Apple促销优惠购买报错：SKErrorDomain 12与ASDServerErrorDomain 3903求助

已成功显示Apple促销优惠，但完成支付流程（输入密码并确认购买）后，弹出提示“无法购买。请联系开发者了解更多信息。”的错误弹窗。

日志错误信息 #

• SKErrorDomain Code=12 "(null)"
• ASDServerErrorDomain Code=3903 "Unable to Purchase"

签名字符串拼接规则及参数 #

签名字符串格式：
appBundleId + '\u2063' + keyIdentifier + '\u2063' + productIdentifier + '\u2063' + offerIdentifier + '\u2063' + appAccountToken + '\u2063' + nonce + '\u2063' + timestamp

使用的参数示例：

• appBundleId: com.app.myapp
• keyIdentifier: 从App Store Connect复制的密钥ID
• productIdentifier: product_identifier
• offerIdentifier: offer_identifier
• appAccountToken: 已尝试使用UUID和空字符串
• nonce: 转为小写的UUID
• timestamp: UNIX时间戳

Java签名生成逻辑 #

/* promotionalOfferKey = value between "-----BEGIN PRIVATE KEY-----" and "-----END PRIVATE KEY-----" from the downloaded p8 file from App Store Connect associated with the keyIdentifier parameter above */

// stringToSign = the combined string above

byte[] encoded = Base64.getDecoder().decode(promotionalOfferKey);
KeyFactory keyFactory = KeyFactory.getInstance("EC");
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encoded);

Signature ecdsaSign = Signature.getInstance("SHA256withECDSA");
ecdsaSign.initSign(keyFactory.generatePrivate(keySpec));

ecdsaSign.update(stringToSign.getBytes(StandardCharsets.UTF_8));
byte[] signature = ecdsaSign.sign();

signatureToReturn = Base64.getEncoder().encodeToString(signature);

请问我哪里操作有误？感谢您的帮助。

内容的提问来源于stack exchange，提问作者Renz