`OpenSSL::PKey::EC#to_pem` or `.new` appears to change EC keys created by CRuby's openssl

[postmodern]

Steps To Reproduce

CRuby

require 'openssl'
ec = OpenSSL::PKey::EC.generate('prime256v1')
ec.generate_key
pem = ec.to_pem
# => "-----BEGIN EC PRIVATE KEY-----\nMHcCAQEEIFGFA23QpFp3ZgFniwlICLAjIc3Zxrt6Dw5ElfETPkoxoAoGCCqGSM49\nAwEHoUQDQgAEfAWhRpiAKNuIlXG54M/vSWN1kam9/1SKp8yeoHBN0YhpGDrh+JC0\ngwPqy/cOYhzzKUleb4+bjvImBkTB/1jvlQ==\n-----END EC PRIVATE KEY-----\n"

JRuby

require 'openssl'
pem = "-----BEGIN EC PRIVATE KEY-----\nMHcCAQEEIFGFA23QpFp3ZgFniwlICLAjIc3Zxrt6Dw5ElfETPkoxoAoGCCqGSM49\nAwEHoUQDQgAEfAWhRpiAKNuIlXG54M/vSWN1kam9/1SKp8yeoHBN0YhpGDrh+JC0\ngwPqy/cOYhzzKUleb4+bjvImBkTB/1jvlQ==\n-----END EC PRIVATE KEY-----\n"
ec = OpenSSL::PKey::EC.new(pem)
pem2 = ec.to_pem

Expected Result

# => "-----BEGIN EC PRIVATE KEY-----\nMHcCAQEEIFGFA23QpFp3ZgFniwlICLAjIc3Zxrt6Dw5ElfETPkoxoAoGCCqGSM49\nAwEHoUQDQgAEfAWhRpiAKNuIlXG54M/vSWN1kam9/1SKp8yeoHBN0YhpGDrh+JC0\ngwPqy/cOYhzzKUleb4+bjvImBkTB/1jvlQ==\n-----END EC PRIVATE KEY-----\n"

Actual Result

# => "-----BEGIN EC PRIVATE KEY-----\nMCUCAQEEIFGFA23QpFp3ZgFniwlICLAjIc3Zxrt6Dw5ElfETPkox\n-----END EC PRIVATE KEY-----\n"

The PEM exported by jruby-openssl appears to be much shorter than the PEM exported by CRuby's openssl.

Versions

• jruby 9.3.2.0 (2.6.8) 2021-12-01 0b8223f905 OpenJDK 64-Bit Server VM 11.0.15+10 on 11.0.15+10 +jit [linux-x86_64]
• jruby-openssl (0.12.2 java, default: 0.11.0 java)

[kares]

not sure about whether the format is expected to be "byte level" same between C-OpenSSL and Java's Bouncy-Castle...
as long as one is able to parse other's PEM encoded format and end up with the same object.

The PEM exported by jruby-openssl appears to be much shorter than the PEM exported by CRuby's openssl.

was due 401749e which explicitly skipped the public part when encoding the private key