Changeset 0f6a85ae in mainline

Timestamp:

2019-02-15T13:34:23Z (6 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

43dd2d4b

Parents:

9f4ce50

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2019-02-15 13:28:51)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2019-02-15 13:34:23)

Message:

Fix version 4 UUID generation

According to the standard, the 4 most significant bits of b[6]
are to be 0x4. Our code accidentally cleared the wrong portion
of the byte.
Also the most significant bit of b[8] should be 1 and the second
most significant should be 0. Our code had them swapped.

Found by Matthieu Riolo, thanks!

File:

• uspace/lib/c/generic/uuid.c (modified) (1 diff)

uspace/lib/c/generic/uuid.c

@@ -64 +64 @@
 
         /* Version 4 UUID from random or pseudo-random numbers */
-        uuid->b[8] = (uuid->b[8] & ~0xc0) | 0x40;
-        uuid->b[6] = (uuid->b[6] & 0xf0) | 0x40;
+        uuid->b[6] = (uuid->b[6] & 0x0f) | 0x40;
+        uuid->b[8] = (uuid->b[8] & 0x3f) | 0x80;
 
         return EOK;