2 years later, Ubuntu is still shipping a broken newlib, and Rob points

out writing 4 bytes into a 1-byte value is probably not a good idea.
So sscanf the string into an array of uint16_t, and copy out the low
bytes. It's a kludge, but the alternatives are worse (e.g. bypass sscanf,
and parse raw bytes).

1 files changed, 23 insertions, 25 deletions

diff --git a/uuid.c b/uuid.c
index dacd031..1ca219d 100644
--- a/uuid.c
+++ b/uuid.c
@@ -4,6 +4,8 @@
  * UUID support for keystore database.
  *
  * Copyright (c) 2016, NORDUnet A/S All rights reserved.
+ * Copyright: 2020, The Commons Conservancy Cryptech Project
+ * SPDX-License-Identifier: BSD-3-Clause
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -15,9 +17,9 @@
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  *
- * - Neither the name of the NORDUnet nor the names of its contributors may
- *   be used to endorse or promote products derived from this software
- *   without specific prior written permission.
+ * - Neither the name of the copyright holder nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
@@ -71,19 +73,19 @@ hal_error_t hal_uuid_gen(hal_uuid_t *uuid)
 hal_error_t hal_uuid_parse(hal_uuid_t *uuid, const char * const string)
 {
   static const char fmt[]
-    = "%2x%2x%2x%2x-%2x%2x-%2x%2x-%2x%2x-%2x%2x%2x%2x%2x%2x";
-
-  if (uuid == NULL || string == NULL ||
-      sscanf(string, fmt,
-             (unsigned *)(uuid->uuid +  0), (unsigned *)(uuid->uuid +  1),
-             (unsigned *)(uuid->uuid +  2), (unsigned *)(uuid->uuid +  3),
-             (unsigned *)(uuid->uuid +  4), (unsigned *)(uuid->uuid +  5),
-             (unsigned *)(uuid->uuid +  6), (unsigned *)(uuid->uuid +  7),
-             (unsigned *)(uuid->uuid +  8), (unsigned *)(uuid->uuid +  9),
-             (unsigned *)(uuid->uuid + 10), (unsigned *)(uuid->uuid + 11),
-             (unsigned *)(uuid->uuid + 12), (unsigned *)(uuid->uuid + 13),
-             (unsigned *)(uuid->uuid + 14), (unsigned *)(uuid->uuid + 15)) != 16)
-    return HAL_ERROR_BAD_ARGUMENTS;
+    = "%2hx%2hx%2hx%2hx-%2hx%2hx-%2hx%2hx-%2hx%2hx-%2hx%2hx%2hx%2hx%2hx%2hx";
+  uint16_t tmp[16];
+
+   if (uuid == NULL || string == NULL ||
+       sscanf(string, fmt,
+	     tmp +  0, tmp +  1, tmp +  2, tmp +  3,
+	     tmp +  4, tmp +  5, tmp +  6, tmp +  7,
+	     tmp +  8, tmp +  9, tmp + 10, tmp + 11,
+	     tmp + 12, tmp + 13, tmp + 14, tmp + 15) != 16)
+     return HAL_ERROR_BAD_ARGUMENTS;
+
+   for (unsigned i = 0; i < 16; ++i)
+     uuid->uuid[i] = tmp[i] & 0xff;
 
   return HAL_OK;
 }
@@ -91,20 +93,16 @@ hal_error_t hal_uuid_parse(hal_uuid_t *uuid, const char * const string)
 hal_error_t hal_uuid_format(const hal_uuid_t * const uuid, char *buffer, const size_t buffer_len)
 {
   static const char fmt[]
-    = "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x";
+    = "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx";
 
   if (uuid == NULL || buffer == NULL || buffer_len < HAL_UUID_TEXT_SIZE)
     return HAL_ERROR_BAD_ARGUMENTS;
 
   if (snprintf(buffer, buffer_len, fmt,
-               (unsigned)uuid->uuid[ 0], (unsigned)uuid->uuid[ 1],
-               (unsigned)uuid->uuid[ 2], (unsigned)uuid->uuid[ 3],
-               (unsigned)uuid->uuid[ 4], (unsigned)uuid->uuid[ 5],
-               (unsigned)uuid->uuid[ 6], (unsigned)uuid->uuid[ 7],
-               (unsigned)uuid->uuid[ 8], (unsigned)uuid->uuid[ 9],
-               (unsigned)uuid->uuid[10], (unsigned)uuid->uuid[11],
-               (unsigned)uuid->uuid[12], (unsigned)uuid->uuid[13],
-               (unsigned)uuid->uuid[14], (unsigned)uuid->uuid[15]) != HAL_UUID_TEXT_SIZE - 1)
+               uuid->uuid[ 0], uuid->uuid[ 1], uuid->uuid[ 2], uuid->uuid[ 3],
+               uuid->uuid[ 4], uuid->uuid[ 5], uuid->uuid[ 6], uuid->uuid[ 7],
+               uuid->uuid[ 8], uuid->uuid[ 9], uuid->uuid[10], uuid->uuid[11],
+               uuid->uuid[12], uuid->uuid[13], uuid->uuid[14], uuid->uuid[15]) != HAL_UUID_TEXT_SIZE - 1)
     return HAL_ERROR_RESULT_TOO_LONG;
 
   return HAL_OK;