libeufin

commit 4e594a248ea62129129c7aec693e39e27d394acd
parent eb459c842f6d9b8516974b6c0940ab07f7156a5e
Author: Antoine A <>
Date:   Tue,  8 Oct 2024 18:00:50 +0200

common: improve use of secure rng

Diffstat:
M
bank/src/main/kotlin/tech/libeufin/bank/api/CoreBankApi.kt
 | 
2
+-
M
bank/src/main/kotlin/tech/libeufin/bank/auth/Tan.kt
 | 
5
++---
M
bank/src/main/kotlin/tech/libeufin/bank/helpers.kt
 | 
2
+-
M
common/src/main/kotlin/TalerCommon.kt
 | 
1
+
M
common/src/main/kotlin/crypto/PwCrypto.kt
 | 
8
++------
M
common/src/main/kotlin/helpers.kt
 | 
13
+++++++++----
M
nexus/src/main/kotlin/tech/libeufin/nexus/ebics/EbicsCommon.kt
 | 
5
+----

7 files changed, 17 insertions(+), 19 deletions(-)
diff --git a/bank/src/main/kotlin/tech/libeufin/bank/api/CoreBankApi.kt b/bank/src/main/kotlin/tech/libeufin/bank/api/CoreBankApi.kt
@@ -101,7 +101,7 @@ private fun Routing.coreBankTokenApi(db: Database, cfg: BankConfig) {
                         TalerErrorCode.GENERIC_TOKEN_PERMISSION_INSUFFICIENT
                     )
             }
-            val token = Base32Crockford32B.rand()
+            val token = Base32Crockford32B.secureRand()
             val tokenDuration: Duration = req.duration?.d_us ?: TOKEN_DEFAULT_DURATION
 
             val creationTime = Instant.now()
diff --git a/bank/src/main/kotlin/tech/libeufin/bank/auth/Tan.kt b/bank/src/main/kotlin/tech/libeufin/bank/auth/Tan.kt
@@ -28,7 +28,7 @@ import tech.libeufin.bank.*
 import tech.libeufin.bank.db.Database
 import tech.libeufin.bank.db.TanDAO.Challenge
 import tech.libeufin.common.X_CHALLENGE_ID
-import java.security.SecureRandom
+import tech.libeufin.common.SECURE_RNG
 import java.text.DecimalFormat
 import java.time.Instant
 
@@ -106,11 +106,10 @@ suspend fun ApplicationCall.checkChallenge(
 
 object Tan {
     private val CODE_FORMAT = DecimalFormat("00000000")
-    private val SECURE_RNG = SecureRandom()
 
     /** Generate a secure random TAN code */
     fun genCode(): String {
-        val rand = SECURE_RNG.nextInt(100000000)
+        val rand = SECURE_RNG.get().nextInt(100000000)
         val code = CODE_FORMAT.format(rand)
         return code
     }
diff --git a/bank/src/main/kotlin/tech/libeufin/bank/helpers.kt b/bank/src/main/kotlin/tech/libeufin/bank/helpers.kt
@@ -86,7 +86,7 @@ fun ApplicationRequest.withdrawConfirmUrl(id: UUID) = url {
 suspend fun createAdminAccount(db: Database, cfg: BankConfig, pw: String? = null): AccountCreationResult {
     var pwStr = pw
     if (pwStr == null) {
-        val pwBuf = ByteArray(32).rand()
+        val pwBuf = ByteArray(32).secureRand()
         pwStr = String(pwBuf, Charsets.UTF_8)
     }
     
diff --git a/common/src/main/kotlin/TalerCommon.kt b/common/src/main/kotlin/TalerCommon.kt
@@ -525,6 +525,7 @@ class Base32Crockford32B {
 
     companion object {
         fun rand(): Base32Crockford32B = Base32Crockford32B(ByteArray(32).rand())
+        fun secureRand(): Base32Crockford32B = Base32Crockford32B(ByteArray(32).secureRand())
     }
 }
 
diff --git a/common/src/main/kotlin/crypto/PwCrypto.kt b/common/src/main/kotlin/crypto/PwCrypto.kt
@@ -22,8 +22,7 @@ package tech.libeufin.common.crypto
 import kotlinx.serialization.Serializable
 import tech.libeufin.common.decodeBase64
 import tech.libeufin.common.encodeBase64
-import tech.libeufin.common.rand
-import java.security.SecureRandom
+import tech.libeufin.common.secureRand
 
 data class PasswordHashCheck(
     val match: Boolean,
@@ -39,7 +38,7 @@ sealed interface PwCrypto {
     fun hashpw(pw: String): String {
         when (this) {
             is Bcrypt -> {
-                val salt = ByteArray(16).rand(SECURE_RNG)
+                val salt = ByteArray(16).secureRand()
                 val pwh = CryptoUtil.bcrypt(pw, salt, cost)
                 return "bcrypt\$$cost\$${salt.encodeBase64()}\$${pwh.encodeBase64()}"
             }
@@ -82,7 +81,4 @@ sealed interface PwCrypto {
             else -> throw Exception("unsupported hash algo: '$algo'")
         }
     }
-    companion object {
-        private val SECURE_RNG = SecureRandom()
-    }
 }
 \ No newline at end of file
diff --git a/common/src/main/kotlin/helpers.kt b/common/src/main/kotlin/helpers.kt
@@ -76,14 +76,19 @@ fun dateTimeToInstant(date: String): Instant =
 fun BigInteger.encodeHex(): String = this.toByteArray().encodeHex()
 fun BigInteger.encodeBase64(): String = this.toByteArray().encodeBase64()
 
+/* ----- Random ----- */
+
+/** Thread local cryptographically strong random number generator */
+val SECURE_RNG = ThreadLocal.withInitial { SecureRandom() }
+
 /* ----- ByteArray ----- */
 
-fun ByteArray.rand(): ByteArray {
-    Random.nextBytes(this)
+fun ByteArray.rand(rng: Random = Random): ByteArray {
+    rng.nextBytes(this)
     return this
 }
-fun ByteArray.rand(rng: SecureRandom): ByteArray {
-    rng.nextBytes(this)
+fun ByteArray.secureRand(): ByteArray {
+    SECURE_RNG.get().nextBytes(this)
     return this
 }
 fun ByteArray.encodeHex(): String = HexFormat.of().formatHex(this)
diff --git a/nexus/src/main/kotlin/tech/libeufin/nexus/ebics/EbicsCommon.kt b/nexus/src/main/kotlin/tech/libeufin/nexus/ebics/EbicsCommon.kt
@@ -34,7 +34,6 @@ import tech.libeufin.nexus.*
 import tech.libeufin.nexus.db.Database
 import java.io.InputStream
 import java.io.SequenceInputStream
-import java.security.SecureRandom
 import java.security.interfaces.RSAPrivateCrtKey
 import java.time.Instant
 import java.util.*
@@ -371,11 +370,9 @@ fun decryptAndDecompressPayload(
         }.inflate()
 }
 
-private val SECURE_RNG = SecureRandom()
-
 /** Generate a secure random nonce of [size] bytes */
 fun getNonce(size: Int): ByteArray {
-    return ByteArray(size / 8).rand(SECURE_RNG)
+    return ByteArray(size / 8).secureRand()
 }
 
 private val EBICS_ID_ALPHABET = ('A'..'Z') + ('0'..'9')