@node-dlc/core

<!doctype html> <html lang="en"> <head> <title>Code coverage report for lib/lightning/CommitmentSecretStore.ts</title> <meta charset="utf-8" /> <link rel="stylesheet" href="../../prettify.css" /> <link rel="stylesheet" href="../../base.css" /> <link rel="shortcut icon" type="image/x-icon" href="../../favicon.png" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <style type='text/css'> .coverage-summary .sorter { background-image: url(../../sort-arrow-sprite.png); } </style> </head> <body> <div class='wrapper'> <div class='pad1'> <h1><a href="../../index.html">All files</a> / <a href="index.html">lib/lightning</a> CommitmentSecretStore.ts</h1> <div class='clearfix'> <div class='fl pad1y space-right2'> 7.69% Statements 2/26 </div> <div class='fl pad1y space-right2'> 0% Branches 0/8 </div> <div class='fl pad1y space-right2'> 0% Functions 0/4 </div> <div class='fl pad1y space-right2'> 9.52% Lines 2/21 </div> </div> Press n or j to go to the next uncovered block, b, p or k for the previous block. </div> <div class='status-line low'></div> <pre><table class="coverage"> <tr><td class="line-count quiet"><a name='L1'></a><a href='#L1'>1</a> <a name='L2'></a><a href='#L2'>2</a> <a name='L3'></a><a href='#L3'>3</a> <a name='L4'></a><a href='#L4'>4</a> <a name='L5'></a><a href='#L5'>5</a> <a name='L6'></a><a href='#L6'>6</a> <a name='L7'></a><a href='#L7'>7</a> <a name='L8'></a><a href='#L8'>8</a> <a name='L9'></a><a href='#L9'>9</a> <a name='L10'></a><a href='#L10'>10</a> <a name='L11'></a><a href='#L11'>11</a> <a name='L12'></a><a href='#L12'>12</a> <a name='L13'></a><a href='#L13'>13</a> <a name='L14'></a><a href='#L14'>14</a> <a name='L15'></a><a href='#L15'>15</a> <a name='L16'></a><a href='#L16'>16</a> <a name='L17'></a><a href='#L17'>17</a> <a name='L18'></a><a href='#L18'>18</a> <a name='L19'></a><a href='#L19'>19</a> <a name='L20'></a><a href='#L20'>20</a> <a name='L21'></a><a href='#L21'>21</a> <a name='L22'></a><a href='#L22'>22</a> <a name='L23'></a><a href='#L23'>23</a> <a name='L24'></a><a href='#L24'>24</a> <a name='L25'></a><a href='#L25'>25</a> <a name='L26'></a><a href='#L26'>26</a> <a name='L27'></a><a href='#L27'>27</a> <a name='L28'></a><a href='#L28'>28</a> <a name='L29'></a><a href='#L29'>29</a> <a name='L30'></a><a href='#L30'>30</a> <a name='L31'></a><a href='#L31'>31</a> <a name='L32'></a><a href='#L32'>32</a> <a name='L33'></a><a href='#L33'>33</a> <a name='L34'></a><a href='#L34'>34</a> <a name='L35'></a><a href='#L35'>35</a> <a name='L36'></a><a href='#L36'>36</a> <a name='L37'></a><a href='#L37'>37</a> <a name='L38'></a><a href='#L38'>38</a> <a name='L39'></a><a href='#L39'>39</a> <a name='L40'></a><a href='#L40'>40</a> <a name='L41'></a><a href='#L41'>41</a> <a name='L42'></a><a href='#L42'>42</a> <a name='L43'></a><a href='#L43'>43</a> <a name='L44'></a><a href='#L44'>44</a> <a name='L45'></a><a href='#L45'>45</a> <a name='L46'></a><a href='#L46'>46</a> <a name='L47'></a><a href='#L47'>47</a> <a name='L48'></a><a href='#L48'>48</a> <a name='L49'></a><a href='#L49'>49</a> <a name='L50'></a><a href='#L50'>50</a> <a name='L51'></a><a href='#L51'>51</a> <a name='L52'></a><a href='#L52'>52</a> <a name='L53'></a><a href='#L53'>53</a> <a name='L54'></a><a href='#L54'>54</a> <a name='L55'></a><a href='#L55'>55</a> <a name='L56'></a><a href='#L56'>56</a> <a name='L57'></a><a href='#L57'>57</a> <a name='L58'></a><a href='#L58'>58</a> <a name='L59'></a><a href='#L59'>59</a> <a name='L60'></a><a href='#L60'>60</a> <a name='L61'></a><a href='#L61'>61</a> <a name='L62'></a><a href='#L62'>62</a> <a name='L63'></a><a href='#L63'>63</a> <a name='L64'></a><a href='#L64'>64</a> <a name='L65'></a><a href='#L65'>65</a> <a name='L66'></a><a href='#L66'>66</a> <a name='L67'></a><a href='#L67'>67</a> <a name='L68'></a><a href='#L68'>68</a> <a name='L69'></a><a href='#L69'>69</a> <a name='L70'></a><a href='#L70'>70</a> <a name='L71'></a><a href='#L71'>71</a> <a name='L72'></a><a href='#L72'>72</a> <a name='L73'></a><a href='#L73'>73</a> <a name='L74'></a><a href='#L74'>74</a> <a name='L75'></a><a href='#L75'>75</a> <a name='L76'></a><a href='#L76'>76</a> <a name='L77'></a><a href='#L77'>77</a> <a name='L78'></a><a href='#L78'>78</a> <a name='L79'></a><a href='#L79'>79</a> <a name='L80'></a><a href='#L80'>80</a> <a name='L81'></a><a href='#L81'>81</a> <a name='L82'></a><a href='#L82'>82</a> <a name='L83'></a><a href='#L83'>83</a> <a name='L84'></a><a href='#L84'>84</a> <a name='L85'></a><a href='#L85'>85</a></td><td class="line-coverage quiet">1x                           1x                                                                                                                                            </td><td class="text"><pre class="prettyprint lang-js">import { CommitmentSecret } from './CommitmentSecret';   export type CommitmentSecretStoreItem = { index: bigint; secret: Buffer };   /** * Defined in BOLT3, this class compactly stored received commitment * secrets from our counterparty. Without this mechanism we are required * to store every commitment secret that we receive (2^48) which can be * a huge amount of data at 32-bytes per secret. * * Instead we can use the fact that later commitment secrets act as * prefixes for prior commitment secrets. We can then compactly store * only the secrets we need to derive older commitment secrets. */ export class CommitmentSecretStore { /** * Returns the index of the least-significant bit. This is used to * determine what the value at I is a prefix for. * @param I commitment */ public static calcIndex(I: bigint): number { for (let i = BigInt(0); i < BigInt(48); i++) { if (I & (BigInt(1) << i)) return Number(i); } return 48; // seed }   private secrets: CommitmentSecretStoreItem[];   constructor() { this.secrets = new Array(49) as CommitmentSecretStoreItem[]; for (let i = 0; i < this.secrets.length; i++) { this.secrets[i] = { index: BigInt(0), secret: undefined }; } }   /** * Insert the commitment secret into the store and verify that the * secret is able to derive all prior commitment secrets that we * already know about. * * @param secret 32-byte secp256k1 secret * @param i commitment number */ public insert(secret: Buffer, i: bigint): void { const B = CommitmentSecretStore.calcIndex(i);   // validate that the new secret allows derivation of known keys // up to the new key for (let b = 0; b < B; b++) { const existing = this.secrets[b].secret; const derived = CommitmentSecret.derive(secret, this.secrets[b].index, B); if (!derived.equals(existing)) { throw new Error('The secret for I is incorrect'); } }   // update the position this.secrets[Number(B)].index = i; this.secrets[Number(B)].secret = secret; }   /** * Derives old commitment secrets from the from the compact store. * Throws if we do not have the commitment secret for the specified * commitment nmber. * @param i derivation number starting at 2^48-1 down to zero. */ public derive(i: bigint): Buffer { for (let b = 0; b < this.secrets.length; b++) { // construct a mask of the upper bits. Basically we lop off // the lower b bits and then right-shift back into place const mask = (BigInt(0xffffffffffff) >> BigInt(b)) << BigInt(b);   // Check if the prefix found using I & mask is one that we // can use to derive our value. If not, we need to try // another bit. if ((i & mask) === this.secrets[b].index && this.secrets[b].secret) { return CommitmentSecret.derive(this.secrets[b].secret, i, b); } } throw new Error("Index I hasn't been received yet"); } }  </pre></td></tr></table></pre> <div class='push'></div> </div> <div class='footer quiet pad2 space-top1 center small'> Code coverage generated by <a href="https://istanbul.js.org/" target="_blank">istanbul</a> at Thu Sep 04 2025 22:31:44 GMT-0400 (Eastern Daylight Saving Time) </div> </div> <script src="../../prettify.js"></script> <script> window.onload = function () { prettyPrint(); }; </script> <script src="../../sorter.js"></script> <script src="../../block-navigation.js"></script> </body> </html>