Mercurial > dropbear
view libtomcrypt/src/pk/asn1/der/bit/der_length_bit_string.c @ 553:8711f20b89ab
- For uclinux, only cleanup on exit for the main process. This avoids
trashing the state when a failing child exits.
author | Matt Johnston <matt@ucc.asn.au> |
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date | Thu, 09 Jul 2009 16:01:30 +0000 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* 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_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: 1.2 $ */ /* $Date: 2006/03/31 14:15:35 $ */