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