From 4b3eca23e980bf96cacb6139ea396ace09986365 Mon Sep 17 00:00:00 2001
From: thesimplekid <tsk@thesimplekid.com>
Date: Tue, 20 Aug 2024 12:08:35 +0200
Subject: [PATCH] fix: check mint and melt quotes are within settings

---
 crates/cdk/src/mint/error.rs | 18 ++++++++++++
 crates/cdk/src/mint/mod.rs   | 54 ++++++++++++++++++++++++++++++++++++
 crates/cdk/src/nuts/nut04.rs | 15 ++++++++++
 crates/cdk/src/nuts/nut05.rs | 15 ++++++++++
 4 files changed, 102 insertions(+)

diff --git a/crates/cdk/src/mint/error.rs b/crates/cdk/src/mint/error.rs
index 619d24ae..52d91b7c 100644
--- a/crates/cdk/src/mint/error.rs
+++ b/crates/cdk/src/mint/error.rs
@@ -62,6 +62,24 @@ pub enum Error {
     /// Sig all cannot be used in melt
     #[error("Sig all cannot be used in melt")]
     SigAllUsedInMelt,
+    /// Minting is disabled
+    #[error("Minting is disabled")]
+    MintingDisabled,
+    /// Minting request is over mint limit
+    #[error("Mint request is over mint limit")]
+    MintOverLimit,
+    /// Mint request is uver mint limit
+    #[error("Mint request is under mint limit")]
+    MintUnderLimit,
+    /// Melting is disabled
+    #[error("Minting is disabled")]
+    MeltingDisabled,
+    /// Melting request is over mint limit
+    #[error("Mint request is over mint limit")]
+    MeltOverLimit,
+    /// Melt request is uver mint limit
+    #[error("Mint request is under mint limit")]
+    MeltUnderLimit,
     /// Cashu Error
     #[error(transparent)]
     Cashu(#[from] crate::error::Error),
diff --git a/crates/cdk/src/mint/mod.rs b/crates/cdk/src/mint/mod.rs
index ce2268c4..214fa020 100644
--- a/crates/cdk/src/mint/mod.rs
+++ b/crates/cdk/src/mint/mod.rs
@@ -201,6 +201,33 @@ impl Mint {
         expiry: u64,
         ln_lookup: String,
     ) -> Result<MintQuote, Error> {
+        let nut04 = &self.mint_info.nuts.nut04;
+
+        if nut04.disabled {
+            return Err(Error::MintingDisabled);
+        }
+
+        match nut04.get_settings(&unit, &PaymentMethod::Bolt11) {
+            Some(settings) => {
+                if settings
+                    .max_amount
+                    .map_or(false, |max_amount| amount > max_amount)
+                {
+                    return Err(Error::MintOverLimit);
+                }
+
+                if settings
+                    .min_amount
+                    .map_or(false, |min_amount| amount < min_amount)
+                {
+                    return Err(Error::MintUnderLimit);
+                }
+            }
+            None => {
+                return Err(Error::UnsupportedUnit);
+            }
+        }
+
         let quote = MintQuote::new(mint_url, request, unit, amount, expiry, ln_lookup.clone());
         tracing::debug!(
             "New mint quote {} for {} {} with request id {}",
@@ -320,6 +347,33 @@ impl Mint {
         expiry: u64,
         request_lookup_id: String,
     ) -> Result<MeltQuote, Error> {
+        let nut05 = &self.mint_info.nuts.nut05;
+
+        if nut05.disabled {
+            return Err(Error::MeltingDisabled);
+        }
+
+        match nut05.get_settings(&unit, &PaymentMethod::Bolt11) {
+            Some(settings) => {
+                if settings
+                    .max_amount
+                    .map_or(false, |max_amount| amount > max_amount)
+                {
+                    return Err(Error::MeltOverLimit);
+                }
+
+                if settings
+                    .min_amount
+                    .map_or(false, |min_amount| amount < min_amount)
+                {
+                    return Err(Error::MeltUnderLimit);
+                }
+            }
+            None => {
+                return Err(Error::UnsupportedUnit);
+            }
+        }
+
         let quote = MeltQuote::new(
             request,
             unit,
diff --git a/crates/cdk/src/nuts/nut04.rs b/crates/cdk/src/nuts/nut04.rs
index 4ce0da75..79216bec 100644
--- a/crates/cdk/src/nuts/nut04.rs
+++ b/crates/cdk/src/nuts/nut04.rs
@@ -222,6 +222,21 @@ impl Settings {
     pub fn new(methods: Vec<MintMethodSettings>, disabled: bool) -> Self {
         Self { methods, disabled }
     }
+
+    /// Get [`MintMethodSettings`] for unit method pair
+    pub fn get_settings(
+        &self,
+        unit: &CurrencyUnit,
+        method: &PaymentMethod,
+    ) -> Option<MintMethodSettings> {
+        for method_settings in self.methods.iter() {
+            if method_settings.method.eq(method) && method_settings.unit.eq(unit) {
+                return Some(method_settings.clone());
+            }
+        }
+
+        None
+    }
 }
 
 impl Default for Settings {
diff --git a/crates/cdk/src/nuts/nut05.rs b/crates/cdk/src/nuts/nut05.rs
index 0b7015cb..63041278 100644
--- a/crates/cdk/src/nuts/nut05.rs
+++ b/crates/cdk/src/nuts/nut05.rs
@@ -257,6 +257,21 @@ impl Settings {
     pub fn new(methods: Vec<MeltMethodSettings>, disabled: bool) -> Self {
         Self { methods, disabled }
     }
+
+    /// Get [`MeltMethodSettings`] for unit method pair
+    pub fn get_settings(
+        &self,
+        unit: &CurrencyUnit,
+        method: &PaymentMethod,
+    ) -> Option<MeltMethodSettings> {
+        for method_settings in self.methods.iter() {
+            if method_settings.method.eq(method) && method_settings.unit.eq(unit) {
+                return Some(method_settings.clone());
+            }
+        }
+
+        None
+    }
 }
 
 /// Melt Settings