WIP

noir-projects/aztec-nr/aztec/src/oracle.nr

@@ -4,6 +4,7 @@
 
 mod arguments;
 mod call_private_function;
+mod encryption;
 mod get_contract_instance;
 mod get_l1_to_l2_membership_witness;
 mod get_nullifier_membership_witness;

noir-projects/aztec-nr/aztec/src/oracle/encryption.nr

@@ -0,0 +1,7 @@
+
+#[oracle(aes128Encrypt)]
+pub fn aes128_encrypt_oracle<N>(input: [u8; N], iv: [u8; 16], key: [u8; 16]) -> [u8; N] {}
+
+unconstrained pub fn aes128_encrypt<N>(input: [u8; N], iv: [u8; 16], key: [u8; 16]) -> [u8; N] {
+    aes128_encrypt_oracle(input, iv, key)
+}

noir-projects/noir-contracts/contracts/test_contract/src/main.nr

@@ -25,7 +25,7 @@ contract Test {
         note_getter_options::NoteStatus
     },
         deploy::deploy_contract as aztec_deploy_contract,
-        oracle::{get_public_key::get_public_key as get_public_key_oracle, unsafe_rand::unsafe_rand}
+        oracle::{encryption::aes128_encrypt, get_public_key::get_public_key as get_public_key_oracle, unsafe_rand::unsafe_rand}
     };
     use dep::token_portal_content_hash_lib::{get_mint_private_content_hash, get_mint_public_content_hash};
     use dep::value_note::value_note::ValueNote;
@@ -309,6 +309,12 @@ contract Test {
         assert(context.version() == version, "Invalid version");
     }
 
+    #[aztec(private)]
+    fn encrypt(input: [u8; 64], iv: [u8; 16], key: [u8; 16]) {
+        let result = aes128_encrypt(input, iv, key);
+        context.emit_unencrypted_log(result);
+    }
+
     #[aztec(public)]
     fn assert_public_global_vars(
         chain_id: Field,

yarn-project/simulator/src/acvm/oracle/oracle.ts

@@ -4,7 +4,6 @@ import { EventSelector, FunctionSelector } from '@aztec/foundation/abi';
 import { AztecAddress } from '@aztec/foundation/aztec-address';
 import { Fr, Point } from '@aztec/foundation/fields';
 import { createDebugLogger } from '@aztec/foundation/log';
-import { to2Fields } from '@aztec/foundation/serialize';
 
 import { type ACVMField } from '../acvm_types.js';
 import { frToBoolean, frToNumber, fromACVMField } from '../deserialize.js';
@@ -380,21 +379,16 @@ export class Oracle {
     return toAcvmEnqueuePublicFunctionResult(enqueuedRequest);
   }
 
-  encrypt([symmetricKey]: ACVMField[], [initializationVector]: ACVMField[], plaintext: ACVMField[]): ACVMField[] {
-    // Symmetric key and initialization vector (IV) are 16 bytes and we store them as big endian in Fr
-    const processedSK = fromACVMField(symmetricKey).toBuffer().subarray(0, 16);
-    const processedIV = fromACVMField(initializationVector).toBuffer().subarray(0, 16);
-    // TODO(benesjan): we could save some info here by not including the 2 empty bits at the end of each serialized
-    // field --> this could be valuable as the ciphertext will go on-chain
-    const processedPlaintext = Buffer.concat(plaintext.map(fromACVMField).map(f => f.toBuffer()));
-    const ciphertext = this.typedOracle.encrypt(processedSK, processedIV, processedPlaintext);
-    // Chunk the ciphertext buffer to 32 bytes and on each chunk call to2Fields function
-    const ciphertextFields: Fr[] = [];
-    for (let i = 0; i < ciphertext.length; i += Fr.SIZE_IN_BYTES) {
-      const chunk = ciphertext.subarray(i, i + Fr.SIZE_IN_BYTES);
-      ciphertextFields.push(...to2Fields(chunk));
-    }
+  aes128Encrypt(input: ACVMField[], initializationVector: ACVMField[], key: ACVMField[]): ACVMField[] {
+    // Convert each field to a number and then to a buffer (1 byte is stored in 1 field)
+    const processedInput = Buffer.from(input.map(fromACVMField).map(f => f.toNumber()));
+    const processedIV = Buffer.from(initializationVector.map(fromACVMField).map(f => f.toNumber()));
+    const processedKey = Buffer.from(key.map(fromACVMField).map(f => f.toNumber()));
+
+    // Encrypt the input
+    const ciphertext = this.typedOracle.aes128Encrypt(processedInput, processedIV, processedKey);
 
-    return ciphertextFields.map(toACVMField);
+    // Convert each byte of ciphertext to a field and return it
+    return Array.from(ciphertext).map(byte => toACVMField(byte));
   }
 }

yarn-project/simulator/src/acvm/oracle/typed_oracle.ts

@@ -234,7 +234,7 @@ export abstract class TypedOracle {
     throw new OracleMethodNotAvailableError('enqueuePublicFunctionCall');
   }
 
-  encrypt(_symmetricKey: Buffer, _initializationVector: Buffer, _plaintext: Buffer): Buffer {
+  aes128Encrypt(_input: Buffer, _initializationVector: Buffer, _key: Buffer): Buffer {
     throw new OracleMethodNotAvailableError('encrypt');
   }
 }

yarn-project/simulator/src/client/client_execution_context.ts

@@ -523,8 +523,8 @@ export class ClientExecutionContext extends ViewDataOracle {
     return values;
   }
 
-  public override encrypt(symmetricKey: Buffer, initializationVector: Buffer, plaintext: Buffer): Buffer {
+  public override aes128Encrypt(input: Buffer, initializationVector: Buffer, key: Buffer): Buffer {
     const aes128 = new Aes128();
-    return aes128.encryptBufferCBC(plaintext, initializationVector, symmetricKey);
+    return aes128.encryptBufferCBC(input, initializationVector, key);
   }
 }