feat: remove asset from create note (#686)

* feat: creating notes without assets

* after review

* pacifying linter

* after review

CHANGELOG.md

@@ -10,6 +10,7 @@
 * [BREAKING] Updated `create_swap_note()` procedure to return `NoteDetails` and defined SWAP note tag format (#665).
 * [BREAKING] Added support for full details of private notes, renamed `OutputNote` variants and changed their meaning (#673).
 * Implemented `OutputNoteBuilder` (#669).
+* [BREAKING] Removed assets from `create_note` procedure and added new procedure `add_asset_to_note` (#686, #674).
 
 ## 0.2.3 (2024-04-26) - `miden-tx` crate only
 

docs/architecture/accounts.md

@@ -110,33 +110,41 @@ There is also a standard for a [basic fungible faucet](https://github.com/0xPoly
   #!
   #! ...
   export.distribute
-    # get max supply of this faucet. We assume it is stored at pos 3 of slot 1
-    push.METADATA_SLOT exec.account::get_item drop drop drop
-    # => [max_supply, amount, tag, note_type, RECIPIENT, ...]
+      # get max supply of this faucet. We assume it is stored at pos 3 of slot 1
+      push.METADATA_SLOT exec.account::get_item drop drop drop
+      # => [max_supply, amount, tag, note_type, RECIPIENT, ...]
 
-    # get total issuance of this faucet so far and add amount to be minted
-    exec.faucet::get_total_issuance
-    # => [total_issuance, max_supply, amount, tag, note_type RECIPIENT, ...]
+      # get total issuance of this faucet so far and add amount to be minted
+      exec.faucet::get_total_issuance
+      # => [total_issuance, max_supply, amount, tag, note_type RECIPIENT, ...]
 
-    # compute maximum amount that can be minted, max_mint_amount = max_supply - total_issuance
-    sub
-    # => [max_supply - total_issuance, amount, tag, note_type, RECIPIENT, ...]
+      # compute maximum amount that can be minted, max_mint_amount = max_supply - total_issuance
+      sub
+      # => [max_supply - total_issuance, amount, tag, note_type, RECIPIENT, ...]
 
-    # check that amount =< max_supply - total_issuance, fails if otherwise
-    dup.1 gte assert.err=ERR_BASIC_FUNGIBLE_MAX_SUPPLY_OVERFLOW
-    # => [asset, tag, note_type, RECIPIENT, ...]
+      # check that amount =< max_supply - total_issuance, fails if otherwise
+      dup.1 gte assert.err=ERR_BASIC_FUNGIBLE_MAX_SUPPLY_OVERFLOW
+      # => [asset, tag, note_type, RECIPIENT, ...]
 
-    # creating the asset
-    exec.asset::create_fungible_asset
-    # => [ASSET, tag, note_type, RECIPIENT, ...]
+      # creating the asset
+      exec.asset::create_fungible_asset
+      # => [ASSET, tag, note_type, RECIPIENT, ...]
 
-    # mint the asset; this is needed to satisfy asset preservation logic.
-    exec.faucet::mint
-    # => [ASSET, tag, note_type, RECIPIENT, ...]
+      # mint the asset; this is needed to satisfy asset preservation logic.
+      exec.faucet::mint
+      # => [ASSET, tag, note_type, RECIPIENT, ...]
 
-    # create a note containing the asset
-    exec.tx::create_note
-    # => [note_ptr, ZERO, ZERO, ...]
+      # store and drop the ASSET
+      mem_storew.3 dropw
+      # => [tag, note_type, RECIPIENT, ...]
+
+      # create a note containing the asset
+      exec.tx::create_note
+      # => [note_ptr, ZERO, ZERO, ...]
+
+      # store and drop the ASSET
+      padw mem_loadw.3 movup.4 exec.tx::add_asset_to_note
+      # => [note_ptr, ASSET, ZERO, ...]
   end
 
   #! Burns fungible assets.
@@ -157,7 +165,7 @@ There is also a standard for a [basic fungible faucet](https://github.com/0xPoly
   ```
 </details>
 
-The contract exposes two functions `distribute` and `burn`. 
+The contract exposes two functions `distribute` and `burn`.
 
 The first function `distribute` can only be called by the faucet owner, otherwise it fails. As inputs, the function expects everything that is needed to create a note containing the freshly minted asset, i.e., amount, metadata, and recipient.
 

miden-lib/asm/kernels/transaction/api.masm

@@ -514,21 +514,28 @@ end
 
 #! Creates a new note and returns a pointer to the memory address at which the note is stored.
 #!
-#! Inputs: [ASSET, tag, note_type, RECIPIENT]
-#! Outputs: [ptr, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+#! Inputs: [tag, note_type, RECIPIENT]
+#! Outputs: [note_ptr, 0, 0, 0, 0, 0]
 #!
-#! ASSET is the asset to be included in the note.
 #! tag is the tag to be included in the note.
 #! note_type is the note storage type
 #! RECIPIENT is the recipient of the note.
-#! ptr is the pointer to the memory address at which the note is stored.
+#! note_ptr is the pointer to the memory address at which the note is stored.
 export.create_note
     # authenticate that the procedure invocation originates from the account context
     exec.authenticate_account_origin
-    # => [ASSET, tag, note_type, RECIPIENT]
+    # => [tag, note_type, RECIPIENT]
 
     exec.tx::create_note
-    # => [ptr, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    # => [note_ptr]
+
+    # prepare stack for return. Note: when create_note is called, the stack looks 
+    # like [tag, note_type, RECIPIENT, x, x, X], with 16 elements and X might be important data 
+    # for the user. Without padding the kernel returns [note_ptr, x, x, X, 0, ZERO] adding 0's. 
+    # To keep the data in position we insert 0's between ptr and the potentially important 
+    # first element x.
+    movupw.3 movup.15 movup.5
+    # => [note_ptr, 0, 0, 0, 0, 0]
 end
 
 #! Adds an ASSET to the specified note and returns a pointer to the memory address

miden-lib/asm/miden/contracts/faucets/basic_fungible.masm

@@ -47,7 +47,7 @@ export.basic::auth_tx_rpo_falcon512
 #! FAILS if:
 #! - The transaction is being executed against an account that is not a fungible asset faucet.
 #! - The total issuance after minting is greater than the maximum allowed supply.
-export.distribute
+export.distribute.1
     # get max supply of this faucet. We assume it is stored at pos 3 of slot 1
     push.METADATA_SLOT exec.account::get_item drop drop drop
     # => [max_supply, amount, tag, note_type, RECIPIENT, ...]
@@ -72,9 +72,17 @@ export.distribute
     exec.faucet::mint
     # => [ASSET, tag, note_type, RECIPIENT, ...]
 
-    # create a note containing the asset
+    # store and drop the ASSET
+    loc_storew.0 dropw
+    # => [tag, note_type, RECIPIENT, ...]
+
+    # create a note
     exec.tx::create_note
     # => [note_ptr, ZERO, ZERO, ...]
+
+    # load the ASSET and add it to the note
+    padw loc_loadw.0 movup.4 exec.tx::add_asset_to_note
+    # => [note_ptr, ASSET, ZERO, ...]
 end
 
 #! Burns fungible assets.
@@ -99,4 +107,4 @@ export.burn
     # clear the stack
     padw swapw dropw
     # => [...]
-end
+end

miden-lib/asm/miden/contracts/wallets/basic.masm

@@ -39,10 +39,14 @@ end
 #! - The fungible asset is not found in the vault.
 #! - The amount of the fungible asset in the vault is less than the amount to be removed.
 #! - The non-fungible asset is not found in the vault.
-export.send_asset
+export.send_asset.1
     exec.account::remove_asset
     # => [ASSET, tag, note_type, RECIPIENT, ...]
 
+    # Store the ASSET for later
+    loc_storew.0 dropw
+    # => [tag, note_type, RECIPIENT, ...]
+
     # This procedure is written to be executed with `exec` or `call`. When this
     # procedure is `call`ed the stack has to be carefully manipulated to avoid
     # inserting unwanted elements between the user data. The convention is to
@@ -53,9 +57,18 @@ export.send_asset
     # is because the VM stack has a minimum size of 16 elements, trying to push
     # elements after the call to `create_note` would increase the stack in
     # addition to the minimum 16 elements.
-    push.0.0 padw movdnw.3 padw movdnw.3 movdn.11 drop
-    # => [ASSET, tag, note_type, RECIPIENT, ZERO, ZERO, 0, ...]
+    push.0 movdn.6 push.0 movdn.6 padw movdnw.2 padw movdnw.2
+    # => [tag, note_type, RECIPIENT, 0, 0, ZERO, ZERO, ...]
 
     exec.tx::create_note
-    # => [note_ptr, ZERO, ZERO, 0, ...]
+    # => [note_ptr, 0, ZERO, ZERO, ...]
+
+    padw loc_loadw.0 movup.4
+    # => [note_ptr, ASSET, 0, ZERO, ZERO, ...]
+
+    exec.tx::add_asset_to_note
+    # => [note_ptr, 0, ZERO, ZERO, ...]
+
+    # prepare the stack for return - stack has 5 elements too many
+    movupw.3 dropw swap drop
 end

miden-lib/asm/miden/kernels/tx/note.masm

@@ -163,7 +163,7 @@ end
 #! Computes the assets hash of the output note located at the specified memory address. The hash
 #! is computed as a sequential hash of the assets contained in the note. If there is an odd number
 #! of assets, then for the final hashing permutation we pad the last word of the hasher rate with
-#! ZERO's.
+#! ZERO's. Returns [ZERO] if no assets are present.
 #!
 #! Stack: [note_data_ptr]
 #! Output: [ASSETS_HASH]

miden-lib/asm/miden/kernels/tx/tx.masm

@@ -243,87 +243,75 @@ end
 
 #! Creates a new note and returns a pointer to the memory address at which the note is stored.
 #!
-#! Inputs: [ASSET, tag, note_type, RECIPIENT]
-#! Outputs: [note_ptr, 0, 0, 0, 0, 0, 0, 0, 0]
+#! Inputs: [tag, note_type, RECIPIENT]
+#! Outputs: [note_ptr]
 #!
-#! ASSET is the asset to be included in the note.
 #! tag is the tag to be included in the note.
 #! RECIPIENT is the recipient of the note.
-#! ptr is the pointer to the memory address at which the note is stored.
+#! note_ptr is the pointer to the memory address at which the note is stored.
+#!
+#! Panics if
+#! - the note_type is not valid
+#! - the note_tag is not an u32
+#! - if note_tag starts with anything but 0b11, note_type must be public
+#! - the number of created notes exceeds the maximum limit of 4096
 export.create_note
-    # validate the asset
-    exec.asset::validate_asset
-    # => [ASSET, tag, note_type, RECIPIENT]
-
     # validate the note type
-    # NOTE: encrypted notes are currently unsupported `dup.6 push.ENCRYPTED_NOTE eq or`
-    dup.5 push.OFFCHAIN_NOTE eq dup.6 push.PUBLIC_NOTE eq or assert.err=ERR_INVALID_NOTE_TYPE
-    # => [ASSET, tag, note_type, RECIPIENT]
+    # NOTE: encrypted notes are currently unsupported
+    dup.1 push.OFFCHAIN_NOTE eq dup.2 push.PUBLIC_NOTE eq or assert.err=ERR_INVALID_NOTE_TYPE
+    # => [tag, note_type, RECIPIENT]
 
     # copy data to validate the tag
-    dup.5 push.PUBLIC_NOTE dup.1 dup.7
-    # => [tag, note_type, public_note, note_type, ASSET, tag, note_type, RECIPIENT]
+    dup.1 push.PUBLIC_NOTE dup.1 dup.3
+    # => [tag, note_type, public_note, note_type, tag, note_type, RECIPIENT]
 
     u32assert.err=ERR_NOTE_TAG_MUST_BE_U32
-    # => [tag, note_type, public_note, note_type, ASSET, tag, note_type, RECIPIENT]
+    # => [tag, note_type, public_note, note_type, tag, note_type, RECIPIENT]
 
     # enforce the note type depending on the tag's bits
     u32shr.30 push.ALL_NOTE_TYPES_ALLOWED eq cdrop assert_eq.err=ERR_NOTE_INVALID_TYPE_FOR_TAG
-    # => [ASSET, tag, note_type, RECIPIENT]
+    # => [tag, note_type, RECIPIENT]
 
     # get the index for the next note to be created and increment counter
     exec.increment_num_created_notes
-    # => [note_idx, ASSET, tag, note_type, RECIPIENT]
+    # => [note_idx, tag, note_type, RECIPIENT]
 
     # get a pointer to the memory address at which the note will be stored
     exec.memory::get_created_note_ptr
-    # => [note_ptr, ASSET, tag, note_type, RECIPIENT]
+    # => [note_ptr, tag, note_type, RECIPIENT]
 
     # populate the metadata
-    movup.5 exec.account::get_id movup.7
-    # => [note_type, sender_acct_id, tag, note_ptr, ASSET, RECIPIENT]
+    swap exec.account::get_id movup.3
+    # => [note_type, sender_acct_id, tag, note_ptr, RECIPIENT]
 
     push.0 # TODO: allow the user to push the aux data
-    # => [aux, note_type, sender_acct_id, tag, note_ptr, ASSET, RECIPIENT]
+    # => [aux, note_type, sender_acct_id, tag, note_ptr, RECIPIENT]
 
     emit.NEW_NOTE_EVENT
 
     # set the metadata for the new created note
     dup.4 exec.memory::set_created_note_metadata
-    # => [note_ptr, ASSET, RECIPIENT]
-
-    # set the number of assets for the note to 1
-    push.1 dup.1 exec.memory::set_created_note_num_assets
-    # => [note_ptr, ASSET, RECIPIENT]
-
-    movdn.4 padw swapw movup.8
-    # => [note_ptr, ASSET, 0, 0, 0, 0, RECIPIENT]
-
-    # add the asset to the note
-    dup movdn.5 exec.memory::get_created_note_asset_data_ptr mem_storew dropw
-    # => [note_ptr, 0, 0, 0, 0, RECIPIENT]
-
-    movdn.8 swapw padw swapw movup.12
-    # => [note_ptr, RECIPIENT, 0, 0, 0, 0, 0, 0, 0, 0]
+    # => [note_ptr, RECIPIENT]
 
     # set the recipient
     dup movdn.5 exec.memory::set_created_note_recipient
-    # => [note_ptr, 0, 0, 0, 0, 0, 0, 0, 0]
+    # => [note_ptr]
 end
 
 #! Adds an ASSET to the specified note and returns a pointer to the memory address
 #! at which the note is stored.
 #!
-#! Panics if
-#! - the ASSET is malformed (invalid faucet ID)
-#! - the max amount of fungible assets is exceeded
-#! - the non-fungible asset already exists in the note
-#!
 #! Inputs: [note_ptr, ASSET]
 #! Outputs: [note_ptr]
 #!
 #! note_ptr is the pointer to the memory address at which the note is stored.
 #! ASSET can be a fungible or non-fungible asset.
+#!
+#! Panics if
+#! - the ASSET is malformed (invalid faucet ID)
+#! - the max amount of fungible assets is exceeded
+#! - the non-fungible asset already exists in the note
+#! - the total number of ASSETs exceeds the maximum of 256
 export.add_asset_to_note
     # get current num of assets
     dup exec.memory::get_created_note_num_assets movdn.5

miden-lib/asm/miden/tx.masm

@@ -58,20 +58,19 @@ end
 
 #! Creates a new note and returns a pointer to the memory address at which the note is stored.
 #!
-#! Inputs: [ASSET, tag, note_type, RECIPIENT]
+#! Inputs: [tag, note_type, RECIPIENT]
 #! Outputs: [note_ptr]
 #!
-#! ASSET is the asset to be included in the note.
 #! tag is the tag to be included in the note.
 #! note_type is the storage type of the note
 #! RECIPIENT is the recipient of the note.
 #! note_ptr is the pointer to the memory address at which the note is stored.
 export.create_note
     syscall.create_note
-    # => [note_ptr, ZERO, ZERO, 0]
+    # => [note_ptr, ZERO, 0]
 
     # clear the padding from the kernel response
-    movdn.8 dropw dropw swap drop
+    movdn.4 dropw swap drop
     # => [note_ptr]
 end