X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Finbound_payment.rs;h=f9e10880afbe5f5eae122d48220f5b8e5dcd9757;hb=297390a882222ca044756f71cb3da3d639dae8d6;hp=956928fd7fa008c89de4713aa78586060ba635c6;hpb=4fafae0733b451754c77c0692f8941d9122b78ed;p=rust-lightning

diff --git a/lightning/src/ln/inbound_payment.rs b/lightning/src/ln/inbound_payment.rs
index 956928fd..f9e10880 100644
--- a/lightning/src/ln/inbound_payment.rs
+++ b/lightning/src/ln/inbound_payment.rs
@@ -86,6 +86,13 @@ impl ExpandedKey {
 		hmac.input(&nonce.0);
 		hmac
 	}
+
+	/// Encrypts or decrypts the given `bytes`. Used for data included in an offer message's
+	/// metadata (e.g., payment id).
+	pub(crate) fn crypt_for_offer(&self, mut bytes: [u8; 32], nonce: Nonce) -> [u8; 32] {
+		ChaCha20::encrypt_single_block_in_place(&self.offers_encryption_key, &nonce.0, &mut bytes);
+		bytes
+	}
 }
 
 /// A 128-bit number used only once.
@@ -277,10 +284,9 @@ fn construct_payment_secret(iv_bytes: &[u8; IV_LEN], metadata_bytes: &[u8; METAD
 	let (iv_slice, encrypted_metadata_slice) = payment_secret_bytes.split_at_mut(IV_LEN);
 	iv_slice.copy_from_slice(iv_bytes);
 
-	let chacha_block = ChaCha20::get_single_block(metadata_key, iv_bytes);
-	for i in 0..METADATA_LEN {
-		encrypted_metadata_slice[i] = chacha_block[i] ^ metadata_bytes[i];
-	}
+	ChaCha20::encrypt_single_block(
+		metadata_key, iv_bytes, encrypted_metadata_slice, metadata_bytes
+	);
 	PaymentSecret(payment_secret_bytes)
 }
 
@@ -412,11 +418,10 @@ fn decrypt_metadata(payment_secret: PaymentSecret, keys: &ExpandedKey) -> ([u8;
 	let (iv_slice, encrypted_metadata_bytes) = payment_secret.0.split_at(IV_LEN);
 	iv_bytes.copy_from_slice(iv_slice);
 
-	let chacha_block = ChaCha20::get_single_block(&keys.metadata_key, &iv_bytes);
 	let mut metadata_bytes: [u8; METADATA_LEN] = [0; METADATA_LEN];
-	for i in 0..METADATA_LEN {
-		metadata_bytes[i] = chacha_block[i] ^ encrypted_metadata_bytes[i];
-	}
+	ChaCha20::encrypt_single_block(
+		&keys.metadata_key, &iv_bytes, &mut metadata_bytes, encrypted_metadata_bytes
+	);
 
 	(iv_bytes, metadata_bytes)
 }