Add secure_getenv(3).

libc/Makefile

@@ -164,6 +164,7 @@ stdlib/qsort.o \
 stdlib/qsort_r.o \
 stdlib/reallocarray.o \
 stdlib/realloc.o \
+stdlib/secure_getenv.o \
 stdlib/strtod.o \
 stdlib/strtof.o \
 stdlib/strtold.o \

libc/include/stdlib.h

@@ -164,6 +164,7 @@ void* reallocarray_trace(struct __allocation_site*, void*, size_t, size_t);
 #else
 void* reallocarray(void*, size_t, size_t);
 #endif
+char* secure_getenv(const char*);
 #endif
 
 #if defined(__is_sortix_libc)

libc/stdlib/secure_getenv.c

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024 Jonas 'Sortie' Termansen.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * stdlib/secure_getenv.c
+ * Get an environment variable securely.
+ */
+
+#include <stdlib.h>
+
+char* secure_getenv(const char* name)
+{
+	// Sortix does not have setuid / setgid executables.
+	return getenv(name);
+}