llcrypto: upgrade x25519-dalek.

This upgrades us to 2.0.0-rc.2, which is the latest in the
not-quite-done-yet 2.0 series.

The only code change that's absolutely needed is opting into the
static_secrets feature.

Cargo.lock

@@ -900,6 +900,20 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "curve25519-dalek"
+version = "4.0.0-rc.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03d928d978dbec61a1167414f5ec534f24bea0d7a0d24dd9b6233d3d8223e585"
+dependencies = [
+ "cfg-if",
+ "fiat-crypto",
+ "packed_simd_2",
+ "platforms",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "cxx"
 version = "1.0.94"
@@ -1187,7 +1201,7 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c762bae6dcaf24c4c84667b8579785430908723d5c889f469d76a41d59cc7a9d"
 dependencies = [
- "curve25519-dalek",
+ "curve25519-dalek 3.2.0",
  "ed25519",
  "merlin",
  "rand 0.7.3",
@@ -1310,6 +1324,12 @@ dependencies = [
  "instant",
 ]
 
+[[package]]
+name = "fiat-crypto"
+version = "0.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e825f6987101665dea6ec934c09ec6d721de7bc1bf92248e1d5810c8cd636b77"
+
 [[package]]
 name = "filetime"
 version = "0.2.21"
@@ -1984,6 +2004,12 @@ version = "0.2.142"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a987beff54b60ffa6d51982e1aa1146bc42f19bd26be28b0586f252fccf5317"
 
+[[package]]
+name = "libm"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fc7aa29613bd6a620df431842069224d8bc9011086b1db4c0e0cd47fa03ec9a"
+
 [[package]]
 name = "libm"
 version = "0.2.6"
@@ -2255,7 +2281,7 @@ checksum = "2399c9463abc5f909349d8aa9ba080e0b88b3ce2885389b60b993f39b1a56905"
 dependencies = [
  "byteorder",
  "lazy_static",
- "libm",
+ "libm 0.2.6",
  "num-integer",
  "num-iter",
  "num-traits",
@@ -2312,7 +2338,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
 dependencies = [
  "autocfg",
- "libm",
+ "libm 0.2.6",
 ]
 
 [[package]]
@@ -2433,6 +2459,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
+[[package]]
+name = "packed_simd_2"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1914cd452d8fccd6f9db48147b29fd4ae05bea9dc5d9ad578509f72415de282"
+dependencies = [
+ "cfg-if",
+ "libm 0.1.4",
+]
+
 [[package]]
 name = "parking"
 version = "2.1.0"
@@ -2601,6 +2637,12 @@ version = "0.3.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ac9a59f73473f1b8d852421e59e64809f025994837ef743615c6d0c5b305160"
 
+[[package]]
+name = "platforms"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3d7ddaed09e0eb771a79ab0fd64609ba0afb0a8366421957936ad14cbd13630"
+
 [[package]]
 name = "polling"
 version = "2.8.0"
@@ -4280,7 +4322,7 @@ dependencies = [
  "base64ct",
  "cipher",
  "ctr",
- "curve25519-dalek",
+ "curve25519-dalek 3.2.0",
  "derive_more",
  "digest 0.10.6",
  "ed25519-dalek",
@@ -5214,12 +5256,13 @@ dependencies = [
 
 [[package]]
 name = "x25519-dalek"
-version = "2.0.0-pre.1"
+version = "2.0.0-rc.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5da623d8af10a62342bcbbb230e33e58a63255a58012f8653c578e54bab48df"
+checksum = "fabd6e16dd08033932fc3265ad4510cc2eab24656058a6dcb107ffe274abcc95"
 dependencies = [
- "curve25519-dalek",
+ "curve25519-dalek 4.0.0-rc.2",
  "rand_core 0.6.4",
+ "serde",
  "zeroize",
 ]
 

crates/tor-llcrypto/Cargo.toml

@@ -49,7 +49,7 @@ simple_asn1 = "0.6"
 subtle = "2"
 thiserror = "1"
 typenum = { version = "1.15.0", optional = true }
-x25519-dalek = "=2.0.0-pre.1"
+x25519-dalek = { version = "=2.0.0-rc.2", features = ["static_secrets"] }
 zeroize = "1"
 
 [dev-dependencies]