diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c')
-rw-r--r-- | core/lib/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c b/core/lib/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c new file mode 100644 index 0000000..a857933 --- /dev/null +++ b/core/lib/libtomcrypt/src/pk/asn1/der/bit/der_decode_raw_bit_string.c @@ -0,0 +1,133 @@ +/* + * Copyright (c) 2001-2007, Tom St Denis + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* 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_decode_bit_string.c + ASN.1 DER, encode a BIT STRING, Tom St Denis +*/ + + +#ifdef LTC_DER + +#define SETBIT(v, n) (v=((unsigned char)(v) | (1U << (unsigned char)(n)))) + +/** + Store a BIT STRING + @param in The DER encoded BIT STRING + @param inlen The size of the DER BIT STRING + @param out [out] The array of bits stored (8 per char) + @param outlen [in/out] The number of bits stored + @return CRYPT_OK if successful +*/ +int der_decode_raw_bit_string(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen) +{ + unsigned long dlen, blen, x, y; + + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + + /* packet must be at least 4 bytes */ + if (inlen < 4) { + return CRYPT_INVALID_ARG; + } + + /* check for 0x03 */ + if ((in[0]&0x1F) != 0x03) { + return CRYPT_INVALID_PACKET; + } + + /* offset in the data */ + x = 1; + + /* get the length of the data */ + if (in[x] & 0x80) { + /* long format get number of length bytes */ + y = in[x++] & 0x7F; + + /* invalid if 0 or > 2 */ + if (y == 0 || y > 2) { + return CRYPT_INVALID_PACKET; + } + + /* read the data len */ + dlen = 0; + while (y--) { + dlen = (dlen << 8) | (unsigned long)in[x++]; + } + } else { + /* short format */ + dlen = in[x++] & 0x7F; + } + + /* is the data len too long or too short? */ + if ((dlen == 0) || (dlen + x > inlen)) { + return CRYPT_INVALID_PACKET; + } + + /* get padding count */ + blen = ((dlen - 1) << 3) - (in[x++] & 7); + + /* too many bits? */ + if (blen > *outlen) { + *outlen = blen; + return CRYPT_BUFFER_OVERFLOW; + } + + /* decode/store the bits */ + for (y = 0; y < blen; y++) { + if (in[x] & (1 << (7 - (y & 7)))) { + SETBIT(out[y/8], 7-(y%8)); + } + if ((y & 7) == 7) { + ++x; + } + } + + /* we done */ + *outlen = blen; + return CRYPT_OK; +} + +#endif + +/* $Source$ */ +/* $Revision$ */ +/* $Date$ */ |