Mercurial > dropbear
view libtomcrypt/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c @ 397:2908122e9eed channel-fix
disapproval of revision '1250b8af44b62d8f4fe0f8d9fc7e7a1cc34e7e1c'
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sat, 03 Feb 2007 08:10:09 +0000 |
parents | 1b9e69c058d2 |
children | 0cbe8f6dbf9e |
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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.org */ #include "tomcrypt.h" /** @file der_decode_object_identifier.c ASN.1 DER, Decode Object Identifier, Tom St Denis */ #ifdef LTC_DER /** Decode OID data and store the array of integers in words @param in The OID DER encoded data @param inlen The length of the OID data @param words [out] The destination of the OID words @param outlen [in/out] The number of OID words @return CRYPT_OK if successful */ int der_decode_object_identifier(const unsigned char *in, unsigned long inlen, unsigned long *words, unsigned long *outlen) { unsigned long x, y, t, len; LTC_ARGCHK(in != NULL); LTC_ARGCHK(words != NULL); LTC_ARGCHK(outlen != NULL); /* header is at least 3 bytes */ if (inlen < 3) { return CRYPT_INVALID_PACKET; } /* must be room for at least two words */ if (*outlen < 2) { return CRYPT_BUFFER_OVERFLOW; } /* decode the packet header */ x = 0; if ((in[x++] & 0x1F) != 0x06) { return CRYPT_INVALID_PACKET; } /* get the length */ if (in[x] < 128) { len = in[x++]; } else { if (in[x] < 0x81 || in[x] > 0x82) { return CRYPT_INVALID_PACKET; } y = in[x++] & 0x7F; len = 0; while (y--) { len = (len << 8) | (unsigned long)in[x++]; } } if (len < 1 || (len + x) > inlen) { return CRYPT_INVALID_PACKET; } /* decode word1 and word2 */ --len; t = in[x++]; words[0] = t/40; words[1] = t%40; /* decode rest */ y = 2; t = 0; while (len--) { t = (t << 7) | (in[x] & 0x7F); if (!(in[x++] & 0x80)) { /* store t */ if (y >= *outlen) { return CRYPT_BUFFER_OVERFLOW; } words[y++] = t; t = 0; } } *outlen = y; return CRYPT_OK; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c,v $ */ /* $Revision: 1.1 $ */ /* $Date: 2005/05/16 15:08:11 $ */