Mercurial > dropbear
diff src/pk/asn1/der/utf8/der_length_utf8_string.c @ 380:d5faf4814ddb libtomcrypt-orig libtomcrypt-1.16
Update to LibTomCrypt 1.16
author | Matt Johnston <matt@ucc.asn.au> |
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date | Thu, 11 Jan 2007 02:22:00 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/pk/asn1/der/utf8/der_length_utf8_string.c Thu Jan 11 02:22:00 2007 +0000 @@ -0,0 +1,83 @@ +/* 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, [email protected], 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 $ */