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Editing: BN_mask_bits.html
<?xml version="1.0" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>BN_set_bit</title> <meta http-equiv="content-type" content="text/html; charset=utf-8" /> <link rev="made" href="mailto:root@localhost" /> </head> <body> <ul id="index"> <li><a href="#NAME">NAME</a></li> <li><a href="#SYNOPSIS">SYNOPSIS</a></li> <li><a href="#DESCRIPTION">DESCRIPTION</a></li> <li><a href="#RETURN-VALUES">RETURN VALUES</a></li> <li><a href="#SEE-ALSO">SEE ALSO</a></li> <li><a href="#COPYRIGHT">COPYRIGHT</a></li> </ul> <h1 id="NAME">NAME</h1> <p>BN_set_bit, BN_clear_bit, BN_is_bit_set, BN_mask_bits, BN_lshift, BN_lshift1, BN_rshift, BN_rshift1 - bit operations on BIGNUMs</p> <h1 id="SYNOPSIS">SYNOPSIS</h1> <pre><code> #include <openssl/bn.h> int BN_set_bit(BIGNUM *a, int n); int BN_clear_bit(BIGNUM *a, int n); int BN_is_bit_set(const BIGNUM *a, int n); int BN_mask_bits(BIGNUM *a, int n); int BN_lshift(BIGNUM *r, const BIGNUM *a, int n); int BN_lshift1(BIGNUM *r, BIGNUM *a); int BN_rshift(BIGNUM *r, BIGNUM *a, int n); int BN_rshift1(BIGNUM *r, BIGNUM *a);</code></pre> <h1 id="DESCRIPTION">DESCRIPTION</h1> <p>BN_set_bit() sets bit <b>n</b> in <b>a</b> to 1 (<code>a|=(1<<n)</code>). The number is expanded if necessary.</p> <p>BN_clear_bit() sets bit <b>n</b> in <b>a</b> to 0 (<code>a&=~(1<<n)</code>). An error occurs if <b>a</b> is shorter than <b>n</b> bits.</p> <p>BN_is_bit_set() tests if bit <b>n</b> in <b>a</b> is set.</p> <p>BN_mask_bits() truncates <b>a</b> to an <b>n</b> bit number (<code>a&=~((~0)<<n)</code>). An error occurs if <b>a</b> already is shorter than <b>n</b> bits.</p> <p>BN_lshift() shifts <b>a</b> left by <b>n</b> bits and places the result in <b>r</b> (<code>r=a*2^n</code>). Note that <b>n</b> must be nonnegative. BN_lshift1() shifts <b>a</b> left by one and places the result in <b>r</b> (<code>r=2*a</code>).</p> <p>BN_rshift() shifts <b>a</b> right by <b>n</b> bits and places the result in <b>r</b> (<code>r=a/2^n</code>). Note that <b>n</b> must be nonnegative. BN_rshift1() shifts <b>a</b> right by one and places the result in <b>r</b> (<code>r=a/2</code>).</p> <p>For the shift functions, <b>r</b> and <b>a</b> may be the same variable.</p> <h1 id="RETURN-VALUES">RETURN VALUES</h1> <p>BN_is_bit_set() returns 1 if the bit is set, 0 otherwise.</p> <p>All other functions return 1 for success, 0 on error. The error codes can be obtained by <a href="../man3/ERR_get_error.html">ERR_get_error(3)</a>.</p> <h1 id="SEE-ALSO">SEE ALSO</h1> <p><a href="../man3/BN_num_bytes.html">BN_num_bytes(3)</a>, <a href="../man3/BN_add.html">BN_add(3)</a></p> <h1 id="COPYRIGHT">COPYRIGHT</h1> <p>Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.</p> <p>Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.</p> </body> </html>
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