EIP-2333: Key derivation

Cargo.toml

@@ -12,6 +12,8 @@ members = [
     "eth2/utils/eth2_config",
     "eth2/utils/eth2_interop_keypairs",
     "eth2/utils/eth2_testnet_config",
+    "eth2/utils/eth2_keystore",
+    "eth2/utils/eth2_key_derivation",
     "eth2/utils/logging",
     "eth2/utils/eth2_hashing",
     "eth2/utils/hashmap_delay",

eth2/utils/eth2_key_derivation/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "eth2_key_derivation"
+version = "0.1.0"
+authors = ["Paul Hauner <paul@paulhauner.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rust-crypto = "0.2.36"
+zeroize = { version = "1.0.0", features = ["zeroize_derive"] }
+num-bigint-dig = { version = "0.6.0", features = ["zeroize"] }
+
+[dev-dependencies]
+hex = "0.3"