diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c')
-rw-r--r-- | core/lib/libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c b/core/lib/libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c new file mode 100644 index 0000000..3966716 --- /dev/null +++ b/core/lib/libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2001-2007, Tom St Denis + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* 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://libtom.org + */ +#include "tomcrypt.h" + +/** + @file der_length_bit_string.c + ASN.1 DER, get length of BIT STRING, Tom St Denis +*/ + +#ifdef LTC_DER +/** + Gets length of DER encoding of BIT STRING + @param nbits The number of bits 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_bit_string(unsigned long nbits, unsigned long *outlen) +{ + unsigned long nbytes; + LTC_ARGCHK(outlen != NULL); + + /* get the number of the bytes */ + nbytes = (nbits >> 3) + ((nbits & 7) ? 1 : 0) + 1; + + if (nbytes < 128) { + /* 03 LL PP DD DD DD ... */ + *outlen = 2 + nbytes; + } else if (nbytes < 256) { + /* 03 81 LL PP DD DD DD ... */ + *outlen = 3 + nbytes; + } else if (nbytes < 65536) { + /* 03 82 LL LL PP DD DD DD ... */ + *outlen = 4 + nbytes; + } else { + return CRYPT_INVALID_ARG; + } + + return CRYPT_OK; +} + +#endif + + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2006/12/28 01:27:24 $ */ |