# BIO_METHOD *   BIO_s_mem(void);

# BIO_set_mem_eof_return(BIO *b,int v)
# long BIO_get_mem_data(BIO *b, char **pp)
# BIO_set_mem_buf(BIO *b,BUF_MEM *bm,int c)
# BIO_get_mem_ptr(BIO *b,BUF_MEM **pp)

# BIO *  BIO_new(const BIO_METHOD *type);
# int    BIO_set(BIO *a, const BIO_METHOD *type);
# # int    BIO_up_ref(BIO *a); # Don't see a use case
# int    BIO_free(BIO *a);
# # void   BIO_vfree(BIO *a);  # Same as BIO_free
# void   BIO_free_all(BIO *a);

s_mem() = ccall((:BIO_s_mem, libssl), Ptr{BIO_Method}, ())

bio_new(mem::Ptr{BIO_Method}) =
    ccall((:BIO_new, libssl), Ptr{Cvoid}, (Ptr{BIO_Method},), mem)
bio_new() = bio_new(s_mem())

function set_bio!(client::SSLClient, rbio, wbio)
    client.rbio = rbio
    client.wbio = wbio
    ccall((:SSL_set_bio, libssl), Ptr{Cvoid}, (Ptr{Cvoid},Ptr{Cvoid},Ptr{Cvoid}),
          client.ssl, rbio, wbio)
end

function bio_write!(client::SSLClient, data)
    ccall((:BIO_write, libssl), Cint, (Ptr{Cvoid},Ptr{Cvoid},Cint),
          client.rbio, data, length(data))
end

function bio_read(client::SSLClient)
    buff_length = 64
    buff = Vector{UInt8}(undef, buff_length)
    n = ccall((:BIO_read, libssl), Cint, (Ptr{Cvoid},Ptr{Cvoid},Cint),
              client.wbio, buff, buff_length)
    n > 0 && splice!(buff, (n+1):buff_length)
    n, buff
end

bio_test_flags(bio, flags) =
    ccall((:BIO_test_flags, libssl), Cint, (Ptr{Cvoid},Cint), bio, flags) != 0
bio_should_retry(bio) = bio_test_flags(bio, BIO_FLAGS_SHOULD_RETRY)