--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtomcrypt/src/hashes/sha2/sha512_256.c	Fri Feb 09 23:49:22 2018 +0800
@@ -0,0 +1,130 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+/**
+   @param sha512_256.c
+   SHA512/256 hash included in sha512.c
+*/
+
+#include "tomcrypt.h"
+
+#if defined(LTC_SHA512_256) && defined(LTC_SHA512)
+
+const struct ltc_hash_descriptor sha512_256_desc =
+{
+    "sha512-256",
+    16,
+    32,
+    128,
+
+    /* OID */
+   { 2, 16, 840, 1, 101, 3, 4, 2, 6,  },
+   9,
+
+    &sha512_256_init,
+    &sha512_process,
+    &sha512_256_done,
+    &sha512_256_test,
+    NULL
+};
+
+/**
+   Initialize the hash state
+   @param md   The hash state you wish to initialize
+   @return CRYPT_OK if successful
+*/
+int sha512_256_init(hash_state * md)
+{
+    LTC_ARGCHK(md != NULL);
+
+    md->sha512.curlen = 0;
+    md->sha512.length = 0;
+    md->sha512.state[0] = CONST64(0x22312194FC2BF72C);
+    md->sha512.state[1] = CONST64(0x9F555FA3C84C64C2);
+    md->sha512.state[2] = CONST64(0x2393B86B6F53B151);
+    md->sha512.state[3] = CONST64(0x963877195940EABD);
+    md->sha512.state[4] = CONST64(0x96283EE2A88EFFE3);
+    md->sha512.state[5] = CONST64(0xBE5E1E2553863992);
+    md->sha512.state[6] = CONST64(0x2B0199FC2C85B8AA);
+    md->sha512.state[7] = CONST64(0x0EB72DDC81C52CA2);
+    return CRYPT_OK;
+}
+
+/**
+   Terminate the hash to get the digest
+   @param md  The hash state
+   @param out [out] The destination of the hash (48 bytes)
+   @return CRYPT_OK if successful
+*/
+int sha512_256_done(hash_state * md, unsigned char *out)
+{
+   unsigned char buf[64];
+
+   LTC_ARGCHK(md  != NULL);
+   LTC_ARGCHK(out != NULL);
+
+    if (md->sha512.curlen >= sizeof(md->sha512.buf)) {
+       return CRYPT_INVALID_ARG;
+    }
+
+   sha512_done(md, buf);
+   XMEMCPY(out, buf, 32);
+#ifdef LTC_CLEAN_STACK
+   zeromem(buf, sizeof(buf));
+#endif
+   return CRYPT_OK;
+}
+
+/**
+  Self-test the hash
+  @return CRYPT_OK if successful, CRYPT_NOP if self-tests have been disabled
+*/
+int  sha512_256_test(void)
+{
+ #ifndef LTC_TEST
+    return CRYPT_NOP;
+ #else
+  static const struct {
+      const char *msg;
+      unsigned char hash[32];
+  } tests[] = {
+    { "abc",
+      { 0x53, 0x04, 0x8E, 0x26, 0x81, 0x94, 0x1E, 0xF9,
+        0x9B, 0x2E, 0x29, 0xB7, 0x6B, 0x4C, 0x7D, 0xAB,
+        0xE4, 0xC2, 0xD0, 0xC6, 0x34, 0xFC, 0x6D, 0x46,
+        0xE0, 0xE2, 0xF1, 0x31, 0x07, 0xE7, 0xAF, 0x23 }
+    },
+    { "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
+      { 0x39, 0x28, 0xE1, 0x84, 0xFB, 0x86, 0x90, 0xF8,
+        0x40, 0xDA, 0x39, 0x88, 0x12, 0x1D, 0x31, 0xBE,
+        0x65, 0xCB, 0x9D, 0x3E, 0xF8, 0x3E, 0xE6, 0x14,
+        0x6F, 0xEA, 0xC8, 0x61, 0xE1, 0x9B, 0x56, 0x3A }
+    },
+  };
+
+  int i;
+  unsigned char tmp[32];
+  hash_state md;
+
+  for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
+      sha512_256_init(&md);
+      sha512_256_process(&md, (unsigned char*)tests[i].msg, (unsigned long)strlen(tests[i].msg));
+      sha512_256_done(&md, tmp);
+      if (compare_testvector(tmp, sizeof(tmp), tests[i].hash, sizeof(tests[i].hash), "SHA512-265", i)) {
+         return CRYPT_FAIL_TESTVECTOR;
+      }
+  }
+  return CRYPT_OK;
+ #endif
+}
+
+#endif /* defined(LTC_SHA384) && defined(LTC_SHA512) */
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */