Hi Caleb,
On Fri, 31 May 2024 at 07:50, Caleb Connolly <caleb.conno...@linaro.org> wrote:
>
> Add support for generating version 5 UUIDs, these are determistic and work
spelling
> 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.
>
> Tests for this are added in an upcoming patch.
>
> Signed-off-by: Caleb Connolly <caleb.conno...@linaro.org>
> ---
> include/uuid.h | 17 +++++++++++++++++
> lib/Kconfig | 8 ++++++++
> lib/uuid.c | 37 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 62 insertions(+)
>
> diff --git a/include/uuid.h b/include/uuid.h
> index f5a941250f48..539affaa47b9 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
> @@ -142,8 +143,24 @@ 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);
>
> +#if IS_ENABLED(CONFIG_UUID_GEN_V5)
> +/**
> + * gen_uuid_v5() - generate UUID v5 from namespace and other seed data.
> + *
> + * @namespace: pointer to UUID namespace salt
> + * @uuid: pointer to allocated UUID output
> + * @...: NULL terminated list of seed data as pairs of pointers
> + * to data and their lengths
> + */
> +void gen_uuid_v5(const struct uuid *namespace, struct uuid *uuid, ...);
> +#else
> +static inline void gen_uuid_v5(const struct uuid *namespace, struct uuid
> *uuid, ...)
> +{
> +}
> +#endif
Can you explain somewhere why the static inline is needed?
> +
> /**
> * 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 189e6eb31aa1..2941532f25cf 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -80,8 +80,16 @@ config RANDOM_UUID
> help
> Enable the generation of partitions with random UUIDs if none
> are provided.
>
> +config UUID_GEN_V5
> + bool "Enable UUID version 5 generation"
> + select LIB_UUID
> + depends on SHA1
> + help
> + Enable the generation of version 5 UUIDs, these are determistic and
spelling
> + generated from a namespace UUID, and a string (such as a board
> name).
> +
> config SPL_LIB_UUID
> depends on SPL
> bool
>
> diff --git a/lib/uuid.c b/lib/uuid.c
> index dfa2320ba267..2df0523e717f 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 +369,44 @@ void uuid_bin_to_str(const unsigned char *uuid_bin, char
> *uuid_str,
> }
> }
> }
>
> +#if IS_ENABLED(CONFIG_UUID_GEN_V5)
> +void gen_uuid_v5(const struct uuid *namespace, struct uuid *uuid, ...)
> +{
> + sha1_context ctx;
> + va_list args;
> + const uint8_t *data;
> + uint8_t hash[SHA1_SUM_LEN];
> + uint32_t tmp;
> +
> + sha1_starts(&ctx);
> + /* Hash the namespace UUID as salt */
> + sha1_update(&ctx, (unsigned char *)namespace, UUID_BIN_LEN);
> + va_start(args, uuid);
> +
> + 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(uuid, hash, sizeof(*uuid));
> +
> + /* Configure variant/version bits */
> + tmp = be32_to_cpu(uuid->time_hi_and_version);
> + tmp = (tmp & ~UUID_VERSION_MASK) | (5 << UUID_VERSION_SHIFT);
> + uuid->time_hi_and_version = cpu_to_be32(tmp);
> +
> + uuid->clock_seq_hi_and_reserved &= UUID_VARIANT_MASK;
> + uuid->clock_seq_hi_and_reserved |= UUID_VARIANT << UUID_VARIANT_SHIFT;
> +}
> +#endif
> +
> #if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
> void gen_rand_uuid(unsigned char *uuid_bin)
> {
> u32 ptr[4];
>
> --
> 2.45.0
>
Regards,
Simon
