/////////////////////////////////////////////////////////////////////
//// ////
//// CRP ////
//// DES Crypt Module ////
//// ////
//// Author: Rudolf Usselmann ////
//// rudi@asics.ws ////
//// ////
/////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2001 Rudolf Usselmann ////
//// rudi@asics.ws ////
//// ////
//// This source file may be used and distributed without ////
//// restriction provided that this copyright statement is not ////
//// removed from the file and that any derivative work contains ////
//// the original copyright notice and the associated disclaimer.////
//// ////
//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY ////
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED ////
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ////
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR ////
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ////
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ////
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE ////
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR ////
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ////
//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ////
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ////
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ////
//// POSSIBILITY OF SUCH DAMAGE. ////
//// ////
/////////////////////////////////////////////////////////////////////
module crp(P, R, K_sub);
output [1:32] P;
input [1:32] R;
input [1:48] K_sub;
wire [1:48] E;
wire [1:48] X;
wire [1:48] S;
assign E[1:48] = { R[32], R[1], R[2], R[3], R[4], R[5], R[4], R[5],
R[6], R[7], R[8], R[9], R[8], R[9], R[10], R[11],
R[12], R[13], R[12], R[13], R[14], R[15], R[16],
R[17], R[16], R[17], R[18], R[19], R[20], R[21],
R[20], R[21], R[22], R[23], R[24], R[25], R[24],
R[25], R[26], R[27], R[28], R[29], R[28], R[29],
R[30], R[31], R[32], R[1]};
assign X = E ^ K_sub;
sbox1 u0( .addr(X[01:06]), .dout(S[01:04]) );
sbox2 u1( .addr(X[07:12]), .dout(S[05:08]) );
sbox3 u2( .addr(X[13:18]), .dout(S[09:12]) );
sbox4 u3( .addr(X[19:24]), .dout(S[13:16]) );
sbox5 u4( .addr(X[25:30]), .dout(S[17:20]) );
sbox6 u5( .addr(X[31:36]), .dout(S[21:24]) );
sbox7 u6( .addr(X[37:42]), .dout(S[25:28]) );
sbox8 u7( .addr(X[43:48]), .dout(S[29:32]) );
assign P[1:32] = { S[16], S[7], S[20], S[21], S[29], S[12], S[28],
S[17], S[1], S[15], S[23], S[26], S[5], S[18],
S[31], S[10], S[2], S[8], S[24], S[14], S[32],
S[27], S[3], S[9], S[19], S[13], S[30], S[6],
S[22], S[11], S[4], S[25]};
endmodule
