From cdadf157ad0df052dda8efae948dd62e29448d8e Mon Sep 17 00:00:00 2001
From: Volker Mische <volker.mische@gmail.com>
Date: Fri, 24 May 2024 17:32:55 +0200
Subject: [PATCH] fix: remove the pairing feature from fvm_shared (#2009)

The `pairing` feature from the `fvm_shared` crate isn't used. It causes
problems, as it forces the `subtle` dependency to v2.4.1, although the
rest is happy to have v2.5.0.

Here is a detailed dependency graph and issue outline:

`fvm_shared` depends on `bls-signatures`.
In `bls-signatures` we depend on an old version (v0.11) of `hkdf`.
That version depends on `hmac` v0.11, which depends on `crypto-mac` v0.11.
`crypto-mac` v0.11.0 depends on `subtle` v2. That is fine, it would
automatically select v2.5.0.
The problem is that `crypto-mac` v0.11.1 pins `subtle` to exactly v2.4,
therefore v2.5.0 won't be selected.

The obvious thing is to upgrade in`bls-signatures` the version of `hkdf`
to the latest v0.12.
That would make it possible to use `subtle` v2.5.0.
The problem is that such an upgrade is not easily possible.
`hkdf` v0.12 depends on a newer version v0.10 of the `sha2` crate.
Updating that breaks the `bls12_381` crate.
The reason is the current version v0.8.0 of `bls12_381` depends on an old
version v0.9 of the `digest` crate.

The obvious thing is to upgrade in `bls12_381` the version of `digest` to
v0.10.
That would make it possible to get `hkdf` v0.12 built.
But such an upgrade is and open issue at
https://github.com/zkcrypto/bls12_381/issues/102, which mentions that it's
blocked on https://github.com/zkcrypto/bls12_381/pull/90.
That pull request is about updating do the hash-to-curve draft v16, currently
it's using v12.
We use that code path in `bls-signatures`, else we wouldn't enable the
`experimental` feature of `bls12_381`.
So it's even not clear if we'd want such a change to v16.
---
 Cargo.lock        | 55 ++++++-----------------------------------------
 shared/Cargo.toml |  1 -
 2 files changed, 7 insertions(+), 49 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ae32bdb64..10ed6b1cd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -443,33 +443,16 @@ version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ecc7fce0356b52c2483bb6188cc8bdc11add526bce75d1a44e5e5d889a6ab008"
 dependencies = [
- "bls12_381",
  "blst",
  "blstrs",
  "ff",
  "group",
- "hkdf",
  "pairing",
  "rand_core",
- "sha2 0.9.9",
  "subtle",
  "thiserror",
 ]
 
-[[package]]
-name = "bls12_381"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d7bc6d6292be3a19e6379786dac800f551e5865a5bb51ebbe3064ab80433f403"
-dependencies = [
- "digest 0.9.0",
- "ff",
- "group",
- "pairing",
- "rand_core",
- "subtle",
-]
-
 [[package]]
 name = "blst"
 version = "0.3.11"
@@ -982,16 +965,6 @@ dependencies = [
  "subtle",
 ]
 
-[[package]]
-name = "crypto-mac"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1d1a86f49236c215f271d40892d5fc950490551400b02ef360692c29815c714"
-dependencies = [
- "generic-array",
- "subtle",
-]
-
 [[package]]
 name = "cs_serde_bytes"
 version = "0.12.2"
@@ -1988,14 +1961,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "hkdf"
-version = "0.11.0"
+name = "hex-literal"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "01706d578d5c281058480e673ae4086a9f4710d8df1ad80a5b03e39ece5f886b"
-dependencies = [
- "digest 0.9.0",
- "hmac 0.11.0",
-]
+checksum = "7ebdb29d2ea9ed0083cd8cece49bbd968021bd99b0849edb4a9a7ee0fdf6a4e0"
 
 [[package]]
 name = "hmac"
@@ -2003,17 +1972,7 @@ version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "126888268dcc288495a26bf004b38c5fdbb31682f992c84ceb046a1f0fe38840"
 dependencies = [
- "crypto-mac 0.8.0",
- "digest 0.9.0",
-]
-
-[[package]]
-name = "hmac"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2a2a2320eb7ec0ebe8da8f744d7812d9fc4cb4d09344ac01898dbcb6a20ae69b"
-dependencies = [
- "crypto-mac 0.11.1",
+ "crypto-mac",
  "digest 0.9.0",
 ]
 
@@ -2025,7 +1984,7 @@ checksum = "17ea0a1394df5b6574da6e0c1ade9e78868c9fb0a4e5ef4428e32da4676b85b1"
 dependencies = [
  "digest 0.9.0",
  "generic-array",
- "hmac 0.8.1",
+ "hmac",
 ]
 
 [[package]]
@@ -3435,9 +3394,9 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "subtle"
-version = "2.4.1"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6bdef32e8150c2a081110b42772ffe7d7c9032b606bc226c8260fd97e0976601"
+checksum = "81cdd64d312baedb58e21336b31bc043b77e01cc99033ce76ef539f78e965ebc"
 
 [[package]]
 name = "supraseal-c2"
diff --git a/shared/Cargo.toml b/shared/Cargo.toml
index e4315643f..fac241a3c 100644
--- a/shared/Cargo.toml
+++ b/shared/Cargo.toml
@@ -50,6 +50,5 @@ crypto = ["libsecp256k1", "blst", "proofs"]
 proofs = ["filecoin-proofs-api"]
 secp256k1 = ["libsecp256k1"]
 blst = ["bls-signatures/blst"]
-pairing = ["bls-signatures/pairing"]
 testing = []
 arb = ["arbitrary"]