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<title>src/Crypt/SHA256.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE CPP, ForeignFunctionInterface #-}</span>
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<a name="line-3"></a><span class='hs-comment'>-- |</span>
<a name="line-4"></a><span class='hs-comment'>-- Module: Data.Digest.SHA256</span>
<a name="line-5"></a><span class='hs-comment'>-- Copyright: Zooko O'Whielacronx</span>
<a name="line-6"></a><span class='hs-comment'>-- License: GPL</span>
<a name="line-7"></a><span class='hs-comment'>--</span>
<a name="line-8"></a><span class='hs-comment'>-- Stability: experimental</span>
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<a name="line-10"></a><span class='hs-comment'>-- ByteString-based, zero-copying binding to Crypto++'s sha interface</span>
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<a name="line-12"></a><span class='hs-comment'>-- thanks to Don Stewart <dons@galois.com>, Matthew Sackman</span>
<a name="line-13"></a><span class='hs-comment'>-- <matthew@wellquite.org>, Brian O'Sullivan, lispy, Adam Langley</span>
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<a name="line-15"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Crypt</span><span class='hs-varop'>.</span><span class='hs-conid'>SHA256</span> <span class='hs-layout'>(</span> <span class='hs-varid'>sha256sum</span> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-16"></a>
<a name="line-17"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span>
<a name="line-18"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>C</span><span class='hs-varop'>.</span><span class='hs-conid'>Types</span>
<a name="line-19"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Numeric</span> <span class='hs-layout'>(</span><span class='hs-varid'>showHex</span><span class='hs-layout'>)</span>
<a name="line-20"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>C</span><span class='hs-varop'>.</span><span class='hs-conid'>String</span> <span class='hs-layout'>(</span> <span class='hs-varid'>withCString</span> <span class='hs-layout'>)</span>
<a name="line-21"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Unsafe</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeUseAsCStringLen</span><span class='hs-layout'>)</span>
<a name="line-22"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>B</span>
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<a name="line-24"></a><a name="sha256sum"></a><span class='hs-definition'>sha256sum</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>B</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span>
<a name="line-25"></a><span class='hs-definition'>sha256sum</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>unsafePerformIO</span> <span class='hs-varop'>$</span>
<a name="line-26"></a> <span class='hs-varid'>withCString</span> <span class='hs-layout'>(</span><span class='hs-varid'>take</span> <span class='hs-num'>64</span> <span class='hs-varop'>$</span> <span class='hs-varid'>repeat</span> <span class='hs-chr'>'x'</span><span class='hs-layout'>)</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>digestCString</span> <span class='hs-keyglyph'>-></span>
<a name="line-27"></a> <span class='hs-varid'>unsafeUseAsCStringLen</span> <span class='hs-varid'>p</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-varid'>ptr</span><span class='hs-layout'>,</span><span class='hs-varid'>n</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-28"></a> <span class='hs-keyword'>do</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>digest</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>castPtr</span> <span class='hs-varid'>digestCString</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Ptr</span> <span class='hs-conid'>Word8</span>
<a name="line-29"></a> <span class='hs-varid'>c_sha256</span> <span class='hs-varid'>ptr</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>n</span><span class='hs-layout'>)</span> <span class='hs-varid'>digest</span>
<a name="line-30"></a> <span class='hs-varid'>go</span> <span class='hs-varid'>digest</span> <span class='hs-num'>0</span> <span class='hs-conid'>[]</span>
<a name="line-31"></a> <span class='hs-keyword'>where</span> <span class='hs-comment'>-- print it in 0-padded hex format</span>
<a name="line-32"></a> <span class='hs-varid'>go</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Ptr</span> <span class='hs-conid'>Word8</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>String</span>
<a name="line-33"></a> <span class='hs-varid'>go</span> <span class='hs-varid'>q</span> <span class='hs-varid'>n</span> <span class='hs-varid'>acc</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>seq</span> <span class='hs-varid'>q</span> <span class='hs-varid'>n</span> <span class='hs-varop'>>=</span> <span class='hs-num'>32</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>concat</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span>
<a name="line-34"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>w</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>peekElemOff</span> <span class='hs-varid'>q</span> <span class='hs-varid'>n</span>
<a name="line-35"></a> <span class='hs-varid'>go</span> <span class='hs-varid'>q</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>draw</span> <span class='hs-varid'>w</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span>
<a name="line-36"></a> <span class='hs-varid'>draw</span> <span class='hs-varid'>w</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>showHex</span> <span class='hs-varid'>w</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>of</span>
<a name="line-37"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-chr'>'0'</span><span class='hs-layout'>,</span> <span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span>
<a name="line-38"></a> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span>
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<a name="line-40"></a><span class='hs-comment'>-- void sha256sum(const unsigned char *d, size_t n, unsigned char *md);</span>
<a name="line-41"></a><span class='hs-comment'>--</span>
<a name="line-42"></a><span class='hs-keyword'>foreign</span> <span class='hs-keyword'>import</span> <span class='hs-keyword'>ccall</span> <span class='hs-keyword'>unsafe</span> <span class='hs-str'>"sha2.h darcs_sha256"</span> <span class='hs-varid'>c_sha256</span>
<a name="line-43"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Ptr</span> <span class='hs-conid'>CChar</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CSize</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Ptr</span> <span class='hs-conid'>Word8</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
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