feat: useable and tested scratchpads

ant-networking/src/lib.rs

@@ -639,15 +639,15 @@ impl Network {
                             continue;
                         };
 
-                        if !scratchpad.is_valid() {
+                        if !scratchpad.verify() {
                             warn!(
                                 "Rejecting Scratchpad for {pretty_key} PUT with invalid signature"
                             );
                             continue;
                         }
 
                         if let Some(old) = &valid_scratchpad {
-                            if old.count() >= scratchpad.count() {
+                            if old.counter() >= scratchpad.counter() {
                                 info!("Rejecting Scratchpad for {pretty_key} with lower count than the previous one");
                                 continue;
                             }

ant-networking/src/record_store.rs

@@ -1296,12 +1296,8 @@ mod tests {
         // Create a scratchpad
         let unencrypted_scratchpad_data = Bytes::from_static(b"Test scratchpad data");
         let owner_sk = SecretKey::random();
-        let owner_pk = owner_sk.public_key();
 
-        let mut scratchpad = Scratchpad::new(owner_pk, 0);
-
-        let _next_version =
-            scratchpad.update_and_sign(unencrypted_scratchpad_data.clone(), &owner_sk);
+        let scratchpad = Scratchpad::new(&owner_sk, 0, &unencrypted_scratchpad_data, 0);
 
         let scratchpad_address = *scratchpad.address();
 

ant-node/src/error.rs

@@ -12,6 +12,8 @@ use thiserror::Error;
 
 pub(super) type Result<T, E = Error> = std::result::Result<T, E>;
 
+const SCRATCHPAD_MAX_SIZE: usize = ant_protocol::storage::Scratchpad::MAX_SIZE;
+
 /// Internal error.
 #[derive(Debug, Error)]
 #[allow(missing_docs)]
@@ -38,12 +40,13 @@ pub enum Error {
     #[error("The Record::key does not match with the key derived from Record::value")]
     RecordKeyMismatch,
 
-    // Scratchpad is old version
+    // ------------ Scratchpad Errors
     #[error("A newer version of this Scratchpad already exists")]
     IgnoringOutdatedScratchpadPut,
-    // Scratchpad is invalid
-    #[error("Scratchpad signature is invalid over the counter + content hash")]
+    #[error("Scratchpad signature is invalid")]
     InvalidScratchpadSignature,
+    #[error("Scratchpad too big: {0}, max size is {SCRATCHPAD_MAX_SIZE}")]
+    ScratchpadTooBig(usize),
 
     #[error("Invalid signature")]
     InvalidSignature,

ant-node/src/put_validation.rs

@@ -447,7 +447,7 @@ impl Node {
     ) -> Result<()> {
         // owner PK is defined herein, so as long as record key and this match, we're good
         let addr = scratchpad.address();
-        let count = scratchpad.count();
+        let count = scratchpad.counter();
         debug!("Validating and storing scratchpad {addr:?} with count {count}");
 
         // check if the deserialized value's ScratchpadAddress matches the record's key
@@ -460,18 +460,24 @@ impl Node {
         // check if the Scratchpad is present locally that we don't have a newer version
         if let Some(local_pad) = self.network().get_local_record(&scratchpad_key).await? {
             let local_pad = try_deserialize_record::<Scratchpad>(&local_pad)?;
-            if local_pad.count() >= scratchpad.count() {
+            if local_pad.counter() >= scratchpad.counter() {
                 warn!("Rejecting Scratchpad PUT with counter less than or equal to the current counter");
                 return Err(Error::IgnoringOutdatedScratchpadPut);
             }
         }
 
         // ensure data integrity
-        if !scratchpad.is_valid() {
+        if !scratchpad.verify() {
             warn!("Rejecting Scratchpad PUT with invalid signature");
             return Err(Error::InvalidScratchpadSignature);
         }
 
+        // ensure the scratchpad is not too big
+        if scratchpad.is_too_big() {
+            warn!("Rejecting Scratchpad PUT with too big size");
+            return Err(Error::ScratchpadTooBig(scratchpad.size()));
+        }
+
         info!(
             "Storing sratchpad {addr:?} with content of {:?} as Record locally",
             scratchpad.encrypted_data_hash()

ant-node/tests/data_with_churn.rs

@@ -408,7 +408,10 @@ fn create_graph_entry_task(
 
             let mut retries = 1;
             loop {
-                match client.graph_entry_put(graph_entry.clone(), &wallet).await {
+                match client
+                    .graph_entry_put(graph_entry.clone(), (&wallet).into())
+                    .await
+                {
                     Ok((cost, addr)) => {
                         println!("Uploaded graph_entry to {addr:?} with cost of {cost:?} after a delay of: {delay:?}");
                         let net_addr = NetworkAddress::GraphEntryAddress(addr);
@@ -498,7 +501,7 @@ fn create_pointers_task(
                     PointerTarget::ChunkAddress(ChunkAddress::new(XorName(rand::random())));
                 loop {
                     match client
-                        .pointer_create(&owner, pointer_target.clone(), &wallet)
+                        .pointer_create(&owner, pointer_target.clone(), (&wallet).into())
                         .await
                     {
                         Ok((cost, addr)) => {

ant-protocol/src/storage/graph.rs

@@ -28,6 +28,9 @@ pub struct GraphEntry {
 }
 
 impl GraphEntry {
+    /// Maximum size of a graph entry
+    pub const MAX_SIZE: usize = 1024;
+
     /// Create a new graph entry, signing it with the provided secret key.
     pub fn new(
         owner: PublicKey,
@@ -101,8 +104,29 @@ impl GraphEntry {
         Self::bytes_to_sign(&self.owner, &self.parents, &self.content, &self.outputs)
     }
 
+    /// Verify the signature of the graph entry
     pub fn verify(&self) -> bool {
         self.owner
             .verify(&self.signature, self.bytes_for_signature())
     }
+
+    /// Size of the graph entry
+    pub fn size(&self) -> usize {
+        size_of::<GraphEntry>()
+            + self
+                .outputs
+                .iter()
+                .map(|(p, c)| p.to_bytes().len() + c.len())
+                .sum::<usize>()
+            + self
+                .parents
+                .iter()
+                .map(|p| p.to_bytes().len())
+                .sum::<usize>()
+    }
+
+    /// Returns true if the graph entry is too big
+    pub fn is_too_big(&self) -> bool {
+        self.size() > Self::MAX_SIZE
+    }
 }

ant-protocol/src/storage/pointer.rs

@@ -27,6 +27,8 @@ pub enum PointerError {
     SerializationError(String),
 }
 
+/// Pointer, a mutable address pointing to other data on the Network
+/// It is stored at the owner's public key and can only be updated by the owner
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct Pointer {
     owner: PublicKey,
@@ -130,6 +132,11 @@ impl Pointer {
         let bytes = self.bytes_for_signature();
         self.owner.verify(&self.signature, &bytes)
     }
+
+    /// Size of the pointer
+    pub fn size() -> usize {
+        size_of::<Pointer>()
+    }
 }
 
 #[cfg(test)]

ant-protocol/src/storage/scratchpad.rs

@@ -15,7 +15,7 @@ use serde::{Deserialize, Serialize};
 
 use xor_name::XorName;
 
-/// Scratchpad, a mutable address for encrypted data
+/// Scratchpad, a mutable space for encrypted data on the Network
 #[derive(
     Hash, Eq, PartialEq, PartialOrd, Ord, Clone, custom_debug::Debug, Serialize, Deserialize,
 )]
@@ -25,30 +25,81 @@ pub struct Scratchpad {
     address: ScratchpadAddress,
     /// Data encoding: custom apps using scratchpad should use this so they can identify the type of data they are storing
     data_encoding: u64,
-    /// Contained data. This should be encrypted
+    /// Encrypted data stored in the scratchpad, it is encrypted automatically by the [`Scratchpad::new`] and [`Scratchpad::update`] methods
     #[debug(skip)]
     encrypted_data: Bytes,
     /// Monotonically increasing counter to track the number of times this has been updated.
+    /// When pushed to the network, the scratchpad with the highest counter is kept.
     counter: u64,
-    /// Signature over `Vec<counter>`.extend(Xorname::from_content(encrypted_data).to_vec()) from the owning key.
-    /// Required for scratchpad to be valid.
-    signature: Option<Signature>,
+    /// Signature over the above fields
+    signature: Signature,
 }
 
 impl Scratchpad {
-    /// Creates a new instance of `Scratchpad`.
-    pub fn new(owner: PublicKey, data_encoding: u64) -> Self {
+    /// Max Scratchpad size is 4MB including the metadata
+    pub const MAX_SIZE: usize = 4 * 1024 * 1024;
+
+    /// Creates a new instance of `Scratchpad`. Encrypts the data, and signs all the elements.
+    pub fn new(
+        owner: &SecretKey,
+        data_encoding: u64,
+        unencrypted_data: &Bytes,
+        counter: u64,
+    ) -> Self {
+        let pk = owner.public_key();
+        let encrypted_data = Bytes::from(pk.encrypt(unencrypted_data).to_bytes());
+        let addr = ScratchpadAddress::new(pk);
+        let signature = owner.sign(Self::bytes_for_signature(
+            addr,
+            data_encoding,
+            &encrypted_data,
+            counter,
+        ));
+        Self {
+            address: addr,
+            encrypted_data,
+            data_encoding,
+            counter,
+            signature,
+        }
+    }
+
+    /// Create a new Scratchpad without provding the secret key
+    /// It is the caller's responsibility to ensure the signature is valid (signs [`Scratchpad::bytes_for_signature`]) and the data is encrypted
+    /// It is recommended to use the [`Scratchpad::new`] method instead when possible
+    pub fn new_with_signature(
+        owner: PublicKey,
+        data_encoding: u64,
+        encrypted_data: Bytes,
+        counter: u64,
+        signature: Signature,
+    ) -> Self {
         Self {
             address: ScratchpadAddress::new(owner),
-            encrypted_data: Bytes::new(),
+            encrypted_data,
             data_encoding,
-            counter: 0,
-            signature: None,
+            counter,
+            signature,
         }
     }
 
-    /// Return the current count
-    pub fn count(&self) -> u64 {
+    /// Returns the bytes to sign for the signature
+    pub fn bytes_for_signature(
+        address: ScratchpadAddress,
+        data_encoding: u64,
+        encrypted_data: &Bytes,
+        counter: u64,
+    ) -> Vec<u8> {
+        let mut bytes_to_sign = data_encoding.to_be_bytes().to_vec();
+        bytes_to_sign.extend(address.to_hex().as_bytes());
+        bytes_to_sign.extend(counter.to_be_bytes().to_vec());
+        bytes_to_sign.extend(encrypted_data.to_vec());
+        bytes_to_sign
+    }
+
+    /// Get the counter of the Scratchpad, the higher the counter, the more recent the Scratchpad is
+    /// Similarly to counter CRDTs only the latest version (highest counter) of the Scratchpad is kept on the network
+    pub fn counter(&self) -> u64 {
         self.counter
     }
 
@@ -57,43 +108,32 @@ impl Scratchpad {
         self.data_encoding
     }
 
-    /// Increments the counter value.
-    pub fn increment(&mut self) -> u64 {
+    /// Updates the content and encrypts it, increments the counter, re-signs the scratchpad
+    pub fn update(&mut self, unencrypted_data: &Bytes, sk: &SecretKey) {
         self.counter += 1;
-
-        self.counter
-    }
-
-    /// Returns the next counter value,
-    ///
-    /// Encrypts data and updates the signature with provided sk
-    pub fn update_and_sign(&mut self, unencrypted_data: Bytes, sk: &SecretKey) -> u64 {
-        let next_count = self.increment();
-
         let pk = self.owner();
-
+        let address = ScratchpadAddress::new(*pk);
         self.encrypted_data = Bytes::from(pk.encrypt(unencrypted_data).to_bytes());
 
-        let encrypted_data_xorname = self.encrypted_data_hash().to_vec();
-
-        let mut bytes_to_sign = self.counter.to_be_bytes().to_vec();
-        bytes_to_sign.extend(encrypted_data_xorname);
-
-        self.signature = Some(sk.sign(&bytes_to_sign));
-        next_count
+        let bytes_to_sign = Self::bytes_for_signature(
+            address,
+            self.data_encoding,
+            &self.encrypted_data,
+            self.counter,
+        );
+        self.signature = sk.sign(&bytes_to_sign);
+        debug_assert!(self.verify(), "Must be valid after being signed. This is a bug, please report it by opening an issue on our github");
     }
 
-    /// Verifies the signature and content of the scratchpad are valid for the
-    /// owner's public key.
-    pub fn is_valid(&self) -> bool {
-        if let Some(signature) = &self.signature {
-            let mut signing_bytes = self.counter.to_be_bytes().to_vec();
-            signing_bytes.extend(self.encrypted_data_hash().to_vec()); // add the count
-
-            self.owner().verify(signature, &signing_bytes)
-        } else {
-            false
-        }
+    /// Verifies that the Scratchpad signature is valid
+    pub fn verify(&self) -> bool {
+        let signing_bytes = Self::bytes_for_signature(
+            self.address,
+            self.data_encoding,
+            &self.encrypted_data,
+            self.counter,
+        );
+        self.owner().verify(&self.signature, &signing_bytes)
     }
 
     /// Returns the encrypted_data.
@@ -140,18 +180,46 @@ impl Scratchpad {
     pub fn payload_size(&self) -> usize {
         self.encrypted_data.len()
     }
+
+    /// Size of the scratchpad
+    pub fn size(&self) -> usize {
+        size_of::<Scratchpad>() + self.payload_size()
+    }
+
+    /// Returns true if the scratchpad is too big
+    pub fn is_too_big(&self) -> bool {
+        self.size() > Self::MAX_SIZE
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
-    fn test_scratchpad_is_valid() {
+    fn test_scratchpad_sig_and_update() {
+        let sk = SecretKey::random();
+        let raw_data = Bytes::from_static(b"data to be encrypted");
+        let mut scratchpad = Scratchpad::new(&sk, 42, &raw_data, 0);
+        assert!(scratchpad.verify());
+        assert_eq!(scratchpad.counter(), 0);
+        assert_ne!(scratchpad.encrypted_data(), &raw_data);
+
+        let raw_data2 = Bytes::from_static(b"data to be encrypted v2");
+        scratchpad.update(&raw_data2, &sk);
+        assert!(scratchpad.verify());
+        assert_eq!(scratchpad.counter(), 1);
+        assert_ne!(scratchpad.encrypted_data(), &raw_data);
+        assert_ne!(scratchpad.encrypted_data(), &raw_data2);
+    }
+
+    #[test]
+    fn test_scratchpad_encryption() {
         let sk = SecretKey::random();
-        let pk = sk.public_key();
-        let mut scratchpad = Scratchpad::new(pk, 42);
-        scratchpad.update_and_sign(Bytes::from_static(b"data to be encrypted"), &sk);
-        assert!(scratchpad.is_valid());
+        let raw_data = Bytes::from_static(b"data to be encrypted");
+        let scratchpad = Scratchpad::new(&sk, 42, &raw_data, 0);
+
+        let decrypted_data = scratchpad.decrypt_data(&sk).unwrap();
+        assert_eq!(decrypted_data, raw_data);
     }
 }