OpenSSL::PKey::PKey subclass for EVP_PKEY_RSA_PSS

[Anstuhrm]

I had the same problem, see #562, to open a key and got the error OpenSSL::PKey::RSAError: incorrect pkey type: RSASSA-PSS.
So I used the mentioned method and called OpenSSL::PKey.read.
But now I have a problem to sign a JWT with the algorithm RSASSA-PSS:

JWT.encode({}, key, "ps256")
# This returns:
# NoMethodError: undefined method `sign_pss' for #<OpenSSL::PKey::PKey oid=RSASSA-PSS>

[rhenium]

You can currently use OpenSSL::PKey::PKey#sign to do RSA-PSS without needing the RSA#sign_pss. The test code may be useful for you today:

openssl/test/openssl/test_pkey_rsa.rb

Lines 96 to 116 in 9569999

	def test_sign_verify_options
	key = Fixtures.pkey("rsa1024")
	data = "Sign me!"
	pssopts = {
	"rsa_padding_mode" => "pss",
	"rsa_pss_saltlen" => 20,
	"rsa_mgf1_md" => "SHA1"
	}
	sig_pss = key.sign("SHA256", data, pssopts)
	assert_equal 128, sig_pss.bytesize
	assert_equal true, key.verify("SHA256", sig_pss, data, pssopts)
	assert_equal true, key.verify_pss("SHA256", sig_pss, data,
	salt_length: 20, mgf1_hash: "SHA1")
	# Defaults to PKCS #1 v1.5 padding => verification failure
	assert_equal false, key.verify("SHA256", sig_pss, data)
	# option type check
	assert_raise_with_message(TypeError, /expected Hash/) {
	key.sign("SHA256", data, ["x"])
	}
	end

[rhenium]

I wonder if we could add a PKey class for EVP_PKEY_RSA_PSS. I think #sign_pss and #verify_pss should just work on the pkey object decoded from PKCS#8.

EVP_PKEY_RSA_PSS seems to be just a variant of EVP_PKEY_RSA that contains default parameters for RSA-PSS and is locked to RSA-PSS operations.

[trkoch]

I'm having the same issue. I'm trying to sign a JWT with a RSASSA-PSS1 private key (created with openssl req -newkey rsa-pss).

Not sure I follow the suggestion. Using #sign instead of #sign_pss does not work.

# jwt-2.7.1/lib/jwt/algos/ps.rb:19
key.sign(translated_algorithm, msg, salt_length: :digest, mgf1_hash: translated_algorithm)

Throws:

OpenSSL::PKey::PKeyError: EVP_PKEY_CTX_ctrl_str(ctx, "salt_length", "digest"): command not supported ([action:2, state:4] name=salt_length, value=digest)

@Anstuhrm Did you mange to work around this?

[trkoch]

It does seem to work with:

key.sign(translated_algorithm, msg)

I have no idea what I'm doing here, frankly. Can someone elaborate?