Add sortedmulti descriptor support (sh/wsh/sh-wsh) with validation and integration tests

package.json

@@ -2,7 +2,7 @@
   "name": "@bitcoinerlab/descriptors",
   "description": "This library parses and creates Bitcoin Miniscript Descriptors and generates Partially Signed Bitcoin Transactions (PSBTs). It provides PSBT finalizers and signers for single-signature, BIP32 and Hardware Wallets.",
   "homepage": "https://github.com/bitcoinerlab/descriptors",
-  "version": "2.3.4",
+  "version": "2.3.5",
   "author": "Jose-Luis Landabaso",
   "license": "MIT",
   "repository": {
@@ -36,13 +36,13 @@
     "build": "npm run build:src && npm run build:test",
     "lint": "./node_modules/@bitcoinerlab/configs/scripts/lint.sh",
     "ensureTester": "./node_modules/@bitcoinerlab/configs/scripts/ensureTester.sh",
-    "test:integration:soft": "npm run ensureTester && node test/integration/standardOutputs.js && echo \"\\n\\n\" && node test/integration/miniscript.js",
+    "test:integration:soft": "npm run ensureTester && node test/integration/standardOutputs.js && echo \"\n\n\" && node test/integration/miniscript.js && echo \"\n\n\" && node test/integration/sortedmulti.js",
     "test:integration:ledger": "npm run ensureTester && node test/integration/ledger.js",
-    "test:integration:deprecated": "npm run ensureTester && node test/integration/standardOutputs-deprecated.js && echo \"\\n\\n\" && node test/integration/miniscript-deprecated.js && echo \"\\n\\n\" && node test/integration/ledger-deprecated.js",
+    "test:integration:deprecated": "npm run ensureTester && node test/integration/standardOutputs-deprecated.js && echo \"\n\n\" && node test/integration/miniscript-deprecated.js && echo \"\n\n\" && node test/integration/ledger-deprecated.js",
     "test:unit": "jest",
     "test": "npm run lint && npm run build && npm run test:unit && npm run test:integration:soft",
     "testledger": "npm run lint && npm run build && npm run test:integration:ledger",
-    "prepublishOnly": "npm run test && echo \"\\n\\n\" && npm run test:integration:deprecated && npm run test:integration:ledger"
+    "prepublishOnly": "npm run test && echo \"\n\n\" && npm run test:integration:deprecated && npm run test:integration:ledger"
   },
   "files": [
     "dist"

src/descriptors.ts

@@ -140,6 +140,32 @@ function evaluate({
   return evaluatedDescriptor;
 }
 
+// Helper: parse sortedmulti(M, k1, k2,...)
+function parseSortedMulti(inner: string) {
+  // inner: "2,key1,key2,key3"
+
+  const parts = inner.split(',').map(p => p.trim());
+  if (parts.length < 2)
+    throw new Error(
+      `sortedmulti(): must contain M and at least one key: ${inner}`
+    );
+
+  const m = Number(parts[0]);
+  if (!Number.isInteger(m) || m < 1 || m > 20)
+    throw new Error(`sortedmulti(): invalid M=${parts[0]}`);
+
+  const keyExpressions = parts.slice(1);
+  if (keyExpressions.length < m)
+    throw new Error(`sortedmulti(): M cannot exceed number of keys: ${inner}`);
+
+  if (keyExpressions.length > 20)
+    throw new Error(
+      `sortedmulti(): descriptors support up to 20 keys (per BIP 380/383).`
+    );
+
+  return { m, keyExpressions };
+}
+
 /**
  * Constructs the necessary functions and classes for working with descriptors
  * using an external elliptic curve (ecc) library.
@@ -451,6 +477,125 @@ export function DescriptorsFactory(ecc: TinySecp256k1Interface) {
         payment = p2wpkh({ pubkey, network });
       }
     }
+    // sortedmulti script expressions
+    // sh(sortedmulti())
+    else if (canonicalExpression.match(RE.reShSortedMultiAnchored)) {
+      isSegwit = false;
+      isTaproot = false;
+
+      const inner = canonicalExpression.match(RE.reShSortedMultiAnchored)?.[1];
+      if (!inner)
+        throw new Error(`Error extracting sortedmulti() in ${descriptor}`);
+
+      const { m, keyExpressions } = parseSortedMulti(inner);
+
+      const pKEs = keyExpressions.map(k =>
+        parseKeyExpression({ keyExpression: k, network, isSegwit: false })
+      );
+
+      const map: ExpansionMap = {};
+      pKEs.forEach((pke, i) => (map['@' + i] = pke));
+      expansionMap = map;
+
+      expandedExpression =
+        'sh(sortedmulti(' +
+        [m, ...Object.keys(expansionMap).map(k => k)].join(',') +
+        '))';
+
+      if (!isCanonicalRanged) {
+        const pubkeys = pKEs.map(p => {
+          if (!p.pubkey) throw new Error(`Error: key has no pubkey`);
+          return p.pubkey;
+        });
+        pubkeys.sort((a, b) => a.compare(b));
+
+        const redeem = payments.p2ms({ m, pubkeys, network });
+        redeemScript = redeem.output;
+        if (!redeemScript) throw new Error(`Error creating redeemScript`);
+
+        payment = payments.p2sh({ redeem, network });
+      }
+    }
+    // wsh(sortedmulti())
+    else if (canonicalExpression.match(RE.reWshSortedMultiAnchored)) {
+      isSegwit = true;
+      isTaproot = false;
+
+      const inner = canonicalExpression.match(RE.reWshSortedMultiAnchored)?.[1];
+      if (!inner)
+        throw new Error(`Error extracting sortedmulti() in ${descriptor}`);
+
+      const { m, keyExpressions } = parseSortedMulti(inner);
+
+      const pKEs = keyExpressions.map(k =>
+        parseKeyExpression({ keyExpression: k, network, isSegwit: true })
+      );
+
+      const map: ExpansionMap = {};
+      pKEs.forEach((pke, i) => (map['@' + i] = pke));
+      expansionMap = map;
+
+      expandedExpression =
+        'wsh(sortedmulti(' +
+        [m, ...Object.keys(expansionMap).map(k => k)].join(',') +
+        '))';
+
+      if (!isCanonicalRanged) {
+        const pubkeys = pKEs.map(p => {
+          if (!p.pubkey) throw new Error(`Error: key has no pubkey`);
+          return p.pubkey;
+        });
+        pubkeys.sort((a, b) => a.compare(b));
+
+        const redeem = payments.p2ms({ m, pubkeys, network });
+        witnessScript = redeem.output;
+        if (!witnessScript) throw new Error(`Error computing witnessScript`);
+
+        payment = payments.p2wsh({ redeem, network });
+      }
+    }
+    // sh(wsh(sortedmulti()))
+    else if (canonicalExpression.match(RE.reShWshSortedMultiAnchored)) {
+      isSegwit = true;
+      isTaproot = false;
+
+      const inner = canonicalExpression.match(
+        RE.reShWshSortedMultiAnchored
+      )?.[1];
+      if (!inner)
+        throw new Error(`Error extracting sortedmulti() in ${descriptor}`);
+
+      const { m, keyExpressions } = parseSortedMulti(inner);
+
+      const pKEs = keyExpressions.map(k =>
+        parseKeyExpression({ keyExpression: k, network, isSegwit: true })
+      );
+
+      const map: ExpansionMap = {};
+      pKEs.forEach((pke, i) => (map['@' + i] = pke));
+      expansionMap = map;
+
+      expandedExpression =
+        'sh(wsh(sortedmulti(' +
+        [m, ...Object.keys(expansionMap).map(k => k)].join(',') +
+        ')))';
+
+      if (!isCanonicalRanged) {
+        const pubkeys = pKEs.map(p => {
+          if (!p.pubkey) throw new Error(`Error: key has no pubkey`);
+          return p.pubkey;
+        });
+        pubkeys.sort((a, b) => a.compare(b));
+
+        const redeem = payments.p2ms({ m, pubkeys, network });
+        const wsh = payments.p2wsh({ redeem, network });
+
+        witnessScript = redeem.output;
+        redeemScript = wsh.output;
+
+        payment = payments.p2sh({ redeem: wsh, network });
+      }
+    }
     //sh(wsh(miniscript))
     else if (canonicalExpression.match(RE.reShWshMiniscriptAnchored)) {
       isSegwit = true;

src/re.ts

@@ -63,6 +63,9 @@ const reWpkh = String.raw`wpkh\(${reSegwitKeyExp}\)`;
 const reShWpkh = String.raw`sh\(wpkh\(${reSegwitKeyExp}\)\)`;
 const reTrSingleKey = String.raw`tr\(${reTaprootKeyExp}\)`; // TODO: tr(KEY,TREE) not yet supported. TrSingleKey used for tr(KEY)
 
+export const reNonSegwitSortedMulti = String.raw`sortedmulti\(((?:1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20)(?:,${reNonSegwitKeyExp})+)\)`;
+export const reSegwitSortedMulti = String.raw`sortedmulti\(((?:1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20)(?:,${reSegwitKeyExp})+)\)`;
+
 const reMiniscript = String.raw`(.*?)`; //Matches anything. We assert later in the code that miniscripts are valid and sane.
 
 //RegExp makers:
@@ -84,6 +87,16 @@ export const reTrSingleKeyAnchored = anchorStartAndEnd(
   composeChecksum(reTrSingleKey)
 );
 
+export const reShSortedMultiAnchored = anchorStartAndEnd(
+  composeChecksum(makeReSh(reNonSegwitSortedMulti))
+);
+export const reWshSortedMultiAnchored = anchorStartAndEnd(
+  composeChecksum(makeReWsh(reSegwitSortedMulti))
+);
+export const reShWshSortedMultiAnchored = anchorStartAndEnd(
+  composeChecksum(makeReShWsh(reSegwitSortedMulti))
+);
+
 export const reShMiniscriptAnchored = anchorStartAndEnd(
   composeChecksum(makeReSh(reMiniscript))
 );

test/fixtures/custom.ts

@@ -571,6 +571,58 @@ export const fixtures = {
           }
         }
       }
+    },
+    {
+      note: 'Native SegWit (P2WSH) sortedmulti descriptor with 2 keys',
+      descriptor:
+        'wsh(sortedmulti(2,03a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd,0260b2003c386519fc9eadf2b5cf124dd8eea4c4e68d5e154050a9346ea98ce600))',
+      checksumRequired: false,
+      script:
+        '0020a18e1931caa82844ddb8294107de1b3e15f1c603983df8d9b6caa0ef6419c5d2',
+      address: 'bc1q5x8pjvw24q5yfhdc99qs0hsm8c2lr3srnq7l3kdke2sw7eqechfq62zxqh',
+      expansion: {
+        expandedExpression: 'wsh(sortedmulti(2,@0,@1))',
+        expansionMap: {
+          '@0': {
+            keyExpression:
+              '03a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd'
+          },
+          '@1': {
+            keyExpression:
+              '0260b2003c386519fc9eadf2b5cf124dd8eea4c4e68d5e154050a9346ea98ce600'
+          }
+        }
+      }
+    },
+    {
+      note: 'Nested SegWit (P2SH-P2WSH) sortedmulti descriptor with 2 of 3',
+      descriptor:
+        "sh(wsh(sortedmulti(2,[d34db33f/44'/0'/0]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1/0/0,[00000000/44'/0'/0]xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y/0/0/0,[11111111/44'/0'/0]xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/0/0/0)))",
+      checksumRequired: false,
+      address: '3FZBUGnutPpKWrhGSRXwcMCv7M2ekUva5c',
+      expansion: {
+        expandedExpression: 'sh(wsh(sortedmulti(2,@0,@1,@2)))',
+        expansionMap: {
+          '@0': {
+            keyExpression:
+              "[d34db33f/44'/0'/0]xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL/1/0/0",
+            originPath: "/44'/0'/0",
+            path: "m/44'/0'/0/1/0/0"
+          },
+          '@1': {
+            keyExpression:
+              "[00000000/44'/0'/0]xpub68NZiKmJWnxxS6aaHmn81bvJeTESw724CRDs6HbuccFQN9Ku14VQrADWgqbhhTHBaohPX4CjNLf9fq9MYo6oDaPPLPxSb7gwQN3ih19Zm4Y/0/0/0",
+            originPath: "/44'/0'/0",
+            path: "m/44'/0'/0/0/0/0"
+          },
+          '@2': {
+            keyExpression:
+              "[11111111/44'/0'/0]xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/0/0/0",
+            originPath: "/44'/0'/0",
+            path: "m/44'/0'/0/0/0/0"
+          }
+        }
+      }
     }
   ],
   invalid: [