp32 = (uint32_t *)&guid->b[0];
> + *tmp32 = cpu_to_le32(be32_to_cpu(*tmp32));
> + tmp16 = (uint16_t *)&guid->b[4];
> + *tmp16 = cpu_to_le16(be16_to_cpu(*tmp16));
> + tmp16 = (uint16_t *)&guid->b[6];
> + *tmp16 = cpu_to_le16(be16_to_cpu(*tmp16));
> +}
> +
> #if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
> void gen_rand_uuid(unsigned char *uuid_bin)
> {
> u32 ptr[4];
> @@ -394,15 +444,9 @@ void gen_rand_uuid(unsigned char *uuid_bin)
> /* Set all fields randomly */
> for (i = 0; i < 4; i++)
> ptr[i] = rand();
>
> - clrsetbits_be16(&uuid->time_hi_and_version,
> - UUID_VERSION_MASK,
> - UUID_VERSION << UUID_VERSION_SHIFT);
> -
> - clrsetbits_8(&uuid->clock_seq_hi_and_reserved,
> - UUID_VARIANT_MASK,
> - UUID_VARIANT << UUID_VARIANT_SHIFT);
> + configure_uuid(uuid, UUID_VERSION);
>
> memcpy(uuid_bin, uuid, 16);
> }
>
>
> --
> 2.46.0
>
The series doesn't apply over -next or -master. Can you rebase and
resend so I can run the CI?
Also, checkpatch reports some minor issues, make sure you address
those on the rebase
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
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