Cryptocode: how to place the oracle and place its arrows?

Question

How the result should look like:

How it looks like right now:

I marked the problem with yellow on both images. Here is my MWE:

\documentclass[a4paper]{article}
\usepackage{mathtools}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{cryptocode}
\newcommand{\gen}{\text{Gen}}

\begin{document}

        \begin{bbrenv}{A}
            \begin{bbrbox}[name=$\mathcal{C}_\text{PRF}$]
                \pseudocode{%
                    K \leftarrow \gen(1^n)\\
                    b \xleftarrow{r} \{0,1\}\\
                    \text{Wenn } b = 0\\
                    \quad \vartheta_0 = F_K(\cdot)\\
                    \text{Wenn } b = 0\\
                    \quad \vartheta_1 = f(\cdot)\\
                    \text{Wenn } b' = b\\
                    \quad \text{return } 1\\
                    \text{Wenn } b' \neq b\\
                    \quad \text{return } 1\\
                }
            \end{bbrbox}
            \begin{bbroracle}{OraA}
                \begin{bbrbox}[name=$\vartheta_b(\cdot)$]
                \end{bbrbox}
            \end{bbroracle}
            \begin{bbroracle}{OraB}
                \begin{bbrbox}
                    \pseudocode{
                        x = 0 \quad b\\
                        x = 1 \quad a+b \rightarrow b\\
                        x = 2 \quad 2a+b\\
                        \text{Wenn } b' = 0\\
                        \text{Ansonsten } b' = 1\\
                        \text{Ausgabe } b'
                    }
            \end{bbrbox}
            \end{bbroracle}
            \bbroracleqryfrom{top=$x$}
            \bbroracleqryto{top={$y$}}
            \bbroracleqryfrom{top=$b'$}
        \end{bbrenv}

    \end{document}

Do you think I could do it with bbrev? I am lost, hope you can help.

Answer 1

I'm not familiar with the cryptocode package, so for me is simpler to draw this algorithm with tikz package:

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{arrows.meta,
                positioning,
                quotes}
\usepackage{mathtools, amssymb}
\DeclareMathOperator{\gen}{gen}
\DeclareMathOperator{\PRF}{PRF}

\begin{document}
    \begin{tikzpicture}[auto,
   box/.style = {draw, minimum height=17mm, align=left, outer sep=0pt},
   lbl/.style = {anchor=south east, outer sep=1mm},
     pin edge = {Straight Barb-, draw=black},
every edge/.style = {draw, semithick, -Straight Barb}
                        ]
\node (n1)  [box, 
             label={[lbl] south east:$\mathcal{C}_{\PRF}$},
             pin=$1^n$]
            {$\begin{aligned}
             K \leftarrow \gen(1^n)     \\
             b \xleftarrow{r} \{0,1\}   \\
             \text{Wenn } b = 0  \text{ denn } \vartheta_0 = F_K(\cdot)  \\
             \text{Wenn } b = 1  \text{ denn } \vartheta_1 = f(\cdot)    \\[1ex]
             \text{Wenn } b' = b \text{return } 1\\
             \text{Wenn } b' \neq b \text{ return } 0\\[5ex]
             \end{aligned}$
                };
\node (n2)  [box, above right=-1ex and 0pt of n1.east]
            {$\vartheta_b(\cdot)$};
\node (n3)  [box, 
             label={[lbl]south east:$\mathcal{A}$},
             pin=???,
             right=9mm of n1 -| n2.east]
            {$\begin{aligned}
             x = 0 \quad b                  \\
             x = 1 \quad a+b \rightarrow b  \\
             x = 2 \quad 2a+b               \\[1ex]
             \text{Wenn } b' = 0            \\
                \text{ sonst } b' = 1       \\
                \text{ return } b'          \\[5ex]
             \end{aligned}$
             };
\draw   ([yshift=+2mm] n2.east) coordinate (aux1) edge["$x$"] (aux1 -| n3.west)
        ([yshift=-2mm] n2.east) coordinate (aux2) (aux2 -| n3.west) edge["$y$"] (aux2)
        ([yshift=-7ex] n3.west) edge["$b'$" '] ([yshift=-7ex] n1.east);
    \end{tikzpicture}
\end{document}