feat: add new get_script_hash kernel procedure

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

@@ -852,6 +852,15 @@ export.get_note_serial_number
     # => [SERIAL_NUMBER, pad(12)]
 end
 
+export.get_note_script_hash
+    exec.note::get_note_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

@@ -160,6 +160,18 @@ export.prepare_note
     # => [note_script_root_ptr, NOTE_ARGS]
 end
 
+#! Returns the current note script hash.
+#!
+#! Inputs:  []
+#! Outputs: [SCRIPT_HASH]
+export.get_note_script_hash
+    exec.memory::get_current_input_note_ptr
+    # => [note_ptr]
+
+    exec.memory::get_input_note_script_root
+    # => [SCRIPT_HASH]
+end
+
 # OUTPUT NOTE PROCEDURES
 # =================================================================================================
 

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_NOTE_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 +405,10 @@ export.get_note_serial_number_offset
     push.GET_NOTE_SERIAL_NUMBER_OFFSET
 end
 
+export.get_note_script_hash_offset
+    push.GET_NOTE_SCRIPT_HASH_OFFSET
+end
+
 #! Returns an offset of the `start_foreign_context` kernel procedure.
 #!
 #! Inputs:  []

miden-lib/asm/miden/note.masm

@@ -225,6 +225,22 @@ export.compute_inputs_hash
     # => [HASH]
 end
 
+export.get_note_script_hash
+    # pad the stack
+    padw padw padw push.0.0.0
+    # => [pad(15)]
+
+    exec.kernel_proc_offsets::get_note_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-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::{
@@ -520,3 +520,32 @@ 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_note_script_hash should return script hash
+    let code = "
+    use.kernel::prologue
+    use.kernel::note->note_internal
+    use.kernel::note
+
+    begin
+        exec.prologue::prepare_transaction
+        exec.note_internal::prepare_note
+        dropw dropw dropw dropw
+        exec.note::get_note_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);
+}