bplist: Fix UID node parsing to match Apple's parser

Apple only allows 32 bit unsigned values for UID nodes. Also the encoding
of the length is different from the encoding used for other node types.
The nibble used to mark the size is 1 less than the actual size of the integer
value data, so 0 means 1 byte length 1 means 2 bytes length, etc.

1 files changed, 7 insertions, 14 deletions

diff --git a/src/bplist.c b/src/bplist.c
index ad8e753..9e6e261 100644
--- a/src/bplist.c
+++ b/src/bplist.c
@@ -496,22 +496,14 @@ static plist_t parse_array_node(struct bplist_data *bplist, const char** bnode,
 static plist_t parse_uid_node(const char **bnode, uint8_t size)
 {
     plist_data_t data = plist_new_plist_data();
-
-    size = 1 << size;                   // make length less misleading
-    switch (size)
-    {
-    case sizeof(uint8_t):
-    case sizeof(uint16_t):
-    case sizeof(uint32_t):
-    case sizeof(uint64_t):
-        memcpy(&data->intval, *bnode, size);
-        data->intval = UINT_TO_HOST(&data->intval, size);
-        break;
-    default:
+    size = size + 1;
+    data->intval = UINT_TO_HOST(*bnode, size);
+    if (data->intval > UINT32_MAX) {
         free(data);
         return NULL;
-    };
+    }
 
+    (*bnode) += size;
     data->type = PLIST_UID;
     data->length = sizeof(uint64_t);
 
@@ -1034,6 +1026,7 @@ static void write_dict(bytearray_t * bplist, node_t* node, hashtable_t* ref_tabl
 
 static void write_uid(bytearray_t * bplist, uint64_t val)
 {
+    val = (uint32_t)val;
     uint64_t size = get_needed_bytes(val);
     uint8_t *buff = NULL;
     //do not write 3bytes int node
@@ -1045,7 +1038,7 @@ static void write_uid(bytearray_t * bplist, uint64_t val)
 #endif
 
     buff = (uint8_t *) malloc(sizeof(uint8_t) + size);
-    buff[0] = BPLIST_UID | Log2(size);
+    buff[0] = BPLIST_UID | (size-1); // yes, this is what Apple does...
     memcpy(buff + 1, &val, size);
     byte_convert(buff + 1, size);
     byte_array_append(bplist, buff, sizeof(uint8_t) + size);