Use curve25519_dalek_ng instead of curve25519_dalek

See dalek-cryptography/curve25519-dalek#338 (comment)

Cargo.toml

@@ -13,11 +13,11 @@ readme = "README.md"
 default = ["u64_backend"]
 slow-hash = ["scrypt"]
 bench = []
-u64_backend = ["curve25519-dalek/u64_backend"]
-u32_backend = ["curve25519-dalek/u32_backend"]
+u64_backend = ["curve25519-dalek-ng/u64_backend"]
+u32_backend = ["curve25519-dalek-ng/u32_backend"]
 
 [dependencies]
-curve25519-dalek = { version = "3.0.0", default-features = false, features = ["std"] }
+curve25519-dalek-ng = { version = "4", default-features = false, features = ["std"] }
 digest = "0.9.0"
 displaydoc = "0.1.7"
 generic-array = "0.14.4"
@@ -51,6 +51,4 @@ required-features = ["bench"]
 
 # TEMPORARY, DO NOT MERGE
 [patch.crates-io]
-x25519-dalek = { git = "https://github.com/PaulGrandperrin/x25519-dalek.git", branch="patch-1" }
-curve25519-dalek = { git = "https://github.com/PaulGrandperrin/curve25519-dalek.git", branch="patch-1" }
 proptest = { git = "https://github.com/PaulGrandperrin/proptest.git", branch="master" }

src/group.rs

@@ -8,7 +8,7 @@
 
 use crate::errors::InternalPakeError;
 
-use curve25519_dalek::{
+use curve25519_dalek_ng::{
     constants::RISTRETTO_BASEPOINT_POINT,
     ristretto::{CompressedRistretto, RistrettoPoint},
     scalar::Scalar,

src/map_to_curve.rs

@@ -10,7 +10,7 @@ use crate::errors::InternalPakeError;
 use crate::group::Group;
 use crate::hash::Hash;
 use crate::serialization::i2osp;
-use curve25519_dalek::ristretto::RistrettoPoint;
+use curve25519_dalek_ng::ristretto::RistrettoPoint;
 use digest::{BlockInput, Digest};
 use generic_array::typenum::Unsigned;
 use generic_array::GenericArray;