initial: Syntrex extraction from sentinel-community (615 files)

internal/domain/mimicry/noise.go

@@ -0,0 +1,80 @@
+package mimicry
+
+import (
+	"math/rand"
+	"strings"
+)
+
+// NoiseInjector mixes legitimate code/facts into prompts for OPSEC (v3.8).
+// Adds 30-40% of legitimate context from Code Crystals (L0/L1) to mask
+// the true intent of the prompt from pattern-matching filters.
+type NoiseInjector struct {
+	crystals []string // Pool of legitimate code snippets
+	ratio    float64  // Noise ratio (default: 0.35 = 35%)
+}
+
+// NewNoiseInjector creates a noise injector with the given crystal pool.
+func NewNoiseInjector(crystals []string, ratio float64) *NoiseInjector {
+	if ratio <= 0 || ratio > 0.5 {
+		ratio = 0.35
+	}
+	return &NoiseInjector{crystals: crystals, ratio: ratio}
+}
+
+// Inject adds legitimate noise around the actual prompt.
+// Returns the augmented prompt with noise before and after the real content.
+func (n *NoiseInjector) Inject(prompt string) string {
+	if len(n.crystals) == 0 {
+		return prompt
+	}
+
+	// Calculate number of noise snippets based on prompt size.
+	promptTokens := estimateTokens(prompt)
+	noiseTokenBudget := int(float64(promptTokens) * n.ratio)
+	if noiseTokenBudget > 300 {
+		noiseTokenBudget = 300 // Token budget cap per spec.
+	}
+
+	var before, after []string
+	usedTokens := 0
+
+	// Randomly select crystals for noise.
+	indices := rand.Perm(len(n.crystals))
+	for _, idx := range indices {
+		crystal := n.crystals[idx]
+		tokens := estimateTokens(crystal)
+		if usedTokens+tokens > noiseTokenBudget {
+			continue
+		}
+		// Alternate placement: before and after.
+		if len(before) <= len(after) {
+			before = append(before, crystal)
+		} else {
+			after = append(after, crystal)
+		}
+		usedTokens += tokens
+	}
+
+	var b strings.Builder
+	if len(before) > 0 {
+		b.WriteString("// Related context:\n")
+		for _, s := range before {
+			b.WriteString(s)
+			b.WriteString("\n\n")
+		}
+	}
+	b.WriteString(prompt)
+	if len(after) > 0 {
+		b.WriteString("\n\n// Additional reference:\n")
+		for _, s := range after {
+			b.WriteString(s)
+			b.WriteString("\n")
+		}
+	}
+	return b.String()
+}
+
+// estimateTokens gives a rough token count (~4 chars per token).
+func estimateTokens(s string) int {
+	return (len(s) + 3) / 4
+}