Add to_hex() and from_hex() to Nullifier struct

objects/src/accounts/account_id.rs

@@ -1,13 +1,10 @@
 use core::fmt;
 
-use miden_crypto::utils::{ByteReader, Deserializable, Serializable};
-use vm_processor::DeserializationError;
-
 use super::{
-    get_account_seed, Account, AccountError, Digest, Felt, FieldElement, Hasher, StarkField,
-    ToString, Vec, Word,
+    get_account_seed, Account, AccountError, ByteReader, Deserializable, DeserializationError,
+    Digest, Felt, FieldElement, Hasher, Serializable, StarkField, String, ToString, Vec, Word,
 };
-use crate::utils::string::String;
+use crate::utils::hex_to_bytes;
 
 // ACCOUNT ID
 // ================================================================================================
@@ -212,7 +209,7 @@ impl AccountId {
     /// Creates an Account Id from a hex string. Assumes the string starts with "0x" and
     /// that the hexadecimal characters are big-endian encoded.
     pub fn from_hex(hex_value: &str) -> Result<AccountId, AccountError> {
-        miden_crypto::utils::hex_to_bytes(hex_value)
+        hex_to_bytes(hex_value)
             .map_err(|err| AccountError::HexParseError(err.to_string()))
             .and_then(|mut bytes: [u8; 8]| {
                 // `bytes` ends up being parsed as felt, and the input to that is assumed to be little-endian

objects/src/assets/mod.rs

@@ -1,16 +1,17 @@
-use vm_processor::DeserializationError;
-
 use super::{
     accounts::{AccountId, AccountType},
-    utils::{collections::Vec, string::ToString},
+    utils::{
+        collections::Vec,
+        serde::{ByteReader, ByteWriter, Deserializable, DeserializationError, Serializable},
+        string::ToString,
+    },
     AssetError, Felt, Hasher, StarkField, Word, ZERO,
 };
 
 mod fungible;
 pub use fungible::FungibleAsset;
 
 mod nonfungible;
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
 pub use nonfungible::{NonFungibleAsset, NonFungibleAssetDetails};
 
 mod token_symbol;

objects/src/lib.rs

@@ -36,7 +36,7 @@ pub mod crypto {
 }
 
 pub mod utils {
-    pub use miden_crypto::utils::{format, vec};
+    pub use miden_crypto::utils::{bytes_to_hex_string, format, hex_to_bytes, vec, HexParseError};
     pub use vm_core::utils::{collections, group_slice_elements, string, IntoBytes};
 
     pub mod serde {

objects/src/notes/assets.rs

@@ -1,9 +1,9 @@
 use core::cell::OnceCell;
 
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
-use vm_processor::DeserializationError;
-
-use super::{Asset, Digest, Felt, Hasher, NoteError, Vec, Word, WORD_SIZE, ZERO};
+use super::{
+    Asset, ByteReader, ByteWriter, Deserializable, DeserializationError, Digest, Felt, Hasher,
+    NoteError, Serializable, Vec, Word, WORD_SIZE, ZERO,
+};
 
 // NOTE ASSETS
 // ================================================================================================

objects/src/notes/envelope.rs

@@ -1,8 +1,9 @@
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
 use vm_core::StarkField;
-use vm_processor::DeserializationError;
 
-use super::{Felt, Note, NoteId, NoteMetadata, Vec, Word};
+use super::{
+    ByteReader, ByteWriter, Deserializable, DeserializationError, Felt, Note, NoteId, NoteMetadata,
+    Serializable, Vec, Word,
+};
 
 // NOTE ENVELOPE
 // ================================================================================================

objects/src/notes/inputs.rs

@@ -1,9 +1,11 @@
 use core::cell::OnceCell;
 
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
 use vm_processor::DeserializationError;
 
-use super::{Digest, Felt, Hasher, NoteError, Vec, ZERO};
+use super::{
+    ByteReader, ByteWriter, Deserializable, Digest, Felt, Hasher, NoteError, Serializable, Vec,
+    ZERO,
+};
 
 // NOTE INPUTS
 // ================================================================================================

objects/src/notes/metadata.rs

@@ -1,7 +1,8 @@
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
 use vm_processor::DeserializationError;
 
-use super::{AccountId, Felt, NoteError, Word};
+use super::{
+    AccountId, ByteReader, ByteWriter, Deserializable, Felt, NoteError, Serializable, Word,
+};
 
 /// Represents metadata associated with a note. This includes the sender, tag, and number of assets.
 /// - sender is the account which created the note.

objects/src/notes/mod.rs

@@ -1,12 +1,14 @@
 use core::cell::OnceCell;
 
-use vm_processor::DeserializationError;
-
 use super::{
     accounts::AccountId,
     assembly::{Assembler, AssemblyContext, ProgramAst},
     assets::Asset,
-    utils::{collections::Vec, string::ToString},
+    utils::{
+        collections::Vec,
+        serde::{ByteReader, ByteWriter, Deserializable, DeserializationError, Serializable},
+        string::{String, ToString},
+    },
     vm::CodeBlock,
     Digest, Felt, Hasher, NoteError, Word, WORD_SIZE, ZERO,
 };
@@ -27,7 +29,6 @@ mod nullifier;
 pub use nullifier::Nullifier;
 
 mod origin;
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
 pub use origin::{NoteInclusionProof, NoteOrigin};
 
 mod script;

objects/src/notes/nullifier.rs

@@ -1,7 +1,8 @@
-use super::{Digest, Felt, Hasher, Note, Word, WORD_SIZE, ZERO};
-use crate::utils::serde::{
-    ByteReader, ByteWriter, Deserializable, DeserializationError, Serializable,
+use super::{
+    ByteReader, ByteWriter, Deserializable, DeserializationError, Digest, Felt, Hasher, Note,
+    Serializable, String, Word, WORD_SIZE, ZERO,
 };
+use crate::utils::{bytes_to_hex_string, hex_to_bytes, HexParseError};
 
 // NULLIFIER
 // ================================================================================================
@@ -43,6 +44,20 @@ impl Nullifier {
     pub fn inner(&self) -> Digest {
         self.0
     }
+
+    /// Creates a Nullifier from a hex string. Assumes that the string starts with "0x" and
+    /// that the hexadecimal characters are big-endian encoded.
+    pub fn from_hex(hex_value: &str) -> Result<Self, HexParseError> {
+        hex_to_bytes(hex_value).and_then(|bytes: [u8; 32]| {
+            let digest = Digest::try_from(bytes)?;
+            Ok(digest.into())
+        })
+    }
+
+    /// Returns a big-endian, hex-encoded string.
+    pub fn to_hex(&self) -> String {
+        bytes_to_hex_string(self.0.as_bytes())
+    }
 }
 
 // CONVERSIONS INTO NULLIFIER
@@ -113,3 +128,19 @@ impl Deserializable for Nullifier {
         Ok(Self(nullifier))
     }
 }
+
+// TESTS
+// ================================================================================================
+
+#[cfg(test)]
+mod tests {
+    use crate::notes::Nullifier;
+
+    #[test]
+    fn test_from_hex_and_back() {
+        let nullifier_hex = "0x41e7dbbc8ce63ec25cf2d76d76162f16ef8fd1195288171f5e5a3e178222f6d2";
+        let nullifier = Nullifier::from_hex(nullifier_hex).unwrap();
+
+        assert_eq!(nullifier_hex, nullifier.to_hex());
+    }
+}

objects/src/notes/origin.rs

@@ -1,7 +1,7 @@
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
-use vm_processor::DeserializationError;
-
-use super::{Digest, NoteError, ToString, NOTE_TREE_DEPTH};
+use super::{
+    ByteReader, ByteWriter, Deserializable, DeserializationError, Digest, NoteError, Serializable,
+    ToString, NOTE_TREE_DEPTH,
+};
 use crate::crypto::merkle::{MerklePath, NodeIndex};
 
 /// Contains information about the origin of a note.

objects/src/transaction/proven_tx.rs

@@ -1,8 +1,9 @@
-use miden_crypto::utils::{ByteReader, ByteWriter, Deserializable, Serializable};
 use miden_verifier::ExecutionProof;
-use vm_processor::DeserializationError;
 
 use super::{AccountId, Digest, InputNotes, NoteEnvelope, Nullifier, OutputNotes, TransactionId};
+use crate::utils::serde::{
+    ByteReader, ByteWriter, Deserializable, DeserializationError, Serializable,
+};
 
 // PROVEN TRANSACTION
 // ================================================================================================