A 16-byte SALT with a leading zero would be sent as only a 15-byte number. The chance of this occuring is 1 in 256, which is small but still significant. Solution is to specify required size of MPI output in loadTLV. This forces mbedtls_mpi_write_binary() to pad with leading zeros.
Also eliminated unused code (TLV pack_old).
HomeSpan now broadcasts a Hashed Setup ID as MDNS "sh", which is used when pairing with a QR Code instead of a Setup Code. A text version of the resulting QR code is output to the Serial Monitor whenever the 9-digit Setup Code is generated or changed. The text version of the QR code can then be input into any QR Code Generator to create a pairable QR Code.
The default Setup ID used to create the Hashed Setup ID is "HSPN". This can be changed with homeSpan.setQRCode(const char *id), where id is exactly 4 alphanumeric characters. If not, the request to change the Setup ID is silently ignored and remains "HSPN."
Convention is that every *.cpp references, in this order:
1) Any required core librries
2) Its own *.h (i.e. Foo.cpp -> Foo.h)
3) All other *.h files needed by the cpp, UNLESS those *.h files are already in its own *.h file. Must include all *.h files that are not in its own *.h file even if it is others that are referenced.
This change allows the user to set the log-level with homeSpan.setLogLevel() instead of needing to change in Settings.h. Next up: Update Example that introduces VERBOSE to instead use setLogLevel(). Consider adding an interactive 'L' command to change this during run-time.
Also, added "#pragma once" to every *.h file to prevent duplication of definitions. TO DO: Review all #include to ensure sanity across all files.
And updated other SRP routines to complete implementation of use of stored verification code instead of live setup code.
Next up: Add method to change setup code in serial interface and implement similar code after network configuration routines.
This generates an SRP verification code from a setupCode and randomly-generated salt. Function creates the salt internally and returns both the resulting verification code and salt that was used. These are stored in NVS permanently.
Next Step: create SRP6A:loadVerifycode()
Gregg