module websocket import rand import crypto.sha1 import encoding.base64 // htonl64 converts payload length to header bits fn htonl64(payload_len u64) []u8 { mut ret := []u8{len: 8} ret[0] = u8(((payload_len & (u64(0xff) << 56)) >> 56) & 0xff) ret[1] = u8(((payload_len & (u64(0xff) << 48)) >> 48) & 0xff) ret[2] = u8(((payload_len & (u64(0xff) << 40)) >> 40) & 0xff) ret[3] = u8(((payload_len & (u64(0xff) << 32)) >> 32) & 0xff) ret[4] = u8(((payload_len & (u64(0xff) << 24)) >> 24) & 0xff) ret[5] = u8(((payload_len & (u64(0xff) << 16)) >> 16) & 0xff) ret[6] = u8(((payload_len & (u64(0xff) << 8)) >> 8) & 0xff) ret[7] = u8(((payload_len & (u64(0xff) << 0)) >> 0) & 0xff) return ret } // create_masking_key returs a new masking key to use when masking websocket messages fn create_masking_key() []u8 { mask_bit := rand.u8() buf := []u8{len: 4, init: `0`} unsafe { C.memcpy(buf.data, &mask_bit, 4) } return buf } // create_key_challenge_response creates a key challange response from security key fn create_key_challenge_response(seckey string) ?string { if seckey.len == 0 { return error('unexpected seckey lengt zero') } guid := '258EAFA5-E914-47DA-95CA-C5AB0DC85B11' sha1buf := seckey + guid shabytes := sha1buf.bytes() hash := sha1.sum(shabytes) b64 := base64.encode(hash) unsafe { hash.free() shabytes.free() } return b64 } // get_nonce creates a randomized array used in handshake process fn get_nonce(nonce_size int) string { mut nonce := []u8{len: nonce_size, cap: nonce_size} alphanum := '0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz' for i in 0 .. nonce_size { nonce[i] = alphanum[rand.intn(alphanum.len) or { 0 }] } return unsafe { tos(nonce.data, nonce.len) }.clone() }