more changes

Author: samkim-crypto

token/confidential-transfer/proof-generation/src/mint.rs

@@ -5,7 +5,6 @@ use {
     },
     solana_zk_sdk::{
         encryption::{
-            auth_encryption::{AeCiphertext, AeKey},
             elgamal::{ElGamalCiphertext, ElGamalKeypair, ElGamalPubkey},
             pedersen::Pedersen,
         },
@@ -28,15 +27,13 @@ pub struct MintProofData {
     pub ciphertext_validity_proof_data_with_ciphertext:
         CiphertextValidityProofWithAuditorCiphertext,
     pub range_proof_data: BatchedRangeProofU128Data,
-    pub new_decryptable_supply: AeCiphertext,
 }
 
 pub fn mint_split_proof_data(
     current_supply_ciphertext: &ElGamalCiphertext,
     mint_amount: u64,
     current_supply: u64,
     supply_elgamal_keypair: &ElGamalKeypair,
-    supply_aes_key: &AeKey,
     destination_elgamal_pubkey: &ElGamalPubkey,
     auditor_elgamal_pubkey: Option<&ElGamalPubkey>,
 ) -> Result<MintProofData, TokenProofGenerationError> {
@@ -161,6 +158,5 @@ pub fn mint_split_proof_data(
         equality_proof_data,
         ciphertext_validity_proof_data_with_ciphertext,
         range_proof_data,
-        new_decryptable_supply: supply_aes_key.encrypt(new_supply),
     })
 }

token/confidential-transfer/proof-tests/tests/proof_test.rs

@@ -222,21 +222,18 @@ fn test_mint_validity(mint_amount: u64, supply: u64) {
     let auditor_pubkey = auditor_keypair.pubkey();
 
     let supply_keypair = ElGamalKeypair::new_rand();
-    let supply_aes_key = AeKey::new_rand();
 
     let supply_ciphertext = supply_keypair.pubkey().encrypt(supply);
 
     let MintProofData {
         equality_proof_data,
         ciphertext_validity_proof_data_with_ciphertext,
         range_proof_data,
-        new_decryptable_supply: _,
     } = mint_split_proof_data(
         &supply_ciphertext,
         mint_amount,
         supply,
         &supply_keypair,
-        &supply_aes_key,
         destination_pubkey,
         Some(auditor_pubkey),
     )

token/program-2022/src/extension/confidential_mint_burn/account_info.rs

@@ -52,7 +52,7 @@ impl SupplyAccountInfo {
     /// Computes the current supply from the decryptable supply and the
     /// difference between the decryptable supply and the ElGamal encrypted
     /// supply ciphertext
-    pub fn decrypt_current_supply(
+    pub fn decrypted_current_supply(
         &self,
         aes_key: &AeKey,
         elgamal_keypair: &ElGamalKeypair,
@@ -91,7 +91,7 @@ impl SupplyAccountInfo {
         new_supply_elgamal_keypair: &ElGamalKeypair,
     ) -> Result<CiphertextCiphertextEqualityProofData, TokenError> {
         let current_supply =
-            self.decrypt_current_supply(aes_key, current_supply_elgamal_keypair)?;
+            self.decrypted_current_supply(aes_key, current_supply_elgamal_keypair)?;
 
         let new_supply_opening = PedersenOpening::new_rand();
         let new_supply_ciphertext = new_supply_elgamal_keypair
@@ -119,7 +119,6 @@ impl SupplyAccountInfo {
         mint_amount: u64,
         current_supply: u64,
         supply_elgamal_keypair: &ElGamalKeypair,
-        aes_key: &AeKey,
         destination_elgamal_pubkey: &ElGamalPubkey,
         auditor_elgamal_pubkey: Option<&ElGamalPubkey>,
     ) -> Result<MintProofData, TokenError> {
@@ -133,12 +132,26 @@ impl SupplyAccountInfo {
             mint_amount,
             current_supply,
             supply_elgamal_keypair,
-            aes_key,
             destination_elgamal_pubkey,
             auditor_elgamal_pubkey,
         )
         .map_err(|e| -> TokenError { e.into() })
     }
+
+    /// Compute the new decryptable supply.
+    pub fn new_decryptable_supply(
+        &self,
+        mint_amount: u64,
+        aes_key: &AeKey,
+        elgamal_keypair: &ElGamalKeypair, // TODO: check consistency of the order of params
+    ) -> Result<AeCiphertext, TokenError> {
+        let current_decrypted_supply = self.decrypted_current_supply(aes_key, elgamal_keypair)?;
+        let new_decrypted_available_balance = current_decrypted_supply
+            .checked_add(mint_amount)
+            .ok_or(TokenError::Overflow)?;
+
+        Ok(aes_key.encrypt(new_decrypted_available_balance))
+    }
 }
 
 /// Confidential Mint Burn extension information needed to construct a