keytool.exe -list -rfc -keystore keystore.jks | openssl x509 -text

Output:

  Enter keystore password:  test*
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 20 (0x14)
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C = FR, O = Test, CN = Test CA
        Validity
            Not Before: Oct 22 14:36:00 2017 GMT
            Not After : Aug  9 13:17:00 2019 GMT
        Subject: C = FR, O = Test, CN = Test
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:b6:18:c9:2a:f8:01:a3:86:e6:32:63
        ...............