taler-typescript-core

commit be373f904cbbd83e309181b2ec1379926da40e01
parent cb66e904aa520cc71da99ba0aa2906a935151a9f
Author: Florian Dold <dold@taler.net>
Date:   Thu, 20 Aug 2026 19:06:43 +0200

wallet-core: select slate outputs from the payment choice

Diffstat:
M
packages/taler-wallet-core/src/crypto/cryptoImplementation.test.ts
 | 
46
+++++++++++++++++++++++++++++++++++++++++++++-
M
packages/taler-wallet-core/src/crypto/cryptoImplementation.ts
 | 
55
+++++++++++++++++++++++++++++++------------------------

2 files changed, 76 insertions(+), 25 deletions(-)
diff --git a/packages/taler-wallet-core/src/crypto/cryptoImplementation.test.ts b/packages/taler-wallet-core/src/crypto/cryptoImplementation.test.ts
@@ -22,12 +22,15 @@ import {
   createEddsaKeyPair,
   decodeCrock,
   durationRoundedToBuffer,
+  DenomKeyType,
   eddsaSign,
   encodeCrock,
   EddsaPublicKeyString,
   EddsaSignatureString,
   ExchangeSignKeyJson,
   GlobalFees,
+  MerchantContractOutputType,
+  MerchantContractTermsV1,
   TalerProtocolDuration,
   TalerProtocolTimestamp,
   TalerSignaturePurpose,
@@ -35,7 +38,10 @@ import {
 } from "@gnu-taler/taler-util";
 import assert from "node:assert";
 import { test } from "node:test";
-import { nativeCryptoR } from "./cryptoImplementation.js";
+import {
+  collectSlateTokenEnvelopes,
+  nativeCryptoR,
+} from "./cryptoImplementation.js";
 
 const master = createEddsaKeyPair();
 const masterPub = encodeCrock(master.eddsaPub);
@@ -77,6 +83,44 @@ const validOver = {
   key: encodeCrock(signKey.eddsaPub),
 };
 
+test("slate creation reads outputs from the selected choice", () => {
+  const contractTerms = {
+    choices: [
+      {
+        outputs: [
+          {
+            type: MerchantContractOutputType.Token,
+            token_family_slug: "first",
+          },
+        ],
+      },
+      {
+        outputs: [
+          {
+            type: MerchantContractOutputType.Token,
+            token_family_slug: "second",
+          },
+        ],
+      },
+    ],
+    token_families: {
+      first: {
+        keys: [{ cipher: DenomKeyType.Rsa, rsa_pub: "first-key" }],
+      },
+      second: {
+        keys: [{ cipher: DenomKeyType.Rsa, rsa_pub: "second-key" }],
+      },
+    },
+  } as unknown as MerchantContractTermsV1;
+
+  assert.deepStrictEqual(collectSlateTokenEnvelopes(contractTerms, 1), [
+    {
+      cipher: DenomKeyType.Rsa,
+      rsa_blinded_planchet: "second-key",
+    },
+  ]);
+});
+
 test("a correctly signed exchange signing key is accepted", async () => {
   const res = await nativeCryptoR.isValidSignKey(nativeCryptoR, {
     masterPub,
diff --git a/packages/taler-wallet-core/src/crypto/cryptoImplementation.ts b/packages/taler-wallet-core/src/crypto/cryptoImplementation.ts
@@ -83,6 +83,7 @@ import {
   Logger,
   MakeSyncSignatureRequest,
   MerchantContractOutputType,
+  MerchantContractTermsV1,
   PayWalletData,
   PlanchetCreationRequest,
   PlanchetUnblindInfo,
@@ -828,6 +829,32 @@ export interface DenominationValidationRequest {
   masterSig: string;
 }
 
+export function collectSlateTokenEnvelopes(
+  contractTerms: MerchantContractTermsV1,
+  choiceIndex: number,
+): TokenEnvelope[] {
+  const choice = contractTerms.choices[choiceIndex];
+  const tokenEvs: TokenEnvelope[] = [];
+  for (const output of choice.outputs) {
+    if (output.type !== MerchantContractOutputType.Token) {
+      continue;
+    }
+    const family = contractTerms.token_families[output.token_family_slug];
+    tokenEvs.push(
+      ...family.keys.map((key) => {
+        if (key.cipher !== DenomKeyType.Rsa) {
+          throw Error(`unsupported cipher (${key.cipher})`);
+        }
+        return {
+          cipher: DenomKeyType.Rsa,
+          rsa_blinded_planchet: key.rsa_pub,
+        } as TokenEnvelope;
+      }),
+    );
+  }
+  return tokenEvs;
+}
+
 export interface PaymentSignatureValidationRequest {
   sig: string;
   contractHash: string;
@@ -1233,30 +1260,10 @@ export const nativeCryptoR: TalerCryptoInterfaceR = {
     const tokenIssuePubHash = hashTokenIssuePub(req.tokenIssuePub);
     const evHash = hashTokenEv(tokenEv, encodeCrock(tokenIssuePubHash));
 
-    const choice = req.contractTerms.choices[req.outputIndex];
-    const tokenEvs: TokenEnvelope[] = [];
-    for (const output of choice.outputs) {
-      if (output.type !== MerchantContractOutputType.Token) {
-        continue;
-      }
-
-      const slug = output.token_family_slug;
-      const family = req.contractTerms.token_families[slug];
-      tokenEvs.push(
-        ...family.keys.map((key) => {
-          let tokenEv: TokenEnvelope;
-          if (key.cipher === DenomKeyType.Rsa) {
-            tokenEv = {
-              cipher: DenomKeyType.Rsa,
-              rsa_blinded_planchet: key.rsa_pub,
-            };
-          } else {
-            throw Error(`unsupported cipher (${req.tokenIssuePub.cipher})`);
-          }
-          return tokenEv;
-        }),
-      );
-    }
+    const tokenEvs = collectSlateTokenEnvelopes(
+      req.contractTerms,
+      req.choiceIndex,
+    );
 
     // wallet data object with envelopes
     const tokenWalletData: PayWalletData = {