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| author | Karel Zak | 2018-08-31 12:27:32 +0200 |
|---|---|---|
| committer | Karel Zak | 2018-08-31 12:43:17 +0200 |
| commit | d6ddf07d31dfdc894eb8e7e6842aa856342c526e (patch) | |
| tree | a498e9dfeac43c6e48716caad52a391e6b92dfbb /libuuid | |
| parent | libuuid: add note about RFC4122 UUID layout (diff) | |
| download | kernel-qcow2-util-linux-d6ddf07d31dfdc894eb8e7e6842aa856342c526e.tar.gz kernel-qcow2-util-linux-d6ddf07d31dfdc894eb8e7e6842aa856342c526e.tar.xz kernel-qcow2-util-linux-d6ddf07d31dfdc894eb8e7e6842aa856342c526e.zip | |
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 <kzak@redhat.com>
Diffstat (limited to 'libuuid')
| -rw-r--r-- | libuuid/src/gen_uuid.c | 34 |
1 files changed, 16 insertions, 18 deletions
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); } - |