1 files changed, 105 insertions, 0 deletions
diff --git a/unix/utils/arm_arch_queries.c b/unix/utils/arm_arch_queries.c
new file mode 100644
index 00000000..c3dc286b
--- /dev/null
+++ b/unix/utils/arm_arch_queries.c
@@ -0,0 +1,105 @@
+/*
+ * Unix implementation of the OS query functions that detect Arm
+ * architecture extensions.
+ */
+
+#include "putty.h"
+#include "ssh.h"
+
+#include "utils/arm_arch_queries.h"
+
+#if defined __arm__ || defined __aarch64__
+
+bool platform_aes_neon_available(void)
+{
+#if defined HWCAP_AES
+    return getauxval(AT_HWCAP) & HWCAP_AES;
+#elif defined HWCAP2_AES
+    return getauxval(AT_HWCAP2) & HWCAP2_AES;
+#elif defined __APPLE__
+    SysctlResult res = test_sysctl_flag("hw.optional.arm.FEAT_AES");
+    /* Older M1 macOS didn't provide this flag, but as far as I know
+     * implemented the crypto extension anyway, so treat 'feature
+     * missing' as 'implemented' */
+    return res != SYSCTL_OFF;
+#else
+    return false;
+#endif
+}
+
+bool platform_pmull_neon_available(void)
+{
+#if defined HWCAP_PMULL
+    return getauxval(AT_HWCAP) & HWCAP_PMULL;
+#elif defined HWCAP2_PMULL
+    return getauxval(AT_HWCAP2) & HWCAP2_PMULL;
+#elif defined __APPLE__
+    SysctlResult res = test_sysctl_flag("hw.optional.arm.FEAT_PMULL");
+    /* As above, treat 'missing' as enabled */
+    return res != SYSCTL_OFF;
+#else
+    return false;
+#endif
+}
+
+bool platform_sha256_neon_available(void)
+{
+#if defined HWCAP_SHA2
+    return getauxval(AT_HWCAP) & HWCAP_SHA2;
+#elif defined HWCAP2_SHA2
+    return getauxval(AT_HWCAP2) & HWCAP2_SHA2;
+#elif defined __APPLE__
+    SysctlResult res = test_sysctl_flag("hw.optional.arm.FEAT_SHA256");
+    /* As above, treat 'missing' as enabled */
+    return res != SYSCTL_OFF;
+#else
+    return false;
+#endif
+}
+
+bool platform_sha1_neon_available(void)
+{
+#if defined HWCAP_SHA1
+    return getauxval(AT_HWCAP) & HWCAP_SHA1;
+#elif defined HWCAP2_SHA1
+    return getauxval(AT_HWCAP2) & HWCAP2_SHA1;
+#elif defined __APPLE__
+    SysctlResult res = test_sysctl_flag("hw.optional.arm.FEAT_SHA1");
+    /* As above, treat 'missing' as enabled */
+    return res != SYSCTL_OFF;
+#else
+    return false;
+#endif
+}
+
+bool platform_sha512_neon_available(void)
+{
+#if defined HWCAP_SHA512
+    return getauxval(AT_HWCAP) & HWCAP_SHA512;
+#elif defined HWCAP2_SHA512
+    return getauxval(AT_HWCAP2) & HWCAP2_SHA512;
+#elif defined __APPLE__
+    /* There are two sysctl flags for this, apparently invented at
+     * different times. Try both, falling back to the older one. */
+    SysctlResult res = test_sysctl_flag("hw.optional.arm.FEAT_SHA512");
+    if (res != SYSCTL_MISSING)
+        return res == SYSCTL_ON;
+
+    res = test_sysctl_flag("hw.optional.armv8_2_sha512");
+    return res == SYSCTL_ON;
+#else
+    return false;
+#endif
+}
+
+#else /* defined __arm__ || defined __aarch64__ */
+
+/*
+ * Include _something_ in this file to prevent an annoying compiler
+ * warning, and to avoid having to condition out this file in
+ * CMakeLists. It's in a library, so this variable shouldn't end up in
+ * any actual program, because nothing will refer to it.
+ */
+const int arm_arch_queries_dummy_variable = 0;
+
+#endif /* defined __arm__ || defined __aarch64__ */