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  <h1>Package rand</h1>


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			<dd><code>import "crypto/rand"</code></dd>
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				<p>
Package rand implements a cryptographically secure
pseudorandom number generator.
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				<dd><a href="index.html#pkg-variables">Variables</a></dd>
			
			
				<dd><a href="index.html#Int">func Int(rand io.Reader, max *big.Int) (n *big.Int, err error)</a></dd>
			
				
				<dd><a href="index.html#Prime">func Prime(rand io.Reader, bits int) (p *big.Int, err error)</a></dd>
			
				
				<dd><a href="index.html#Read">func Read(b []byte) (n int, err error)</a></dd>
			
			
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			<h4>Package files</h4>
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				<a href="http://localhost:6060/src/crypto/rand/eagain.go">eagain.go</a>
			
				<a href="http://localhost:6060/src/crypto/rand/rand.go">rand.go</a>
			
				<a href="http://localhost:6060/src/crypto/rand/rand_linux.go">rand_linux.go</a>
			
				<a href="http://localhost:6060/src/crypto/rand/rand_unix.go">rand_unix.go</a>
			
				<a href="http://localhost:6060/src/crypto/rand/util.go">util.go</a>
			
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			<h2 id="pkg-variables">Variables</h2>
			
				<pre>var <span id="Reader">Reader</span> <a href="../../io/index.html">io</a>.<a href="../../io/index.html#Reader">Reader</a></pre>
				<p>
Reader is a global, shared instance of a cryptographically
strong pseudo-random generator.
</p>
<p>
On Unix-like systems, Reader reads from /dev/urandom.
On Linux, Reader uses getrandom(2) if available, /dev/urandom otherwise.
On Windows systems, Reader uses the CryptGenRandom API.
</p>

			
			<h2 id="Int">func <a href="http://localhost:6060/src/crypto/rand/util.go?s=3072:3134#L96">Int</a></h2>
			<pre>func Int(rand <a href="../../io/index.html">io</a>.<a href="../../io/index.html#Reader">Reader</a>, max *<a href="../../math/big/index.html">big</a>.<a href="../../math/big/index.html#Int">Int</a>) (n *<a href="../../math/big/index.html">big</a>.<a href="../../math/big/index.html#Int">Int</a>, err <a href="../../builtin/index.html#error">error</a>)</pre>
			<p>
Int returns a uniform random value in [0, max). It panics if max &lt;= 0.
</p>

			
			<h2 id="Prime">func <a href="http://localhost:6060/src/crypto/rand/util.go?s=1126:1186#L21">Prime</a></h2>
			<pre>func Prime(rand <a href="../../io/index.html">io</a>.<a href="../../io/index.html#Reader">Reader</a>, bits <a href="../../builtin/index.html#int">int</a>) (p *<a href="../../math/big/index.html">big</a>.<a href="../../math/big/index.html#Int">Int</a>, err <a href="../../builtin/index.html#error">error</a>)</pre>
			<p>
Prime returns a number, p, of the given size, such that p is prime
with high probability.
Prime will return error for any error returned by rand.Read or if bits &lt; 2.
</p>

			
			<h2 id="Read">func <a href="http://localhost:6060/src/crypto/rand/rand.go?s=714:752#L11">Read</a></h2>
			<pre>func Read(b []<a href="../../builtin/index.html#byte">byte</a>) (n <a href="../../builtin/index.html#int">int</a>, err <a href="../../builtin/index.html#error">error</a>)</pre>
			<p>
Read is a helper function that calls Reader.Read using io.ReadFull.
On return, n == len(b) if and only if err == nil.
</p>

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		<p class="exampleHeading toggleButton">▾ <span class="text">Example</span></p>
		<p>This example reads 10 cryptographically secure pseudorandom numbers from
rand.Reader and writes them to a byte slice.
</p>
		
		
			<p>Code:</p>
			<pre class="code">c := 10
b := make([]byte, c)
_, err := rand.Read(b)
if err != nil {
    fmt.Println(&#34;error:&#34;, err)
    return
}
<span class="comment">// The slice should now contain random bytes instead of only zeroes.</span>
fmt.Println(bytes.Equal(b, make([]byte, c)))

<span class="comment"></pre>
			
			<p>Output:</p>
			<pre class="output">false
</pre>
			
		
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