Add support for ESP32 and RISC-V

[ellenhp]

Related to #1436 and #1297

Fixes #1455
Will likely address #1419 but I don't know for sure.

A few points:

• The code for bn_mult_mont is from Add basic support for s390x #1297
• I know you expressed reluctance to accepting variable-length arrays in the past, so let me know if you want that changed to something else.
• Embedded targets are usually compiled with size-optimization so the compiler is very, very reluctant to inline things like the value barrier code in crypto/internal.h. Since we treat warnings as errors I needed to add a way to disable the -Winline flag.
• I'm adding architecture support here, and also adding support for the ESP-IDF RTOS. Architecture support seems fairly uncontroversial if the code meets standards, but I understand if you're reluctant to add support for a new OS target for maintenance burden reasons. Just let me know and I can yank that part and maintain it myself as a patch. I'd obviously prefer it we could upstream it though.
• This has been lightly tested through rustls on both xtensa based ESP32 micros and RISC-V based ESP32's, but we haven't been able to run a full test suite on them on account of not having a full general purpose OS, so no cargo test. Let me know if this is a blocker and I'll figure out how to at least make the tests work on RISC-V. I think linux on RISC-V would work in qemu or something.

[ellenhp]

This is ready for review!

[sajattack]

@ellenhp Greetings, I have a rv64gc linux board I can use to test this, would it just be a case of checking out your branch and something like cargo test --target=riscv64gc-unknown-linux-gnu?

[sajattack]

https://gist.github.com/sajattack/57f413217325d53446c550dd0cc830c7

Well done, hopefully that helps get this merged.

[ellenhp]

Yeah I'm not sure how hopeful I am of this getting looked at but hopefully the patch is useful for someone :)

[ellenhp]

@briansmith sorry for the ping, but is there anything here that you're interested in reviewing/merging or would you like me to close this?

[devyn]

I ran cargo test on RV64GC Linux on a StarFive VisionFive SBC. All tests passed. I would very much like to see this merged as it's a blocker for building a number of other crates at the moment.

    Finished test [unoptimized + debuginfo] target(s) in 3m 56s
     Running unittests (target/debug/deps/ring-c6d073b842a83d14)

running 88 tests
test aead::aes_gcm::tests::max_input_len_test ... ok
test aead::aes::tests::test_aes ... ok
test aead::chacha20_poly1305::tests::max_input_len_test ... ok
test aead::chacha::tests::chacha20_test_fallback ... ok
test aead::chacha::tests::chacha20_test_default ... ok
test aead::poly1305::tests::test_poly1305 ... ok
test arithmetic::bigint::tests::test_elem_mul ... ok
test arithmetic::bigint::tests::test_elem_reduced ... ok
test arithmetic::bigint::tests::test_elem_reduced_once ... ok
test arithmetic::bigint::tests::test_elem_squared ... ok
test arithmetic::bigint::tests::test_modulus_debug ... ok
test arithmetic::bigint::tests::test_mul_add_words ... ok
test bssl::tests::result::semantics ... ok
test bssl::tests::result::size_and_alignment ... ok
test c::tests::test_libc_compatible ... ok
test constant_time::tests::test_constant_time ... ok
test digest::tests::max_input::SHA1_FOR_LEGACY_USE_ONLY::max_input_test ... ok
test digest::tests::max_input::SHA1_FOR_LEGACY_USE_ONLY::too_long_input_test_block - should panic ... ok
test digest::tests::max_input::SHA1_FOR_LEGACY_USE_ONLY::too_long_input_test_byte - should panic ... ok
test digest::tests::max_input::SHA256::max_input_test ... ok
test digest::tests::max_input::SHA256::too_long_input_test_block - should panic ... ok
test digest::tests::max_input::SHA256::too_long_input_test_byte - should panic ... ok
test digest::tests::max_input::SHA384::max_input_test ... ok
test digest::tests::max_input::SHA384::too_long_input_test_block - should panic ... ok
test digest::tests::max_input::SHA384::too_long_input_test_byte - should panic ... ok
test digest::tests::max_input::SHA512::max_input_test ... ok
test digest::tests::max_input::SHA512::too_long_input_test_block - should panic ... ok
test digest::tests::max_input::SHA512::too_long_input_test_byte - should panic ... ok
test ec::suite_b::ecdh::tests::test_agreement_suite_b_ecdh_generate ... ok
test ec::suite_b::ecdsa::digest_scalar::tests::test ... ok
test ec::suite_b::ecdsa::signing::tests::signature_ecdsa_sign_asn1_test ... ok
test arithmetic::bigint::tests::test_elem_exp_consttime ... ok
test ec::suite_b::ecdsa::signing::tests::signature_ecdsa_sign_fixed_test ... ok
test ec::suite_b::ops::tests::p256_elem_add_test ... ok
test ec::suite_b::ops::tests::p256_elem_mul_test ... ok
test ec::suite_b::ops::tests::p256_point_double_test ... ok
test ec::suite_b::ops::tests::p256_point_mul_base_test ... ok
test ec::suite_b::ops::tests::p256_point_mul_serialized_test ... ok
test ec::suite_b::ops::tests::p256_point_mul_test ... ok
test ec::suite_b::ops::tests::p256_point_sum_mixed_test ... ok
test ec::suite_b::ops::tests::p256_point_sum_test ... ok
test ec::suite_b::ops::tests::p256_q_minus_n_plus_n_equals_0_test ... ok
test ec::suite_b::ops::tests::p256_scalar_inv_to_mont_zero_panic_test - should panic ... ok
test ec::suite_b::ops::tests::p256_scalar_mul_test ... ok
test ec::suite_b::ops::tests::p256_scalar_square_test ... ok
test ec::suite_b::ops::tests::p384_elem_add_test ... ok
test ec::suite_b::ops::tests::p384_elem_div_by_2_test ... ok
test ec::suite_b::ops::tests::p384_elem_mul_test ... ok
test ec::suite_b::ops::tests::p384_elem_neg_test ... ok
test ec::suite_b::ops::tests::p384_elem_sub_test ... ok
test ec::suite_b::ops::tests::p384_point_double_test ... ok
test ec::suite_b::ecdsa::verification::tests::test_digest_based_test_vectors ... ok
test ec::suite_b::ops::tests::p384_point_mul_base_test ... ok
test ec::suite_b::ops::tests::p384_point_sum_test ... ok
test ec::suite_b::ops::tests::p384_q_minus_n_plus_n_equals_0_test ... ok
test ec::suite_b::ops::tests::p384_scalar_inv_to_mont_zero_panic_test - should panic ... ok
test ec::suite_b::ops::tests::p384_scalar_mul_test ... ok
test ec::suite_b::public_key::tests::parse_uncompressed_point_test ... ok
test endian::tests::test_big_endian ... ok
test hmac::tests::hmac_signing_key_coverage ... ok
test io::der::tests::test_positive_integer ... ok
test io::der::tests::test_small_nonnegative_integer ... ok
test io::positive::tests::test_from_be_bytes ... ok
test limb::tests::test_big_endian_from_limbs_fewer_limbs - should panic ... ok
test limb::tests::test_big_endian_from_limbs_same_length ... ok
test limb::tests::test_limbs_are_even ... ok
test limb::tests::test_limbs_are_zero ... ok
test limb::tests::test_limbs_equal_limb ... ok
test limb::tests::test_limbs_less_than_limb_constant_time ... ok
test limb::tests::test_limbs_minimal_bits ... ok
test limb::tests::test_parse_big_endian_and_pad_consttime ... ok
test polyfill::array_flat_map::tests::test_array_flat_map ... ok
test polyfill::array_flat_map::tests::test_array_flat_map_len_overflow ... ok
test polyfill::leading_zeros_skipped::tests::test_leading_zeroes_stripped ... ok
test rsa::padding::test::test_pss_padding_encode ... ok
test rsa::padding::test::test_pss_padding_verify ... ok
test rsa::public_exponent::tests::test_public_exponent_constants ... ok
test test::tests::first_err - should panic ... ok
test test::tests::first_panic - should panic ... ok
test test::tests::last_err - should panic ... ok
test test::tests::last_panic - should panic ... ok
test test::tests::middle_err - should panic ... ok
test test::tests::middle_panic - should panic ... ok
test test::tests::one_err - should panic ... ok
test test::tests::one_ok ... ok
test test::tests::one_panics - should panic ... ok
test test::tests::syntax_error - should panic ... ok
test ec::suite_b::ops::tests::p384_point_mul_test ... ok

test result: ok. 88 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 81.07s

     Running tests/aead_tests.rs (target/debug/deps/aead_tests-085d136fa7e3df31)

running 38 tests
test aead_test::AES_128_GCM::key_sizes ... ok
test aead_chacha20_poly1305_openssh ... ok
test aead_test::AES_128_GCM::less_safe_key_open_in_place ... ok
test aead_test::AES_128_GCM::less_safe_key_seal_in_place_append_tag ... ok
test aead_test::AES_128_GCM::less_safe_key_seal_in_place_separate_tag ... ok
test aead_test::AES_128_GCM::opening_key_open_in_place ... ok
test aead_test::AES_128_GCM::less_safe_key_open_within ... ok
test aead_test::AES_128_GCM::sealing_key_seal_in_place_append_tag ... ok
test aead_test::AES_128_GCM::sealing_key_seal_in_place_separate_tag ... ok
test aead_test::AES_128_GCM::test_open_in_place_seperate_tag ... ok
test aead_test::AES_256_GCM::key_sizes ... ok
test aead_test::AES_256_GCM::less_safe_key_open_in_place ... ok
test aead_test::AES_128_GCM::opening_key_open_within ... ok
test aead_test::AES_256_GCM::less_safe_key_seal_in_place_append_tag ... ok
test aead_test::AES_256_GCM::less_safe_key_seal_in_place_separate_tag ... ok
test aead_test::AES_256_GCM::opening_key_open_in_place ... ok
test aead_test::AES_256_GCM::less_safe_key_open_within ... ok
test aead_test::AES_256_GCM::sealing_key_seal_in_place_append_tag ... ok
test aead_test::AES_256_GCM::opening_key_open_within ... ok
test aead_test::AES_256_GCM::sealing_key_seal_in_place_separate_tag ... ok
test aead_test::CHACHA20_POLY1305::key_sizes ... ok
test aead_test::AES_256_GCM::test_open_in_place_seperate_tag ... ok
test aead_test::CHACHA20_POLY1305::less_safe_key_open_in_place ... ok
test aead_test::CHACHA20_POLY1305::less_safe_key_seal_in_place_append_tag ... ok
test aead_test::CHACHA20_POLY1305::less_safe_key_seal_in_place_separate_tag ... ok
test aead_test::CHACHA20_POLY1305::opening_key_open_in_place ... ok
test aead_test::CHACHA20_POLY1305::less_safe_key_open_within ... ok
test aead_test::CHACHA20_POLY1305::sealing_key_seal_in_place_append_tag ... ok
test aead_test::CHACHA20_POLY1305::sealing_key_seal_in_place_separate_tag ... ok
test aead_test::CHACHA20_POLY1305::test_open_in_place_seperate_tag ... ok
test aead_test_aad_traits ... ok
test test_aead_key_debug ... ok
test test_aead_lesssafekey_clone_aes_128_gcm ... ok
test test_aead_lesssafekey_clone_aes_256_gcm ... ok
test test_aead_lesssafekey_clone_chacha20_poly1305 ... ok
test test_aead_nonce_sizes ... ok
test test_tag_traits ... ok
test aead_test::CHACHA20_POLY1305::opening_key_open_within ... ok

test result: ok. 38 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 14.12s

     Running tests/agreement_tests.rs (target/debug/deps/agreement_tests-4aab5875e9f7e71e)

running 3 tests
test agreement_traits ... ok
test agreement_agree_ephemeral ... ok
test test_agreement_ecdh_x25519_rfc_iterated ... ok

test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 58.03s

     Running tests/constant_time_tests.rs (target/debug/deps/constant_time_tests-23d5b831c0a84aee)

running 1 test
test test_verify_slices_are_equal ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 5.07s

     Running tests/digest_tests.rs (target/debug/deps/digest_tests-1a6c3f3ed60a188b)

running 15 tests
test digest_shavs::SHA1_FOR_LEGACY_USE_ONLY::long_msg_known_answer_test ... ok
test digest_misc ... ok
test digest_shavs::SHA1_FOR_LEGACY_USE_ONLY::short_msg_known_answer_test ... ok
test digest_shavs::SHA256::long_msg_known_answer_test ... ok
test digest_shavs::SHA1_FOR_LEGACY_USE_ONLY::monte_carlo_test ... ok
test digest_shavs::SHA256::short_msg_known_answer_test ... ok
test digest_shavs::SHA384::long_msg_known_answer_test ... ok
test digest_shavs::SHA256::monte_carlo_test ... ok
test digest_shavs::SHA384::short_msg_known_answer_test ... ok
test digest_shavs::SHA512::long_msg_known_answer_test ... ok
test digest_shavs::SHA384::monte_carlo_test ... ok
test digest_shavs::SHA512::short_msg_known_answer_test ... ok
test digest_test_fmt ... ok
test test_fmt_algorithm ... ok
test digest_shavs::SHA512::monte_carlo_test ... ok

test result: ok. 15 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 71.02s

     Running tests/ecdsa_tests.rs (target/debug/deps/ecdsa_tests-2edcdf4ccc44407c)

running 7 tests
test ecdsa_generate_pkcs8_test ... ok
test ecdsa_test_public_key_coverage ... ok
test signature_ecdsa_sign_asn1_test ... ok
test ecdsa_from_pkcs8_test ... ok
test signature_ecdsa_sign_fixed_sign_and_verify_test ... ok
test signature_ecdsa_verify_fixed_test ... ok
test signature_ecdsa_verify_asn1_test ... ok

test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 14.14s

     Running tests/ed25519_tests.rs (target/debug/deps/ed25519_tests-b459ab5765fbf12d)

running 6 tests
test ed25519_test_public_key_coverage ... ok
test test_ed25519_from_pkcs8 ... ok
test test_ed25519_from_seed_and_public_key_misuse ... ok
test test_ed25519_from_pkcs8_unchecked ... ok
test test_signature_ed25519_verify ... ok
test test_signature_ed25519 ... ok

test result: ok. 6 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 13.44s

     Running tests/error_tests.rs (target/debug/deps/error_tests-aca5a980037aeffe)

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

     Running tests/hkdf_tests.rs (target/debug/deps/hkdf_tests-e8c9c1b3eafc78f8)

running 2 tests
test hkdf_tests ... ok
test hkdf_output_len_tests ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.23s

     Running tests/hmac_tests.rs (target/debug/deps/hmac_tests-7d489e0301b42fd3)

running 2 tests
test hmac_debug ... ok
test hmac_tests ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.08s

     Running tests/pbkdf2_tests.rs (target/debug/deps/pbkdf2_tests-755fd7e742e54d6e)

running 1 test
test pbkdf2_tests has been running for over 60 seconds
test pbkdf2_tests ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 88.54s

     Running tests/quic_tests.rs (target/debug/deps/quic_tests-6cac78a5b36e04c3)

running 3 tests
test quic_aes_128 ... ok
test quic_aes_256 ... ok
test quic_chacha20 ... ok

test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

     Running tests/rand_tests.rs (target/debug/deps/rand_tests-9bcad0892ddd12ae)

running 2 tests
test test_system_random_traits ... ok
test test_system_random_lengths ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.02s

     Running tests/rsa_tests.rs (target/debug/deps/rsa_tests-53a7f41730d8dab9)

running 8 tests
test rsa_test_keypair_coverage ... ok
test rsa_from_pkcs8_test ... ok
test test_signature_rsa_pkcs1_sign_output_buffer_len ... ok
test test_signature_rsa_pkcs1_verify ... ok
test test_signature_rsa_primitive_verification ... ok
test test_signature_rsa_pss_sign ... ok
test test_signature_rsa_pss_verify ... ok
test test_signature_rsa_pkcs1_sign has been running for over 60 seconds
test test_signature_rsa_pkcs1_sign ... ok

test result: ok. 8 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 81.73s

     Running tests/signature_tests.rs (target/debug/deps/signature_tests-f5f76a4d0ef81b4a)

running 1 test
test signature_impl_test ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

   Doc-tests ring

running 11 tests
test src/digest.rs - digest::Context (line 127) ... ok
test src/agreement.rs - agreement (line 23) ... ok
test src/digest.rs - digest::digest (line 215) ... ok
test src/error.rs - error::Unspecified (line 34) ... ok
test src/hmac.rs - hmac (line 31) ... ok
test src/hmac.rs - hmac (line 51) ... ok
test src/hmac.rs - hmac (line 75) ... ok
test src/signature.rs - signature (line 129) ... ok
test src/signature.rs - signature (line 193) ... ok
test src/test.rs - test (line 53) ... ignored
test src/pbkdf2.rs - pbkdf2 (line 32) has been running for over 60 seconds
test src/pbkdf2.rs - pbkdf2 (line 32) ... ok

test result: ok. 10 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 106.04s

[ellenhp]

Closing this for now. Feel free to salvage, rebase, etc, but I'm not going to put effort into getting this merged anymore because the maintainer clearly doesn't want it.

[MabezDev]

Thank you very much for the PR @ellenhp. It's a shame we didn't get a response here. For the time being, I've forked and applied your patch in this repo: https://github.com/esp-rs-compat/ring for all those who still need to use it.

Espressif will most likely try to get this patch upstreamed again in the near future.