diff options
Diffstat (limited to 'crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c')
-rw-r--r-- | crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c b/crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c new file mode 100644 index 00000000000..c49415951b2 --- /dev/null +++ b/crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c @@ -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, tomstdenis@gmail.com, http://libtom.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: 1.3 $ */ +/* $Date: 2006/12/28 01:27:24 $ */ |