Mercurial > dropbear
diff src/pk/asn1/der/octet/der_length_octet_string.c @ 209:39d5d58461d6 libtomcrypt-orig LTC_1.05
Import of libtomcrypt 1.05
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 06 Jul 2005 03:53:40 +0000 |
parents | |
children | d5faf4814ddb |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/pk/asn1/der/octet/der_length_octet_string.c Wed Jul 06 03:53:40 2005 +0000 @@ -0,0 +1,53 @@ +/* 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.org + */ +#include "tomcrypt.h" + +/** + @file der_length_octet_string.c + ASN.1 DER, get length of OCTET STRING, Tom St Denis +*/ + +#ifdef LTC_DER +/** + Gets length of DER encoding of OCTET STRING + @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_octet_string(unsigned long noctets, unsigned long *outlen) +{ + LTC_ARGCHK(outlen != NULL); + + if (noctets < 128) { + /* 04 LL DD DD DD ... */ + *outlen = 2 + noctets; + } else if (noctets < 256) { + /* 04 81 LL DD DD DD ... */ + *outlen = 3 + noctets; + } else if (noctets < 65536UL) { + /* 04 82 LL LL DD DD DD ... */ + *outlen = 4 + noctets; + } else if (noctets < 16777216UL) { + /* 04 83 LL LL LL DD DD DD ... */ + *outlen = 5 + noctets; + } else { + return CRYPT_INVALID_ARG; + } + + return CRYPT_OK; +} + +#endif + + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/octet/der_length_octet_string.c,v $ */ +/* $Revision: 1.1 $ */ +/* $Date: 2005/05/16 15:08:11 $ */