From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Thu, 20 Apr 2023 20:27:57 +0000 (+0300)
Subject: lib: guid - Add guid_uuid4_generate()
X-Git-Tag: 2.4.0~2776
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=07e2010125fe44525bab646b9230c374e0cf2690;p=thirdparty%2Fdovecot%2Fcore.git

lib: guid - Add guid_uuid4_generate()

Generates a UUIDv4 UUID
---

diff --git a/src/lib/guid.c b/src/lib/guid.c
index 7a825fd5cd..1bafbcf25d 100644
--- a/src/lib/guid.c
+++ b/src/lib/guid.c
@@ -9,6 +9,7 @@
 #include "hex-binary.h"
 #include "hostpid.h"
 #include "guid.h"
+#include "randgen.h"
 
 #include <unistd.h>
 #include <time.h>
@@ -93,6 +94,13 @@ void guid_128_generate(guid_128_t guid_r)
 	memcpy(guid_r + 8, guid_static, 8);
 }
 
+void guid_128_uuid4_generate(guid_128_t uuid)
+{
+	random_fill(uuid, sizeof(guid_128_t));
+	uuid[6] = (uuid[6] & 0x0F) | 0x40; /* Set version 4 */
+	uuid[8] = (uuid[8] & 0xBF) | 0x80; /* Set variant 2 (first 2 bits to 10) */
+}
+
 bool guid_128_is_empty(const guid_128_t guid)
 {
 	unsigned int i;
diff --git a/src/lib/guid.h b/src/lib/guid.h
index 0bf58d85f7..5ed628c78f 100644
--- a/src/lib/guid.h
+++ b/src/lib/guid.h
@@ -8,6 +8,10 @@ typedef uint8_t guid_128_t[GUID_128_SIZE];
 
 ARRAY_DEFINE_TYPE(guid_128_t, guid_128_t);
 
+/* Very liberal check, checks only version. */
+#define GUID_128_IS_UUID4(uuid) \
+	(((uuid)[6] & 0xF0) == 0x40)
+
 enum uuid_format {
 	FORMAT_RECORD,
 	FORMAT_COMPACT,
@@ -17,6 +21,9 @@ enum uuid_format {
 const char *guid_generate(void);
 /* Generate 128 bit GUID */
 void guid_128_generate(guid_128_t guid_r);
+/* Generate UUID4gen1 */
+void guid_128_uuid4_generate(guid_128_t guid_r);
+
 /* Returns TRUE if GUID is empty (not set / unknown). */
 bool guid_128_is_empty(const guid_128_t guid) ATTR_PURE;
 static inline void guid_128_empty(guid_128_t guid)
diff --git a/src/lib/test-guid.c b/src/lib/test-guid.c
index 0a13cf1142..268a89b13e 100644
--- a/src/lib/test-guid.c
+++ b/src/lib/test-guid.c
@@ -174,7 +174,7 @@ void test_guid(void)
 	  0xab, 0xcd, 0xef,
 	  0xAB, 0xCD, 0xEF,
 	  0x00, 0x00, 0x00, 0x00, 0x00 };
-	guid_128_t guid1, guid2, guid3;
+	guid_128_t guid1, guid2, guid3, guid_empty;
 	const char *str;
 	char guidbuf[GUID_128_SIZE*2 + 2];
 	unsigned int i;
@@ -242,6 +242,8 @@ void test_guid(void)
 	guidbuf[0] = ' ';
 	test_assert(guid_128_from_string(guidbuf, guid3) < 0);
 
+	test_assert(guid_128_from_uuid_string("00000000-0000-0000-0000-000000000000", guid_empty) == 0);
+	test_assert(guid_128_is_empty(guid_empty));
 	test_assert(guid_128_from_uuid_string("fee0ceac-0327-11e7-ad39-52540078f374", guid3) == 0);
 	test_assert(guid_128_from_uuid_string("fee0ceac032711e7ad3952540078f374", guid2) == 0);
 	test_assert(guid_128_cmp(guid3, guid2) == 0);
@@ -253,6 +255,12 @@ void test_guid(void)
 	/* failure test */
 	test_assert(guid_128_from_uuid_string("fe-e0ceac-0327-11e7-ad39-52540078f374", guid3) < 0);
 
+	/* UUIDv4 */
+	guid_128_t uuidv4;
+	guid_128_uuid4_generate(uuidv4);
+	test_assert((uuidv4[6] & 0xF0) == 0x40);
+	test_assert((uuidv4[8] & 0xC0) == 0x80);
+
 	test_end();
 
 	test_ioloop_guid_128_generate();