add option to have external port

LN invoice expiry param & use it for ctx timeout

.gitignore

@@ -7,6 +7,7 @@
 boltcard
 createboltcard/createboltcard
 wipeboltcard/wipeboltcard
+cli/cli
 
 # Test binary, built with `go test -c`
 *.test

cli/main.go

@@ -0,0 +1,198 @@
+package main
+
+import (
+	"bytes"
+	"crypto/aes"
+	"encoding/hex"
+	"fmt"
+	"github.com/aead/cmac"
+	"github.com/boltcard/boltcard/crypto"
+	"os"
+)
+
+// inspired by parse_request() in lnurlw_request.go
+
+func aes_cmac(key_sdm_file_read_mac []byte, sv2 []byte, ba_c []byte) (bool, error) {
+
+	c2, err := aes.NewCipher(key_sdm_file_read_mac)
+	if err != nil {
+		return false, err
+	}
+
+	ks, err := cmac.Sum(sv2, c2, 16)
+	if err != nil {
+		return false, err
+	}
+
+	fmt.Println("ks = ", ks)
+
+	c3, err := aes.NewCipher(ks)
+	if err != nil {
+		return false, err
+	}
+
+	cm, err := cmac.Sum([]byte{}, c3, 16)
+	if err != nil {
+		return false, err
+	}
+
+	fmt.Println("cm = ", cm)
+
+	ct := make([]byte, 8)
+	ct[0] = cm[1]
+	ct[1] = cm[3]
+	ct[2] = cm[5]
+	ct[3] = cm[7]
+	ct[4] = cm[9]
+	ct[5] = cm[11]
+	ct[6] = cm[13]
+	ct[7] = cm[15]
+
+	fmt.Println("ct = ", ct)
+
+	res_cmac := bytes.Compare(ct, ba_c)
+	if res_cmac != 0 {
+		return false, nil
+	}
+
+	return true, nil
+}
+
+func check_cmac(uid []byte, ctr []byte, k2_cmac_key []byte, cmac []byte) (bool, error) {
+
+	sv2 := make([]byte, 16)
+	sv2[0] = 0x3c
+	sv2[1] = 0xc3
+	sv2[2] = 0x00
+	sv2[3] = 0x01
+	sv2[4] = 0x00
+	sv2[5] = 0x80
+	sv2[6] = uid[0]
+	sv2[7] = uid[1]
+	sv2[8] = uid[2]
+	sv2[9] = uid[3]
+	sv2[10] = uid[4]
+	sv2[11] = uid[5]
+	sv2[12] = uid[6]
+	sv2[13] = ctr[2]
+	sv2[14] = ctr[1]
+	sv2[15] = ctr[0]
+
+	fmt.Println("sv2 = ", sv2)
+
+	cmac_verified, err := aes_cmac(k2_cmac_key, sv2, cmac)
+
+	if err != nil {
+		return false, err
+	}
+
+	return cmac_verified, nil
+}
+
+func main() {
+
+	fmt.Println("-- bolt card crypto test vectors --")
+	fmt.Println()
+
+	args := os.Args[1:]
+
+	if len(args) != 4 {
+		fmt.Println("error: should have arguments for: p c aes_decrypt_key aes_cmac_key")
+		os.Exit(1)
+	}
+
+	// get from args
+	p_hex := args[0]
+	c_hex := args[1]
+	aes_decrypt_key_hex := args[2]
+	aes_cmac_key_hex := args[3]
+
+	fmt.Println("p = ", p_hex)
+	fmt.Println("c = ", c_hex)
+	fmt.Println("aes_decrypt_key = ", aes_decrypt_key_hex)
+	fmt.Println("aes_cmac_key = ", aes_cmac_key_hex)
+	fmt.Println()
+
+	p, err := hex.DecodeString(p_hex)
+
+	if err != nil {
+		fmt.Println("ERROR: p not valid hex", err)
+		os.Exit(1)
+	}
+
+	c, err := hex.DecodeString(c_hex)
+
+	if err != nil {
+		fmt.Println("ERROR: c not valid hex", err)
+		os.Exit(1)
+	}
+
+	if len(p) != 16 {
+		fmt.Println("ERROR: p length not valid")
+		os.Exit(1)
+	}
+
+	if len(c) != 8 {
+		fmt.Println("ERROR: c length not valid")
+		os.Exit(1)
+	}
+
+	// decrypt p with aes_decrypt_key
+
+	aes_decrypt_key, err := hex.DecodeString(aes_decrypt_key_hex)
+
+	if err != nil {
+		fmt.Println("ERROR: DecodeString() returned an error", err)
+		os.Exit(1)
+	}
+
+	dec_p, err := crypto.Aes_decrypt(aes_decrypt_key, p)
+
+	if err != nil {
+		fmt.Println("ERROR: Aes_decrypt() returned an error", err)
+		os.Exit(1)
+	}
+
+	if dec_p[0] != 0xC7 {
+		fmt.Println("ERROR: decrypted data does not start with 0xC7 so is invalid")
+		os.Exit(1)
+	}
+
+	uid := dec_p[1:8]
+
+	ctr := make([]byte, 3)
+	ctr[0] = dec_p[10]
+	ctr[1] = dec_p[9]
+	ctr[2] = dec_p[8]
+
+	// set up uid & ctr for card record if needed
+
+	uid_str := hex.EncodeToString(uid)
+	ctr_str := hex.EncodeToString(ctr)
+
+	fmt.Println("decrypted card data : uid", uid_str, ", ctr", ctr_str)
+
+	// check cmac
+
+	aes_cmac_key, err := hex.DecodeString(aes_cmac_key_hex)
+
+	if err != nil {
+		fmt.Println("ERROR: aes_cmac_key is not valid hex", err)
+		os.Exit(1)
+	}
+
+	cmac_valid, err := check_cmac(uid, ctr, aes_cmac_key, c)
+
+	if err != nil {
+		fmt.Println("ERROR: check_cmac() returned an error", err)
+		os.Exit(1)
+	}
+
+	if cmac_valid == false {
+		fmt.Println("ERROR: cmac incorrect")
+		os.Exit(1)
+	}
+
+	fmt.Println("cmac validates ok")
+	os.Exit(0)
+}

docker_init.sh

@@ -32,3 +32,4 @@ sed -i "s/[(]'FEE_LIMIT_PERCENT'[^)]*[)]/(\'FEE_LIMIT_PERCENT\', \'0.5\')/" sql/
 sed -i "s/[(]'FUNCTION_LNURLW'[^)]*[)]/(\'FUNCTION_LNURLW\', \'ENABLE\')/" sql/settings.sql
 sed -i "s/[(]'FUNCTION_LNURLP'[^)]*[)]/(\'FUNCTION_LNURLP\', \'DISABLE\')/" sql/settings.sql
 sed -i "s/[(]'FUNCTION_EMAIL'[^)]*[)]/(\'FUNCTION_EMAIL\', \'DISABLE\')/" sql/settings.sql
+sed -i "s/[(]'LN_INVOICE_EXPIRY_SEC'[^)]*[)]/(\'LN_INVOICE_EXPIRY_SEC\', \'3600\')/" sql/settings.sql

docs/CARD_MANUAL.md

@@ -46,7 +46,9 @@ lnurlw://card.yourdomain.com/ln
 ```
 lnurlw://card.yourdomain.com/ln?p=00000000000000000000000000000000&c=0000000000000000
 ```
+
 - click after `p=` and note the p_position (41 in this case)
+![find the p_position](images/posn-p.webp)
 - click after `c=` and note the c_position (76 in this case)
 - select `Write To Tag`
 
@@ -101,7 +103,7 @@ lnurlw://card.yourdomain.com/ln?p=00000000000000000000000000000000&c=00000000000
 
 - set up the values in the order shown
 
-![file and SDM options with field entry order](images/fs-add.webp)
+![file and SDM options with field entry order](images/fs-add-2.webp)
 
 - select `Change File Settings`
 

docs/DEEPLINK.md

@@ -0,0 +1,113 @@
+## Abstract
+
+Boltcard NFC Programmer App is a native app on iOS and Android able to program or reset NTag424 into a Boltcard, the typical steps in the setup a Boltcard are:
+
+1. The `Boltcard Service` generates the keys, and format them into a QR Code
+2. The user opens the Boltcard NFC Programmer, go to `Create Bolt Card`, scans the QR code
+3. The user then taps the card
+
+The QR code contains all the keys necessary for the app to create the Boltcard.
+
+Here are the shortcomings of this process that we aim to address in this specification:
+
+1. If the QR code get displayed on the mobile device itself, it is difficult to scan it
+2. The `Boltcard Service`, not knowing the UID when the keys are requested, isn't able to assign a specific pair of keys for the NTag424 being setup (for example, the [deterministic key generation](./DETERMINISTIC.md) needs the UID before generating the keys)
+
+## Boltcard deeplinks
+
+The solution is for the `Boltcard Service` to generate deep links with the following format: `boltcard://[program|reset]?url=[keys-request-url]`.
+
+When clicked, `Boltcard NFC Programmer` would open and either allow the user to program their NTag424 or reset it after asking for the NTags keys to the `keys-request-url`.
+
+The `Boltcard NFC Programmer` should send an HTTP POST request with `Content-Type: application/json` in the following format:
+
+```json
+{
+    "UID": "[UID]"
+}
+```
+
+Or
+
+```json
+{
+    "LNURLW": "lnurlw://..."
+}
+```
+
+In `curl`:
+
+```bash
+curl -X POST "[keys-request-url]" -H "Content-Type: application/json" -d '{"UID": "[UID]"}'
+```
+
+* `UID` needs to be 7 bytes. (Program action)
+* `LNURLW` needs to be read from the Boltcard's NDEF and can be sent in place of `UID`. It must contains the `p=` and `c=` arguments of the Boltcard. (Reset action)
+
+The response will be similar to the format of the QR code:
+
+```json
+{
+  "LNURLW": "lnurlw://...",
+  "K0":"[Key0]",
+  "K1":"[Key1]",
+  "K2":"[Key2]",
+  "K3":"[Key3]",
+  "K4":"[Key4]"
+}
+```
+
+## The Program action
+
+If `program` is specified in the Boltcard link, the `Boltcard NFC Programmer` must:
+
+1. Check if the lnurlw `NDEF` can be read.
+    * If the record can be read, then the card isn't blank, an error should be displayed to the user to first reset the Boltcard.
+    * If the record can't be read, assume `K0` is `00000000000000000000000000000000` authenticate and call `GetUID` on the card again. (Since `GetUID` is called after authentication, the real `UID` will be returned even if `Random UID` has been activated)
+2. Send a request to the `keys-request-url` using the UID as explained above to get the NTag424 app keys
+3. Program the Boltcard with the app keys
+
+## The Reset action
+
+If `reset` is specified in the Boltcard link, the `Boltcard NFC Programmer` must:
+1. Check if the lnurlw `NDEF` can be read.
+    * If the record can't be read, then the card is already reset, show an error message to the user.
+    * If the record can be read, continue to step 2.
+2. Send a request to the `keys-request-url` using the lnurlw as explained above to get the NTag424 app keys
+3. Reset the Boltcard to factory state with the app keys
+
+## Handling setup/reset cycles for Boltcard Services
+
+When a NTag424 is reset, its counter is reset too.
+This means that if the user:
+
+* Setup a Boltcard
+* Make `5` payments
+* Reset the Boltcard
+* Setup the Boltcard on same `keys-request-url`
+
+With a naive implementation, the server will expect the next counter to be above `5`, but the next payment will have a counter of `0`.
+
+More precisely, the user will need to tap the card `5` times before being able to use the Boltcard for a payment successfully again.
+
+To avoid this issue the `Boltcard Service`, if using [Deterministic key generation](./DETERMINISTIC.md), should ensure it updates the key version during a `program` action.
+
+This can be done easily by the `Boltcard Service` by adding a parameter in the `keys-request-url` which specifies that the version need to be updated.
+
+When the `Boltcard NFC Programmer` queries the URL with the UID of the card, the `Boltcard Service` will detect this parameter, and update the version.
+
+## Test vectors
+
+Here is an example of two links for respectively program the Boltcard and Reset it.
+
+```html
+<p>
+    <a id="SetupBoltcard" href="boltcard://program?url=https%3A%2F%2Flocalhost%3A14142%2Fapi%2Fv1%2Fpull-payments%2FfUDXsnySxvb5LYZ1bSLiWzLjVuT%2Fboltcards%3FonExisting%3DUpdateVersion" target="_blank">
+        Setup Boltcard
+    </a>
+    <span>&nbsp;|&nbsp;</span>
+    <a id="ResetBoltcard" href="boltcard://reset?url=https%3A%2F%2Flocalhost%3A14142%2Fapi%2Fv1%2Fpull-payments%2FfUDXsnySxvb5LYZ1bSLiWzLjVuT%2Fboltcards%3FonExisting%3DKeepVersion" target="_blank">
+        Reset Boltcard
+    </a>
+</p>
+```

docs/DETERMINISTIC.md

@@ -0,0 +1,216 @@
+## Abstract
+
+The NXP NTAG424DNA allows applications to configure five application keys, named `K0`, `K1`, `K2`, `K3`, and `K4`. In the BoltCard configuration:
+
+* `K0` is the `App Master Key`, it is the only key permitted to change the application keys.
+* `K1` serves as the `encryption key` for the `PICCData`, represented by the `p=` parameter.
+* `K2` is the `authentication key` used for calculating the SUN MAC of the `PICCData`, represented by the `c=` parameter.
+* `K3` and `K4` are not used but should be configured as recommended in the [NTag424 application notes](https://www.nxp.com/docs/en/application-note/AN12196.pdf).
+
+A simple approach to issuing BoltCards would involve randomly generating the five different keys and storing them in a database.
+
+When a validation request is made, the verifier would attempt to decrypt the `p=` parameter using all existing encryption keys until finding a match. Once decrypted, the `p=` parameter would reveal the card's uid, which can then be used to retrieve the remaining keys.
+
+The primary drawback of this method is its lack of scalability. If many cards have been issued, identifying the correct encryption key could become a computationally intensive task.
+
+In this document, we propose a solution to this issue.
+
+## Keys generation
+
+First, the `LNUrl Withdraw Service` generates a `IssuerKey` that it will use to generate the keys for every NTag424.
+
+Then, configure a BoltCard as follows:
+
+* `CardKey = PRF(IssuerKey, '2d003f75' || UID || Version)`
+* `K0 = PRF(CardKey, '2d003f76')`
+* `K1 = PRF(IssuerKey, '2d003f77')`
+* `K2 = PRF(CardKey, '2d003f78')`
+* `K3 = PRF(CardKey, '2d003f79')`
+* `K4 = PRF(CardKey, '2d003f7a')`
+* `ID = PRF(IssuerKey, '2d003f7b' || UID)`
+
+With the following parameters:
+* `IssuerKey`: This 16-bytes key is used by an `LNUrl Withdraw Service` to setup all its BoltCards.
+* `UID`: This is the 7-byte ID of the card. You can retrieve it from the NTag424 using the `GetCardUID` function after identification with K1, or by decrypting the `p=` parameter, also known as `PICCData`.
+* `Version`: A 4-bytes little endian version number. This must be incremented every time the user re-programs (reset/setup) the same BoltCard on the same `LNUrl Withdraw Service`.
+
+The Pseudo Random Function `PRF(key, message)` applied during the key generation is the CMAC algorithm described in NIST Special Publication 800-38B. [See implementation notes](#notes)
+
+## How to setup a new BoltCard
+
+1. Execute `ReadData` or `ISOReaDBinary` on the BoltCard to ensure the card is blank.
+2. Execute `AuthenticateEV2First` with the application key `00000000000000000000000000000000`
+3. Fetch the `UID` with `GetCardUID`.
+4. Calculate `ID`
+5. Fetch the `State` and `Version` of the BoltCard with the specified `ID` from the database.
+6. Ensure either:
+    * If no BoltCard is found, insert an entry in the database with `Version=0` and its state set to `Configured`.
+    * If a BoltCard is found and its state is `Reset` then increment `Version` by `1`, and change its state to `Configured`.
+7. Generate `CardKey` with `UID` and `Version`.
+8. Calculate `K0`, `K1`, `K2`, `K3`, `K4`.
+9. [Setup the BoltCard](./CARD_MANUAL.md).
+
+## How to implement a Reset feature
+
+If a `LNUrl Withdraw Service` offers a factory reset feature for a user's BoltCard, here is the recommended procedure:
+
+1. Read the NDEF lnurlw URL, extract `p=` and `c=`.
+2. Derive `Encryption Key (K1)`, decrypt `p=` to obtain the `PICCData`.
+3. Check `PICCData[0] == 0xc7`. 
+4. Calculate `ID` with the `UID` from the `PICCData`.
+5. Fetch the BoltCard's `Version` with `ID` from the database.
+6. Ensure the BoltCard's state is `Configured`.
+7. Generate `CardKey` with `UID` and `Version`.
+8. Derive `K0`, `K2`, `K3`, `K4` with `CardKey` and the `UID`.
+9. Verify that the SUN MAC in `c=` matches the one calculated using `Authentication Key (K2)`.
+10. Execute `AuthenticateEV2First` with `K0`
+11. Erase the NDEF data file using `WriteData` or `ISOUpdateBinary`
+12. Restore the NDEF file settings to default values with `ChangeFileSettings`.
+13. Use `ChangeKey` with the recovered application keys to reset `K4` through `K0` to `00000000000000000000000000000000`.
+14. Update the BoltCard's state to `Reset` in the database.
+
+Rational: Attempting to call `AuthenticateEV2First` without validating the `p=` and `c=` parameters could render the NTag inoperable after a few attempts.
+
+## How to implement a verification
+
+If a `LNUrl Withdraw Service` needs to verify a payment request, follow these steps:
+
+1. Read the NDEF lnurlw URL, extract `p=` and `c=`.
+2. Derive `Encryption Key (K1)`, decrypts `p=` to get the `PICCData`.
+3. Check `PICCData[0] == 0xc7`. 
+4. Calculate `ID` with the `UID` from the `PICCData`.
+5. Fetch the BoltCard's `Version` with `ID` from the database.
+6. Ensure the BoltCard's state in the database is not `Reset`.
+7. Generate `CardKey` with `UID` and `Version`.
+8. Derive `Authentication Key (K2)` with `CardKey` and the `UID`.
+9. Verify that the SUN MAC in `c=` matches the one calculated using `Authentication Key (K2)`.
+10. Confirm that the last-seen counter for `ID` is lower than what is stored in `counter=PICCData[8..11]`. (Little Endian)
+11. Update the last-seen counter.
+
+Rationale: The `ID` is calculated to prevent the exposure of the `UID` in the `LNUrl Withdraw Service` database. This approach provides both privacy and security. Specifically, because the `UID` is used to derive keys, it is preferable not to store it outside the NTag.
+
+## Multiple IssuerKeys
+
+A single `LNUrl Withdraw Service` can own multiple `IssuerKeys`. In such cases, it will need to attempt them all to decrypt `p=`, and pick the first one which satisfies `PICCData[0] == 0xc7` and verifies the `c=` checksum.
+
+Using multiple `IssuerKeys` can decrease the impact of a compromised `Encryption Key (K1)` at the cost of performance.
+
+## Security consideration
+
+### K1 security
+
+Since `K1` is shared among multiple BoltCards, the security of this scheme is based on the following assumptions:
+
+* `K1` cannot be extracted from a legitimate NTag424.
+* BoltCard setup occurs in a trusted environment.
+
+While NXP gives assurance keys can't be extracted, a non genuine NTag424 could potentially expose these keys.
+
+Furthermore, because blank NTag424 uses the well-known initial application keys `00000000000000000000000000000000`, communication between the PCD and the PICC could be intercepted. If the BoltCard setup does not occur in a trusted environment, `K1` could be exposed during the calls to `ChangeKey`.
+
+However, if `K1` is compromised, the attacker still cannot produce a valid checksum and can only recover the `UID` for tracking purposes.
+
+Note that verifying the signature returned by `Read_Sig` can only prove NXP issued a card with a specific `UID`. It cannot prove that the current communication channel is established with an authentic NTag424. This is because the signature returned by `Read_Sig` covers only the `UID` and can therefore be replayed by a non-genuine NTag424.
+
+### Issuer database security
+
+If the issuer's database is compromised, revealing both the IssuerKey and CardKeys, it would still be infeasible for an attacker to derive `K2` and thus to forge signatures for an arbitrary card.
+
+This is because the database only stores `ID` and not the `UID` itself.
+
+## Implementation notes {#notes}
+
+Here is a C# implementation of the CMAC algorithm described in NIST Special Publication 800-38B.
+
+```csharp
+public byte[] CMac(byte[] data)
+{
+    var key = _bytes;
+    // SubKey generation
+    // step 1, AES-128 with key K is applied to an all-zero input block.
+    byte[] L = AesEncrypt(key, new byte[16], new byte[16]);
+
+    // step 2, K1 is derived through the following operation:
+    byte[]
+        FirstSubkey =
+            RotateLeft(L); //If the most significant bit of L is equal to 0, K1 is the left-shift of L by 1 bit.
+    if ((L[0] & 0x80) == 0x80)
+        FirstSubkey[15] ^=
+            0x87; // Otherwise, K1 is the exclusive-OR of const_Rb and the left-shift of L by 1 bit.
+
+    // step 3, K2 is derived through the following operation:
+    byte[]
+        SecondSubkey =
+            RotateLeft(FirstSubkey); // If the most significant bit of K1 is equal to 0, K2 is the left-shift of K1 by 1 bit.
+    if ((FirstSubkey[0] & 0x80) == 0x80)
+        SecondSubkey[15] ^=
+            0x87; // Otherwise, K2 is the exclusive-OR of const_Rb and the left-shift of K1 by 1 bit.
+
+    // MAC computing
+    if (((data.Length != 0) && (data.Length % 16 == 0)) == true)
+    {
+        // If the size of the input message block is equal to a positive multiple of the block size (namely, 128 bits),
+        // the last block shall be exclusive-OR'ed with K1 before processing
+        for (int j = 0; j < FirstSubkey.Length; j++)
+            data[data.Length - 16 + j] ^= FirstSubkey[j];
+    }
+    else
+    {
+        // Otherwise, the last block shall be padded with 10^i
+        byte[] padding = new byte[16 - data.Length % 16];
+        padding[0] = 0x80;
+
+        data = data.Concat(padding.AsEnumerable()).ToArray();
+
+        // and exclusive-OR'ed with K2
+        for (int j = 0; j < SecondSubkey.Length; j++)
+            data[data.Length - 16 + j] ^= SecondSubkey[j];
+    }
+
+    // The result of the previous process will be the input of the last encryption.
+    byte[] encResult = AesEncrypt(key, new byte[16], data);
+
+    byte[] HashValue = new byte[16];
+    Array.Copy(encResult, encResult.Length - HashValue.Length, HashValue, 0, HashValue.Length);
+
+    return HashValue;
+}
+static byte[] RotateLeft(byte[] b)
+{
+    byte[] r = new byte[b.Length];
+    byte carry = 0;
+
+    for (int i = b.Length - 1; i >= 0; i--)
+    {
+        ushort u = (ushort)(b[i] << 1);
+        r[i] = (byte)((u & 0xff) + carry);
+        carry = (byte)((u & 0xff00) >> 8);
+    }
+
+    return r;
+}
+```
+
+## Implementation
+
+* [BTCPayServer.BoltCardTools](https://github.com/btcpayserver/BTCPayServer.BoltCardTools), a BoltCard/NTag424 library in C#.
+
+## Test vectors
+
+Input:
+```
+UID: 04a39493cc8680
+Issuer Key: 00000000000000000000000000000001
+Version: 1
+```
+
+Expected:
+```
+K0: a29119fcb48e737d1591d3489557e49b
+K1: 55da174c9608993dc27bb3f30a4a7314
+K2: f4b404be700ab285e333e32348fa3d3b
+K3: 73610ba4afe45b55319691cb9489142f
+K4: addd03e52964369be7f2967736b7bdb5
+ID: e07ce1279d980ecb892a81924b67bf18
+CardKey: ebff5a4e6da5ee14cbfe720ae06fbed9
+```

docs/SETTINGS.md

@@ -34,3 +34,4 @@ Here are the descriptions of values available to use in the `settings` table:
 | FUNCTION_INTERNAL_API | DISABLE | system level switch for activating the internal API |
 | SENDGRID_API_KEY      | | User API Key from SendGrid.com             |
 | SENDGRID_EMAIL_SENDER | | Single Sender email address verified by SendGrid |
+| LN_INVOICE_EXPIRY_SEC | 3600 | LN invoice's expiry time in seconds |

docs/SPEC.md

@@ -3,11 +3,21 @@
 The bolt card system is built on the technologies listed below.
 
 - [LUD-03: withdrawRequest base spec.](https://github.com/fiatjaf/lnurl-rfc/blob/luds/03.md)
+  - with the exception of maxWithdrawable which must be returned as higher than the actual maximum amount
 - [LUD-17: Protocol schemes and raw (non bech32-encoded) URLs.](https://github.com/fiatjaf/lnurl-rfc/blob/luds/17.md)
 - NFC Data Exchange Format (NDEF)
 - Replay protection
   - NXP Secure Unique NFC Message (SUN) technology as implemented in the NXP NTAG 424 DNA card
 
+Bolt card systems should implement the best possible privacy.
+
+- [Privacy levels](https://github.com/boltcard/boltcard/blob/main/docs/CARD_PRIVACY.md)
+
+Bolt card systems may optionally support these technogies.
+
+- [LUD-19: Pay link discoverable from withdraw link.](https://github.com/lnurl/luds/blob/luds/19.md)
+- [LUD-21: pinLimit for withdrawRequest](https://github.com/bitcoin-ring/luds/blob/withdraw-pin/21.md)
+
 ## Bolt card and POS interaction
 
 the point-of-sale (POS) will read a NDEF message from the card, which changes with each use, for example

docs/TECHNOLOGY.md

@@ -4,6 +4,8 @@
 | --- | --- |
 | [System](SYSTEM.md) | Bolt card system overview |
 | [Specification](SPEC.md) | Bolt card specifications |
+| [Deterministic Keys (DRAFT FOR COMMENT)](DETERMINISTIC.md) | Consideration about key generation |
+| [Boltcard Setup via Deeplink](DEEPLINK.md) | Deeplink for Boltcard creator apps |
 | [Privacy](CARD_PRIVACY.md) | Bolt card privacy |
 | [NXP 424 Datasheet](NT4H2421Gx.pdf) | NXP NTAG424DNA datasheet |
 | [NXP 424 Application Note](NT4H2421Gx.pdf) | NXP NTAG424DNA features and hints |

docs/TEST_VECTORS.md

@@ -0,0 +1,54 @@
+# test vectors
+
+some test vectors to help with developing code to AES decode and validate lnurlw:// requests
+
+these have been created by using an actual card and with [a small command line utility](https://github.com/boltcard/boltcard/blob/main/cli/main.go)
+
+```
+-- bolt card crypto test vectors --
+
+p =  4E2E289D945A66BB13377A728884E867
+c =  E19CCB1FED8892CE
+aes_decrypt_key =  0c3b25d92b38ae443229dd59ad34b85d
+aes_cmac_key =  b45775776cb224c75bcde7ca3704e933
+
+decrypted card data : uid 04996c6a926980 , ctr 000003
+sv2 =  [60 195 0 1 0 128 4 153 108 106 146 105 128 3 0 0]
+ks =  [242 92 75 92 230 171 63 244 5 242 135 175 172 78 77 26]
+cm =  [118 225 233 156 238 203 64 31 163 237 110 136 112 146 124 206]
+ct =  [225 156 203 31 237 136 146 206]
+cmac validates ok
+
+
+
+-- bolt card crypto test vectors --
+
+p =  00F48C4F8E386DED06BCDC78FA92E2FE
+c =  66B4826EA4C155B4
+aes_decrypt_key =  0c3b25d92b38ae443229dd59ad34b85d
+aes_cmac_key =  b45775776cb224c75bcde7ca3704e933
+
+decrypted card data : uid 04996c6a926980 , ctr 000005
+sv2 =  [60 195 0 1 0 128 4 153 108 106 146 105 128 5 0 0]
+ks =  [73 70 39 105 116 24 126 152 96 101 139 189 130 16 200 190]
+cm =  [94 102 243 180 93 130 2 110 198 164 241 193 67 85 112 180]
+ct =  [102 180 130 110 164 193 85 180]
+cmac validates ok
+
+
+
+-- bolt card crypto test vectors --
+
+p =  0DBF3C59B59B0638D60B5842A997D4D1
+c =  CC61660C020B4D96
+aes_decrypt_key =  0c3b25d92b38ae443229dd59ad34b85d
+aes_cmac_key =  b45775776cb224c75bcde7ca3704e933
+
+decrypted card data : uid 04996c6a926980 , ctr 000007
+sv2 =  [60 195 0 1 0 128 4 153 108 106 146 105 128 7 0 0]
+ks =  [97 189 177 81 15 79 217 5 102 95 162 58 192 199 38 97]
+cm =  [40 204 202 97 87 102 6 12 101 2 250 11 199 77 73 150]
+ct =  [204 97 102 12 2 11 77 150]
+cmac validates ok
+
+```

internalapi/createboltcard.go

@@ -1,12 +1,13 @@
 package internalapi
 
 import (
-	"github.com/boltcard/boltcard/db"
-	"github.com/boltcard/boltcard/resp_err"
-	log "github.com/sirupsen/logrus"
 	"net/http"
 	"strconv"
 	"strings"
+
+	"github.com/boltcard/boltcard/db"
+	"github.com/boltcard/boltcard/resp_err"
+	log "github.com/sirupsen/logrus"
 )
 
 // random_hex() from Createboltcardwithpin used here
@@ -100,11 +101,16 @@ func Createboltcard(w http.ResponseWriter, r *http.Request) {
 	// return the URI + one_time_code
 
 	hostdomain := db.Get_setting("HOST_DOMAIN")
+	hostdomainPort := db.Get_setting("HOST_DOMAIN_PORT")
+	hostdomainsuffix := ""
+	if hostdomainPort != "" {
+		hostdomainsuffix = ":" + hostdomainPort
+	}
 	url := ""
 	if strings.HasSuffix(hostdomain, ".onion") {
-		url = "http://" + hostdomain + "/new?a=" + one_time_code
+		url = "http://" + hostdomain + hostdomainsuffix + "/new?a=" + one_time_code
 	} else {
-		url = "https://" + hostdomain + "/new?a=" + one_time_code
+		url = "https://" + hostdomain + hostdomainsuffix + "/new?a=" + one_time_code
 	}
 
 	// log the response

internalapi/createboltcardwithpin.go

@@ -3,12 +3,13 @@ package internalapi
 import (
 	"crypto/rand"
 	"encoding/hex"
-	"github.com/boltcard/boltcard/db"
-	"github.com/boltcard/boltcard/resp_err"
-	log "github.com/sirupsen/logrus"
 	"net/http"
 	"strconv"
 	"strings"
+
+	"github.com/boltcard/boltcard/db"
+	"github.com/boltcard/boltcard/resp_err"
+	log "github.com/sirupsen/logrus"
 )
 
 func random_hex() string {
@@ -132,11 +133,16 @@ func Createboltcardwithpin(w http.ResponseWriter, r *http.Request) {
 	// return the URI + one_time_code
 
 	hostdomain := db.Get_setting("HOST_DOMAIN")
+	hostdomainPort := db.Get_setting("HOST_DOMAIN_PORT")
+	hostdomainsuffix := ""
+	if hostdomainPort != "" {
+		hostdomainsuffix = ":" + hostdomainPort
+	}
 	url := ""
 	if strings.HasSuffix(hostdomain, ".onion") {
-		url = "http://" + hostdomain + "/new?a=" + one_time_code
+		url = "http://" + hostdomain + hostdomainsuffix + "/new?a=" + one_time_code
 	} else {
-		url = "https://" + hostdomain + "/new?a=" + one_time_code
+		url = "https://" + hostdomain + hostdomainsuffix + "/new?a=" + one_time_code
 	}
 
 	// log the response

lnd/lnd.go

@@ -81,6 +81,10 @@ func Add_invoice(amount_sat int64, metadata string) (payment_request string, r_h
 	if err != nil {
 		return "", nil, err
 	}
+	ln_invoice_expiry, err := strconv.ParseInt(db.Get_setting("LN_INVOICE_EXPIRY_SEC"), 10, 64)
+	if err != nil {
+		return "", nil, err
+	}
 
 	dh := sha256.Sum256([]byte(metadata))
 
@@ -98,6 +102,7 @@ func Add_invoice(amount_sat int64, metadata string) (payment_request string, r_h
 	result, err := l_client.AddInvoice(ctx, &lnrpc.Invoice{
 		Value:           amount_sat,
 		DescriptionHash: dh[:],
+		Expiry:          ln_invoice_expiry,
 	})
 
 	if err != nil {
@@ -120,6 +125,11 @@ func Monitor_invoice_state(r_hash []byte) {
 		log.Warn(err)
 		return
 	}
+	ln_invoice_expiry, err := strconv.Atoi(db.Get_setting("LN_INVOICE_EXPIRY_SEC"))
+	if err != nil {
+		log.Warn(err)
+		return
+	}
 
 	connection := getGrpcConn(
 		db.Get_setting("LN_HOST"),
@@ -129,7 +139,7 @@ func Monitor_invoice_state(r_hash []byte) {
 
 	i_client := invoicesrpc.NewInvoicesClient(connection)
 
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(ln_invoice_expiry)*time.Second)
 	defer cancel()
 
 	stream, err := i_client.SubscribeSingleInvoice(ctx, &invoicesrpc.SubscribeSingleInvoiceRequest{
@@ -228,10 +238,11 @@ func PayInvoice(card_payment_id int, invoice string) {
 
 	bolt11, _ := decodepay.Decodepay(invoice)
 	invoice_msats := bolt11.MSatoshi
+	invoice_expiry := bolt11.Expiry
 
 	fee_limit_product := int64((fee_limit_percent / 100) * (float64(invoice_msats) / 1000))
 
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(invoice_expiry)*time.Second)
 	defer cancel()
 
 	stream, err := r_client.SendPaymentV2(ctx, &routerrpc.SendPaymentRequest{

lnurlp/lnurlp_callback.go

@@ -2,13 +2,14 @@ package lnurlp
 
 import (
 	"encoding/hex"
+	"net/http"
+	"strconv"
+
 	"github.com/boltcard/boltcard/db"
 	"github.com/boltcard/boltcard/lnd"
 	"github.com/boltcard/boltcard/resp_err"
 	"github.com/gorilla/mux"
 	log "github.com/sirupsen/logrus"
-	"net/http"
-	"strconv"
 )
 
 func Callback(w http.ResponseWriter, r *http.Request) {
@@ -37,6 +38,11 @@ func Callback(w http.ResponseWriter, r *http.Request) {
 		}).Info("lnurlp_callback")
 
 	domain := db.Get_setting("HOST_DOMAIN")
+	hostdomainPort := db.Get_setting("HOST_DOMAIN_PORT")
+	hostdomainsuffix := ""
+	if hostdomainPort != "" {
+		hostdomainsuffix = ":" + hostdomainPort
+	}
 	if r.Host != domain {
 		log.Warn("wrong host domain")
 		resp_err.Write(w)
@@ -52,7 +58,7 @@ func Callback(w http.ResponseWriter, r *http.Request) {
 
 	amount_sat := amount_msat / 1000
 
-	metadata := "[[\"text/identifier\",\"" + name + "@" + domain + "\"],[\"text/plain\",\"bolt card deposit\"]]"
+	metadata := "[[\"text/identifier\",\"" + name + "@" + domain + hostdomainsuffix + "\"],[\"text/plain\",\"bolt card deposit\"]]"
 	pr, r_hash, err := lnd.Add_invoice(amount_sat, metadata)
 	if err != nil {
 		log.Warn("could not add_invoice")

lnurlp/lnurlp_request.go

@@ -1,11 +1,12 @@
 package lnurlp
 
 import (
+	"net/http"
+
 	"github.com/boltcard/boltcard/db"
 	"github.com/boltcard/boltcard/resp_err"
 	"github.com/gorilla/mux"
 	log "github.com/sirupsen/logrus"
-	"net/http"
 )
 
 func Response(w http.ResponseWriter, r *http.Request) {
@@ -26,6 +27,11 @@ func Response(w http.ResponseWriter, r *http.Request) {
 	// look up domain setting (HOST_DOMAIN)
 
 	domain := db.Get_setting("HOST_DOMAIN")
+	hostdomainPort := db.Get_setting("HOST_DOMAIN_PORT")
+	hostdomainsuffix := ""
+	if hostdomainPort != "" {
+		hostdomainsuffix = ":" + hostdomainPort
+	}
 	if r.Host != domain {
 		log.Warn("wrong host domain")
 		resp_err.Write(w)
@@ -47,10 +53,10 @@ func Response(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	metadata := "[[\\\"text/identifier\\\",\\\"" + name + "@" + domain + "\\\"],[\\\"text/plain\\\",\\\"bolt card deposit\\\"]]"
+	metadata := "[[\\\"text/identifier\\\",\\\"" + name + "@" + domain + hostdomainsuffix + "\\\"],[\\\"text/plain\\\",\\\"bolt card deposit\\\"]]"
 
 	jsonData := []byte(`{"status":"OK",` +
-		`"callback":"https://` + domain + `/lnurlp/` + name + `",` +
+		`"callback":"https://` + domain + hostdomainsuffix + `/lnurlp/` + name + `",` +
 		`"tag":"payRequest",` +
 		`"maxSendable":1000000000,` +
 		`"minSendable":1000,` +

lnurlw/lnurlw_request.go

@@ -4,14 +4,15 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
-	"github.com/boltcard/boltcard/crypto"
-	"github.com/boltcard/boltcard/db"
-	"github.com/boltcard/boltcard/resp_err"
-	log "github.com/sirupsen/logrus"
 	"net/http"
 	"os"
 	"strconv"
 	"strings"
+
+	"github.com/boltcard/boltcard/crypto"
+	"github.com/boltcard/boltcard/db"
+	"github.com/boltcard/boltcard/resp_err"
+	log "github.com/sirupsen/logrus"
 )
 
 func get_p_c(req *http.Request, p_name string, c_name string) (p string, c string) {
@@ -246,6 +247,11 @@ func parse_request(req *http.Request) (int, error) {
 func Response(w http.ResponseWriter, req *http.Request) {
 
 	env_host_domain := db.Get_setting("HOST_DOMAIN")
+	hostdomainPort := db.Get_setting("HOST_DOMAIN_PORT")
+	hostdomainsuffix := ""
+	if hostdomainPort != "" {
+		hostdomainsuffix = ":" + hostdomainPort
+	}
 
 	if req.Host != env_host_domain {
 		log.Warn("wrong host domain")
@@ -280,10 +286,10 @@ func Response(w http.ResponseWriter, req *http.Request) {
 	}
 
 	lnurlw_cb_url := ""
-	if strings.HasSuffix(req.Host, ".onion") {
+	if strings.HasSuffix(env_host_domain, ".onion") {
-		lnurlw_cb_url = "http://" + req.Host + "/cb"
+		lnurlw_cb_url = "http://" + env_host_domain + hostdomainsuffix + "/cb"
 	} else {
-		lnurlw_cb_url = "https://" + req.Host + "/cb"
+		lnurlw_cb_url = "https://" + env_host_domain + hostdomainsuffix + "/cb"
 	}
 
 	min_withdraw_sats_str := db.Get_setting("MIN_WITHDRAW_SATS")

new_card_request.go

@@ -3,10 +3,11 @@ package main
 import (
 	"database/sql"
 	"encoding/json"
+	"net/http"
+
 	"github.com/boltcard/boltcard/db"
 	"github.com/boltcard/boltcard/resp_err"
 	log "github.com/sirupsen/logrus"
-	"net/http"
 )
 
 /**
@@ -55,7 +56,12 @@ func new_card_request(w http.ResponseWriter, req *http.Request) {
 
 	a := params_a[0]
 
-	lnurlw_base := "lnurlw://" + db.Get_setting("HOST_DOMAIN") + "/ln"
+	hostdomainPort := db.Get_setting("HOST_DOMAIN_PORT")
+	hostdomainsuffix := ""
+	if hostdomainPort != "" {
+		hostdomainsuffix = ":" + hostdomainPort
+	}
+	lnurlw_base := "lnurlw://" + db.Get_setting("HOST_DOMAIN") + hostdomainsuffix + "/ln"
 
 	c, err := db.Get_new_card(a)
 

sql/settings.sql

@@ -31,3 +31,4 @@ INSERT INTO settings (name, value) VALUES ('LNDHUB_URL', '');
 INSERT INTO settings (name, value) VALUES ('FUNCTION_INTERNAL_API', '');
 INSERT INTO settings (name, value) VALUES ('SENDGRID_API_KEY', '');
 INSERT INTO settings (name, value) VALUES ('SENDGRID_EMAIL_SENDER', '');
+INSERT INTO settings (name, value) VALUES ('LN_INVOICE_EXPIRY_SEC', '3600');