public static String toRsaSsaPkcs1Algo(HashType hash) throws GeneralSecurityException {
    Validators.validateSignatureHash(hash);
    return hash + "withRSA";
  }
Returns the RSA SSA (Signature with Appendix) PKCS1 algorithm name corresponding to a hash
type.

@param hash the hash type.
@return the JCE's RSA SSA PKCS1 algorithm name for the hash.
@throws GeneralSecurityException if {@code hash} is not supported or is not safe for digital
    signature.
java_src/src/main/java/com/google/crypto/tink/subtle/SubtleUtil.java