Function mbedtls_x509_csr_info 

pub unsafe extern "C" fn mbedtls_x509_csr_info(
    buf: *mut c_char,
    size: usize,
    prefix: *const c_char,
    csr: *const mbedtls_x509_csr,
) -> c_int

\brief Returns an informational string about the CSR.

\param buf Buffer to write to \param size Maximum size of buffer \param prefix A line prefix \param csr The X509 CSR to represent

\return The length of the string written (not including the terminated nul byte), or a negative error code.