- if (ret < CHALLENGE_SIZE + 2 * CHALLENGE_SIZE + 41) {
- PARA_WARNING_LOG("rsa key for %s too small\n", n);
+ /*
+ * In order to encrypt len := CHALLENGE_SIZE + 2 * RC4_KEY_LEN
+ * bytes using RSA_public_encrypt() with EME-OAEP padding mode,
+ * RSA_size(rsa) must be greater than len + 41. So ignore keys
+ * which are too short. For details see RSA_public_encrypt(3).
+ */
+ if (ret <= CHALLENGE_SIZE + 2 * RC4_KEY_LEN + 41) {
+ PARA_WARNING_LOG("rsa key %s too short (%d)\n",
+ k, ret);