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module SSHData
module PublicKey
class SKECDSA < ECDSA
include SecurityKey
attr_reader :application
OPENSSL_CURVE_NAME_FOR_CURVE = {
NISTP256 => "prime256v1",
}
def self.check_algorithm!(algo, curve)
unless algo == ALGO_SKECDSA256
raise DecodeError, "bad algorithm: #{algo.inspect}"
end
unless algo == "sk-ecdsa-sha2-#{curve}@openssh.com"
raise DecodeError, "bad curve: #{curve.inspect}"
end
end
def initialize(algo:, curve:, public_key:, application:)
@application = application
super(algo: algo, curve: curve, public_key: public_key)
end
# RFC4253 binary encoding of the public key.
#
# Returns a binary String.
def rfc4253
Encoding.encode_fields(
[:string, algo],
[:string, curve],
[:string, public_key_bytes],
[:string, application],
)
end
def verify(signed_data, signature, **opts)
opts = DEFAULT_SK_VERIFY_OPTS.merge(opts)
unknown_opts = opts.keys - DEFAULT_SK_VERIFY_OPTS.keys
raise UnsupportedError, "Verification options #{unknown_opts.inspect} are not supported." unless unknown_opts.empty?
sig_algo, raw_sig, sk_flags, blob = build_signing_blob(application, signed_data, signature)
self.class.check_algorithm!(sig_algo, curve)
openssl_sig = self.class.openssl_signature(raw_sig)
digest = DIGEST_FOR_CURVE[curve]
result = openssl.verify(digest.new, openssl_sig, blob)
# We don't know that the flags are correct until after we've validated the signature
# which embeds the flags, so always verify the signature first.
return false if opts[:user_presence_required] && (sk_flags & SK_FLAG_USER_PRESENCE != SK_FLAG_USER_PRESENCE)
return false if opts[:user_verification_required] && (sk_flags & SK_FLAG_USER_VERIFICATION != SK_FLAG_USER_VERIFICATION)
result
end
def ==(other)
super && other.application == application
end
end
end
end
|
