--- nettle-3.9.1_orig/fat-arm64.c	2023-12-05 02:16:50
+++ nettle-3.9.1/fat-arm64.c	2023-12-05 02:15:23
@@ -50,6 +50,8 @@
 # include <sys/sysctl.h>
 # include <machine/cpu.h>
 # include <machine/armreg.h>
+#elif defined(__APPLE__)
+# include <sys/sysctl.h>
 #endif
 
 #include "nettle-types.h"
@@ -85,6 +87,16 @@
 
 #define MATCH(s, slen, literal, llen) \
   ((slen) == (llen) && memcmp ((s), (literal), llen) == 0)
+
+#if defined(__APPLE__)
+static int
+check_sysctlbyname(const char* name)
+{
+  int val;
+  size_t s = sizeof(val);
+  return sysctlbyname(name, &val, &s, NULL, 0) ? 0 : val;
+}
+#endif
 
 static void
 get_arm64_features (struct arm64_features *features)
@@ -141,6 +153,12 @@
         = (ID_AA64ISAR0_SHA1(isar0) >= ID_AA64ISAR0_SHA1_BASE);
       features->have_sha2
         = (ID_AA64ISAR0_SHA2(isar0) >= ID_AA64ISAR0_SHA2_BASE);
+#elif defined(__APPLE__)
+      /* See https://developer.apple.com/documentation/kernel/1387446-sysctlbyname/determining_instruction_set_characteristics */
+      features->have_aes = check_sysctlbyname("hw.optional.arm.FEAT_AES");
+      features->have_pmull = check_sysctlbyname("hw.optional.arm.FEAT_PMULL");
+      features->have_sha1 = check_sysctlbyname("hw.optional.arm.FEAT_SHA1");
+      features->have_sha2 = check_sysctlbyname("hw.optional.arm.FEAT_SHA2");
 #endif
     }
 }