add vorbiscomment validation functions to format.c and test code; validate name part of vorbiscomment in metadata and metadata++ interfaces

1 files changed, 71 insertions, 0 deletions

diff --git a/src/libFLAC/format.c b/src/libFLAC/format.c
index d4ac5acb..d149928c 100644
--- a/src/libFLAC/format.c
+++ b/src/libFLAC/format.c
@@ -254,6 +254,77 @@ FLAC_API unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *se
         return j;
 }
 
+static __inline unsigned utf8len_(const FLAC__byte *utf8)
+{
+        FLAC__ASSERT(0 != utf8);
+        if ((utf8[0] & 0x80) == 0)
+                return 1;
+        else if ((utf8[0] & 0xE0) == 0xC0 && (utf8[1] & 0xC0) == 0x80)
+                return 2;
+        else if ((utf8[0] & 0xF0) == 0xE0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80)
+                return 3;
+        else
+                return 0;
+}
+
+FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name)
+{
+        char c;
+        for(c = *name; c; c = *(++name))
+                if(c < 0x20 || c == 0x3d || c > 0x7d)
+                        return false;
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, unsigned length)
+{
+        if(length == (unsigned)(-1)) {
+                while(*value) {
+                        unsigned n = utf8len_(value);
+                        if(n == 0)
+                                return false;
+                        value += n;
+                }
+        }
+        else {
+                const FLAC__byte *end = value + length;
+                while(value < end) {
+                        unsigned n = utf8len_(value);
+                        if(n == 0)
+                                return false;
+                        value += n;
+                }
+                if(value != end)
+                        return false;
+        }
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, unsigned length)
+{
+        const FLAC__byte *s, *end;
+
+        for(s = entry, end = s + length; s < end && *s != '='; s++) {
+                if(*s < 0x20 || *s > 0x7D)
+                        return false;
+        }
+        if(s == end)
+                return false;
+
+        s++; /* skip '=' */
+
+        while(s < end) {
+                unsigned n = utf8len_(s);
+                if(n == 0)
+                        return false;
+                s += n;
+        }
+        if(s != end)
+                return false;
+
+        return true;
+}
+
 FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation)
 {
         unsigned i, j;