unichar: Do not accept invalid ranges

As per RFC3629

diff --git a/src/lib/unichar.c b/src/lib/unichar.c
index 944d08d43787b890a43ad42b0fd2613d715d3ca3..7ff0b53caebcca40b65dac06a610e56dcd545000 100644 (file)
--- a/src/lib/unichar.c
+++ b/src/lib/unichar.c
@@ -95,6 +95,10 @@ int uni_utf8_get_char_n(const void *_input, size_t max_len, unichar_t *chr_r)
                chr <<= 6;
                chr |= input[i] & 0x3f;
        }
+       /* these are specified as invalid encodings by standards
+          see RFC3629 */
+       if (!uni_is_valid_ucs4(chr))
+               return -1;
        if (chr < lowest_valid_chr) {
                /* overlong encoding */
                return -1;
@@ -153,7 +157,7 @@ void uni_ucs4_to_utf8_c(unichar_t chr, buffer_t *output)
                return;
        }
 
-       i_assert(chr < 0x80000000); /* 1 << (5*6 + 1) */
+       i_assert(uni_is_valid_ucs4(chr));
 
        if (chr < (1 << (6 + 5))) {
                /* 110xxxxx */