I want to build OpenSSL 1.0.2 for optee_os. But OpenSSL is very large and has a lot of dependencies(c library f.e.). OP-TEE has no c-library (and others).
Can I build OpenSSL with only crypto algorithms? (without files, z-lib and so on).
OpenSSL has a large number of compile time options which enable you to switch off various features. However there is no way to remove the need for an underlying C library, e.g. it sill needs basics like malloc/free/memcpy/strcpy etc.
z-lib support is not built by default anyway. You can switch off various i/o capabilities with the "no-stdio", "no-posix-io", "no-sock" and "no-dgram" compile time options. You might also want to consider the "no-async" and "no-dso" options.
Full details of the compile time options are available here: https://github.com/openssl/openssl/blob/OpenSSL_1_1_1-stable/INSTALL