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Hi,
I am using Keil v5 (RTX5) with the EVBK-IMXRT1050 board.
I have successfully sent an email using the example code given through the pack installer, SMTP_client. Now I want to send a secure email, SMTPS, using the same example but adding mbedTLS. I followed the instructions given from Keil, but have not been able to get a secure email to send. www.keil.com/.../use_secure_components.html
Below is my event recorder when trying to send out a SMTPS using mbedTLS, everything works fine until I reach line 41 where TLS should begin. The socket is closed right when TLS should begin and I am not sure why. Wireshark matched the event recorder.
If anyone has had this issue or have any tips on getting around this error, please reply. Thanks.
Event recorder: Event, Time (sec), Component, Event Property, Value 0, 5.45808617, EvCtrl, EventRecorderInitialize, Restart Count = 3 1, 5.45812999, EvCtrl, EventRecorderStart, 2, 5.45863391, Net_SYS, InitSystem, ver=7.10.0 3, 5.45974125, Net_DHCP, InitClient, vcid=0 opt=0 4, 5.45976630, Net_DHCP, StartClient, 5, 5.45981325, Net_SMTP, InitClient, smtp 6, 5.45986813, Net_SYS, InitComplete, success 7, 5.46012398, Net_SMTP, SendMail, recipients=1 8, 5.46044442, Net_ETH, LinkDownError, no-link 9, 5.66058112, Net_ETH, LinkDownError, no-link 10, 7.66053657, Net_ETH, LinkDownError, no-link 11, 8.36051481, Net_DHCP, ClientState, state=INIT 12, 8.36055019, Net_DHCP, SendDhcpMessage, type=DHCP_DISCOVER bcast=1 13, 8.36076685, Net_DHCP, NextState, state=SELECTING 14, 8.36318817, Net_DHCP, ReceiveFrame, server=10.0.2.17 len=300 15, 8.36321537, Net_DHCP, ClientState, state=SELECTING 16, 8.36322062, Net_DHCP, DhcpOfferReceived, 17, 8.36322724, Net_DHCP, ShowServerId, server_id=10.0.2.17 18, 8.36323507, Net_DHCP, ShowOfferedIpAddress, ip=10.0.2.157 19, 8.36323565, Net_DHCP, SendDhcpMessage, type=DHCP_REQUEST bcast=1 20, 8.36334852, Net_DHCP, NextState, state=REQUESTING 21, 8.36697469, Net_DHCP, ReceiveFrame, server=10.0.2.17 len=300 22, 8.36698434, Net_DHCP, ClientState, state=REQUESTING 23, 8.36699382, Net_DHCP, DhcpAckReceived, 24, 8.36699851, Net_DHCP, ShowAssignedAddress, ip=10.0.2.157 25, 8.36705461, Net_DHCP, ShowLeaseTime, time=171072 26, 8.36705907, Net_DHCP, ShowNetMask, mask=255.255.0.0 27, 8.36706187, Net_DHCP, ShowGatewayAddress, gateway=10.0.2.2 28, 8.36707048, Net_DHCP, ShowDnsServers, pri=8.8.8.8 sec=8.8.4.4 29, 8.36707621, Net_DHCP, NextState, state=BOUND 30, 9.66583049, Net_SMTP, ConnectIp4, ip=10.0.1.2 port=587 31, 9.66751124, Net_SMTP, SocketConnected, sock=1 32, 9.66857944, Net_SMTP, ReceiveFrame, sock=1 len=58 33, 9.66860121, Net_SMTP, ServerReady, 34, 9.66878471, Net_SMTP, SendCommand, command=EHLO evkb-imxrt1050 35, 9.66962207, Net_SMTP, ReceiveFrame, sock=1 len=146 36, 9.66966114, Net_SMTP, EsmtpModeActive, 37, 9.66966166, Net_SMTP, TlsSupportIndicated, 38, 9.66977401, Net_SMTP, SendCommand, command=STARTTLS 39, 9.76064354, Net_SMTP, ReceiveFrame, sock=1 len=30 40, 9.76066607, Net_SMTP, StartTlsAccepted, 41, 9.76085824, Net_SMTP, TlsModeStarted, 42, 9.76109192, Net_SMTP, SocketClosed, sock=1 43, 9.76116411, Net_SMTP, ClientCloseSocket, sock=1 44, 9.86054282, Net_SMTP, ClientDone, cb_event=Error
Also,
I can send the mbed SMTPS TLS1.2 using ports 587 and 25 successfully, is that how it is supposed to work?
My mbedTLS SMTPS program does not work every single run. Sometimes the program will hang or fail. Why is the program not running the same every time? Most of the time when it does hang, it will hang right after:
39, 4.21519186, Net_SMTP, ConnectIp4, ip=10.0.1.2 port=587
Even in the successful email cases, I sometimes receive events like:
19, 2.21033839, Net_ETH, LinkDownError, no-link
39, 4.21497440, Net_DNS, RecordTypeNotSupported, rr_type=TYPE_CNAME
41, 4.21587020, Net_TCP, FrameUnrecognised, sock=1
42, 4.89372711, Net_TCP, NoRetriesLeft, sock=1
43, 4.89384738, Net_SMTP, SocketAborted, sock=1
One example of a failed SMTPS email Keil event recorder:
Event, Time (sec), Component, Event Property, Value 0, 0.00391493, EvCtrl, EventRecorderInitialize, Restart Count = 2 1, 0.00393650, EvCtrl, EventRecorderStart, 2, 0.00445639, Net_SYS, InitSystem, ver=7.10.0 3, 0.00548874, Net_DHCP, InitClient, vcid=0 opt=0 4, 0.00549881, Net_DHCP, StartClient, 5, 0.00554865, Net_SMTP, InitClient, smtp 6, 0.00562303, Net_SYS, InitComplete, success 7, 0.00579318, STDIO, stdout, 0x4D 0x57 0x20 0x4E 0x65 0x74 0x77 0x6F 8, 0.00582144, STDIO, stdout, 0x72 0x6B 0x20 0x20 0x20 0x20 0x20 0x20 9, 0.00582199, STDIO, stdout, 0x0A 0x00 0x00 0x00 0x00 0x00 0x00 0x00 10, 0.00587034, STDIO, stdout, 0x0D 0x53 0x4D 0x54 0x50 0x20 0x43 0x6C 11, 0.00587143, STDIO, stdout, 0x69 0x65 0x6E 0x74 0x20 0x20 0x20 0x20 12, 0.00587204, STDIO, stdout, 0x20 0x0A 0x00 0x00 0x00 0x00 0x00 0x00 13, 0.00588006, STDIO, stdout, 0x0D 0x53 0x65 0x6E 0x64 0x69 0x6E 0x67 14, 0.00588113, STDIO, stdout, 0x20 0x65 0x6D 0x61 0x69 0x6C 0x2E 0x2E 15, 0.00588173, STDIO, stdout, 0x2E 0x0A 0x00 0x00 0x00 0x00 0x00 0x00 16, 0.00593655, Net_SMTP, SendMail, recipients=1 17, 0.00626456, Net_ETH, LinkDownError, no-link 18, 0.21044865, Net_ETH, LinkDownError, no-link 19, 2.21036563, Net_ETH, LinkDownError, no-link 20, 2.91042894, Net_DHCP, ClientState, state=INIT 21, 2.91045321, Net_DHCP, SendDhcpMessage, type=DHCP_DISCOVER bcast=1 22, 2.91066462, Net_DHCP, NextState, state=SELECTING 23, 2.91300110, Net_DHCP, ReceiveFrame, server=10.0.2.17 len=300 24, 2.91304104, Net_DHCP, ClientState, state=SELECTING 25, 2.91308409, Net_DHCP, DhcpOfferReceived, 26, 2.91309079, Net_DHCP, ShowServerId, server_id=10.0.2.17 27, 2.91311357, Net_DHCP, ShowOfferedIpAddress, ip=10.0.2.157 28, 2.91311873, Net_DHCP, SendDhcpMessage, type=DHCP_REQUEST bcast=1 29, 2.91328019, Net_DHCP, NextState, state=REQUESTING 30, 2.91706581, Net_DHCP, ReceiveFrame, server=10.0.2.17 len=300 31, 2.91708329, Net_DHCP, ClientState, state=REQUESTING 32, 2.91709156, Net_DHCP, DhcpAckReceived, 33, 2.91709607, Net_DHCP, ShowAssignedAddress, ip=10.0.2.157 34, 2.91711923, Net_DHCP, ShowLeaseTime, time=171072 35, 2.91715024, Net_DHCP, ShowNetMask, mask=255.255.0.0 36, 2.91716467, Net_DHCP, ShowGatewayAddress, gateway=10.0.2.2 37, 2.91716525, Net_DHCP, ShowDnsServers, pri=8.8.8.8 sec=8.8.4.4 38, 2.91718709, Net_DHCP, NextState, state=BOUND 39, 4.21523585, Net_DNS, RecordTypeNotSupported, rr_type=TYPE_CNAME 40, 4.21535812, Net_SMTP, ConnectIp4, ip=74.125.141.108 port=587 41, 4.89372711, Net_TCP, NoRetriesLeft, sock=1 42, 4.89384738, Net_SMTP, SocketAborted, sock=1 43, 4.89390436, Net_SMTP, ClientCloseSocket, sock=1 44, 4.99372952, Net_SMTP, ClientDone, cb_event=Error 45, 4.99384296, STDIO, stdout, 0x0D 0x53 0x65 0x6E 0x64 0x20 0x65 0x6D 46, 4.99384931, STDIO, stdout, 0x61 0x69 0x6C 0x20 0x66 0x61 0x69 0x6C 47, 4.99385004, STDIO, stdout, 0x65 0x64 0x2E 0x0A 0x00 0x00 0x00 0x00
It looks like you have an invalid system clock configuration. Message 40 starts the TCP connection. If the remote host does not respond, TCP resends the SYN packet. It takes 15 seconds before the message 41 is recorded.
If I calculate the delay, the kernel clock is 25 Mhz, but it is likely to be set at 600 MHz. The errors you mention are the result of invalid clock settings.
Thanks for letting me know about the clock settings. Do you have any advise on my earlier message about the bare metal environment?
My questions are: 1. Will this mbedTLS SMTPS application work on a bare metal environment without a RTOS? 2. Does mbedTLS require an outside API, such as Windows API, to run TLS? 3. Is it possible to move over all the source code to the Arm9 Keilv4 project and get it to work with mbedTLS SMTPS? 4. I read that some TLS certificates require a date verification and my Arm9 embedded system does not keep track of the current date and time, is this involved in SMTPS? 5. Can I just copy over all the source and header files from my working SMTPS Arm Cortex 7 project to my bare metal Arm9 project, including all the RTOS and mbedTLS files?
For a bare metal implementation, mbedTLS requires a socket API. It does not matter on which platform. The network socket interface is in the "net_socket.c".
For MDK middleware, the interface is in:
C:\Keil\ARM\PACK\ARM\mbedTLS\1.6.0\MDK\library\mw_network\net_sockets.c
The SMTPS client demo example is in:
C:\Keil\ARM\PACK\ARM\mbedTLS\1.6.0\programs\ssl\ssl_mail_client.c
You can use those as a reference. However the SMTPS client demo example from mbedTLS pack is only a basic implementation and does not support attachments, multiple recipients, address friendly names and different character encodings.
Note that MDK Middleware version 7 uses a different mbedTLS interface, which allows integration into the MDK MW as an external component.
The latest version of the MDK MW that supports ARM9 devices is Version 4. Subsequent versions only support Cortex-M devices.
And NO, you can not simply move the code to ARM9 device and expect it to work. The SMTP client in MDK MW version 4 is very limited, has a different API, and does not support SMTPS.