#include "rbtdb.h"
/*
   SipHash reference C implementation
   Trivially adapted by Eric Wong for ruby-tdb

   Written in 2012 by
   Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
   Daniel J. Bernstein <djb@cr.yp.to>

   To the extent possible under law, the author(s) have dedicated all copyright
   and related and neighboring rights to this software to the public domain
   worldwide. This software is distributed without any warranty.

   You should have received a copy of the CC0 Public Domain Dedication along with
   this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#include <stdint.h>
#include <stdio.h>
#include <string.h>
typedef uint64_t u64;
typedef uint32_t u32;
typedef uint8_t u8;

#define ROTL(x,b) (u64)( ((x) << (b)) | ( (x) >> (64 - (b))) )

#define U32TO8_LE(p, v)         \
    (p)[0] = (u8)((v)      ); (p)[1] = (u8)((v) >>  8); \
    (p)[2] = (u8)((v) >> 16); (p)[3] = (u8)((v) >> 24);

#define U64TO8_LE(p, v)         \
  U32TO8_LE((p),     (u32)((v)      ));   \
  U32TO8_LE((p) + 4, (u32)((v) >> 32));

#define U8TO64_LE(p) \
  (((u64)((p)[0])      ) | \
   ((u64)((p)[1]) <<  8) | \
   ((u64)((p)[2]) << 16) | \
   ((u64)((p)[3]) << 24) | \
   ((u64)((p)[4]) << 32) | \
   ((u64)((p)[5]) << 40) | \
   ((u64)((p)[6]) << 48) | \
   ((u64)((p)[7]) << 56))

#define SIPROUND            \
  do {              \
    v0 += v1; v1=ROTL(v1,13); v1 ^= v0; v0=ROTL(v0,32); \
    v2 += v3; v3=ROTL(v3,16); v3 ^= v2;     \
    v0 += v3; v3=ROTL(v3,21); v3 ^= v0;     \
    v2 += v1; v1=ROTL(v1,17); v1 ^= v2; v2=ROTL(v2,32); \
  } while(0)

/* SipHash-2-4 */
static int
crypto_auth(unsigned char *out, const unsigned char *in,
	    size_t inlen, const unsigned char *k)
{
	/* "somepseudorandomlygeneratedbytes" */
	u64 v0 = 0x736f6d6570736575ULL;
	u64 v1 = 0x646f72616e646f6dULL;
	u64 v2 = 0x6c7967656e657261ULL;
	u64 v3 = 0x7465646279746573ULL;
	u64 b;
	u64 k0 = U8TO64_LE(k);
	u64 k1 = U8TO64_LE(k + 8);
	u64 m;
	const u8 *end = in + inlen - (inlen % sizeof(u64));
	const int left = inlen & 7;
	b = ((u64) inlen) << 56;
	v3 ^= k1;
	v2 ^= k0;
	v1 ^= k1;
	v0 ^= k0;

	for (; in != end; in += 8) {
		m = U8TO64_LE(in);
#ifdef DEBUG
		printf("(%3d) v0 %08x %08x\n", (int)inlen, (u32) (v0 >> 32),
		       (u32) v0);
		printf("(%3d) v1 %08x %08x\n", (int)inlen, (u32) (v1 >> 32),
		       (u32) v1);
		printf("(%3d) v2 %08x %08x\n", (int)inlen, (u32) (v2 >> 32),
		       (u32) v2);
		printf("(%3d) v3 %08x %08x\n", (int)inlen, (u32) (v3 >> 32),
		       (u32) v3);
		printf("(%3d) compress %08x %08x\n", (int)inlen,
		       (u32) (m >> 32), (u32) m);
#endif
		v3 ^= m;
		SIPROUND;
		SIPROUND;
		v0 ^= m;
	}

	switch (left) {
	case 7:
		b |= ((u64) in[6]) << 48;

	case 6:
		b |= ((u64) in[5]) << 40;

	case 5:
		b |= ((u64) in[4]) << 32;

	case 4:
		b |= ((u64) in[3]) << 24;

	case 3:
		b |= ((u64) in[2]) << 16;

	case 2:
		b |= ((u64) in[1]) << 8;

	case 1:
		b |= ((u64) in[0]);
		break;

	case 0:
		break;
	}

#ifdef DEBUG
	printf("(%3d) v0 %08x %08x\n", (int)inlen, (u32) (v0 >> 32), (u32) v0);
	printf("(%3d) v1 %08x %08x\n", (int)inlen, (u32) (v1 >> 32), (u32) v1);
	printf("(%3d) v2 %08x %08x\n", (int)inlen, (u32) (v2 >> 32), (u32) v2);
	printf("(%3d) v3 %08x %08x\n", (int)inlen, (u32) (v3 >> 32), (u32) v3);
	printf("(%3d) padding   %08x %08x\n", (int)inlen, (u32) (b >> 32),
	       (u32) b);
#endif
	v3 ^= b;
	SIPROUND;
	SIPROUND;
	v0 ^= b;
#ifdef DEBUG
	printf("(%3d) v0 %08x %08x\n", (int)inlen, (u32) (v0 >> 32), (u32) v0);
	printf("(%3d) v1 %08x %08x\n", (int)inlen, (u32) (v1 >> 32), (u32) v1);
	printf("(%3d) v2 %08x %08x\n", (int)inlen, (u32) (v2 >> 32), (u32) v2);
	printf("(%3d) v3 %08x %08x\n", (int)inlen, (u32) (v3 >> 32), (u32) v3);
#endif
	v2 ^= 0xff;
	SIPROUND;
	SIPROUND;
	SIPROUND;
	SIPROUND;
	b = v0 ^ v1 ^ v2 ^ v3;
	U64TO8_LE(out, b);
	return 0;
}

/*
   SipHash-2-4 output with
   k = 00 01 02 ...
   and
   in = (empty string)
   in = 00 (1 byte)
   in = 00 01 (2 bytes)
   in = 00 01 02 (3 bytes)
   ...
   in = 00 01 02 ... 3e (63 bytes)
*/
u8 vectors[64][8] = {
	{0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72,}
	,
	{0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74,}
	,
	{0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d,}
	,
	{0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85,}
	,
	{0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf,}
	,
	{0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18,}
	,
	{0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb,}
	,
	{0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab,}
	,
	{0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93,}
	,
	{0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e,}
	,
	{0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a,}
	,
	{0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4,}
	,
	{0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75,}
	,
	{0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14,}
	,
	{0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7,}
	,
	{0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1,}
	,
	{0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f,}
	,
	{0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69,}
	,
	{0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b,}
	,
	{0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb,}
	,
	{0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe,}
	,
	{0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0,}
	,
	{0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93,}
	,
	{0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8,}
	,
	{0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8,}
	,
	{0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc,}
	,
	{0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17,}
	,
	{0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f,}
	,
	{0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde,}
	,
	{0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6,}
	,
	{0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad,}
	,
	{0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32,}
	,
	{0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71,}
	,
	{0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7,}
	,
	{0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12,}
	,
	{0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15,}
	,
	{0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31,}
	,
	{0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02,}
	,
	{0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca,}
	,
	{0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a,}
	,
	{0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e,}
	,
	{0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad,}
	,
	{0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18,}
	,
	{0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4,}
	,
	{0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9,}
	,
	{0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9,}
	,
	{0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb,}
	,
	{0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0,}
	,
	{0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6,}
	,
	{0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7,}
	,
	{0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee,}
	,
	{0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1,}
	,
	{0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a,}
	,
	{0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81,}
	,
	{0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f,}
	,
	{0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24,}
	,
	{0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7,}
	,
	{0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea,}
	,
	{0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60,}
	,
	{0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66,}
	,
	{0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c,}
	,
	{0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f,}
	,
	{0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5,}
	,
	{0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95,}
};

int rbtdb_siphash_test_vectors(void)
{
#define MAXLEN 64
	u8 in[MAXLEN], out[8], k[16];
	int i;
	int ok = 1;

	for (i = 0; i < 16; ++i)
		k[i] = i;

	for (i = 0; i < MAXLEN; ++i) {
		in[i] = i;
		crypto_auth(out, in, i, k);

		if (memcmp(out, vectors[i], 8)) {
			printf("test vector failed for %d bytes\n", i);
			ok = 0;
		}
	}

	return ok;
}

unsigned int rbtdb_siphash24(TDB_DATA *data)
{
	/* n.b.: tdb is for persistent storage, so the key must be constant */
	static uint8_t key[] = "trivial database";
	/* static const uint8_t check[(sizeof(key) >= 16)]; */
	union {
		uint32_t x32[2];
		uint64_t x64;
	} out;
	unsigned char *in = data->dptr;
	size_t len = data->dsize;

	crypto_auth((unsigned char *)&out, in, len, key);

	return (unsigned int)(out.x32[0] ^ out.x32[1]);
}