diff options
Diffstat (limited to 'challenge')
| -rw-r--r-- | challenge/c32.go | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/challenge/c32.go b/challenge/c32.go new file mode 100644 index 0000000..5cfc3b9 --- /dev/null +++ b/challenge/c32.go @@ -0,0 +1,173 @@ +// Copyright © 2021 rsiddharth <s@ricketyspace.net> +// SPDX-License-Identifier: ISC + +package challenge + +import ( + "fmt" + "net/http" + "net/url" + "time" + + "ricketyspace.net/cryptopals/lib" +) + +func C32(serve bool) { + // In-Secure Byte Compare. + inSecureCompare := func(a, b []byte) bool { + for i := 0; i < len(a); i++ { + if len(b) <= i { + return false + } + if a[i] != b[i] { + return false + } + lib.Sleep(500000) // Sleep 0.5ms + } + return true + } + + // HMAC HTTP Server. + httpServer := func() { + // Secret for HMAC + sec := lib.StrToBytes("Rae Street") + + // Signature checkker. + sigCheck := func(f, s string) bool { + // Check signature. + h := lib.HmacSha1(sec, lib.StrToBytes(f)) + + if inSecureCompare(h, lib.HexStrToBytes(s)) { + return true + } + return false + } + + // HTTP Handler. + http.HandleFunc("/test", func(w http.ResponseWriter, r *http.Request) { + // Read query. + var f, s []string + var ok bool + q := r.URL.Query() + if f, ok = q["file"]; !ok { + w.WriteHeader(400) + fmt.Fprintf(w, "file not specified\n") + return + } + if len(f) > 1 { + w.WriteHeader(400) + fmt.Fprintf(w, "Cannot specify more than one file\n") + return + } + if s, ok = q["signature"]; !ok { + w.WriteHeader(400) + fmt.Fprintf(w, "signature not specified\n") + return + } + if len(s) > 1 { + w.WriteHeader(400) + fmt.Fprintf(w, + "Cannot specify more than one signature\n") + return + } + if !sigCheck(f[0], s[0]) { + w.WriteHeader(500) // Signature check failed. + } + }) + + // Start HTTP Server + http.ListenAndServe(":9000", nil) + } + + // Makes HTTP POST request to the server. + makeRequest := func(f, s string) int { + // Make HTTP request. + q := fmt.Sprintf("file=%s&signature=%s", f, s) + u, err := url.Parse("http://localhost:9000/test?" + q) + if err != nil { + fmt.Printf("url parse failed: %v\n", err) + return 0 + } + res, err := http.Post(u.String(), "text/plain", nil) + if err != nil { + fmt.Printf("http post failed: %v\n", err) + return res.StatusCode + } + return res.StatusCode + } + + // Crack signature for file "foo". + crack := func() { + stc := time.Now() // Start time of crack + + f := "foo" // File + s := make([]byte, 20) // Signature + + i := 0 + g := byte(0) // Guess byte. + tl := int64(50 + 1000) // Time limit. + tries := 0 + for { + st := time.Now() + sc := makeRequest(f, lib.BytesToHexStr(s)) + et := time.Now().Sub(st) // Elapsed time. + + if sc == 200 { + fmt.Printf("Signature Cracked: %x"+ + " [tot. elapsed time: %v]\n", + s, time.Now().Sub(stc)) + break + } + if et.Microseconds() >= tl { + if tries < 5 { // Try guess at least 5 times. + tries += 1 + continue + } + fmt.Printf("Signature Cracked Status: %x"+ + " [tot. elapsed time: %v]\n", + s, time.Now().Sub(stc)) + tl = et.Microseconds() + 50 + 200 + g = 0 + i += 1 + tries = 0 + } else { + g += 1 // Change guess. + s[i] = g // Set guess. + tries = 0 + } + } + } + + if serve { + httpServer() + } else { + crack() + } +} + +// Output: +// +// # Server: +// $ ./cryptopals -c 32 -s +// # Client: +// $ ./cryptopals -c 32 +// Signature Cracked Status: 4400000000000000000000000000000000000000 [tot. elapsed time: 126.869763ms] +// Signature Cracked Status: 44ee000000000000000000000000000000000000 [tot. elapsed time: 5.146844063s] +// Signature Cracked Status: 44ee570000000000000000000000000000000000 [tot. elapsed time: 9.026893144s] +// Signature Cracked Status: 44ee574500000000000000000000000000000000 [tot. elapsed time: 13.646937167s] +// Signature Cracked Status: 44ee5745d3000000000000000000000000000000 [tot. elapsed time: 31.367079778s] +// Signature Cracked Status: 44ee5745d3240000000000000000000000000000 [tot. elapsed time: 35.807108716s] +// Signature Cracked Status: 44ee5745d324fd00000000000000000000000000 [tot. elapsed time: 1m8.247369106s] +// Signature Cracked Status: 44ee5745d324fda7000000000000000000000000 [tot. elapsed time: 1m32.867563308s] +// Signature Cracked Status: 44ee5745d324fda71e0000000000000000000000 [tot. elapsed time: 1m38.747613348s] +// Signature Cracked Status: 44ee5745d324fda71ec000000000000000000000 [tot. elapsed time: 2m15.067906592s] +// Signature Cracked Status: 44ee5745d324fda71ec0cb000000000000000000 [tot. elapsed time: 2m57.588228069s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd0000000000000000 [tot. elapsed time: 3m49.198625184s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e00000000000000 [tot. elapsed time: 4m20.99889498s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e0c000000000000 [tot. elapsed time: 4m25.798911645s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e0c620000000000 [tot. elapsed time: 4m55.039159294s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e0c621c00000000 [tot. elapsed time: 5m5.359239694s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e0c621c70000000 [tot. elapsed time: 5m43.219684819s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e0c621c70ba0000 [tot. elapsed time: 6m49.610083935s] +// Signature Cracked Status: 44ee5745d324fda71ec0cbdd7e0c621c70bae700 [tot. elapsed time: 8m15.280753257s] +// Signature Cracked: 44ee5745d324fda71ec0cbdd7e0c621c70bae785 [tot. elapsed time: 9m6.221153561s] |