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<h1>Package hmac</h1>
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<dd><code>import "crypto/hmac"</code></dd>
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<p>
Package hmac implements the Keyed-Hash Message Authentication Code (HMAC) as
defined in U.S. Federal Information Processing Standards Publication 198.
An HMAC is a cryptographic hash that uses a key to sign a message.
The receiver verifies the hash by recomputing it using the same key.
</p>
<p>
Receivers should be careful to use Equal to compare MACs in order to avoid
timing side-channels:
</p>
<pre>// CheckMAC reports whether messageMAC is a valid HMAC tag for message.
func CheckMAC(message, messageMAC, key []byte) bool {
mac := hmac.New(sha256.New, key)
mac.Write(message)
expectedMAC := mac.Sum(nil)
return hmac.Equal(messageMAC, expectedMAC)
}
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<dd><a href="index.html#Equal">func Equal(mac1, mac2 []byte) bool</a></dd>
<dd><a href="index.html#New">func New(h func() hash.Hash, key []byte) hash.Hash</a></dd>
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<h4>Package files</h4>
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<a href="http://localhost:6060/src/crypto/hmac/hmac.go">hmac.go</a>
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<h2 id="Equal">func <a href="http://localhost:6060/src/crypto/hmac/hmac.go?s=2448:2482#L87">Equal</a></h2>
<pre>func Equal(mac1, mac2 []<a href="../../builtin/index.html#byte">byte</a>) <a href="../../builtin/index.html#bool">bool</a></pre>
<p>
Equal compares two MACs for equality without leaking timing information.
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<h2 id="New">func <a href="http://localhost:6060/src/crypto/hmac/hmac.go?s=1969:2019#L68">New</a></h2>
<pre>func New(h func() <a href="../../hash/index.html">hash</a>.<a href="../../hash/index.html#Hash">Hash</a>, key []<a href="../../builtin/index.html#byte">byte</a>) <a href="../../hash/index.html">hash</a>.<a href="../../hash/index.html#Hash">Hash</a></pre>
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New returns a new HMAC hash using the given hash.Hash type and key.
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