diff --git a/nbase/nbase.h b/nbase/nbase.h
index 0740f71ff..ff795329c 100644
--- a/nbase/nbase.h
+++ b/nbase/nbase.h
@@ -427,6 +427,8 @@ int Snprintf(char *, size_t, const char *, ...)
      __attribute__ ((format (printf, 3, 4)));
 
 char *mkstr(const char *start, const char *end);
+/* Like strchr, but don't go past end. Nulls not handled specially. */
+const char *strchr_p(const char *str, const char *end, char c);
 
 int alloc_vsprintf(char **strp, const char *fmt, va_list va)
      __attribute__ ((format (printf, 2, 0)));
diff --git a/nbase/nbase_str.c b/nbase/nbase_str.c
index 9da209c60..fa522f127 100644
--- a/nbase/nbase_str.c
+++ b/nbase/nbase_str.c
@@ -156,6 +156,16 @@ char *mkstr(const char *start, const char *end) {
   return s;
 }
 
+/* Like strchr, but don't go past end. Nulls not handled specially. */
+const char *strchr_p(const char *str, const char *end, char c) {
+  assert(str && end >= str);
+  for (const char *q = str; q < end; q++) {
+    if (*q == c)
+      return q;
+  }
+  return NULL;
+}
+
 /* vsprintf into a dynamically allocated buffer, similar to asprintf in
    Glibc. Return the length of the buffer or -1 on error. */
 int alloc_vsprintf(char **strp, const char *fmt, va_list va) {
diff --git a/nsock/tests/proxychain.c b/nsock/tests/proxychain.c
new file mode 100644
index 000000000..7ddb56d14
--- /dev/null
+++ b/nsock/tests/proxychain.c
@@ -0,0 +1,93 @@
+/*
+ * Nsock regression test suite
+ * Same license as nmap -- see https://nmap.org/book/man-legal.html
+ */
+
+#include "test-common.h"
+
+#define END_OF_TESTS -1
+#define GOOD 0
+#define BAD 1
+struct proxy_test {
+  int ttype;
+  const char *input;
+}
+
+static const struct proxy_test Tests[] = {
+  /* single proxy */
+  /* http */
+  {GOOD, "http://example.com"},
+  {GOOD, "http://example.com/some/crazy.path"},
+  {GOOD, "http://example.com/some/path?q=@!weird&other=;"},
+  {GOOD, "http://127.0.0.1/"},
+  {GOOD, "http://[::1]/"},
+  {GOOD, "http://example.com:80/"},
+  {GOOD, "http://127.0.0.1:1234/"},
+  {GOOD, "http://[::1]:8080/"},
+  /* https not supported! */
+  {BAD, "https://example.com/"},
+  /* No username/password in URI */
+  {BAD, "https://scott:tiger@example.com/"},
+  /* Port out of range */
+  {BAD, "http://example.com:65536/"},
+  /* Bad IPv6 syntax */
+  {BAD, "http://::1/"},
+  /* Missing host name */
+  {BAD, "http://:8080/"},
+  /* socks4 */
+  {GOOD, "socks4://example.com"},
+  /* Does SOCKS4 really support a path like this? */
+  {GOOD, "socks4://example.com/path?"},
+  /* multiple proxies */
+  {GOOD, "http://example.com:8080/,socks4://127.0.0.1/"},
+  {GOOD, "http://[::1]/,socks4://example.com:5000/"},
+  {GOOD, "socks4://[::1]/,socks4://example.com/,http://[::1]:9090"},
+  /* Dumb stuff */
+  {BAD, ""},
+  {BAD, "com"},
+  {BAD, "example.com"},
+  {BAD, "/example.com/"},
+  {BAD, "//example.com/"},
+  {BAD, "http/example.com/"},
+  {BAD, "http//example.com/"},
+  {BAD, "sptth://example.com/"},
+  {BAD, ","},
+  {BAD, ", "},
+  {BAD, " ,"},
+  {BAD, ",,"},
+  {BAD, ", ,"},
+  {BAD, " , , "},
+  {BAD, "http://example.com/,asdf"},
+  {BAD, "http://example.com/,"},
+  {BAD, "http://example.com/,,"},
+  {BAD, ",http://example.com/"},
+  {BAD, ",,http://example.com/"},
+  {BAD, "socks4://127.0.0.1/,http://example.com/,"},
+  {BAD, "socks4://127.0.0.1/,,http://example.com/"},
+  {BAD, ",socks4://127.0.0.1/,http://example.com/"},
+  {END_OF_TESTS, NULL}
+};
+
+static int parser_test(void *testdata) {
+  int tn = 0;
+  struct proxy_test *pt = &Tests[tn];
+  while (pt->ttype != END_OF_TESTS) {
+    nsock_proxychain pxc = NULL;
+    int ret = nsock_proxychain_new(pt->input, &pxc, NULL);
+    if (ret > 0 && pt->ttype == BAD) {
+      return -1;
+    }
+    else if (ret <= 0 && pt->ttype == GOOD) {
+      return -2;
+    }
+    nsock_proxychain_delete(pxc);
+  }
+  return 0;
+}
+
+const struct test_case TestProxyParse = {
+  .t_name     = "test nsock proxychain parsing",
+  .t_setup    = NULL,
+  .t_run      = parser_test,
+  .t_teardown = NULL
+};
diff --git a/osscan.cc b/osscan.cc
index 800f7d2bd..97ce5d006 100644
--- a/osscan.cc
+++ b/osscan.cc
@@ -566,16 +566,6 @@ error:
   return -1;
 }
 
-// Like strchr, but don't go past end. Nulls not handled specially.
-static const char *strchr_p(const char *str, const char *end, char c) {
-  assert(str && end >= str);
-  for (const char *q = str; q < end; q++) {
-    if (*q == c)
-      return q;
-  }
-  return NULL;
-}
-
 static std::vector<struct AVal> *str2AVal(const char *str, const char *end) {
   int i = 1;
   int count = 1;