tpdu: error decoding SmsDeliver.ud.sm at octet XX: overlength about sms HOT 3 CLOSED

How do you perform the decode? Using smsdecode? That strictly decodes SMSs, not USSD.

The check that is tripping is sm[sml] != 0, which checks that any pad character at the end of user data is 0, which is correct for SMS encoding, but is incorrect for USSD where the trailing pad character is a CR.
But even a strict USSD decoder would fail this message as it pads the user data with a space (0x20), not a CR (0x0d).

Making the decoder less strict by removing that check gives:

$ ./smsdecode -p 07912180958739F144038102F100001211304113338A2F0608041E9602026177F85C06E5DF7539283C1EBFEB6E3A284C0785E974D7F8DD7EB5F37079191E4E9341
SMSC: +12085978931
TPDU: SMS-DELIVER
TP-MTI: 0x00 Deliver
TP-MMS: true
TP-LP: false
TP-RP: false
TP-UDHI: true
TP-SRI: false
TP-OA: 201
TP-PID: 0x00
TP-DCS: 0x00 7bit
TP-SCTS: 2021-11-03 14:31:33 -0700
TP-UDH: ID: 8  Data: [30 150 2 2]
TP-UD: 00000000  61 6e 61 67 65 20 79 6f  75 72 20 61 63 63 6f 75  |anage your accou|
       00000010  6e 74 20 61 74 20 61 74  74 2e 63 6f 6d 2f 6d 79  |nt at att.com/my|
       00000020  70 72 65 70 61 69 64                              |prepaid|

so that might be a simple option for you.

from sms.

My decode is process more or less same as smsdecode. I did make a fork of this repo and ignored the check. So far it has worked well for me.

Another example is TikTok's verification sms:

PDU:
07912160130380F0040B916113888998F800001201825172218A771B1E35BDA6BED7A02079BEF18170315C0D949E83F2EFBA1C642FCBD3E6F4384C4FBFDDA0F19B5C6681EC61769A0C32BFE5A01AA89D76D7E9E5B90B447D83D6E5321C947FD7E5A0F078FCAEBBE9A079D85C6681DC657B590E32BFE5F7B09C0CA2A3D373D0F84D2EBB1A

Decoded with the check ignored:

"[TikTok Ads] 8185 is your verification code, valid for 5 minutes. To keep your account safe, never forward this code.\r",

Should something be added to support less strict decoding, such as UnmarshalOption? That would be nice :) But for now, for people running into this problem, adding this to go.mod file will work:

replace github.com/warthog618/sms => github.com/frifox/sms master

from sms.

Yeah, it might be nice to allow the decoder to be less strict, and for it to support USSD for that matter, but so far no one has asked or offered a pull request, and my interest was primarily SMS so I haven't bothered.
If you already have your own fork and are happy with that then why are you bothering me?

from sms.