first

README.md

@@ -0,0 +1,15 @@
+```
+<@acidvegas> darkmage: how easily do you think you could
+<@acidvegas> isolate masscans
+<@acidvegas> range function
+<@acidvegas> into golang or python
+<@acidvegas> aka
+<@acidvegas> generating ip addresses
+<@acidvegas> randomly
+<@acidvegas> for massive ranges like 0.0.0.0/0
+<@acidvegas> in a memory safe manner
+```
+
+Really easily, it turns out.
+
+You can generate numbers in a predictable manner by feeding a custom seed to an RNG to find a random starting position, modifying it with an offset relative to which shard (assuming you're using multiple shards but not required) is generating addresses (so that no two shards generate the same address

main.go

@@ -0,0 +1,83 @@
+// linear congruential generator written in go
+// by darkmage
+// https://www.evildojo.com
+// https://www.twitter.com/evildojo666
+
+package main
+
+import (
+    "fmt"
+    "time"
+    "os"
+    "math"
+    "math/rand"
+    "strconv"
+    "sync"
+)
+
+// define a global sieve
+var sieve []bool
+var wg sync.WaitGroup
+
+
+func run_sieve(max int64, start int64, move int64, shard_num int64, shard_count int64) {
+    var current int64 = start + shard_num
+    if current > max-1 {
+        current = current % max
+    }
+    for i := int64(0); i <= max/shard_count; i++ {
+        sieve[current] = true
+        current = current + move 
+        if current > max-1 {
+            current = current % max
+        }
+    }
+    defer wg.Done()
+}
+
+
+func main() {
+    if len(os.Args) != 3 {
+        fmt.Println("Usage: go run main.go <seed> <shard_count>")
+        os.Exit(1)
+    }
+    seed, err := strconv.ParseInt(os.Args[1], 10, 64)
+    if err != nil {
+        fmt.Println("Error: ", err)
+        os.Exit(1)
+    }
+    rand := rand.New(rand.NewSource(seed))
+    var max int64 = 256*256*256*256
+    var start int64 = rand.Int63n(max)
+    fmt.Println("start:", start)
+    shard_count, err := strconv.ParseInt(os.Args[2], 10, 64)
+    if err != nil {
+        fmt.Println("Error: ", err)
+        os.Exit(1)
+    }
+    fmt.Println("shard_count:", shard_count)
+    var move int64 = (int64(math.Sqrt(float64(max))) + 1) * shard_count
+    fmt.Println("move:", move)
+    sieve = make([]bool, max)
+    start_time := time.Now()
+    for i := int64(0); i < shard_count; i++ {
+        fmt.Println("shard:", i)
+        wg.Add(1)
+        go run_sieve(max, start, move, i, shard_count)
+    }
+    wg.Wait()
+    end_time := time.Now()
+    fmt.Println("Completed iterating numbers")
+    fmt.Println("Time elapsed:", end_time.Sub(start_time))
+    fmt.Println("Checking sieve")
+    start_time = time.Now()
+    for i := int64(0); i < max; i++ {
+        if !sieve[i] {
+            fmt.Println(os.Stderr, "Error, not all numbers flipped")
+            os.Exit(1)
+        }
+    }
+    end_time = time.Now()
+    fmt.Println("Time elapsed:", end_time.Sub(start_time))
+}
+