From d6ddf07d31dfdc894eb8e7e6842aa856342c526e Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Fri, 31 Aug 2018 12:27:32 +0200 Subject: libuuid: fix name-based UUIDs The current version is not fully compatible with RFC4122. It incorrectly encodes UUID variant xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx where M is UUID version and N is UUID variant. $ python -c "import uuid ; print(uuid.uuid5(uuid.UUID(int=0), 'foo'))" aa752cea-8222-5bc8-acd9-555b090c0ccb ^^ Old version: $ uuidgen --namespace 00000000-0000-0000-0000-000000000000 --name 'foo' --sha1 aa752cea-8222-5bc8-8cd9-555b090c0ccb ^^ Fixed version: ./uuidgen --namespace 00000000-0000-0000-0000-000000000000 --name 'foo' --sha1; aa752cea-8222-5bc8-acd9-555b090c0ccb ^^ The patch uses uuid_unpack and uuid_pack. It makes code more readable and allow to access proper octens. The same way we already use for time and random based UUIDs. Addresses: https://github.com/karelzak/util-linux/issues/683 Signed-off-by: Karel Zak --- libuuid/src/gen_uuid.c | 34 ++++++++++++++++------------------ 1 file changed, 16 insertions(+), 18 deletions(-) (limited to 'libuuid') diff --git a/libuuid/src/gen_uuid.c b/libuuid/src/gen_uuid.c index a374e75c9..27c135db5 100644 --- a/libuuid/src/gen_uuid.c +++ b/libuuid/src/gen_uuid.c @@ -96,9 +96,6 @@ #define THREAD_LOCAL static #endif -/* index with UUID_VARIANT_xxx and shift 5 bits */ -static unsigned char variant_bits[] = { 0x00, 0x04, 0x06, 0x07 }; - #ifdef _WIN32 static void gettimeofday (struct timeval *tv, void *dummy) { @@ -566,21 +563,22 @@ void uuid_generate_md5(uuid_t out, const uuid_t ns, const char *name, size_t len { UL_MD5_CTX ctx; char hash[UL_MD5LENGTH]; + uuid_t buf; + struct uuid uu; ul_MD5Init(&ctx); - /* hash concatenation of well-known UUID with name */ ul_MD5Update(&ctx, ns, sizeof(uuid_t)); ul_MD5Update(&ctx, (const unsigned char *)name, len); - ul_MD5Final((unsigned char *)hash, &ctx); - memcpy(out, hash, sizeof(uuid_t)); + assert(sizeof(buf) <= sizeof(hash)); - out[6] &= ~(UUID_TYPE_MASK << UUID_TYPE_SHIFT); - out[6] |= (UUID_TYPE_DCE_MD5 << UUID_TYPE_SHIFT); + memcpy(buf, hash, sizeof(buf)); + uuid_unpack(buf, &uu); - out[8] &= ~(UUID_VARIANT_MASK << UUID_VARIANT_SHIFT); - out[8] |= (variant_bits[UUID_VARIANT_DCE] << UUID_VARIANT_SHIFT); + uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000; + uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x3000; + uuid_pack(&uu, out); } /* @@ -591,20 +589,20 @@ void uuid_generate_sha1(uuid_t out, const uuid_t ns, const char *name, size_t le { UL_SHA1_CTX ctx; char hash[UL_SHA1LENGTH]; + uuid_t buf; + struct uuid uu; ul_SHA1Init(&ctx); - /* hash concatenation of well-known UUID with name */ ul_SHA1Update(&ctx, ns, sizeof(uuid_t)); ul_SHA1Update(&ctx, (const unsigned char *)name, len); - ul_SHA1Final((unsigned char *)hash, &ctx); - memcpy(out, hash, sizeof(uuid_t)); + assert(sizeof(buf) <= sizeof(hash)); - out[6] &= ~(UUID_TYPE_MASK << UUID_TYPE_SHIFT); - out[6] |= (UUID_TYPE_DCE_SHA1 << UUID_TYPE_SHIFT); + memcpy(buf, hash, sizeof(buf)); + uuid_unpack(buf, &uu); - out[8] &= ~(UUID_VARIANT_MASK << UUID_VARIANT_SHIFT); - out[8] |= (variant_bits[UUID_VARIANT_DCE] << UUID_VARIANT_SHIFT); + uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000; + uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x5000; + uuid_pack(&uu, out); } - -- cgit v1.2.3-55-g7522