Hello Keishi Just curious - Are even the length fields coded in ASCII ?
So a length of eg. decimal 27 is coded as hex 32 37 ? If the fields TLV (Type specifier, length field and value field) are all coded in ASCII it would be possible to convert to hex and then choose an appropriate standard tool. Could you mail possible a few lines of the contents so we could see what you have come across ? After the conversion to hex I would assume that data are BER coded - Packed encoding just does not sound right in this case... Regards Steen Oluf Karlsen Soholtvej 6 Vester Vandet DK-7700 Thisted Danmark Tel +45 97 97 72 72 email [EMAIL PROTECTED] -----Oprindelig meddelelse----- Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]Pa vegne af SADANAMI Keishi Sendt: 21. december 2001 20:09 Til: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Emne: [ASN.1] Reverse Engineering Hello all, I'm a bioinformatics student currently creating small in-house protein-ligand database. I'm very new to ASN, (started a few days ago) and facing practical problems with it right now. I have to extract information from ASCII-encoded ASN.1 datafile which I have received from a certain obsolete biological database. Unfortunately, I couldn't get any ASN.1 specification of this database, though I had tried every possible means. So I'm considering reverse-engineer ASN.1 definition from the ASCII-decoded ASN.1 data. 1) I assume I can accomplish this by trial and error: First presume certain ASN.1 definition, judging from instances of the database, then make a parser. If the parsing fails, modify previous definition, create a new parser, and so on. Are there better ways to automate these tasks? The number of instances in this database is about 50,000. 2) There seems to be many ASN.1 compilers which can encode/decode data as a binary stream like BER, but I couldn't find ASCII decoder(parser). Is it just a matter of using tools like yacc when it comes to decoding *ASCII* data of ASN.1, or are there any such tools publicly available on the web? (so that I would rather not re-invent the wheel.) Sorry if these questions aren't appropriate for this list. Regards, Keishi
