Create a dedicated crate for the DKG (#141)

* Add dkg crate

* Remove F_len and G_len

They're generally no longer used.

* Replace hash_to_vec with a provided method around associated type H: Digest

Part of trying to minimize this trait so it can be moved elsewhere. Vec, 
which isn't std, may have been a blocker.

* Encrypt secret shares within the FROST library

Reduces requirements on callers in order to be correct.

* Update usage of Zeroize within FROST

* Inline functions in key_gen

There was no reason to have them separated as they were. sign probably 
has the same statement available, yet that isn't the focus right now.

* Add a ciphersuite package which provides hash_to_F

* Set the Ciphersuite version to something valid

* Have ed448 export Scalar/FieldElement/Point at the top level

* Move FROST over to Ciphersuite

* Correct usage of ff in ciphersuite

* Correct documentation handling

* Move Schnorr signatures to their own crate

* Remove unused feature from schnorr

* Fix Schnorr tests

* Split DKG into a separate crate

* Add serialize to Commitments and SecretShare

Helper for buf = vec![]; .write(buf).unwrap(); buf

* Move FROST over to the new dkg crate

* Update Monero lib to latest FROST

* Correct ethereum's usage of features

* Add serialize to GeneratorProof

* Add serialize helper function to FROST

* Rename AddendumSerialize to WriteAddendum

* Update processor

* Slight fix to processor

Cargo.lock

@@ -43,7 +43,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9e8b47f52ea9bae42228d07ec09eb676433d7c4ed1ebdf0f1d1c29ed446f1ab8"
 dependencies = [
  "cfg-if",
- "cipher",
+ "cipher 0.3.0",
  "cpufeatures",
  "opaque-debug 0.3.0",
 ]
@@ -56,7 +56,7 @@ checksum = "df5f85a83a7d8b0442b6aa7b504b8212c1733da07b98aae43d4bc21b2cb3cdf6"
 dependencies = [
  "aead",
  "aes",
- "cipher",
+ "cipher 0.3.0",
  "ctr",
  "ghash",
  "subtle",
@@ -818,11 +818,22 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c80e5460aa66fe3b91d40bcbdab953a597b60053e34d684ac6903f863b680a6"
 dependencies = [
  "cfg-if",
- "cipher",
+ "cipher 0.3.0",
  "cpufeatures",
  "zeroize",
 ]
 
+[[package]]
+name = "chacha20"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7fc89c7c5b9e7a02dfe45cd2367bae382f9ed31c61ca8debe5f827c420a2f08"
+dependencies = [
+ "cfg-if",
+ "cipher 0.4.3",
+ "cpufeatures",
+]
+
 [[package]]
 name = "chacha20poly1305"
 version = "0.9.1"
@@ -830,8 +841,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a18446b09be63d457bbec447509e85f662f32952b035ce892290396bc0b0cff5"
 dependencies = [
  "aead",
- "chacha20",
- "cipher",
+ "chacha20 0.8.2",
+ "cipher 0.3.0",
  "poly1305",
  "zeroize",
 ]
@@ -873,6 +884,36 @@ dependencies = [
  "generic-array 0.14.6",
 ]
 
+[[package]]
+name = "cipher"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d1873270f8f7942c191139cb8a40fd228da6c3fd2fc376d7e92d47aa14aeb59e"
+dependencies = [
+ "crypto-common",
+ "inout",
+ "zeroize",
+]
+
+[[package]]
+name = "ciphersuite"
+version = "0.1.1"
+dependencies = [
+ "dalek-ff-group",
+ "digest 0.10.5",
+ "elliptic-curve",
+ "ff",
+ "group",
+ "k256",
+ "minimal-ed448",
+ "p256",
+ "rand_core 0.6.4",
+ "sha2 0.10.6",
+ "sha3",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "clang-sys"
 version = "1.4.0"
@@ -1361,7 +1402,7 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "049bb91fb4aaf0e3c7efa6cd5ef877dbbbd15b39dad06d9948de4ec8a75761ea"
 dependencies = [
- "cipher",
+ "cipher 0.3.0",
 ]
 
 [[package]]
@@ -1612,6 +1653,26 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "dkg"
+version = "0.1.0"
+dependencies = [
+ "chacha20 0.9.0",
+ "ciphersuite",
+ "digest 0.10.5",
+ "dleq",
+ "flexible-transcript",
+ "group",
+ "hex",
+ "hkdf",
+ "multiexp",
+ "rand_core 0.6.4",
+ "schnorr-signatures",
+ "subtle",
+ "thiserror",
+ "zeroize",
+]
+
 [[package]]
 name = "dleq"
 version = "0.1.2"
@@ -2990,6 +3051,15 @@ version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7ebdb29d2ea9ed0083cd8cece49bbd968021bd99b0849edb4a9a7ee0fdf6a4e0"
 
+[[package]]
+name = "hkdf"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "791a029f6b9fc27657f6f188ec6e5e43f6911f6f878e0dc5501396e09809d437"
+dependencies = [
+ "hmac 0.12.1",
+]
+
 [[package]]
 name = "hmac"
 version = "0.8.1"
@@ -3469,6 +3539,15 @@ dependencies = [
  "synstructure",
 ]
 
+[[package]]
+name = "inout"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a0c10553d664a4d0bcff9f4215d0aac67a639cc68ef660840afe309b807bc9f5"
+dependencies = [
+ "generic-array 0.14.6",
+]
+
 [[package]]
 name = "instant"
 version = "0.1.12"
@@ -4509,21 +4588,21 @@ dependencies = [
 name = "modular-frost"
 version = "0.3.0"
 dependencies = [
+ "chacha20 0.9.0",
+ "ciphersuite",
  "dalek-ff-group",
+ "digest 0.10.5",
+ "dkg",
  "dleq",
- "elliptic-curve",
- "ff",
  "flexible-transcript",
  "group",
  "hex",
- "k256",
+ "hkdf",
  "minimal-ed448",
  "multiexp",
- "p256",
  "rand_core 0.6.4",
+ "schnorr-signatures",
  "serde_json",
- "sha2 0.10.6",
- "sha3",
  "subtle",
  "thiserror",
  "zeroize",
@@ -6370,7 +6449,7 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c0fbb5f676da676c260ba276a8f43a8dc67cf02d1438423aeb1c677a7212686"
 dependencies = [
- "cipher",
+ "cipher 0.3.0",
 ]
 
 [[package]]
@@ -7266,6 +7345,18 @@ dependencies = [
  "windows-sys 0.36.1",
 ]
 
+[[package]]
+name = "schnorr-signatures"
+version = "0.1.0"
+dependencies = [
+ "ciphersuite",
+ "dalek-ff-group",
+ "group",
+ "multiexp",
+ "rand_core 0.6.4",
+ "zeroize",
+]
+
 [[package]]
 name = "schnorrkel"
 version = "0.9.1"