A feature to check enabled/disabled PQC signature algorithms, key exchange groups considering OpenSSL config #1075

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1. junaruga

   changed the title [-]A feature to check enabled/disabled PQC signature algorithms, key exchange groups consideirng OpenSSL config[/-] [+]A feature to check enabled/disabled PQC signature algorithms, key exchange groups considering OpenSSL config[/+] on Jun 26, 2026
2. rhenium commented on Jun 27, 2026

   

   rhenium

   on Jun 27, 2026

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   The current OpenSSL C API doesn't appear to expose the corresponding getters for SSL_CTX_set1_sigalgs() and SSL_CTX_set1_groups(). If they were available, I think we could expose them, similar to how we do for SSL options and TLS 1.2 cipher suites.

   If the intent of the test is to "test PQC algorithms whenever the system supports them", then I think ruby/rubygems#9643 would be the most straightforward option at the moment. Alternatively, I think it could just special-case RHEL >= 9.7, < 10.1(?) since other distros are unlikely to do the same.
3. junaruga commented on Jun 29, 2026

   

   junaruga

   on Jun 29, 2026

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   Alternatively, I think it could just special-case RHEL >= 9.7, < 10.1(?) since other distros are unlikely to do the same.

   I investigated the case of RHEL 10.0. RHEL 10.0 is a unique feature for PQC[1] before RHEL 10.1 supports PQC by DEFAULT security policy[2].

   You are right. In RHEL 10.0, PQC is also disabled by default.

   Below is my command log in RHEL 10.0. OpenSSL version is 3.2.2.

   # cat /etc/redhat-release
   Red Hat Enterprise Linux release 10.0 (Coughlan)
   
   # rpm -q openssl
   openssl-3.2.2-16.el10.x86_64
   
   # openssl list -providers
   Providers:
     default
       name: OpenSSL Default Provider
       version: 3.2.2
       status: active
   

   However, when installing the following RPM packages, oqsprovider (PQC provider)[3] RPM is installed as a dependency of crypto-policies-pq-preview RPM package.

   # dnf install crypto-policies-pq-preview crypto-policies-scripts
   

   # rpm -q oqsprovider
   oqsprovider-0.8.0-5.el10.x86_64
   

   Then oqsprovider provider appeared. OpenSSL doesn't enable PQC yet at this moment.

   # openssl list -providers
   Providers:
     default
       name: OpenSSL Default Provider
       version: 3.2.2
       status: active
     oqsprovider
       name: OpenSSL OQS Provider
       version: 0.8.0
       status: active
   

   But after running the following command, PQC is enabled in /etc/crypto-policies/back-ends/opensslcnf.config.

   # update-crypto-policies --set DEFAULT:TEST-PQ
   

   # cat /etc/crypto-policies/back-ends/opensslcnf.config
   CipherString = @SECLEVEL=2:kEECDH:kEDH:kPSK:kDHEPSK:kECDHEPSK:kRSAPSK:-kRSA:-aDSS:-3DES:!DES:!RC4:!RC2:!IDEA:-SEED:!eNULL:!aNULL:!MD5:-SHA384:-CAMELLIA:-ARIA:-AESCCM8
   Ciphersuites = TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256:TLS_AES_128_CCM_SHA256
   TLS.MinProtocol = TLSv1.2
   TLS.MaxProtocol = TLSv1.3
   DTLS.MinProtocol = DTLSv1.2
   DTLS.MaxProtocol = DTLSv1.2
   SignatureAlgorithms = ?mldsa44:?p256_mldsa44:?rsa3072_mldsa44:?mldsa44_pss2048:?mldsa44_rsa2048:?mldsa44_ed25519:?mldsa44_p256:?mldsa65:?p384_mldsa65:?mldsa65_pss3072:?mldsa65_rsa3072:?mldsa65_p256:?mldsa65_ed25519:?mldsa87:?p521_mldsa87:?mldsa87_p384:?mldsa87_ed448:ECDSA+SHA256:ECDSA+SHA384:ECDSA+SHA512:ed25519:ed448:rsa_pss_pss_sha256:rsa_pss_pss_sha384:rsa_pss_pss_sha512:rsa_pss_rsae_sha256:rsa_pss_rsae_sha384:rsa_pss_rsae_sha512:RSA+SHA256:RSA+SHA384:RSA+SHA512:ECDSA+SHA224:RSA+SHA224
   Groups = ?mlkem512:?p256_mlkem512:?x25519_mlkem512:?mlkem768:?p384_mlkem768:?x448_mlkem768:?X25519MLKEM768:?x25519_mlkem768:?SecP256r1MLKEM768:?p256_mlkem768:?mlkem1024:?p521_mlkem1024:?SecP384r1MLKEM1024:?p384_mlkem1024:X25519:secp256r1:X448:secp521r1:secp384r1:ffdhe2048:ffdhe3072:ffdhe4096:ffdhe6144:ffdhe8192
   

   References

   • [1] PQC in RHEL 10.0 - https://www.redhat.com/en/blog/post-quantum-cryptography-red-hat-enterprise-linux-10
   • [2] PQC in RHEL 10.1 - https://www.redhat.com/en/blog/whats-new-post-quantum-cryptography-rhel-101
   • [3] oqsprovider - https://github.com/open-quantum-safe/oqs-provider
4. junaruga commented on Jun 30, 2026

   

   junaruga

   on Jun 30, 2026

   Last edited by junaruga

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   The current OpenSSL C API doesn't appear to expose the corresponding getters for SSL_CTX_set1_sigalgs() and SSL_CTX_set1_groups(). If they were available, I think we could expose them, similar to how we do for SSL options and TLS 1.2 cipher suites.

   Right. This sounds good idea to me. If we have such getters, we can implement the logic to check if used PQC signature algorithms and key exchange groups are available in OpenSSL. The example is below.

   def pqc_available?
     ctx = OpenSSL::SSL::SSLContext.new
     # ctx.sigalgs # => ["mldsa44", "mldsa65", ..]
     # ctx.groups # => ["X25519MLKEM768", "x25519_mlkem768", ..]
     return ctx.sigalgs.include?("mldsa65") && ctx.groups.include?("X25519MLKEM768")
   end
   

   And I confirmed such pattern was already used for OpenSSL::SSL::SSLContext#options (SSL_CTX_get_options) and OpenSSL::SSL::SSLContext#ciphers (SSL_CTX_get_ciphers).

   If the intent of the test is to "test PQC algorithms whenever the system supports them", then I think ruby/rubygems#9643 would be the most straightforward option at the moment. Alternatively, I think it could just special-case RHEL >= 9.7, < 10.1(?) since other distros are unlikely to do the same.

   Yes, my motivation of this feature is to "test PQC algorithms whenever the system supports them". The current implementation TestGemRemoteFetcherLocalSSLServer.support_pqc_handshake? is okay when it is used in ruby/rubygems repository. But it is not convenient if the method is used in all the ruby/* repositories or generally in user's Ruby program. I am thinking that moving such logic to test-unit-ruby-core gem to be used from ruby/* repositories. But TestGemRemoteFetcherLocalSSLServer.support_pqc_handshake? needs mldsa65_ssl_cert.pem and mldsa65_ssl_key.pem files.
5. junaruga commented on Jun 30, 2026

   

   junaruga

   on Jun 30, 2026

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   I opened feature request issue ticket openssl/openssl#31804 for openssl/openssl.