--- /dev/null
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+#include "tomcrypt.h"
+
+/**
+ @file der_length_utf8_string.c
+ ASN.1 DER, get length of UTF8 STRING, Tom St Denis
+*/
+
+#ifdef LTC_DER
+
+/** Return the size in bytes of a UTF-8 character
+ @param c The UTF-8 character to measure
+ @return The size in bytes
+*/
+unsigned long der_utf8_charsize(const wchar_t c)
+{
+ if (c <= 0x7F) {
+ return 1;
+ } else if (c <= 0x7FF) {
+ return 2;
+ } else if (c <= 0xFFFF) {
+ return 3;
+ } else {
+ return 4;
+ }
+}
+
+/**
+ Gets length of DER encoding of UTF8 STRING
+ @param in The characters to measure the length of
+ @param noctets The number of octets in the string to encode
+ @param outlen [out] The length of the DER encoding for the given string
+ @return CRYPT_OK if successful
+*/
+int der_length_utf8_string(const wchar_t *in, unsigned long noctets, unsigned long *outlen)
+{
+ unsigned long x, len;
+
+ LTC_ARGCHK(in != NULL);
+ LTC_ARGCHK(outlen != NULL);
+
+ len = 0;
+ for (x = 0; x < noctets; x++) {
+ if (in[x] < 0 || in[x] > 0x10FFFF) {
+ return CRYPT_INVALID_ARG;
+ }
+ len += der_utf8_charsize(in[x]);
+ }
+
+ if (len < 128) {
+ /* 0C LL DD DD DD ... */
+ *outlen = 2 + len;
+ } else if (len < 256) {
+ /* 0C 81 LL DD DD DD ... */
+ *outlen = 3 + len;
+ } else if (len < 65536UL) {
+ /* 0C 82 LL LL DD DD DD ... */
+ *outlen = 4 + len;
+ } else if (len < 16777216UL) {
+ /* 0C 83 LL LL LL DD DD DD ... */
+ *outlen = 5 + len;
+ } else {
+ return CRYPT_INVALID_ARG;
+ }
+
+ return CRYPT_OK;
+}
+
+#endif
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/utf8/der_length_utf8_string.c,v $ */
+/* $Revision: 1.5 $ */
+/* $Date: 2006/12/16 17:41:21 $ */