| /*- |
| * 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> |
| |
| #ifdef USE_OPENSSL_PBKDF2 |
| #include <openssl/evp.h> |
| #else |
| #include "sha256.h" |
| #endif |
| #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) */ |
| #ifdef USE_OPENSSL_PBKDF2 |
| PKCS5_PBKDF2_HMAC((const char *)passwd, passwdlen, salt, saltlen, 1, EVP_sha256(), p * 128 * r, B); |
| #else |
| PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, 1, B, p * 128 * r); |
| #endif |
| |
| /* 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) */ |
| #ifdef USE_OPENSSL_PBKDF2 |
| PKCS5_PBKDF2_HMAC((const char *)passwd, passwdlen, B, p * 128 * r, 1, EVP_sha256(), buflen, buf); |
| #else |
| PBKDF2_SHA256(passwd, passwdlen, B, p * 128 * r, 1, buf, buflen); |
| #endif |
| |
| /* Free memory. */ |
| free(V); |
| free(XY); |
| free(B); |
| |
| /* Success! */ |
| return (0); |
| |
| err2: |
| free(XY); |
| err1: |
| free(B); |
| err0: |
| /* Failure! */ |
| return (-1); |
| } |