thodg/cgminer

diff --git a/Makefile.am b/Makefile.am
index d17414d..a784ef9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -56,6 +56,10 @@ cgminer_SOURCES	+= \
 # the CPU portion extracted from original main.c
 cgminer_SOURCES += driver-cpu.h driver-cpu.c
 
+if HAS_SCRYPT
+cgminer_SOURCES += scrypt.c
+endif
+
 if HAS_YASM
 AM_CFLAGS	= -DHAS_YASM
 if HAVE_x86_64
diff --git a/cgminer.c b/cgminer.c
index 64d0431..f5044e2 100644
--- a/cgminer.c
+++ b/cgminer.c
@@ -5198,6 +5198,11 @@ int main(int argc, char *argv[])
 		opt_log_output = true;
 
 #ifdef WANT_CPUMINE
+#ifdef USE_SCRYPT
+	if (opt_scrypt)
+		set_scrypt_algo(&opt_algo);
+	else
+#endif
 	if (0 <= opt_bench_algo) {
 		double rate = bench_algo_stage3(opt_bench_algo);
 
diff --git a/driver-cpu.c b/driver-cpu.c
index 09ca478..bd502b3 100644
--- a/driver-cpu.c
+++ b/driver-cpu.c
@@ -131,6 +131,9 @@ extern bool scanhash_sse2_32(struct thr_info*, const unsigned char *pmidstate, u
 	uint32_t max_nonce, uint32_t *last_nonce,
 	uint32_t nonce);
 
+extern bool scanhash_scrypt(struct thr_info *thr, int thr_id, unsigned char *pdata, unsigned char *scratchbuf,
+	const unsigned char *ptarget,
+	uint32_t max_nonce, unsigned long *hashes_done);
 
 
 
@@ -161,6 +164,9 @@ const char *algo_names[] = {
 #ifdef WANT_ALTIVEC_4WAY
     [ALGO_ALTIVEC_4WAY] = "altivec_4way",
 #endif
+#ifdef WANT_SCRYPT
+    [ALGO_SCRYPT] = "scrypt",
+#endif
 };
 
 static const sha256_func sha256_funcs[] = {
@@ -185,7 +191,10 @@ static const sha256_func sha256_funcs[] = {
 	[ALGO_SSE2_64]		= (sha256_func)scanhash_sse2_64,
 #endif
 #ifdef WANT_X8664_SSE4
-	[ALGO_SSE4_64]		= (sha256_func)scanhash_sse4_64
+	[ALGO_SSE4_64]		= (sha256_func)scanhash_sse4_64,
+#endif
+#ifdef WANT_SCRYPT
+	[ALGO_SCRYPT]		= (sha256_func)scanhash_scrypt
 #endif
 };
 #endif
@@ -662,6 +671,9 @@ char *set_algo(const char *arg, enum sha256_algos *algo)
 {
 	enum sha256_algos i;
 
+	if (opt_scrypt)
+		return "Can only use scrypt algorithm";
+
 	if (!strcmp(arg, "auto")) {
 		*algo = pick_fastest_algo();
 		return NULL;
@@ -676,6 +688,13 @@ char *set_algo(const char *arg, enum sha256_algos *algo)
 	return "Unknown algorithm";
 }
 
+#ifdef WANT_SCRYPT
+void set_scrypt_algo(enum sha256_algos *algo)
+{
+	*algo = ALGO_SCRYPT;
+}
+#endif
+
 void show_algo(char buf[OPT_SHOW_LEN], const enum sha256_algos *algo)
 {
 	strncpy(buf, algo_names[*algo], OPT_SHOW_LEN);
diff --git a/driver-cpu.h b/driver-cpu.h
index ced400a..3cf268b 100644
--- a/driver-cpu.h
+++ b/driver-cpu.h
@@ -34,6 +34,10 @@
 #define WANT_X8664_SSE4 1
 #endif
 
+#ifdef USE_SCRYPT
+#define WANT_SCRYPT
+#endif
+
 enum sha256_algos {
 	ALGO_C,			/* plain C */
 	ALGO_4WAY,		/* parallel SSE2 */
@@ -44,6 +48,7 @@ enum sha256_algos {
 	ALGO_SSE2_64,		/* SSE2 for x86_64 */
 	ALGO_SSE4_64,		/* SSE4 for x86_64 */
 	ALGO_ALTIVEC_4WAY,	/* parallel Altivec */
+	ALGO_SCRYPT,		/* scrypt */
 };
 
 extern const char *algo_names[];
diff --git a/scrypt.c b/scrypt.c
new file mode 100644
index 0000000..569eeb9
--- /dev/null
+++ b/scrypt.c
@@ -0,0 +1,452 @@
+/*-
+ * Copyright 2009 Colin Percival, 2011 ArtForz
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file was originally written by Colin Percival as part of the Tarsnap
+ * online backup system.
+ */
+
+#include "config.h"
+#include "miner.h"
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#define byteswap(x) ((((x) << 24) & 0xff000000u) | (((x) << 8) & 0x00ff0000u) | (((x) >> 8) & 0x0000ff00u) | (((x) >> 24) & 0x000000ffu))
+
+typedef struct SHA256Context {
+	uint32_t state[8];
+	uint32_t buf[16];
+} SHA256_CTX;
+
+/*
+ * Encode a length len/4 vector of (uint32_t) into a length len vector of
+ * (unsigned char) in big-endian form.  Assumes len is a multiple of 4.
+ */
+static inline void
+be32enc_vect(uint32_t *dst, const uint32_t *src, uint32_t len)
+{
+	uint32_t i;
+
+	for (i = 0; i < len; i++)
+		dst[i] = byteswap(src[i]);
+}
+
+/* Elementary functions used by SHA256 */
+#define Ch(x, y, z)	((x & (y ^ z)) ^ z)
+#define Maj(x, y, z)	((x & (y | z)) | (y & z))
+#define SHR(x, n)	(x >> n)
+#define ROTR(x, n)	((x >> n) | (x << (32 - n)))
+#define S0(x)		(ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define S1(x)		(ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define s0(x)		(ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
+#define s1(x)		(ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
+
+/* SHA256 round function */
+#define RND(a, b, c, d, e, f, g, h, k)			\
+	t0 = h + S1(e) + Ch(e, f, g) + k;		\
+	t1 = S0(a) + Maj(a, b, c);			\
+	d += t0;					\
+	h  = t0 + t1;
+
+/* Adjusted round function for rotating state */
+#define RNDr(S, W, i, k)			\
+	RND(S[(64 - i) % 8], S[(65 - i) % 8],	\
+	    S[(66 - i) % 8], S[(67 - i) % 8],	\
+	    S[(68 - i) % 8], S[(69 - i) % 8],	\
+	    S[(70 - i) % 8], S[(71 - i) % 8],	\
+	    W[i] + k)
+
+/*
+ * SHA256 block compression function.  The 256-bit state is transformed via
+ * the 512-bit input block to produce a new state.
+ */
+static void
+SHA256_Transform(uint32_t * state, const uint32_t block[16], int swap)
+{
+	uint32_t W[64];
+	uint32_t S[8];
+	uint32_t t0, t1;
+	int i;
+
+	/* 1. Prepare message schedule W. */
+	if(swap)
+		for (i = 0; i < 16; i++)
+			W[i] = byteswap(block[i]);
+	else
+		memcpy(W, block, 64);
+	for (i = 16; i < 64; i += 2) {
+		W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
+		W[i+1] = s1(W[i - 1]) + W[i - 6] + s0(W[i - 14]) + W[i - 15];
+	}
+
+	/* 2. Initialize working variables. */
+	memcpy(S, state, 32);
+
+	/* 3. Mix. */
+	RNDr(S, W, 0, 0x428a2f98);
+	RNDr(S, W, 1, 0x71374491);
+	RNDr(S, W, 2, 0xb5c0fbcf);
+	RNDr(S, W, 3, 0xe9b5dba5);
+	RNDr(S, W, 4, 0x3956c25b);
+	RNDr(S, W, 5, 0x59f111f1);
+	RNDr(S, W, 6, 0x923f82a4);
+	RNDr(S, W, 7, 0xab1c5ed5);
+	RNDr(S, W, 8, 0xd807aa98);
+	RNDr(S, W, 9, 0x12835b01);
+	RNDr(S, W, 10, 0x243185be);
+	RNDr(S, W, 11, 0x550c7dc3);
+	RNDr(S, W, 12, 0x72be5d74);
+	RNDr(S, W, 13, 0x80deb1fe);
+	RNDr(S, W, 14, 0x9bdc06a7);
+	RNDr(S, W, 15, 0xc19bf174);
+	RNDr(S, W, 16, 0xe49b69c1);
+	RNDr(S, W, 17, 0xefbe4786);
+	RNDr(S, W, 18, 0x0fc19dc6);
+	RNDr(S, W, 19, 0x240ca1cc);
+	RNDr(S, W, 20, 0x2de92c6f);
+	RNDr(S, W, 21, 0x4a7484aa);
+	RNDr(S, W, 22, 0x5cb0a9dc);
+	RNDr(S, W, 23, 0x76f988da);
+	RNDr(S, W, 24, 0x983e5152);
+	RNDr(S, W, 25, 0xa831c66d);
+	RNDr(S, W, 26, 0xb00327c8);
+	RNDr(S, W, 27, 0xbf597fc7);
+	RNDr(S, W, 28, 0xc6e00bf3);
+	RNDr(S, W, 29, 0xd5a79147);
+	RNDr(S, W, 30, 0x06ca6351);
+	RNDr(S, W, 31, 0x14292967);
+	RNDr(S, W, 32, 0x27b70a85);
+	RNDr(S, W, 33, 0x2e1b2138);
+	RNDr(S, W, 34, 0x4d2c6dfc);
+	RNDr(S, W, 35, 0x53380d13);
+	RNDr(S, W, 36, 0x650a7354);
+	RNDr(S, W, 37, 0x766a0abb);
+	RNDr(S, W, 38, 0x81c2c92e);
+	RNDr(S, W, 39, 0x92722c85);
+	RNDr(S, W, 40, 0xa2bfe8a1);
+	RNDr(S, W, 41, 0xa81a664b);
+	RNDr(S, W, 42, 0xc24b8b70);
+	RNDr(S, W, 43, 0xc76c51a3);
+	RNDr(S, W, 44, 0xd192e819);
+	RNDr(S, W, 45, 0xd6990624);
+	RNDr(S, W, 46, 0xf40e3585);
+	RNDr(S, W, 47, 0x106aa070);
+	RNDr(S, W, 48, 0x19a4c116);
+	RNDr(S, W, 49, 0x1e376c08);
+	RNDr(S, W, 50, 0x2748774c);
+	RNDr(S, W, 51, 0x34b0bcb5);
+	RNDr(S, W, 52, 0x391c0cb3);
+	RNDr(S, W, 53, 0x4ed8aa4a);
+	RNDr(S, W, 54, 0x5b9cca4f);
+	RNDr(S, W, 55, 0x682e6ff3);
+	RNDr(S, W, 56, 0x748f82ee);
+	RNDr(S, W, 57, 0x78a5636f);
+	RNDr(S, W, 58, 0x84c87814);
+	RNDr(S, W, 59, 0x8cc70208);
+	RNDr(S, W, 60, 0x90befffa);
+	RNDr(S, W, 61, 0xa4506ceb);
+	RNDr(S, W, 62, 0xbef9a3f7);
+	RNDr(S, W, 63, 0xc67178f2);
+
+	/* 4. Mix local working variables into global state */
+	for (i = 0; i < 8; i++)
+		state[i] += S[i];
+}
+
+static inline void
+SHA256_InitState(uint32_t * state)
+{
+	/* Magic initialization constants */
+	state[0] = 0x6A09E667;
+	state[1] = 0xBB67AE85;
+	state[2] = 0x3C6EF372;
+	state[3] = 0xA54FF53A;
+	state[4] = 0x510E527F;
+	state[5] = 0x9B05688C;
+	state[6] = 0x1F83D9AB;
+	state[7] = 0x5BE0CD19;
+}
+
+static const uint32_t passwdpad[12] = {0x00000080, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x80020000};
+static const uint32_t outerpad[8] = {0x80000000, 0, 0, 0, 0, 0, 0, 0x00000300};
+
+/**
+ * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen):
+ * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and
+ * write the output to buf.  The value dkLen must be at most 32 * (2^32 - 1).
+ */
+static inline void
+PBKDF2_SHA256_80_128(const uint32_t * passwd, uint32_t * buf)
+{
+	SHA256_CTX PShictx, PShoctx;
+	uint32_t tstate[8];
+	uint32_t ihash[8];
+	uint32_t i;
+	uint32_t pad[16];
+	
+	static const uint32_t innerpad[11] = {0x00000080, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xa0040000};
+
+	/* If Klen > 64, the key is really SHA256(K). */
+	SHA256_InitState(tstate);
+	SHA256_Transform(tstate, passwd, 1);
+	memcpy(pad, passwd+16, 16);
+	memcpy(pad+4, passwdpad, 48);
+	SHA256_Transform(tstate, pad, 1);
+	memcpy(ihash, tstate, 32);
+
+	SHA256_InitState(PShictx.state);
+	for (i = 0; i < 8; i++)
+		pad[i] = ihash[i] ^ 0x36363636;
+	for (; i < 16; i++)
+		pad[i] = 0x36363636;
+	SHA256_Transform(PShictx.state, pad, 0);
+	SHA256_Transform(PShictx.state, passwd, 1);
+	be32enc_vect(PShictx.buf, passwd+16, 4);
+	be32enc_vect(PShictx.buf+5, innerpad, 11);
+
+	SHA256_InitState(PShoctx.state);
+	for (i = 0; i < 8; i++)
+		pad[i] = ihash[i] ^ 0x5c5c5c5c;
+	for (; i < 16; i++)
+		pad[i] = 0x5c5c5c5c;
+	SHA256_Transform(PShoctx.state, pad, 0);
+	memcpy(PShoctx.buf+8, outerpad, 32);
+
+	/* Iterate through the blocks. */
+	for (i = 0; i < 4; i++) {
+		uint32_t istate[8];
+		uint32_t ostate[8];
+		
+		memcpy(istate, PShictx.state, 32);
+		PShictx.buf[4] = i + 1;
+		SHA256_Transform(istate, PShictx.buf, 0);
+		memcpy(PShoctx.buf, istate, 32);
+
+		memcpy(ostate, PShoctx.state, 32);
+		SHA256_Transform(ostate, PShoctx.buf, 0);
+		be32enc_vect(buf+i*8, ostate, 8);
+	}
+}
+
+
+static inline uint32_t
+PBKDF2_SHA256_80_128_32(const uint32_t * passwd, const uint32_t * salt)
+{
+	uint32_t tstate[8];
+	uint32_t ostate[8];
+	uint32_t ihash[8];
+	uint32_t i;
+
+	/* Compute HMAC state after processing P and S. */
+	uint32_t pad[16];
+	
+	static const uint32_t ihash_finalblk[16] = {0x00000001,0x80000000,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0x00000620};
+
+	/* If Klen > 64, the key is really SHA256(K). */
+	SHA256_InitState(tstate);
+	SHA256_Transform(tstate, passwd, 1);
+	memcpy(pad, passwd+16, 16);
+	memcpy(pad+4, passwdpad, 48);
+	SHA256_Transform(tstate, pad, 1);
+	memcpy(ihash, tstate, 32);
+
+	SHA256_InitState(ostate);
+	for (i = 0; i < 8; i++)
+		pad[i] = ihash[i] ^ 0x5c5c5c5c;
+	for (; i < 16; i++)
+		pad[i] = 0x5c5c5c5c;
+	SHA256_Transform(ostate, pad, 0);
+
+	SHA256_InitState(tstate);
+	for (i = 0; i < 8; i++)
+		pad[i] = ihash[i] ^ 0x36363636;
+	for (; i < 16; i++)
+		pad[i] = 0x36363636;
+	SHA256_Transform(tstate, pad, 0);
+	SHA256_Transform(tstate, salt, 1);
+	SHA256_Transform(tstate, salt+16, 1);
+	SHA256_Transform(tstate, ihash_finalblk, 0);
+	memcpy(pad, tstate, 32);
+	memcpy(pad+8, outerpad, 32);
+
+	/* Feed the inner hash to the outer SHA256 operation. */
+	SHA256_Transform(ostate, pad, 0);
+	/* Finish the outer SHA256 operation. */
+	return byteswap(ostate[7]);
+}
+
+
+/**
+ * salsa20_8(B):
+ * Apply the salsa20/8 core to the provided block.
+ */
+static inline void
+salsa20_8(uint32_t B[16], const uint32_t Bx[16])
+{
+	uint32_t x00,x01,x02,x03,x04,x05,x06,x07,x08,x09,x10,x11,x12,x13,x14,x15;
+	size_t i;
+
+	x00 = (B[ 0] ^= Bx[ 0]);
+	x01 = (B[ 1] ^= Bx[ 1]);
+	x02 = (B[ 2] ^= Bx[ 2]);
+	x03 = (B[ 3] ^= Bx[ 3]);
+	x04 = (B[ 4] ^= Bx[ 4]);
+	x05 = (B[ 5] ^= Bx[ 5]);
+	x06 = (B[ 6] ^= Bx[ 6]);
+	x07 = (B[ 7] ^= Bx[ 7]);
+	x08 = (B[ 8] ^= Bx[ 8]);
+	x09 = (B[ 9] ^= Bx[ 9]);
+	x10 = (B[10] ^= Bx[10]);
+	x11 = (B[11] ^= Bx[11]);
+	x12 = (B[12] ^= Bx[12]);
+	x13 = (B[13] ^= Bx[13]);
+	x14 = (B[14] ^= Bx[14]);
+	x15 = (B[15] ^= Bx[15]);
+	for (i = 0; i < 8; i += 2) {
+#define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
+		/* Operate on columns. */
+		x04 ^= R(x00+x12, 7);	x09 ^= R(x05+x01, 7);	x14 ^= R(x10+x06, 7);	x03 ^= R(x15+x11, 7);
+		x08 ^= R(x04+x00, 9);	x13 ^= R(x09+x05, 9);	x02 ^= R(x14+x10, 9);	x07 ^= R(x03+x15, 9);
+		x12 ^= R(x08+x04,13);	x01 ^= R(x13+x09,13);	x06 ^= R(x02+x14,13);	x11 ^= R(x07+x03,13);
+		x00 ^= R(x12+x08,18);	x05 ^= R(x01+x13,18);	x10 ^= R(x06+x02,18);	x15 ^= R(x11+x07,18);
+
+		/* Operate on rows. */
+		x01 ^= R(x00+x03, 7);	x06 ^= R(x05+x04, 7);	x11 ^= R(x10+x09, 7);	x12 ^= R(x15+x14, 7);
+		x02 ^= R(x01+x00, 9);	x07 ^= R(x06+x05, 9);	x08 ^= R(x11+x10, 9);	x13 ^= R(x12+x15, 9);
+		x03 ^= R(x02+x01,13);	x04 ^= R(x07+x06,13);	x09 ^= R(x08+x11,13);	x14 ^= R(x13+x12,13);
+		x00 ^= R(x03+x02,18);	x05 ^= R(x04+x07,18);	x10 ^= R(x09+x08,18);	x15 ^= R(x14+x13,18);
+#undef R
+	}
+	B[ 0] += x00;
+	B[ 1] += x01;
+	B[ 2] += x02;
+	B[ 3] += x03;
+	B[ 4] += x04;
+	B[ 5] += x05;
+	B[ 6] += x06;
+	B[ 7] += x07;
+	B[ 8] += x08;
+	B[ 9] += x09;
+	B[10] += x10;
+	B[11] += x11;
+	B[12] += x12;
+	B[13] += x13;
+	B[14] += x14;
+	B[15] += x15;
+}
+
+/* cpu and memory intensive function to transform a 80 byte buffer into a 32 byte output
+   scratchpad size needs to be at least 63 + (128 * r * p) + (256 * r + 64) + (128 * r * N) bytes
+ */
+static uint32_t scrypt_1024_1_1_256_sp(const uint32_t* input, char* scratchpad)
+{
+	uint32_t * V;
+	uint32_t X[32];
+	uint32_t i;
+	uint32_t j;
+	uint32_t k;
+	uint64_t *p1, *p2;
+
+	p1 = (uint64_t *)X;
+	V = (uint32_t *)(((uintptr_t)(scratchpad) + 63) & ~ (uintptr_t)(63));
+
+	PBKDF2_SHA256_80_128(input, X);
+
+	for (i = 0; i < 1024; i += 2) {
+		memcpy(&V[i * 32], X, 128);
+
+		salsa20_8(&X[0], &X[16]);
+		salsa20_8(&X[16], &X[0]);
+
+		memcpy(&V[(i + 1) * 32], X, 128);
+
+		salsa20_8(&X[0], &X[16]);
+		salsa20_8(&X[16], &X[0]);
+	}
+	for (i = 0; i < 1024; i += 2) {
+		j = X[16] & 1023;
+		p2 = (uint64_t *)(&V[j * 32]);
+		for(k = 0; k < 16; k++)
+			p1[k] ^= p2[k];
+
+		salsa20_8(&X[0], &X[16]);
+		salsa20_8(&X[16], &X[0]);
+
+		j = X[16] & 1023;
+		p2 = (uint64_t *)(&V[j * 32]);
+		for(k = 0; k < 16; k++)
+			p1[k] ^= p2[k];
+
+		salsa20_8(&X[0], &X[16]);
+		salsa20_8(&X[16], &X[0]);
+	}
+
+	return PBKDF2_SHA256_80_128_32(input, X);
+}
+
+bool scanhash_scrypt(struct thr_info *thr, const unsigned char *pmidstate, unsigned char *pdata,
+	unsigned char *phash1, unsigned char *phash,
+	const unsigned char *ptarget,
+	uint32_t max_nonce, uint32_t *last_nonce,
+	uint32_t n)
+{
+	uint32_t *nonce = (uint32_t *)(pdata + 76);
+	unsigned char *scratchbuf;
+	uint32_t data[20];
+	uint32_t tmp_hash7;
+	uint32_t Htarg = ((const uint32_t *)ptarget)[7];
+	bool ret = false;
+	int i;
+
+	be32enc_vect(data, (const uint32_t *)pdata, 19);
+
+	scratchbuf = malloc(131583);
+	if (unlikely(!scratchbuf)) {
+		applog(LOG_ERR, "Failed to malloc scratchbuf in scanhash_scrypt");
+		return ret;
+	}
+
+	while(1) {
+		*nonce = ++n;
+		data[19] = n;
+		tmp_hash7 = scrypt_1024_1_1_256_sp(data, scratchbuf);
+
+		if (tmp_hash7 <= Htarg) {
+			((uint32_t *)pdata)[19] = byteswap(n);
+			*last_nonce = n;
+			ret = true;
+			break;
+		}
+
+		if ((n >= max_nonce) || thr->work_restart) {
+			*last_nonce = n;
+			break;
+		}
+	}
+out_ret:
+	return ret;
+}
+