From f942ba2c4c14b6bf7720e8316afe1971231553bc Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Fri, 31 Aug 2018 12:27:32 +0200
Subject: [PATCH 7/8] 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.
Upstream: http://github.com/karelzak/util-linux/commit/d6ddf07d31dfdc894eb8e7e6842aa856342c526e
Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1624877
Addresses: https://github.com/karelzak/util-linux/issues/683
Signed-off-by: Karel Zak <kzak@redhat.com>
---
libuuid/src/gen_uuid.c | 34 ++++++++++++++++------------------
1 file 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);
}
-
--
2.14.4