4 files changed, 115 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3906454
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+*~
+config.h
+godzilla
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..15311e6
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,18 @@
+VERSION = 0.1
+
+CFLAGS += -Wall -Os -pedantic -std=c99
+CFLAGS += -DVERSION=\"${VERSION}\"
+
+all: godzilla
+
+again: clean all
+
+clean:
+	rm -f godzilla
+
+config.h:
+	cp config.def.h $@
+
+godzilla: config.h godzilla.c
+	${CC} ${CFLAGS} -o godzilla godzilla.c -lcrypt
+
diff --git a/config.def.h b/config.def.h
new file mode 100644
index 0000000..b2d1b26
--- /dev/null
+++ b/config.def.h
@@ -0,0 +1,2 @@
+const char *script = "";
+const char *realm = "godzilla";
diff --git a/godzilla.c b/godzilla.c
new file mode 100644
index 0000000..002ed96
--- /dev/null
+++ b/godzilla.c
@@ -0,0 +1,92 @@
+#define _XOPEN_SOURCE
+#define _DEFAULT_SOURCE
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <shadow.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <grp.h>
+#include <sys/types.h>
+
+#include "config.h"
+
+extern char **environ;
+
+int unauthorized() {
+  printf("Status: 401\n");
+  printf("WWW-Authenticate: Basic realm=\"%s\"\n", realm);
+  printf("Content-Type: text/plain\n\n");
+  printf("ooooo\n");
+  return 1;
+}
+
+char b64[] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+char *d64(char *src, char *dec) {
+  char *tail;
+  while(1) {
+    unsigned char c[4];
+    int n = 0;
+    tail = src;
+    while(n < 4) {
+      char *p;
+      int ch;
+      do {
+        ch = *src;
+        if(ch == '\0') {
+          if(n == 0) {
+            tail = src;
+          }
+          goto ret;
+        }
+        src++;
+        p = strchr(b64, ch);
+      } while(!p);
+      ch = p - b64;
+      if(ch == 64)
+        break;
+        c[n] = ch;
+        n++;
+    }
+    if(n > 1)
+      *dec++ = c[0] << 2 | c[1] >> 4;
+    if(n > 2)
+      *dec++ = c[1] << 4 | c[2] >> 2;
+    if(n > 3)
+      *dec++ = c[2] << 6 | c[3];
+  }
+ret:
+  return tail;
+}
+
+int main(int argc, char **argv) {
+  char *auth, *raw, *login, *passw, *result;
+  struct spwd *s;
+  auth = getenv("HTTP_AUTHORIZATION");
+  if(!auth || !*auth) return unauthorized();
+  if(strncmp("Basic ", auth, 6)) return unauthorized();
+  auth = auth + 6;
+  raw = calloc(1, strlen(auth));
+  d64(auth, raw);
+  login = raw;
+  passw = strchr(raw, ':');
+  if(!login || !passw) return unauthorized();
+  *passw++ = '\0';
+  s = getspnam(login);
+  if(!s) return unauthorized();
+  result = crypt(passw, s->sp_pwdp);
+  if(!strcmp(result, s->sp_pwdp)) {
+    struct passwd *user = getpwnam(login);
+    setgid(user->pw_gid);
+    setuid(user->pw_uid);
+    seteuid(user->pw_uid);
+    initgroups(login, user->pw_gid);
+    setenv("REMOTE_USER", login, 1);
+    unsetenv("HTTP_AUTHORIZATION");
+    return execve(script, argv, environ);
+  }
+  return unauthorized();
+}
+