mirror of
https://github.com/c-cube/moonpool.git
synced 2026-01-22 09:16:51 -05:00
2 lines
12 KiB
HTML
2 lines
12 KiB
HTML
<!DOCTYPE html>
|
||
<html xmlns="http://www.w3.org/1999/xhtml"><head><title>Digest (ocaml.Stdlib.Digest)</title><meta charset="utf-8"/><link rel="stylesheet" href="../../../_odoc-theme/odoc.css"/><meta name="generator" content="odoc 3.1.0"/><meta name="viewport" content="width=device-width,initial-scale=1.0"/><script src="../../../highlight.pack.js"></script><script>hljs.initHighlightingOnLoad();</script></head><body class="odoc"><nav class="odoc-nav"><a href="../index.html">Up</a> – <a href="../../../index.html">Index</a> » <a href="../../index.html">ocaml</a> » <a href="../index.html">Stdlib</a> » Digest</nav><header class="odoc-preamble"><h1>Module <code><span>Stdlib.Digest</span></code></h1><p>Message digest.</p><p>This module provides functions to compute 'digests', also known as 'hashes', of arbitrary-length strings or files. The supported hashing algorithms are BLAKE2 and MD5.</p></header><div class="odoc-tocs"><nav class="odoc-toc odoc-local-toc"><ul><li><a href="#basic-functions">Basic functions</a></li><li><a href="#generic-interface">Generic interface</a></li><li><a href="#specific-hash-functions">Specific hash functions</a></li></ul></nav></div><div class="odoc-content"><h2 id="basic-functions"><a href="#basic-functions" class="anchor"></a>Basic functions</h2><p>The functions in this section use the MD5 hash function to produce 128-bit digests (16 bytes). MD5 is not cryptographically secure. Hence, these functions should not be used for security-sensitive applications. The BLAKE2 functions below are cryptographically secure.</p><div class="odoc-spec"><div class="spec type anchored" id="type-t"><a href="#type-t" class="anchor"></a><code><span><span class="keyword">type</span> t</span><span> = string</span></code></div><div class="spec-doc"><p>The type of digests: 16-byte strings.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-compare"><a href="#val-compare" class="anchor"></a><code><span><span class="keyword">val</span> compare : <span><a href="#type-t">t</a> <span class="arrow">-></span></span> <span><a href="#type-t">t</a> <span class="arrow">-></span></span> int</span></code></div><div class="spec-doc"><p>The comparison function for 16-byte digests, with the same specification as <a href="../index.html#val-compare"><code>Stdlib.compare</code></a> and the implementation shared with <a href="../String/index.html#val-compare"><code>String.compare</code></a>. Along with the type <code>t</code>, this function <code>compare</code> allows the module <code>Digest</code> to be passed as argument to the functors <a href="../Set/Make/index.html"><code>Set.Make</code></a> and <a href="../Map/Make/index.html"><code>Map.Make</code></a>.</p><ul class="at-tags"><li class="since"><span class="at-tag">since</span> 4.00</li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-equal"><a href="#val-equal" class="anchor"></a><code><span><span class="keyword">val</span> equal : <span><a href="#type-t">t</a> <span class="arrow">-></span></span> <span><a href="#type-t">t</a> <span class="arrow">-></span></span> bool</span></code></div><div class="spec-doc"><p>The equal function for 16-byte digests.</p><ul class="at-tags"><li class="since"><span class="at-tag">since</span> 4.03</li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-string"><a href="#val-string" class="anchor"></a><code><span><span class="keyword">val</span> string : <span>string <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>Return the digest of the given string.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-bytes"><a href="#val-bytes" class="anchor"></a><code><span><span class="keyword">val</span> bytes : <span>bytes <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>Return the digest of the given byte sequence.</p><ul class="at-tags"><li class="since"><span class="at-tag">since</span> 4.02</li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-substring"><a href="#val-substring" class="anchor"></a><code><span><span class="keyword">val</span> substring : <span>string <span class="arrow">-></span></span> <span>int <span class="arrow">-></span></span> <span>int <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p><code>Digest.substring s ofs len</code> returns the digest of the substring of <code>s</code> starting at index <code>ofs</code> and containing <code>len</code> characters.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-subbytes"><a href="#val-subbytes" class="anchor"></a><code><span><span class="keyword">val</span> subbytes : <span>bytes <span class="arrow">-></span></span> <span>int <span class="arrow">-></span></span> <span>int <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p><code>Digest.subbytes s ofs len</code> returns the digest of the subsequence of <code>s</code> starting at index <code>ofs</code> and containing <code>len</code> bytes.</p><ul class="at-tags"><li class="since"><span class="at-tag">since</span> 4.02</li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-channel"><a href="#val-channel" class="anchor"></a><code><span><span class="keyword">val</span> channel : <span><a href="../index.html#type-in_channel">in_channel</a> <span class="arrow">-></span></span> <span>int <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>If <code>len</code> is nonnegative, <code>Digest.channel ic len</code> reads <code>len</code> characters from channel <code>ic</code> and returns their digest, or raises <code>End_of_file</code> if end-of-file is reached before <code>len</code> characters are read. If <code>len</code> is negative, <code>Digest.channel ic len</code> reads all characters from <code>ic</code> until end-of-file is reached and return their digest.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-file"><a href="#val-file" class="anchor"></a><code><span><span class="keyword">val</span> file : <span>string <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>Return the digest of the file whose name is given.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-output"><a href="#val-output" class="anchor"></a><code><span><span class="keyword">val</span> output : <span><a href="../index.html#type-out_channel">out_channel</a> <span class="arrow">-></span></span> <span><a href="#type-t">t</a> <span class="arrow">-></span></span> unit</span></code></div><div class="spec-doc"><p>Write a digest on the given output channel.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-input"><a href="#val-input" class="anchor"></a><code><span><span class="keyword">val</span> input : <span><a href="../index.html#type-in_channel">in_channel</a> <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>Read a digest from the given input channel.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-to_hex"><a href="#val-to_hex" class="anchor"></a><code><span><span class="keyword">val</span> to_hex : <span><a href="#type-t">t</a> <span class="arrow">-></span></span> string</span></code></div><div class="spec-doc"><p>Return the printable hexadecimal representation of the given digest.</p><ul class="at-tags"><li class="raises"><span class="at-tag">raises</span> <a href="../index.html#exception-Invalid_argument"><code>Invalid_argument</code></a> <p>if the argument is not exactly 16 bytes.</p></li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-of_hex"><a href="#val-of_hex" class="anchor"></a><code><span><span class="keyword">val</span> of_hex : <span>string <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>Convert a hexadecimal representation back into the corresponding digest.</p><ul class="at-tags"><li class="raises"><span class="at-tag">raises</span> <a href="../index.html#exception-Invalid_argument"><code>Invalid_argument</code></a> <p>if the argument is not exactly 32 hexadecimal characters.</p></li></ul><ul class="at-tags"><li class="since"><span class="at-tag">since</span> 5.2</li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-from_hex"><a href="#val-from_hex" class="anchor"></a><code><span><span class="keyword">val</span> from_hex : <span>string <span class="arrow">-></span></span> <a href="#type-t">t</a></span></code></div><div class="spec-doc"><p>Same function as <a href="#val-of_hex"><code>Digest.of_hex</code></a>.</p><ul class="at-tags"><li class="since"><span class="at-tag">since</span> 4.00</li></ul></div></div><h2 id="generic-interface"><a href="#generic-interface" class="anchor"></a>Generic interface</h2><div class="odoc-spec"><div class="spec module-type anchored" id="module-type-S"><a href="#module-type-S" class="anchor"></a><code><span><span class="keyword">module</span> <span class="keyword">type</span> <a href="module-type-S/index.html">S</a></span><span> = <span class="keyword">sig</span> ... <span class="keyword">end</span></span></code></div><div class="spec-doc"><p>The signature for a hash function that produces digests of length <code>hash_length</code> from character strings, byte arrays, and files.</p></div></div><h2 id="specific-hash-functions"><a href="#specific-hash-functions" class="anchor"></a>Specific hash functions</h2><div class="odoc-spec"><div class="spec module anchored" id="module-BLAKE128"><a href="#module-BLAKE128" class="anchor"></a><code><span><span class="keyword">module</span> <a href="BLAKE128/index.html">BLAKE128</a></span><span> : <a href="module-type-S/index.html">S</a></span></code></div><div class="spec-doc"><p><code>BLAKE128</code> is the BLAKE2b hash function producing 128-bit (16-byte) digests. It is cryptographically secure. However, the small size of the digests enables brute-force attacks in <code>2{^64}</code> attempts.</p></div></div><div class="odoc-spec"><div class="spec module anchored" id="module-BLAKE256"><a href="#module-BLAKE256" class="anchor"></a><code><span><span class="keyword">module</span> <a href="BLAKE256/index.html">BLAKE256</a></span><span> : <a href="module-type-S/index.html">S</a></span></code></div><div class="spec-doc"><p><code>BLAKE256</code> is the BLAKE2b hash function producing 256-bit (32-byte) digests. It is cryptographically secure, and the digests are large enough to thwart brute-force attacks.</p></div></div><div class="odoc-spec"><div class="spec module anchored" id="module-BLAKE512"><a href="#module-BLAKE512" class="anchor"></a><code><span><span class="keyword">module</span> <a href="BLAKE512/index.html">BLAKE512</a></span><span> : <a href="module-type-S/index.html">S</a></span></code></div><div class="spec-doc"><p><code>BLAKE512</code> is the BLAKE2b hash function producing 512-bit (64-byte) digests. It is cryptographically secure, and the digests are large enough to thwart brute-force attacks.</p></div></div><div class="odoc-spec"><div class="spec module anchored" id="module-MD5"><a href="#module-MD5" class="anchor"></a><code><span><span class="keyword">module</span> <a href="MD5/index.html">MD5</a></span><span> : <a href="module-type-S/index.html">S</a></span></code></div><div class="spec-doc"><p><code>MD5</code> is the MD5 hash function. It produces 128-bit (16-byte) digests and is not cryptographically secure at all. It should be used only for compatibility with earlier designs that mandate the use of MD5.</p></div></div></div></body></html>
|