feat: add new get_script_hash kernel procedure

CHANGELOG.md

@@ -10,6 +10,7 @@
 - [BREAKING] Add error messages to errors and implement `core::error::Error` (#974).
 - Implemented new `digest_from_hex!` macro (#984).
 - Added Format Guidebook to the `miden-lib` crate (#987).
+- Added `miden::note::get_script_hash` procedure (#995).
 
 ## 0.6.2 (2024-11-20)
 

docs/architecture/transactions/procedures.md

@@ -43,6 +43,8 @@ To import the note procedures, set `use.miden::note` at the beginning of the fil
 | `get_inputs`          | `[dest_ptr]`               | `[dest_ptr]`             | note    | <ul> <li>Writes the inputs of the currently executed note into memory starting at the specified address, `dest_ptr`. </li> </ul>                                                                                 |
 | `get_sender`          | `[]`                       | `[sender]`               | note    | <ul> <li>Returns the `sender` of the note currently being processed. Panics if a note is not being processed. </li> </ul>                                                                                        |
 | `compute_inputs_hash` | `[inputs_ptr, num_inputs]` | `[HASH]`                 | note    | <ul> <li>Computes hash of note inputs starting at the specified memory address.</li> </ul>                                                                                                                       |
+| `get_note_serial_number`| `[]`                     | `[SERIAL_NUMBER]`        | note    | <ul> <li>Returns the serial number of the note currently being processed.</li> </ul>                                                                                                                          |
+| `get_script_hash`       | `[]`                     | `[SCRIPT_HASH]`          | note    | <ul> <li>Returns the script hash of the note currently being processed.</li> </ul>                                                                                                                            |
 
 ### Tx
 

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

@@ -852,6 +852,27 @@ export.get_note_serial_number
     # => [SERIAL_NUMBER, pad(12)]
 end
 
+#! Returns the script hash of the note currently being processed.
+#!
+#! Inputs:  [pad(16)]
+#! Outputs: [SCRIPT_HASH, pad(12)]
+#!
+#! Where:
+#! - SCRIPT_HASH is the script hash of the note currently being processed.
+#!
+#! Panics if:
+#! - no note is not being processed.
+#!
+#! Invocation: dynexec
+export.get_script_hash
+    exec.note::get_script_hash
+    # => [SCRIPT_HASH, pad(16)]
+
+    # truncate the stack
+    swapw dropw
+    # => [SCRIPT_HASH, pad(12)]
+end
+
 #! Tells the transaction kernel that we are about to execute a procedure on a foreign account.
 #!
 #! Checks whether the current foreign account was already loaded to the memory, and loads it if not.

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

@@ -337,3 +337,21 @@ export.get_serial_number
     exec.memory::get_input_note_serial_num
     # => [SERIAL_NUMBER, ...]
 end
+
+#! Returns the script hash of the note currently being processed.
+#!
+#! Inputs:  []
+#! Outputs: [SCRIPT_HASH]
+#!
+#! Where:
+#! - SCRIPT_HASH is the serial number of the note currently being processed.
+#!
+#! Panics if:
+#! - no note is being processed.
+export.get_script_hash
+    exec.memory::get_current_input_note_ptr
+    # => [note_ptr]
+
+    exec.memory::get_input_note_script_root
+    # => [SCRIPT_HASH]
+end

miden-lib/asm/miden/kernel_proc_offsets.masm

@@ -31,15 +31,16 @@ const.GET_NOTE_ASSETS_INFO_OFFSET=21
 const.GET_NOTE_INPUTS_HASH_OFFSET=22
 const.GET_NOTE_SENDER_OFFSET=23
 const.GET_NOTE_SERIAL_NUMBER_OFFSET=24
-const.GET_OUTPUT_NOTES_COMMITMENT_OFFSET=25
+const.GET_SCRIPT_HASH_OFFSET=25
+const.GET_OUTPUT_NOTES_COMMITMENT_OFFSET=26
 
 # Transaction
-const.GET_BLOCK_HASH_OFFSET=26
-const.GET_BLOCK_NUMBER_OFFSET=27
-const.START_FOREIGN_CONTEXT_OFFSET=28
-const.END_FOREIGN_CONTEXT_OFFSET=29
-const.UPDATE_EXPIRATION_BLOCK_NUM_OFFSET=30
-const.GET_EXPIRATION_DELTA_OFFSET=31
+const.GET_BLOCK_HASH_OFFSET=27
+const.GET_BLOCK_NUMBER_OFFSET=28
+const.START_FOREIGN_CONTEXT_OFFSET=29
+const.END_FOREIGN_CONTEXT_OFFSET=30
+const.UPDATE_EXPIRATION_BLOCK_NUM_OFFSET=31
+const.GET_EXPIRATION_DELTA_OFFSET=32
 
 # ACCESSORS
 # -------------------------------------------------------------------------------------------------
@@ -404,6 +405,18 @@ export.get_note_serial_number_offset
     push.GET_NOTE_SERIAL_NUMBER_OFFSET
 end
 
+#! Returns an offset of the `get_script_hash` kernel procedure.
+#!
+#! Inputs:  []
+#! Outputs: [proc_offset]
+#!
+#! Where:
+#! - proc_offset is the offset of the `get_script_hash` kernel procedure required to get the
+#!   address where this procedure is stored.
+export.get_script_hash_offset
+    push.GET_SCRIPT_HASH_OFFSET
+end
+
 #! Returns an offset of the `start_foreign_context` kernel procedure.
 #!
 #! Inputs:  []

miden-lib/asm/miden/note.masm

@@ -225,6 +225,34 @@ export.compute_inputs_hash
     # => [HASH]
 end
 
+#! Returns the script hash of the note currently being processed.
+#!
+#! Inputs:  []
+#! Outputs: [SCRIPT_HASH]
+#!
+#! Where:
+#! - SCRIPT_HASH is the script hash of the note currently being processed.
+#!
+#! Panics if:
+#! - no note is being processed.
+#!
+#! Invocation: exec
+export.get_script_hash
+    # pad the stack
+    padw padw padw push.0.0.0
+    # => [pad(15)]
+
+    exec.kernel_proc_offsets::get_script_hash_offset
+    # => [offset, pad(15)]
+
+    syscall.exec_kernel_proc
+    # => [SCRIPT_HASH, pad(12)]
+
+    # clean the stack
+    swapdw dropw dropw swapw dropw
+    # => [SCRIPT_HASH]
+end
+
 # PROCEDURES COPIED FROM KERNEL (TODO: get rid of this duplication)
 # =================================================================================================
 

miden-lib/src/transaction/procedures/kernel_v0.rs

@@ -6,7 +6,7 @@ use miden_objects::{digest, Digest};
 // ================================================================================================
 
 /// Hashes of all dynamically executed procedures from the kernel 0.
-pub const KERNEL0_PROCEDURES: [Digest; 32] = [
+pub const KERNEL0_PROCEDURES: [Digest; 33] = [
     // account_vault_add_asset
     digest!("0xc69b608da541fea9a41322359cc049cac55f816858f530005e333d0b54f2f284"),
     // account_vault_get_balance
@@ -57,6 +57,8 @@ pub const KERNEL0_PROCEDURES: [Digest; 32] = [
     digest!("0xc579a0432b8f7b9640c13ab3f73c8afb6f0aa409b14a3cfaff536e60d04ea2fd"),
     // get_note_serial_number
     digest!("0xad91130ec219756213c6cadeaf8a38de8768e50c620cb7c347c531874c6054b6"),
+    // get_script_hash
+    digest!("0x82a32c90566e7de09e99b2151851c77a6b4117aa05aba20fe7d8244f065d6870"),
     // get_output_notes_commitment
     digest!("0x5d5aa6e32c3e7eafa7dd16683c090cd260c84d980199029d98ea7d5cec68998a"),
     // get_block_hash

miden-tx/src/tests/kernel_tests/test_note.rs

@@ -7,7 +7,7 @@ use miden_lib::{
 use miden_objects::{
     notes::Note, testing::prepare_word, transaction::TransactionArgs, Hasher, WORD_SIZE,
 };
-use vm_processor::{ProcessState, EMPTY_WORD, ONE};
+use vm_processor::{ProcessState, Word, EMPTY_WORD, ONE};
 
 use super::{Felt, Process, ZERO};
 use crate::{
@@ -403,13 +403,10 @@ fn test_get_note_serial_number() {
     // calling get_serial_number should return the serial number of the note
     let code = "
         use.kernel::prologue
-        use.kernel::note->note_internal
-        use.kernel::note
+        use.miden::note
 
         begin
             exec.prologue::prepare_transaction
-            exec.note_internal::prepare_note
-            dropw dropw dropw dropw
             exec.note::get_serial_number
 
             # truncate the stack
@@ -520,3 +517,29 @@ fn test_get_inputs_hash() {
 
     assert_eq!(process.get_stack_state()[0..16], expected_stack);
 }
+
+#[test]
+fn test_get_current_script_hash() {
+    let tx_context = TransactionContextBuilder::with_standard_account(ONE)
+        .with_mock_notes_preserved()
+        .build();
+
+    // calling get_script_hash should return script hash
+    let code = "
+    use.kernel::prologue
+    use.miden::note
+
+    begin
+        exec.prologue::prepare_transaction
+        exec.note::get_script_hash
+
+        # truncate the stack
+        swapw dropw
+    end
+    ";
+
+    let process = tx_context.execute_code(code).unwrap();
+
+    let script_hash: Word = tx_context.input_notes().get_note(0).note().script().hash().into();
+    assert_eq!(process.stack.get_word(0), script_hash);
+}