Quick hacks to get it working

src/crypto/axtls/rsa.c

     else /* randomize the encryption padding with non-zero bytes */   
     {
         out_data[1] = 2;
+        memset(&out_data[2], 0x01, num_pads_needed);
+#if 0
         get_random_NZ(num_pads_needed, &out_data[2]);
+#endif
     }
 
     out_data[2+num_pads_needed] = 0;
     return byte_size;
 }
 
+#if 0
+
 /**
  * Take a signature and decrypt it.
  */
     return bir;
 }
 
+#endif
+
 #endif  /* CONFIG_SSL_CERT_VERIFICATION */