chore: enforce minimum number of account procedures in tx kernel

CHANGELOG.md

@@ -9,6 +9,7 @@
 ### Changes
 
 - [BREAKING] Make `AccountProcedureIndexMap` construction infallible ([#2163](https://github.com/0xMiden/miden-base/pull/2163)).
+- [BREAKING] Enforce minimum number of account procedures in tx kernel ([#2171](https://github.com/0xMiden/miden-base/pull/2171)).
 
 ## 0.12.2 (unreleased)
 - Add proc-macro `WordWrapper` to ease implementation of `Word`-wrapping types ([#2071](https://github.com/0xMiden/miden-base/pull/2108)).

crates/miden-lib/asm/kernels/transaction/lib/account.masm

@@ -41,6 +41,8 @@ const.ERR_FAUCET_INVALID_STORAGE_OFFSET="storage offset is invalid for a faucet
 
 const.ERR_ACCOUNT_CODE_COMMITMENT_MISMATCH="computed account code commitment does not match recorded account code commitment"
 
+const.ERR_ACCOUNT_NOT_ENOUGH_PROCEDURES="number of account procedures must be at least 2"
+
 const.ERR_ACCOUNT_TOO_MANY_PROCEDURES="number of account procedures exceeds the maximum limit of 256"
 
 const.ERR_ACCOUNT_TOO_MANY_STORAGE_SLOTS="number of account storage slots exceeds the maximum limit of 255"
@@ -77,6 +79,9 @@ const.MAX_STORAGE_SLOT_INDEX=254
 # The maximum number of account storage slots.
 const.MAX_NUM_STORAGE_SLOTS=MAX_STORAGE_SLOT_INDEX+1
 
+# The minimum number of account interface procedures.
+const.MIN_NUM_PROCEDURES=2
+
 # The maximum number of account interface procedures.
 const.MAX_NUM_PROCEDURES=256
 
@@ -1377,8 +1382,18 @@ export.save_account_procedure_data
     # OS => [num_procs, CODE_COMMITMENT]
     # AS => [[ACCOUNT_PROCEDURE_DATA]]
 
-    # assert that account does not exceed allowed maximum number of procedures
-    dup exec.get_max_num_procedures lte assert.err=ERR_ACCOUNT_TOO_MANY_PROCEDURES
+    # make sure number of procedures is a valid u32, so we can use u32 operations for validation
+    u32assert.err=ERR_ACCOUNT_TOO_MANY_PROCEDURES
+    # OS => [num_procs, CODE_COMMITMENT]
+    # AS => [[ACCOUNT_PROCEDURE_DATA]]
+
+    # assert the account has at least the minimum number of procedures
+    dup u32gte.MIN_NUM_PROCEDURES assert.err=ERR_ACCOUNT_NOT_ENOUGH_PROCEDURES
+    # OS => [num_procs, CODE_COMMITMENT]
+    # AS => [[ACCOUNT_PROCEDURE_DATA]]
+
+    # assert the account does not exceed the maximum number of procedures
+    dup u32lte.MAX_NUM_PROCEDURES assert.err=ERR_ACCOUNT_TOO_MANY_PROCEDURES
     # OS => [num_procs, CODE_COMMITMENT]
     # AS => [[ACCOUNT_PROCEDURE_DATA]]
 

crates/miden-lib/src/errors/tx_kernel_errors.rs

@@ -34,6 +34,8 @@ pub const ERR_ACCOUNT_IS_NOT_NATIVE: MasmError = MasmError::from_static_str("the
 pub const ERR_ACCOUNT_NONCE_AT_MAX: MasmError = MasmError::from_static_str("account nonce is already at its maximum possible value");
 /// Error Message: "account nonce can only be incremented once"
 pub const ERR_ACCOUNT_NONCE_CAN_ONLY_BE_INCREMENTED_ONCE: MasmError = MasmError::from_static_str("account nonce can only be incremented once");
+/// Error Message: "number of account procedures must be at least 2"
+pub const ERR_ACCOUNT_NOT_ENOUGH_PROCEDURES: MasmError = MasmError::from_static_str("number of account procedures must be at least 2");
 /// Error Message: "provided procedure index is out of bounds"
 pub const ERR_ACCOUNT_PROC_INDEX_OUT_OF_BOUNDS: MasmError = MasmError::from_static_str("provided procedure index is out of bounds");
 /// Error Message: "account procedure is not the authentication procedure; some procedures (e.g. `incr_nonce`) can be called only from the authentication procedure"

crates/miden-lib/src/transaction/kernel_procedures.rs

@@ -104,7 +104,7 @@ pub const KERNEL_PROCEDURES: [Word; 52] = [
     // tx_get_block_timestamp
     word!("0x7903185b847517debb6c2072364e3e757b99ee623e97c2bd0a4661316c5c5418"),
     // tx_start_foreign_context
-    word!("0x4bfde60ab4b1e42148ceea2845ecf9aae061a577972baf348379701760d476d7"),
+    word!("0x3755ddea584a3575bc3c97820f739d562334b91ab8c00642b519b4e22792b191"),
     // tx_end_foreign_context
     word!("0xaa0018aa8da890b73511879487f65553753fb7df22de380dd84c11e6f77eec6f"),
     // tx_get_expiration_delta