Initial code.

src/lib/crypto/crypto_scrypt-ref.c

+/*-
+ * Copyright 2009 Colin Percival
+ * 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 "scrypt_platform.h"
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sha256.h"
+#include "sysendian.h"
+
+#include "crypto_scrypt.h"
+
+static void blkcpy(uint8_t *, uint8_t *, size_t);
+static void blkxor(uint8_t *, uint8_t *, size_t);
+static void salsa20_8(uint8_t[64]);
+static void blockmix_salsa8(uint8_t *, uint8_t *, size_t);
+static uint64_t integerify(uint8_t *, size_t);
+static void smix(uint8_t *, size_t, uint64_t, uint8_t *, uint8_t *);
+
+static void
+blkcpy(uint8_t * dest, uint8_t * src, size_t len)
+{
+        size_t i;
+
+        for (i = 0; i < len; i++)
+                dest[i] = src[i];
+}
+
+static void
+blkxor(uint8_t * dest, uint8_t * src, size_t len)
+{
+        size_t i;
+
+        for (i = 0; i < len; i++)
+                dest[i] ^= src[i];
+}
+
+/**
+ * salsa20_8(B):
+ * Apply the salsa20/8 core to the provided block.
+ */
+static void
+salsa20_8(uint8_t B[64])
+{
+        uint32_t B32[16];
+        uint32_t x[16];
+        size_t i;
+
+        /* Convert little-endian values in. */
+        for (i = 0; i < 16; i++)
+                B32[i] = le32dec(&B[i * 4]);
+
+        /* Compute x = doubleround^4(B32). */
+        for (i = 0; i < 16; i++)
+                x[i] = B32[i];
+        for (i = 0; i < 8; i += 2) {
+#define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
+                /* Operate on columns. */
+                x[ 4] ^= R(x[ 0]+x[12], 7);  x[ 8] ^= R(x[ 4]+x[ 0], 9);
+                x[12] ^= R(x[ 8]+x[ 4],13);  x[ 0] ^= R(x[12]+x[ 8],18);
+
+                x[ 9] ^= R(x[ 5]+x[ 1], 7);  x[13] ^= R(x[ 9]+x[ 5], 9);
+                x[ 1] ^= R(x[13]+x[ 9],13);  x[ 5] ^= R(x[ 1]+x[13],18);
+
+                x[14] ^= R(x[10]+x[ 6], 7);  x[ 2] ^= R(x[14]+x[10], 9);
+                x[ 6] ^= R(x[ 2]+x[14],13);  x[10] ^= R(x[ 6]+x[ 2],18);
+
+                x[ 3] ^= R(x[15]+x[11], 7);  x[ 7] ^= R(x[ 3]+x[15], 9);
+                x[11] ^= R(x[ 7]+x[ 3],13);  x[15] ^= R(x[11]+x[ 7],18);
+
+                /* Operate on rows. */
+                x[ 1] ^= R(x[ 0]+x[ 3], 7);  x[ 2] ^= R(x[ 1]+x[ 0], 9);
+                x[ 3] ^= R(x[ 2]+x[ 1],13);  x[ 0] ^= R(x[ 3]+x[ 2],18);
+
+                x[ 6] ^= R(x[ 5]+x[ 4], 7);  x[ 7] ^= R(x[ 6]+x[ 5], 9);
+                x[ 4] ^= R(x[ 7]+x[ 6],13);  x[ 5] ^= R(x[ 4]+x[ 7],18);
+
+                x[11] ^= R(x[10]+x[ 9], 7);  x[ 8] ^= R(x[11]+x[10], 9);
+                x[ 9] ^= R(x[ 8]+x[11],13);  x[10] ^= R(x[ 9]+x[ 8],18);
+
+                x[12] ^= R(x[15]+x[14], 7);  x[13] ^= R(x[12]+x[15], 9);
+                x[14] ^= R(x[13]+x[12],13);  x[15] ^= R(x[14]+x[13],18);
+#undef R
+        }
+
+        /* Compute B32 = B32 + x. */
+        for (i = 0; i < 16; i++)
+                B32[i] += x[i];
+
+        /* Convert little-endian values out. */
+        for (i = 0; i < 16; i++)
+                le32enc(&B[4 * i], B32[i]);
+}
+
+/**
+ * blockmix_salsa8(B, Y, r):
+ * Compute B = BlockMix_{salsa20/8, r}(B).  The input B must be 128r bytes in
+ * length; the temporary space Y must also be the same size.
+ */
+static void
+blockmix_salsa8(uint8_t * B, uint8_t * Y, size_t r)
+{
+        uint8_t X[64];
+        size_t i;
+
+        /* 1: X <-- B_{2r - 1} */
+        blkcpy(X, &B[(2 * r - 1) * 64], 64);
+
+        /* 2: for i = 0 to 2r - 1 do */
+        for (i = 0; i < 2 * r; i++) {
+                /* 3: X <-- H(X \xor B_i) */
+                blkxor(X, &B[i * 64], 64);
+                salsa20_8(X);
+
+                /* 4: Y_i <-- X */
+                blkcpy(&Y[i * 64], X, 64);
+        }
+
+        /* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
+        for (i = 0; i < r; i++)
+                blkcpy(&B[i * 64], &Y[(i * 2) * 64], 64);
+        for (i = 0; i < r; i++)
+                blkcpy(&B[(i + r) * 64], &Y[(i * 2 + 1) * 64], 64);
+}
+
+/**
+ * integerify(B, r):
+ * Return the result of parsing B_{2r-1} as a little-endian integer.
+ */
+static uint64_t
+integerify(uint8_t * B, size_t r)
+{
+        uint8_t * X = &B[(2 * r - 1) * 64];
+
+        return (le64dec(X));
+}
+
+/**
+ * smix(B, r, N, V, XY):
+ * Compute B = SMix_r(B, N).  The input B must be 128r bytes in length; the
+ * temporary storage V must be 128rN bytes in length; the temporary storage
+ * XY must be 256r bytes in length.  The value N must be a power of 2.
+ */
+static void
+smix(uint8_t * B, size_t r, uint64_t N, uint8_t * V, uint8_t * XY)
+{
+        uint8_t * X = XY;
+        uint8_t * Y = &XY[128 * r];
+        uint64_t i;
+        uint64_t j;
+
+        /* 1: X <-- B */
+        blkcpy(X, B, 128 * r);
+
+        /* 2: for i = 0 to N - 1 do */
+        for (i = 0; i < N; i++) {
+                /* 3: V_i <-- X */
+                blkcpy(&V[i * (128 * r)], X, 128 * r);
+
+                /* 4: X <-- H(X) */
+                blockmix_salsa8(X, Y, r);
+        }
+
+        /* 6: for i = 0 to N - 1 do */
+        for (i = 0; i < N; i++) {
+                /* 7: j <-- Integerify(X) mod N */
+                j = integerify(X, r) & (N - 1);
+
+                /* 8: X <-- H(X \xor V_j) */
+                blkxor(X, &V[j * (128 * r)], 128 * r);
+                blockmix_salsa8(X, Y, r);
+        }
+
+        /* 10: B' <-- X */
+        blkcpy(B, X, 128 * r);
+}
+
+/**
+ * crypto_scrypt(passwd, passwdlen, salt, saltlen, N, r, p, buf, buflen):
+ * Compute scrypt(passwd[0 .. passwdlen - 1], salt[0 .. saltlen - 1], N, r,
+ * p, buflen) and write the result into buf.  The parameters r, p, and buflen
+ * must satisfy r * p < 2^30 and buflen <= (2^32 - 1) * 32.  The parameter N
+ * must be a power of 2.
+ *
+ * Return 0 on success; or -1 on error.
+ */
+int
+crypto_scrypt(const uint8_t * passwd, size_t passwdlen,
+    const uint8_t * salt, size_t saltlen, uint64_t N, uint32_t r, uint32_t p,
+    uint8_t * buf, size_t buflen)
+{
+        uint8_t * B;
+        uint8_t * V;
+        uint8_t * XY;
+        uint32_t i;
+
+        /* Sanity-check parameters. */
+#if SIZE_MAX > UINT32_MAX
+        if (buflen > (((uint64_t)(1) << 32) - 1) * 32) {
+                errno = EFBIG;
+                goto err0;
+        }
+#endif
+        if ((uint64_t)(r) * (uint64_t)(p) >= (1 << 30)) {
+                errno = EFBIG;
+                goto err0;
+        }
+        if (((N & (N - 1)) != 0) || (N == 0)) {
+                errno = EINVAL;
+                goto err0;
+        }
+        if ((r > SIZE_MAX / 128 / p) ||
+#if SIZE_MAX / 256 <= UINT32_MAX
+            (r > SIZE_MAX / 256) ||
+#endif
+            (N > SIZE_MAX / 128 / r)) {
+                errno = ENOMEM;
+                goto err0;
+        }
+
+        /* Allocate memory. */
+        if ((B = malloc(128 * r * p)) == NULL)
+                goto err0;
+        if ((XY = malloc(256 * r)) == NULL)
+                goto err1;
+        if ((V = malloc(128 * r * N)) == NULL)
+                goto err2;
+
+        /* 1: (B_0 ... B_{p-1}) <-- PBKDF2(P, S, 1, p * MFLen) */
+        PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, 1, B, p * 128 * r);
+
+        /* 2: for i = 0 to p - 1 do */
+        for (i = 0; i < p; i++) {
+                /* 3: B_i <-- MF(B_i, N) */
+                smix(&B[i * 128 * r], r, N, V, XY);
+        }
+
+        /* 5: DK <-- PBKDF2(P, B, 1, dkLen) */
+        PBKDF2_SHA256(passwd, passwdlen, B, p * 128 * r, 1, buf, buflen);
+
+        /* Free memory. */
+        free(V);
+        free(XY);
+        free(B);
+
+        /* Success! */
+        return (0);
+
+err2:
+        free(XY);
+err1:
+        free(B);
+err0:
+        /* Failure! */
+        return (-1);
+}