Accessing scalars from Python code

[devos50]

I'm currently trying to write a few Python bindings around the FROST algorithm. To get this up and running, I need to call the secp256k1_scalar_chacha20 function, which signature seems to be defined here. The problem, however, is that I'm not entirely sure how to write the appropriate CFFI bindings to this function, given that the scalar.h file is in the src directory. The existing CFFI bindings are all related to header files in the include directory.

I tried to add the following line to the _cffi_build/build.py file:

Source('scalar.h', '#include <scalar.h>'),

I also created a scalar.h file in the _cffi_build directory with the following contents:

typedef struct {
    uint64_t d[4];
} secp256k1_scalar;

static void secp256k1_scalar_chacha20(
    secp256k1_scalar *r1,
    secp256k1_scalar *r2,
    const unsigned char *seed,
    uint64_t idx
);

When running python3 setup.py build, I'm getting the following error:

build/temp.macosx-11-x86_64-3.9/_libsecp256k1.c:570:10: fatal error: 'scalar.h' file not found

Anyone knows what I'm doing wrong here? Any help would be highly appreciated!

[MementoRC]

coincurve provides bindings for libsecp256k1, not libsecp256k1-zkp. The feature you are trying to access are not implemented in libsecp256k1.
@ofek given how old this is, I surmise the issue can be closed

[ofek]

Feel free to close this yourself at your leisure!

[MementoRC]

@devos50 Please re-open if you feel my assessment was incorrect or this was closed inappropriately. Thank you