Mercurial > dropbear
view libtomcrypt/src/pk/asn1/der/bit/der_decode_bit_string.c @ 1368:10df23099071 fuzz
split out checkpubkey_line() separately
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 23 May 2017 22:29:21 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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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.com */ #include "tomcrypt.h" /** @file der_decode_bit_string.c ASN.1 DER, encode a BIT STRING, Tom St Denis */ #ifdef LTC_DER /** 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 (one per char) @param outlen [in/out] The number of bits stored @return CRYPT_OK if successful */ int der_decode_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++) { out[y] = (in[x] & (1 << (7 - (y & 7)))) ? 1 : 0; if ((y & 7) == 7) { ++x; } } /* we done */ *outlen = blen; return CRYPT_OK; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/bit/der_decode_bit_string.c,v $ */ /* $Revision: 1.4 $ */ /* $Date: 2006/06/16 21:53:41 $ */