openssl/doc/life-cycles/kdf.dot

strict digraph kdf {
    bgcolor="transparent";

    begin [label=start, color="#deeaee", style="filled"];
    newed [label="newed", fontcolor="#c94c4c", style="solid"];
    deriving [label="deriving", fontcolor="#c94c4c"];
    end [label="freed", color="#deeaee", style="filled"];

    begin -> newed [label="EVP_KDF_CTX_new"];
    newed -> deriving [label="EVP_KDF_derive"];
    deriving -> deriving [label="EVP_KDF_derive", style=dashed];
    deriving -> end [label="EVP_KDF_CTX_free"];
    deriving -> newed [label="EVP_KDF_CTX_reset", style=dashed,
                      color="#034f84", fontcolor="#034f84"];
}