diff options
Diffstat (limited to 'src/pk/asn1/der/utf8/der_encode_utf8_string.c')
-rw-r--r-- | src/pk/asn1/der/utf8/der_encode_utf8_string.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/src/pk/asn1/der/utf8/der_encode_utf8_string.c b/src/pk/asn1/der/utf8/der_encode_utf8_string.c new file mode 100644 index 0000000..2dd6081 --- /dev/null +++ b/src/pk/asn1/der/utf8/der_encode_utf8_string.c @@ -0,0 +1,105 @@ +/* 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_encode_utf8_string.c + ASN.1 DER, encode a UTF8 STRING, Tom St Denis +*/ + + +#ifdef LTC_DER + +/** + Store an UTF8 STRING + @param in The array of UTF8 to store (one per wchar_t) + @param inlen The number of UTF8 to store + @param out [out] The destination for the DER encoded UTF8 STRING + @param outlen [in/out] The max size and resulting size of the DER UTF8 STRING + @return CRYPT_OK if successful +*/ +int der_encode_utf8_string(const wchar_t *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen) +{ + unsigned long x, y, len; + + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + + /* get the size */ + for (x = len = 0; x < inlen; x++) { + if (in[x] < 0 || in[x] > 0x1FFFF) { + return CRYPT_INVALID_ARG; + } + len += der_utf8_charsize(in[x]); + } + + if (len < 128) { + y = 2 + len; + } else if (len < 256) { + y = 3 + len; + } else if (len < 65536UL) { + y = 4 + len; + } else if (len < 16777216UL) { + y = 5 + len; + } else { + return CRYPT_INVALID_ARG; + } + + /* too big? */ + if (y > *outlen) { + *outlen = len; + return CRYPT_BUFFER_OVERFLOW; + } + + /* encode the header+len */ + x = 0; + out[x++] = 0x0C; + if (len < 128) { + out[x++] = len; + } else if (len < 256) { + out[x++] = 0x81; + out[x++] = len; + } else if (len < 65536UL) { + out[x++] = 0x82; + out[x++] = (len>>8)&255; + out[x++] = len&255; + } else if (len < 16777216UL) { + out[x++] = 0x83; + out[x++] = (len>>16)&255; + out[x++] = (len>>8)&255; + out[x++] = len&255; + } else { + return CRYPT_INVALID_ARG; + } + + /* store UTF8 */ + for (y = 0; y < inlen; y++) { + switch (der_utf8_charsize(in[y])) { + case 1: out[x++] = in[y]; break; + case 2: out[x++] = 0xC0 | ((in[y] >> 6) & 0x1F); out[x++] = 0x80 | (in[y] & 0x3F); break; + case 3: out[x++] = 0xE0 | ((in[y] >> 12) & 0x0F); out[x++] = 0x80 | ((in[y] >> 6) & 0x3F); out[x++] = 0x80 | (in[y] & 0x3F); break; + case 4: out[x++] = 0xF0 | ((in[y] >> 18) & 0x07); out[x++] = 0x80 | ((in[y] >> 12) & 0x3F); out[x++] = 0x80 | ((in[y] >> 6) & 0x3F); out[x++] = 0x80 | (in[y] & 0x3F); break; + } + } + + /* retun length */ + *outlen = x; + + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/utf8/der_encode_utf8_string.c,v $ */ +/* $Revision: 1.7 $ */ +/* $Date: 2006/12/16 17:41:21 $ */ |