From e6e4f59af9263ae4152af11d793c95288e656fc5 Mon Sep 17 00:00:00 2001
From: Graham Percival <gperciva@tarsnap.com>
Date: Sat, 8 Feb 2025 16:17:00 -0800
Subject: [PATCH] build: import libcperciva_crypto_aes

---
 Makefile.am                                       | 13 ++++++++++++-
 .../Build/apisupport-LIBCRYPTO-LOW_LEVEL_AES.c    | 15 +++++++++++++++
 libcperciva/crypto/crypto_aes.c                   |  4 ++++
 3 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 libcperciva/apisupport/Build/apisupport-LIBCRYPTO-LOW_LEVEL_AES.c

diff --git a/Makefile.am b/Makefile.am
index 57ea489c..74f4b015 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -10,6 +10,7 @@ noinst_LIBRARIES=							\
 	lib/libcperciva_arm_aes.a					\
 	lib/libcperciva_arm_sha256.a					\
 	lib/libcperciva_cpusupport_detect.a				\
+	lib/libcperciva_crypto_aes.a					\
 	lib/libcperciva_rdrand.a					\
 	lib/libcperciva_shani.a						\
 	lib/libtarsnap.a						\
@@ -188,7 +189,6 @@ lib_libtarsnap_a_SOURCES=						\
 	libcperciva/alg/sha256_shani.h					\
 	libcperciva/alg/sha256_sse2.h					\
 	libcperciva/cpusupport/cpusupport.h				\
-	libcperciva/crypto/crypto_aes.c					\
 	libcperciva/crypto/crypto_aes.h					\
 	libcperciva/crypto/crypto_aes_aesni.h				\
 	libcperciva/crypto/crypto_aes_aesni_m128i.h			\
@@ -346,6 +346,17 @@ CLEANFILES+=								\
 	cpusupport-config.h						\
 	cpusupport-config.h.tmp
 
+# libcperciva_crypto_aes depends on libcperciva_cpusupport_detect, so _crypto_aes
+# must come before _cpusupport_detect in LIBTARSNAP_A.
+lib_libcperciva_crypto_aes_a_SOURCES=					\
+	libcperciva/crypto/crypto_aes.c
+nodist_lib_libcperciva_crypto_aes_a_SOURCES=				\
+	apisupport-config.h						\
+	cpusupport-config.h
+lib_libcperciva_crypto_aes_a_CPPFLAGS=$(lib_libtarsnap_a_CPPFLAGS)
+lib_libcperciva_crypto_aes_a_CFLAGS=`. ./apisupport-config.h; echo $${CFLAGS_LIBCRYPTO_LOW_LEVEL_AES}`
+LIBTARSNAP_A+=	lib/libcperciva_crypto_aes.a
+
 lib_libcperciva_aesni_a_SOURCES=					\
 	libcperciva/crypto/crypto_aes_aesni.c				\
 	libcperciva/crypto/crypto_aesctr_aesni.c
diff --git a/libcperciva/apisupport/Build/apisupport-LIBCRYPTO-LOW_LEVEL_AES.c b/libcperciva/apisupport/Build/apisupport-LIBCRYPTO-LOW_LEVEL_AES.c
new file mode 100644
index 00000000..1864f011
--- /dev/null
+++ b/libcperciva/apisupport/Build/apisupport-LIBCRYPTO-LOW_LEVEL_AES.c
@@ -0,0 +1,15 @@
+#include <stdint.h>
+
+#include <openssl/aes.h>
+
+int
+main(void)
+{
+	AES_KEY kexp_actual;
+	const uint8_t key_unexpanded[16] = { 0 };
+
+	AES_set_encrypt_key(key_unexpanded, 128, &kexp_actual);
+
+	/* Success! */
+	return (0);
+}
diff --git a/libcperciva/crypto/crypto_aes.c b/libcperciva/crypto/crypto_aes.c
index f884605b..d88f9510 100644
--- a/libcperciva/crypto/crypto_aes.c
+++ b/libcperciva/crypto/crypto_aes.c
@@ -1,3 +1,7 @@
+/**
+ * APISUPPORT CFLAGS: LIBCRYPTO_LOW_LEVEL_AES
+ */
+
 #include <assert.h>
 #include <stdint.h>
 #include <stdlib.h>