X-Git-Url: https://git.pterodactylus.net/?p=fms.git;a=blobdiff_plain;f=libs%2Flibtomcrypt%2Fpk%2Fasn1%2Fder%2Fobject_identifier%2Fder_encode_object_identifier.c;fp=libs%2Flibtomcrypt%2Fpk%2Fasn1%2Fder%2Fobject_identifier%2Fder_encode_object_identifier.c;h=b343aaa74361ac332a47df5a3c3d21620b558815;hp=0000000000000000000000000000000000000000;hb=109c20e6f822c6efa465af31249e5608469253b6;hpb=9ae3b1434e51788e6feb72e1415ec800d05c535a diff --git a/libs/libtomcrypt/pk/asn1/der/object_identifier/der_encode_object_identifier.c b/libs/libtomcrypt/pk/asn1/der/object_identifier/der_encode_object_identifier.c new file mode 100644 index 0000000..b343aaa --- /dev/null +++ b/libs/libtomcrypt/pk/asn1/der/object_identifier/der_encode_object_identifier.c @@ -0,0 +1,111 @@ +/* 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_object_identifier.c + ASN.1 DER, Encode Object Identifier, Tom St Denis +*/ + +#ifdef LTC_DER +/** + Encode an OID + @param words The words to encode (upto 32-bits each) + @param nwords The number of words in the OID + @param out [out] Destination of OID data + @param outlen [in/out] The max and resulting size of the OID + @return CRYPT_OK if successful +*/ +int der_encode_object_identifier(unsigned long *words, unsigned long nwords, + unsigned char *out, unsigned long *outlen) +{ + unsigned long i, x, y, z, t, mask, wordbuf; + int err; + + LTC_ARGCHK(words != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + + /* check length */ + if ((err = der_length_object_identifier(words, nwords, &x)) != CRYPT_OK) { + return err; + } + if (x > *outlen) { + *outlen = x; + return CRYPT_BUFFER_OVERFLOW; + } + + /* compute length to store OID data */ + z = 0; + wordbuf = words[0] * 40 + words[1]; + for (y = 1; y < nwords; y++) { + t = der_object_identifier_bits(wordbuf); + z += t/7 + ((t%7) ? 1 : 0) + (wordbuf == 0 ? 1 : 0); + if (y < nwords - 1) { + wordbuf = words[y + 1]; + } + } + + /* store header + length */ + x = 0; + out[x++] = 0x06; + if (z < 128) { + out[x++] = (unsigned char)z; + } else if (z < 256) { + out[x++] = 0x81; + out[x++] = (unsigned char)z; + } else if (z < 65536UL) { + out[x++] = 0x82; + out[x++] = (unsigned char)((z>>8)&255); + out[x++] = (unsigned char)(z&255); + } else { + return CRYPT_INVALID_ARG; + } + + /* store first byte */ + wordbuf = words[0] * 40 + words[1]; + for (i = 1; i < nwords; i++) { + /* store 7 bit words in little endian */ + t = wordbuf & 0xFFFFFFFF; + if (t) { + y = x; + mask = 0; + while (t) { + out[x++] = (unsigned char)((t & 0x7F) | mask); + t >>= 7; + mask |= 0x80; /* upper bit is set on all but the last byte */ + } + /* now swap bytes y...x-1 */ + z = x - 1; + while (y < z) { + t = out[y]; out[y] = out[z]; out[z] = (unsigned char)t; + ++y; + --z; + } + } else { + /* zero word */ + out[x++] = 0x00; + } + + if (i < nwords - 1) { + wordbuf = words[i + 1]; + } + } + + *outlen = x; + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/object_identifier/der_encode_object_identifier.c,v $ */ +/* $Revision: 1.6 $ */ +/* $Date: 2006/12/04 21:34:03 $ */