[libeufin] branch master updated: nexus fetch: removing noise around payment subject

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ms pushed a commit to branch master
in repository libeufin.

The following commit(s) were added to refs/heads/master by this push:
     new 9d15c730 nexus fetch: removing noise around payment subject
9d15c730 is described below

commit 9d15c7304e3eaea5c98373c8ed465c824203e56d
Author: MS <ms@taler.net>
AuthorDate: Fri Nov 17 17:37:49 2023 +0100

    nexus fetch: removing noise around payment subject
---
 .../main/kotlin/tech/libeufin/nexus/EbicsFetch.kt  | 23 ++++++++++-
 nexus/src/test/kotlin/Parsing.kt                   | 47 ++++++++++++++++++++--
 util/src/main/kotlin/strings.kt                    | 12 ------
 3 files changed, 65 insertions(+), 17 deletions(-)

diff --git a/nexus/src/main/kotlin/tech/libeufin/nexus/EbicsFetch.kt 
b/nexus/src/main/kotlin/tech/libeufin/nexus/EbicsFetch.kt
index 506e8c60..713a3f6a 100644
--- a/nexus/src/main/kotlin/tech/libeufin/nexus/EbicsFetch.kt
+++ b/nexus/src/main/kotlin/tech/libeufin/nexus/EbicsFetch.kt
@@ -329,6 +329,10 @@ data class OutgoingPaymentWithLink(
     val initiatedPaymentLink: String
 )
 
+/**
+ * Collects incoming and outgoing payments which are
+ * the result of parsing one camt.054 notification.
+ */
 data class Camt054Result(
     val incoming: MutableList<IncomingPayment> = mutableListOf(),
     val outgoing: MutableList<OutgoingPaymentWithLink> = mutableListOf()
@@ -403,6 +407,21 @@ fun isReservePub(maybeReservePub: String): ByteArray? {
     }
     return dec
 }
+
+/**
+ * Extract the part of the subject that might represent a
+ * valid Taler reserve public key.  That addresses some bank
+ * policies of adding extra information around the payment
+ * subject.
+ *
+ * @param subject raw subject as read from the bank.
+ */
+fun removeSubjectNoise(subject: String): String? {
+    val re = "\\b[a-z0-9A-Z]{52}\\b".toRegex()
+    val result = re.find(subject.replace("[\n]+".toRegex(), "")) ?: return null
+    return result.value
+}
+
 /**
  * Checks the two conditions that may invalidate one incoming
  * payment: subject validity and availability.
@@ -416,8 +435,10 @@ suspend fun getTalerReservePub(
     db: Database,
     payment: IncomingPayment
 ): ByteArray? {
+    // Removing noise around the potential reserve public key.
+    val maybeReservePub = removeSubjectNoise(payment.wireTransferSubject) ?: 
return null
     // Checking validity first.
-    val dec = isReservePub(payment.wireTransferSubject) ?: return null
+    val dec = isReservePub(maybeReservePub) ?: return null
     // Now checking availability.
     val maybeUnavailable = db.isReservePubFound(dec)
     if (maybeUnavailable) {
diff --git a/nexus/src/test/kotlin/Parsing.kt b/nexus/src/test/kotlin/Parsing.kt
index e1e61286..45737e1f 100644
--- a/nexus/src/test/kotlin/Parsing.kt
+++ b/nexus/src/test/kotlin/Parsing.kt
@@ -1,9 +1,6 @@
 import org.junit.Test
 import org.junit.jupiter.api.assertThrows
-import tech.libeufin.nexus.TalerAmount
-import tech.libeufin.nexus.getAmountNoCurrency
-import tech.libeufin.nexus.getTalerAmount
-import tech.libeufin.nexus.isReservePub
+import tech.libeufin.nexus.*
 import tech.libeufin.util.parseBookDate
 import tech.libeufin.util.parseCamtTime
 import java.lang.StringBuilder
@@ -24,6 +21,48 @@ class Parsing {
     @Test
     fun bookDateTest() {
         parseBookDate("1970-01-01")
+        assertThrows<Exception> { parseBookDate("1970-01-01T00:00:01Z") }
+    }
+
+    @Test
+    fun reservePublicKey() {
+        assertNull(removeSubjectNoise("does not contain any reserve"))
+        // 4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0
+        
assertNotNull(removeSubjectNoise("4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0"))
+        assertEquals(
+            "4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0",
+            removeSubjectNoise(
+                "noise 4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0 
noise"
+            )
+        )
+        assertEquals(
+            "4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0",
+            removeSubjectNoise(
+                "4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0 noise to 
the right"
+            )
+        )
+        assertEquals(
+            "4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0",
+            removeSubjectNoise(
+                "noise to the left 
4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0"
+            )
+        )
+        assertEquals(
+            "4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0",
+            removeSubjectNoise(
+                "    4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0     "
+            )
+        )
+        assertEquals(
+            "4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0",
+            removeSubjectNoise("""
+                noise
+                4MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0
+                noise
+            """)
+        )
+        // Got the first char removed.
+        
assertNull(removeSubjectNoise("MZT6RS3RVB3B0E2RDMYW0YRA3Y0VPHYV0CYDE6XBB0YMPFXCEG0"))
     }
 
     @Test // Could be moved in a dedicated Amounts.kt test module.
diff --git a/util/src/main/kotlin/strings.kt b/util/src/main/kotlin/strings.kt
index 43002151..54d6d5a3 100644
--- a/util/src/main/kotlin/strings.kt
+++ b/util/src/main/kotlin/strings.kt
@@ -83,15 +83,3 @@ fun getQueryParam(uriQueryString: String, param: String): 
String? {
     return null
 }
 
-fun extractReservePubFromSubject(rawSubject: String): String? {
-    val re = "\\b[a-z0-9A-Z]{52}\\b".toRegex()
-    val result = re.find(rawSubject.replace("[\n]+".toRegex(), "")) ?: return 
null
-    try {
-        Base32Crockford.decode(result.value)
-    } catch (e: Exception) {
-        logger.debug("Not containing a reserve pub: $rawSubject")
-        return null
-    }
-    return result.value.uppercase()
-}
-

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