#include "xf_security/chacha20.hpp"
void chacha20 ( hls::stream <ap_uint <256>>& keyStrm, hls::stream <ap_uint <128>>& counterNonceStrm, hls::stream <ap_uint <512>>& plainStrm, hls::stream <bool>& ePlainStrm, hls::stream <ap_uint <512>>& cipherStrm, hls::stream <bool>& eCipherStrm )
chahcha20 is a basic function for stream ciphering when key is “keylayout-chacha”, its layout in a 256-bit ap_uint<> likes this,
0 - 7 bit: ‘k’ 8 - 15 bit: ‘e’ 16 - 23 bit: ‘y’ 24 - 31 bit: ‘l’ … 232- 239 bit: ‘c’ 240- 247 bit: ‘h’ 248- 255 bit: ‘a’
state matrix: s[0] s[1] s[2] s[3] s[4] s[5] s[6] s[7] s[8] s[9] s[10] s[11] s[12] s[13] s[14] s[15]
128bits counterNonceStrm = counter 32 bits + nonce 96 bits the layout of the data from counteStrm 0-31 bit: counter s[12] 32-63 bit: nonce1 s[13] 64-95 bit: nonce2 s[14] 96-127 bit: nonce3 s[15]
Parameters:
| keyStrm | initail key |
| counterNonceStm | initial counter and nonce |
| plainStrm | input plain text to be encrypted |
| ePlainStrm | the end flag of plainStrm |
| cipherStrm | output encrypted text |
| eCipherStrm | the end flag of cipherStrm |