diff --git a/internal/middleware/nollamas.go b/internal/middleware/nollamas.go
index e5be014f5..eedf3b9b7 100644
--- a/internal/middleware/nollamas.go
+++ b/internal/middleware/nollamas.go
@@ -72,8 +72,7 @@ func NoLLaMas(
var nollamas nollamas
nollamas.seed = seed
nollamas.ttl = time.Hour
- nollamas.diff1 = 4
- nollamas.diff2 = '4'
+ nollamas.diff = 4
nollamas.getInstanceV1 = getInstanceV1
nollamas.policy = cookiePolicy
return nollamas.Serve
@@ -101,16 +100,9 @@ type nollamas struct {
ttl time.Duration
// algorithm difficulty knobs.
- // diff1 determines the number of
- // leading zeroes required, while
- // diff2 checks the next byte at
- // index is less than it.
- //
- // e.g. you look for say:
- // - b[0:3] must be '0'
- // - b[4] can be < '5'
- diff1 uint8
- diff2 uint8
+ // diff determines the number
+ // of leading zeroes required.
+ diff uint8
// extra fields required for
// our template rendering.
@@ -187,6 +179,12 @@ func (m *nollamas) Serve(c *gin.Context) {
return
}
+ // From here-on out, all
+ // possibilities are handled
+ // by us. Prevent further http
+ // handlers from being called.
+ c.Abort()
+
// Prepare new log entry.
l := log.WithContext(ctx).
WithField("userAgent", userAgent).
@@ -225,10 +223,6 @@ func (m *nollamas) Serve(c *gin.Context) {
l.Infof("challenge passed: %s", nonce)
- // Don't pass to further
- // handlers, we'll redirect.
- c.Abort()
-
// Drop solution query and encode.
query.Del("nollamas_solution")
c.Request.URL.RawQuery = query.Encode()
@@ -240,11 +234,6 @@ func (m *nollamas) Serve(c *gin.Context) {
}
func (m *nollamas) renderChallenge(c *gin.Context, challenge string) {
- // Don't pass to further
- // handlers, they only get
- // our challenge page.
- c.Abort()
-
// Fetch current instance information for templating vars.
instance, errWithCode := m.getInstanceV1(c.Request.Context())
if errWithCode != nil {
@@ -263,12 +252,8 @@ func (m *nollamas) renderChallenge(c *gin.Context, challenge string) {
"/assets/Fork-Awesome/css/fork-awesome.min.css",
},
Extra: map[string]any{
- "challenge": challenge,
- "difficulty1": m.diff1,
-
- // must be a str otherwise template
- // renders uint8 as int, not char
- "difficulty2": hexStrs[m.diff2],
+ "challenge": challenge,
+ "difficulty": m.diff,
},
Javascript: []apiutil.JavascriptEntry{
{
@@ -289,8 +274,7 @@ func (m *nollamas) token(hash *hashWithBufs, userAgent, clientIP string) string
// Include difficulty level in
// hash input data so if config
// changes then token invalidates.
- hash.hash.Write([]byte{m.diff1})
- hash.hash.Write([]byte{m.diff2})
+ hash.hash.Write([]byte{m.diff})
// Also seed the generated input with
// current time rounded to TTL, so our
@@ -326,40 +310,18 @@ func (m *nollamas) checkChallenge(hash *hashWithBufs, challenge, nonce string) b
hex.Encode(hash.ebuf, hash.hbuf)
solution := hash.ebuf
- // Compiler bound-check-elimination hint.
- if len(solution) < int(m.diff1+1) {
+ // Compiler bound-check hint.
+ if len(solution) < int(m.diff) {
panic(gtserror.New("BCE"))
}
// Check that the first 'diff'
// many chars are indeed zeroes.
- for i := range m.diff1 {
+ for i := range m.diff {
if solution[i] != '0' {
return false
}
}
- // Check that next char is < 'diff2'.
- return solution[m.diff1] < m.diff2
-}
-
-// hexStrs is a quick lookup of ASCII hex
-// bytes to their string equivalent.
-var hexStrs = [...]string{
- '0': "0",
- '1': "1",
- '2': "2",
- '3': "3",
- '4': "4",
- '5': "5",
- '6': "6",
- '7': "7",
- '8': "8",
- '9': "9",
- 'a': "a",
- 'b': "b",
- 'c': "c",
- 'd': "d",
- 'e': "e",
- 'f': "f",
+ return true
}
diff --git a/internal/middleware/nollamas_test.go b/internal/middleware/nollamas_test.go
index d6fdb5ff6..37b66e5e9 100644
--- a/internal/middleware/nollamas_test.go
+++ b/internal/middleware/nollamas_test.go
@@ -96,8 +96,7 @@ func testNoLLaMasMiddleware(t *testing.T, e *gin.Engine, userAgent string) {
}
var challenge string
- var diff1 uint64
- var diff2 uint8
+ var difficulty uint64
// Parse output body and find the challenge / difficulty.
for _, line := range strings.Split(string(b), "\n") {
@@ -107,22 +106,17 @@ func testNoLLaMasMiddleware(t *testing.T, e *gin.Engine, userAgent string) {
line = line[25:]
line = line[:len(line)-1]
challenge = line
- case strings.HasPrefix(line, "data-nollamas-difficulty1=\""):
- line = line[27:]
+ case strings.HasPrefix(line, "data-nollamas-difficulty=\""):
+ line = line[26:]
line = line[:len(line)-1]
var err error
- diff1, err = strconv.ParseUint(line, 10, 8)
+ difficulty, err = strconv.ParseUint(line, 10, 8)
assert.NoError(t, err)
- case strings.HasPrefix(line, "data-nollamas-difficulty2=\""):
- line = line[27:]
- line = line[:len(line)-1]
- diff2 = line[0]
}
}
// Ensure valid posed challenge.
- assert.NotZero(t, diff1)
- assert.NotZero(t, diff2)
+ assert.NotZero(t, difficulty)
assert.NotEmpty(t, challenge)
// Prepare a test request for gin engine.
@@ -131,12 +125,11 @@ func testNoLLaMasMiddleware(t *testing.T, e *gin.Engine, userAgent string) {
rw = httptest.NewRecorder()
// Now compute and set solution query paramater.
- solution := computeSolution(challenge, diff1, diff2)
+ solution := computeSolution(challenge, difficulty)
r.URL.RawQuery = "nollamas_solution=" + solution
t.Logf("challenge=%s", challenge)
- t.Logf("diff1=%d", diff1)
- t.Logf("diff2='%c'", diff2)
+ t.Logf("difficulty=%d", difficulty)
t.Logf("solution=%s", solution)
// Pass req through
@@ -159,21 +152,18 @@ func testNoLLaMasMiddleware(t *testing.T, e *gin.Engine, userAgent string) {
}
// computeSolution does the functional equivalent of our nollamas workerTask.js.
-func computeSolution(challenge string, diff1 uint64, diff2 uint8) string {
+func computeSolution(challenge string, diff uint64) string {
outer:
for i := 0; ; i++ {
solution := strconv.Itoa(i)
combined := challenge + solution
hash := sha256.Sum256(byteutil.S2B(combined))
encoded := hex.EncodeToString(hash[:])
- for i := range diff1 {
+ for i := range diff {
if encoded[i] != '0' {
continue outer
}
}
- if encoded[diff1] >= diff2 {
- continue outer
- }
return solution
}
}
diff --git a/web/source/.eslintignore b/web/source/.eslintignore
index 46d39d131..4ce4ebebe 100644
--- a/web/source/.eslintignore
+++ b/web/source/.eslintignore
@@ -1,3 +1,4 @@
node_modules
prism.js
-prism.css
\ No newline at end of file
+prism.css
+nollamasworker/sha256.js
\ No newline at end of file
diff --git a/web/source/nollamas/index.js b/web/source/nollamas/index.js
index 94bac4fc7..4e162182c 100644
--- a/web/source/nollamas/index.js
+++ b/web/source/nollamas/index.js
@@ -19,7 +19,7 @@
const explanation = "Your browser is currently solving a proof-of-work challenge designed to deter \"ai\" scrapers. This should take no more than a few seconds...";
-document.addEventListener('DOMContentLoaded', function() {
+document.addEventListener("DOMContentLoaded", function() {
// Get the nollamas section container.
const nollamas = document.querySelector(".nollamas");
@@ -44,20 +44,17 @@ document.addEventListener('DOMContentLoaded', function() {
// Read the challenge and difficulty from
// data attributes on the nollamas section.
const challenge = nollamas.dataset.nollamasChallenge;
- const difficulty1 = nollamas.dataset.nollamasDifficulty1;
- const difficulty2 = nollamas.dataset.nollamasDifficulty2;
+ const difficulty = nollamas.dataset.nollamasDifficulty;
- console.log('challenge:', challenge); // eslint-disable-line no-console
- console.log('difficulty1:', difficulty1); // eslint-disable-line no-console
- console.log('difficulty2:', difficulty2); // eslint-disable-line no-console
+ console.log("challenge:", challenge); // eslint-disable-line no-console
+ console.log("difficulty:", difficulty); // eslint-disable-line no-console
// Prepare the worker with task function.
const worker = new Worker("/assets/dist/nollamasworker.js");
const startTime = performance.now();
worker.postMessage({
challenge: challenge,
- difficulty1: difficulty1,
- difficulty2: difficulty2,
+ difficulty: difficulty,
});
// Set the main worker function.
@@ -65,13 +62,13 @@ document.addEventListener('DOMContentLoaded', function() {
if (e.data.done) {
const endTime = performance.now();
const duration = endTime - startTime;
-
+
// Remove spinner and replace it with a tick
// and info about how long it took to solve.
nollamas.removeChild(spinner);
const solutionWrapper = document.createElement("div");
solutionWrapper.className = "nollamas-status";
-
+
const tick = document.createElement("i");
tick.className = "fa fa-check fa-2x fa-fw";
tick.setAttribute("title","Solved!");
@@ -79,17 +76,18 @@ document.addEventListener('DOMContentLoaded', function() {
solutionWrapper.appendChild(tick);
const took = document.createElement("span");
- took.appendChild(document.createTextNode(`Solved in ${duration.toString()}ms!`));
+ const solvedText = `Solved after ${e.data.nonce} iterations, in ${duration.toString()}ms!`;
+ took.appendChild(document.createTextNode(solvedText));
solutionWrapper.appendChild(took);
nollamas.appendChild(solutionWrapper);
-
+
// Wait for 500ms before redirecting, to give
// visitors a shot at reading the message, but
// not so long that they have to wait unduly.
setTimeout(() => {
let url = new URL(window.location.href);
- url.searchParams.set('nollamas_solution', e.data.nonce);
+ url.searchParams.set("nollamas_solution", e.data.nonce);
window.location.replace(url.toString());
}, 500);
}
diff --git a/web/source/nollamasworker/index.js b/web/source/nollamasworker/index.js
index 37a54349a..2762b125e 100644
--- a/web/source/nollamasworker/index.js
+++ b/web/source/nollamasworker/index.js
@@ -17,43 +17,51 @@
along with this program. If not, see .
*/
-onmessage = async function(e) {
- console.log('worker started'); // eslint-disable-line no-console
+import sha256 from "./sha256";
- const challenge = e.data.challenge;
+let compute = async function(challengeStr, diffStr) {
const textEncoder = new TextEncoder();
- // Get difficulty and generate the expected
- // zero ASCII prefix to check for in hashes.
- const difficulty1Str = e.data.difficulty1;
- const difficulty2Str = e.data.difficulty2;
- const difficulty1 = parseInt(difficulty1Str, 10);
- const zeroPrefix = '0'.repeat(difficulty1);
+ // Get difficulty1 as number and generate
+ // expected zero ASCII prefix to check for.
+ const diff1 = parseInt(diffStr, 10);
+ const zeros = "0".repeat(diff1);
+
+ // Calculate hex encoded prefix required to check solution, where we
+ // need diff1 no. chars in hex, and hex encoding doubles input length.
+ const prefixLen = diff1 / 2 + (diff1 % 2 != 0 ? 2 : 0);
let nonce = 0;
while (true) { // eslint-disable-line no-constant-condition
- // Create possible solution string from challenge + nonce.
- const solution = textEncoder.encode(challenge + nonce.toString());
+ // Create possible solution string from challenge string + nonce.
+ const solution = textEncoder.encode(challengeStr + nonce.toString());
- // Generate SHA256 hashsum of solution string and hex encode the result.
- const hashBuffer = await crypto.subtle.digest('SHA-256', solution);
- const hashArray = Array.from(new Uint8Array(hashBuffer));
- const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
+ // Generate SHA256 hashsum of solution string, and hex encode the
+ // necessary prefix length we need to check for a valid solution.
+ const prefixArray = Array.from(sha256(solution).slice(0, prefixLen));
+ const prefixHex = prefixArray.map(b => b.toString(16).padStart(2, "0")).join("");
// Check if the hex encoded hash has
// difficulty defined zeroes prefix.
- if (hashHex.startsWith(zeroPrefix)) {
-
- // Check if the next char after zero prefix
- // is specifically less than difficulty2 char.
- if (hashHex.charAt(difficulty1) < difficulty2Str) {
- postMessage({ nonce: nonce, done: true });
- break;
- }
+ if (prefixHex.startsWith(zeros)) {
+ return nonce;
}
// Iter.
nonce++;
}
};
+
+onmessage = async function(e) {
+ console.log('worker started'); // eslint-disable-line no-console
+
+ const challenge = e.data.challenge;
+ const difficulty = e.data.difficulty;
+
+ // Compute the nonce that produces solution with args.
+ let nonce = await compute(challenge, difficulty);
+
+ // Post the solution nonce back to caller.
+ postMessage({ nonce: nonce, done: true });
+};
diff --git a/web/source/nollamasworker/sha256.js b/web/source/nollamasworker/sha256.js
new file mode 100644
index 000000000..553442d7c
--- /dev/null
+++ b/web/source/nollamasworker/sha256.js
@@ -0,0 +1,113 @@
+/*
+ Copyright 2022 Andrea Griffini
+
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ "Software"), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject to
+ the following conditions:
+
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+// sha256(data) returns the digest of an input piece of data.
+// sha256(none) returns an object you can call .add(data), and .digest() at the end.
+// the returned digest is a 32-byte Uint8Array instance with an added .hex() function.
+// input should be string (that will be encoded as UTF-8) or an array-like with values 0..255.
+// source: https://github.com/6502/sha256
+export default function sha256(data) {
+ let h0 = 0x6a09e667, h1 = 0xbb67ae85, h2 = 0x3c6ef372, h3 = 0xa54ff53a,
+ h4 = 0x510e527f, h5 = 0x9b05688c, h6 = 0x1f83d9ab, h7 = 0x5be0cd19,
+ tsz = 0, bp = 0;
+ const k = [0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+ 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+ 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+ 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+ 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+ 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+ 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+ 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2],
+ rrot = (x, n) => (x >>> n) | (x << (32-n)),
+ w = new Uint32Array(64),
+ buf = new Uint8Array(64),
+ process = () => {
+ for (let j=0,r=0; j<16; j++,r+=4) {
+ w[j] = (buf[r]<<24) | (buf[r+1]<<16) | (buf[r+2]<<8) | buf[r+3];
+ }
+ for (let j=16; j<64; j++) {
+ let s0 = rrot(w[j-15], 7) ^ rrot(w[j-15], 18) ^ (w[j-15] >>> 3);
+ let s1 = rrot(w[j-2], 17) ^ rrot(w[j-2], 19) ^ (w[j-2] >>> 10);
+ w[j] = (w[j-16] + s0 + w[j-7] + s1) | 0;
+ }
+ let a = h0, b = h1, c = h2, d = h3, e = h4, f = h5, g = h6, h = h7;
+ for (let j=0; j<64; j++) {
+ let S1 = rrot(e, 6) ^ rrot(e, 11) ^ rrot(e, 25),
+ ch = (e & f) ^ ((~e) & g),
+ t1 = (h + S1 + ch + k[j] + w[j]) | 0,
+ S0 = rrot(a, 2) ^ rrot(a, 13) ^ rrot(a, 22),
+ maj = (a & b) ^ (a & c) ^ (b & c),
+ t2 = (S0 + maj) | 0;
+ h = g; g = f; f = e; e = (d + t1)|0; d = c; c = b; b = a; a = (t1 + t2)|0;
+ }
+ h0 = (h0 + a)|0; h1 = (h1 + b)|0; h2 = (h2 + c)|0; h3 = (h3 + d)|0;
+ h4 = (h4 + e)|0; h5 = (h5 + f)|0; h6 = (h6 + g)|0; h7 = (h7 + h)|0;
+ bp = 0;
+ },
+ add = data => {
+ if (typeof data === "string") {
+ data = typeof TextEncoder === "undefined" ? Buffer.from(data) : (new TextEncoder).encode(data);
+ }
+ for (let i=0; i {
+ buf[bp++] = 0x80; if (bp == 64) {process();}
+ if (bp + 8 > 64) {
+ while (bp < 64) {buf[bp++] = 0x00;}
+ process();
+ }
+ while (bp < 58) {buf[bp++] = 0x00;}
+ // Max number of bytes is 35,184,372,088,831
+ let L = tsz * 8;
+ buf[bp++] = (L / 1099511627776.) & 255;
+ buf[bp++] = (L / 4294967296.) & 255;
+ buf[bp++] = L >>> 24;
+ buf[bp++] = (L >>> 16) & 255;
+ buf[bp++] = (L >>> 8) & 255;
+ buf[bp++] = L & 255;
+ process();
+ let reply = new Uint8Array(32);
+ reply[ 0] = h0 >>> 24; reply[ 1] = (h0 >>> 16) & 255; reply[ 2] = (h0 >>> 8) & 255; reply[ 3] = h0 & 255;
+ reply[ 4] = h1 >>> 24; reply[ 5] = (h1 >>> 16) & 255; reply[ 6] = (h1 >>> 8) & 255; reply[ 7] = h1 & 255;
+ reply[ 8] = h2 >>> 24; reply[ 9] = (h2 >>> 16) & 255; reply[10] = (h2 >>> 8) & 255; reply[11] = h2 & 255;
+ reply[12] = h3 >>> 24; reply[13] = (h3 >>> 16) & 255; reply[14] = (h3 >>> 8) & 255; reply[15] = h3 & 255;
+ reply[16] = h4 >>> 24; reply[17] = (h4 >>> 16) & 255; reply[18] = (h4 >>> 8) & 255; reply[19] = h4 & 255;
+ reply[20] = h5 >>> 24; reply[21] = (h5 >>> 16) & 255; reply[22] = (h5 >>> 8) & 255; reply[23] = h5 & 255;
+ reply[24] = h6 >>> 24; reply[25] = (h6 >>> 16) & 255; reply[26] = (h6 >>> 8) & 255; reply[27] = h6 & 255;
+ reply[28] = h7 >>> 24; reply[29] = (h7 >>> 16) & 255; reply[30] = (h7 >>> 8) & 255; reply[31] = h7 & 255;
+ reply.hex = () => {
+ let res = "";
+ reply.forEach(x => res += ("0" + x.toString(16)).slice(-2)); // eslint-disable-line no-return-assign
+ return res;
+ };
+ return reply;
+ };
+ if (data === undefined) {return {add, digest};}
+ add(data);
+ return digest();
+}
diff --git a/web/template/nollamas.tmpl b/web/template/nollamas.tmpl
index cc0f0f617..a02fd92f7 100644
--- a/web/template/nollamas.tmpl
+++ b/web/template/nollamas.tmpl
@@ -21,8 +21,7 @@
Checking you're not a creepy crawler...