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Diffstat (limited to 'Crypto/src/util/zlib/Adler32.cs')
-rw-r--r-- | Crypto/src/util/zlib/Adler32.cs | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/Crypto/src/util/zlib/Adler32.cs b/Crypto/src/util/zlib/Adler32.cs new file mode 100644 index 000000000..c38258f2a --- /dev/null +++ b/Crypto/src/util/zlib/Adler32.cs @@ -0,0 +1,88 @@ +using System; +/* + * $Id: Adler32.cs,v 1.1 2006-07-31 13:59:25 bouncy Exp $ + * +Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. 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. + + 3. The names of the authors may not be used to endorse or promote products + derived from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 JCRAFT, +INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE 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. + */ +/* + * This program is based on zlib-1.1.3, so all credit should go authors + * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu) + * and contributors of zlib. + */ + +namespace Org.BouncyCastle.Utilities.Zlib { + + internal sealed class Adler32{ + + // largest prime smaller than 65536 + private const int BASE=65521; + // NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 + private const int NMAX=5552; + + internal long adler32(long adler, byte[] buf, int index, int len){ + if(buf == null){ return 1L; } + + long s1=adler&0xffff; + long s2=(adler>>16)&0xffff; + int k; + + while(len > 0) { + k=len<NMAX?len:NMAX; + len-=k; + while(k>=16){ + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + s1+=buf[index++]&0xff; s2+=s1; + k-=16; + } + if(k!=0){ + do{ + s1+=buf[index++]&0xff; s2+=s1; + } + while(--k!=0); + } + s1%=BASE; + s2%=BASE; + } + return (s2<<16)|s1; + } + + } +} \ No newline at end of file |