external: new subdirectory for all external libraries and submodules.

You will want to 'make distclean' after this.

I also removed libsecp; we use the one in in libwally anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

external/libwally-core/src/scrypt.c

@@ -0,0 +1,76 @@
+#include "internal.h"
+#include <include/wally_bip38.h>
+#include <include/wally_crypto.h>
+#include "hmac.h"
+#include "ccan/ccan/endian/endian.h"
+
+/* Use scrypts internal malloc/free */
+#undef malloc
+#undef free
+
+/* Implement functions required by the scrypt core */
+static uint32_t le32dec(const void *p)
+{
+    leint32_t tmp;
+    memcpy(&tmp, p, sizeof(tmp));
+    return le32_to_cpu(tmp);
+}
+
+static void le32enc(void *p, uint32_t value)
+{
+    leint32_t tmp = cpu_to_le32(value);
+    memcpy(p, &tmp, sizeof(tmp));
+}
+
+static void PBKDF2_SHA256(const unsigned char *pass, size_t pass_len,
+                          const unsigned char *salt, size_t salt_len,
+                          uint64_t cost,
+                          unsigned char *bytes_out, size_t len)
+{
+    const uint32_t flags = 0;
+    wally_pbkdf2_hmac_sha256(pass, pass_len, (unsigned char *)salt, salt_len,
+                             flags, (uint32_t)cost, bytes_out, len);
+}
+
+/* Include a suitable smix function/functions */
+#if defined(__ARM_NEON__) || defined(__ARM_NEON)
+# include <arm_neon.h>
+# include "scrypt/crypto_scrypt_smix_neon.c"
+# if !defined(__ANDROID__)
+/* No way to check for support, assume Neon present */
+#  define crypto_scrypt_smix_fn crypto_scrypt_smix_neon
+# else
+/* On Android, detect Neon support at runtime */
+#  include "cpufeatures/cpu-features.h"
+#  include "scrypt/crypto_scrypt_smix.c"
+static void
+crypto_scrypt_smix_fn(uint8_t *B, size_t r, uint64_t N, void *_V, void *XY)
+{
+    if (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON)
+        crypto_scrypt_smix_neon(B, r, N, _V, XY);
+    else
+        crypto_scrypt_smix_c(B, r, N, _V, XY);
+}
+# endif
+#elif defined(__SSE2__)
+/* Use the SSE2 version */
+# include "scrypt/crypto_scrypt_smix_sse2.c"
+# define crypto_scrypt_smix_fn crypto_scrypt_smix_sse2
+#else
+/* Use the C version */
+# include "scrypt/crypto_scrypt_smix.c"
+# define crypto_scrypt_smix_fn crypto_scrypt_smix_c
+#endif
+
+#include "scrypt/crypto_scrypt.c"
+
+/* Our scrypt wrapper. */
+int wally_scrypt(const unsigned char *pass, size_t pass_len,
+                 const unsigned char *salt, size_t salt_len,
+                 uint32_t cost, uint32_t block_size, uint32_t parallelism,
+                 unsigned char *bytes_out, size_t len)
+{
+    return _crypto_scrypt(pass, pass_len, salt, salt_len,
+                          cost, block_size, parallelism,
+                          bytes_out, len, crypto_scrypt_smix_fn);
+}