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comparison libtomcrypt/src/pk/asn1/der/utf8/der_length_utf8_string.c @ 382:0cbe8f6dbf9e

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propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f) to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 02:41:05 +0000
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children f849a5ca2efc
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379:b66a00272a90 382:0cbe8f6dbf9e
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtomcrypt.com
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file der_length_utf8_string.c
15 ASN.1 DER, get length of UTF8 STRING, Tom St Denis
16 */
17
18 #ifdef LTC_DER
19
20 /** Return the size in bytes of a UTF-8 character
21 @param c The UTF-8 character to measure
22 @return The size in bytes
23 */
24 unsigned long der_utf8_charsize(const wchar_t c)
25 {
26 if (c <= 0x7F) {
27 return 1;
28 } else if (c <= 0x7FF) {
29 return 2;
30 } else if (c <= 0xFFFF) {
31 return 3;
32 } else {
33 return 4;
34 }
35 }
36
37 /**
38 Gets length of DER encoding of UTF8 STRING
39 @param in The characters to measure the length of
40 @param noctets The number of octets in the string to encode
41 @param outlen [out] The length of the DER encoding for the given string
42 @return CRYPT_OK if successful
43 */
44 int der_length_utf8_string(const wchar_t *in, unsigned long noctets, unsigned long *outlen)
45 {
46 unsigned long x, len;
47
48 LTC_ARGCHK(in != NULL);
49 LTC_ARGCHK(outlen != NULL);
50
51 len = 0;
52 for (x = 0; x < noctets; x++) {
53 if (in[x] < 0 || in[x] > 0x10FFFF) {
54 return CRYPT_INVALID_ARG;
55 }
56 len += der_utf8_charsize(in[x]);
57 }
58
59 if (len < 128) {
60 /* 0C LL DD DD DD ... */
61 *outlen = 2 + len;
62 } else if (len < 256) {
63 /* 0C 81 LL DD DD DD ... */
64 *outlen = 3 + len;
65 } else if (len < 65536UL) {
66 /* 0C 82 LL LL DD DD DD ... */
67 *outlen = 4 + len;
68 } else if (len < 16777216UL) {
69 /* 0C 83 LL LL LL DD DD DD ... */
70 *outlen = 5 + len;
71 } else {
72 return CRYPT_INVALID_ARG;
73 }
74
75 return CRYPT_OK;
76 }
77
78 #endif
79
80
81 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/utf8/der_length_utf8_string.c,v $ */
82 /* $Revision: 1.5 $ */
83 /* $Date: 2006/12/16 17:41:21 $ */