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BN_dec2bn.html
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<?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_bn2bin</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_bn2binpad, BN_bn2bin, BN_bin2bn, BN_bn2lebinpad, BN_lebin2bn, BN_bn2hex, BN_bn2dec, BN_hex2bn, BN_dec2bn, BN_print, BN_print_fp, BN_bn2mpi, BN_mpi2bn - format conversions</p> <h1 id="SYNOPSIS">SYNOPSIS</h1> <pre><code> #include <openssl/bn.h> int BN_bn2bin(const BIGNUM *a, unsigned char *to); int BN_bn2binpad(const BIGNUM *a, unsigned char *to, int tolen); BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret); int BN_bn2lebinpad(const BIGNUM *a, unsigned char *to, int tolen); BIGNUM *BN_lebin2bn(const unsigned char *s, int len, BIGNUM *ret); char *BN_bn2hex(const BIGNUM *a); char *BN_bn2dec(const BIGNUM *a); int BN_hex2bn(BIGNUM **a, const char *str); int BN_dec2bn(BIGNUM **a, const char *str); int BN_print(BIO *fp, const BIGNUM *a); int BN_print_fp(FILE *fp, const BIGNUM *a); int BN_bn2mpi(const BIGNUM *a, unsigned char *to); BIGNUM *BN_mpi2bn(unsigned char *s, int len, BIGNUM *ret);</code></pre> <h1 id="DESCRIPTION">DESCRIPTION</h1> <p>BN_bn2bin() converts the absolute value of <b>a</b> into big-endian form and stores it at <b>to</b>. <b>to</b> must point to BN_num_bytes(<b>a</b>) bytes of memory.</p> <p>BN_bn2binpad() also converts the absolute value of <b>a</b> into big-endian form and stores it at <b>to</b>. <b>tolen</b> indicates the length of the output buffer <b>to</b>. The result is padded with zeros if necessary. If <b>tolen</b> is less than BN_num_bytes(<b>a</b>) an error is returned.</p> <p>BN_bin2bn() converts the positive integer in big-endian form of length <b>len</b> at <b>s</b> into a <b>BIGNUM</b> and places it in <b>ret</b>. If <b>ret</b> is NULL, a new <b>BIGNUM</b> is created.</p> <p>BN_bn2lebinpad() and BN_lebin2bn() are identical to BN_bn2binpad() and BN_bin2bn() except the buffer is in little-endian format.</p> <p>BN_bn2hex() and BN_bn2dec() return printable strings containing the hexadecimal and decimal encoding of <b>a</b> respectively. For negative numbers, the string is prefaced with a leading '-'. The string must be freed later using OPENSSL_free().</p> <p>BN_hex2bn() takes as many characters as possible from the string <b>str</b>, including the leading character '-' which means negative, to form a valid hexadecimal number representation and converts them to a <b>BIGNUM</b> and stores it in **<b>a</b>. If *<b>a</b> is NULL, a new <b>BIGNUM</b> is created. If <b>a</b> is NULL, it only computes the length of valid representation. A "negative zero" is converted to zero. BN_dec2bn() is the same using the decimal system.</p> <p>BN_print() and BN_print_fp() write the hexadecimal encoding of <b>a</b>, with a leading '-' for negative numbers, to the <b>BIO</b> or <b>FILE</b> <b>fp</b>.</p> <p>BN_bn2mpi() and BN_mpi2bn() convert <b>BIGNUM</b>s from and to a format that consists of the number's length in bytes represented as a 4-byte big-endian number, and the number itself in big-endian format, where the most significant bit signals a negative number (the representation of numbers with the MSB set is prefixed with null byte).</p> <p>BN_bn2mpi() stores the representation of <b>a</b> at <b>to</b>, where <b>to</b> must be large enough to hold the result. The size can be determined by calling BN_bn2mpi(<b>a</b>, NULL).</p> <p>BN_mpi2bn() converts the <b>len</b> bytes long representation at <b>s</b> to a <b>BIGNUM</b> and stores it at <b>ret</b>, or in a newly allocated <b>BIGNUM</b> if <b>ret</b> is NULL.</p> <h1 id="RETURN-VALUES">RETURN VALUES</h1> <p>BN_bn2bin() returns the length of the big-endian number placed at <b>to</b>. BN_bin2bn() returns the <b>BIGNUM</b>, NULL on error.</p> <p>BN_bn2binpad() returns the number of bytes written or -1 if the supplied buffer is too small.</p> <p>BN_bn2hex() and BN_bn2dec() return a null-terminated string, or NULL on error. BN_hex2bn() and BN_dec2bn() return the number of characters used in parsing, or 0 on error, in which case no new <b>BIGNUM</b> will be created.</p> <p>BN_print_fp() and BN_print() return 1 on success, 0 on write errors.</p> <p>BN_bn2mpi() returns the length of the representation. BN_mpi2bn() returns the <b>BIGNUM</b>, and NULL on error.</p> <p>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/ERR_get_error.html">ERR_get_error(3)</a>, <a href="../man3/BN_zero.html">BN_zero(3)</a>, <a href="../man3/ASN1_INTEGER_to_BN.html">ASN1_INTEGER_to_BN(3)</a>, <a href="../man3/BN_num_bytes.html">BN_num_bytes(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>