+#ifdef ENCODED_CHARACTER
+/*************************************************
+* Decode hex-encoded-character string *
+*************************************************/
+
+/*
+Encoding definition:
+ blank = SP / TAB / CRLF
+ hex-pair-seq = *blank hex-pair *(1*blank hex-pair) *blank
+ hex-pair = 1*2HEXDIG
+
+Arguments:
+ src points to a hex-pair-seq
+ end points to its end
+ dst points to the destination of the decoded octets,
+ optionally to (uschar*)0 for checking only
+
+Returns: >= 0 number of decoded octets
+ -1 syntax error
+*/
+
+static int
+hex_decode(uschar *src, uschar *end, uschar *dst)
+{
+int decoded = 0;
+
+while (*src == ' ' || *src == '\t' || *src == '\n') ++src;
+do
+ {
+ int x, d, n;
+
+ for (x = 0, d = 0;
+ d<2 && src<end && isxdigit(n = tolower(*src));
+ x = (x<<4)|(n>= '0' && n<= '9' ? n-'0' : 10+(n-'a')) , ++d, ++src) ;
+ if (d == 0) return -1;
+ if (dst) *dst++ = x;
+ ++decoded;
+ if (src == end) return decoded;
+ if (*src == ' ' || *src == '\t' || *src == '\n')
+ while (*src == ' ' || *src == '\t' || *src == '\n') ++src;
+ else
+ return -1;
+ }
+while (src < end);
+return decoded;
+}
+
+
+/*************************************************
+* Decode unicode-encoded-character string *
+*************************************************/
+
+/*
+Encoding definition:
+ blank = SP / TAB / CRLF
+ unicode-hex-seq = *blank unicode-hex *(blank unicode-hex) *blank
+ unicode-hex = 1*HEXDIG
+
+ It is an error for a script to use a hexadecimal value that isn't in
+ either the range 0 to D7FF or the range E000 to 10FFFF.
+
+ At this time, strings are already scanned, thus the CRLF is converted
+ to the internally used \n (should RFC_EOL have been used).
+
+Arguments:
+ src points to a unicode-hex-seq
+ end points to its end
+ dst points to the destination of the decoded octets,
+ optionally to (uschar*)0 for checking only
+
+Returns: >= 0 number of decoded octets
+ -1 syntax error
+ -2 semantic error (character range violation)
+*/
+
+static int
+unicode_decode(uschar *src, uschar *end, uschar *dst)
+{
+int decoded = 0;
+
+while (*src == ' ' || *src == '\t' || *src == '\n') ++src;
+do
+ {
+ uschar *hex_seq;
+ int c, d, n;
+
+ unicode_hex:
+ for (hex_seq = src; src < end && *src == '0'; ) src++;
+ for (c = 0, d = 0;
+ d < 7 && src < end && isxdigit(n = tolower(*src));
+ c = (c<<4)|(n>= '0' && n<= '9' ? n-'0' : 10+(n-'a')), ++d, ++src) ;
+ if (src == hex_seq) return -1;
+ if (d == 7 || (!((c >= 0 && c <= 0xd7ff) || (c >= 0xe000 && c <= 0x10ffff)))) return -2;
+ if (c<128)
+ {
+ if (dst) *dst++ = c;
+ ++decoded;
+ }
+ else if (c>= 0x80 && c<= 0x7ff)
+ {
+ if (dst)
+ {
+ *dst++ = 192+(c>>6);
+ *dst++ = 128+(c&0x3f);
+ }
+ decoded += 2;
+ }
+ else if (c>= 0x800 && c<= 0xffff)
+ {
+ if (dst)
+ {
+ *dst++ = 224+(c>>12);
+ *dst++ = 128+((c>>6)&0x3f);
+ *dst++ = 128+(c&0x3f);
+ }
+ decoded += 3;
+ }
+ else if (c>= 0x10000 && c<= 0x1fffff)
+ {
+ if (dst)
+ {
+ *dst++ = 240+(c>>18);
+ *dst++ = 128+((c>>10)&0x3f);
+ *dst++ = 128+((c>>6)&0x3f);
+ *dst++ = 128+(c&0x3f);
+ }
+ decoded += 4;
+ }
+ if (*src == ' ' || *src == '\t' || *src == '\n')
+ {
+ while (*src == ' ' || *src == '\t' || *src == '\n') ++src;
+ if (src == end) return decoded;
+ goto unicode_hex;
+ }
+ }
+while (src < end);
+return decoded;
+}
+
+