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authorWilliam Pitcock <nenolod@dereferenced.org>2011-12-19 01:25:09 -0600
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2011-12-22 14:07:08 +0100
commit3ac5fd7ecaeb6721d812c2b93e446bf9a31acdde (patch)
tree8c4213f8174516406a1e3f830fcfb34ddea909f4
parent4c24dabb9cea4c8148d7a7efc7a1df694424c483 (diff)
libcrypt: add support for SHA256-CRYPT password hashing
This is based on Ulrich Drepper's implementation in GLIBC, but hacked up to work in uClibc. The differences from the GLIBC version are as follows: - b64_from_24bit() has been converted into a macro - Usage of GLIBC-isms (such as libc_freeres_ptr) have been removed It is enabled by the UCLIBC_HAS_SHA256_CRYPT_IMPL configuration symbol. You must have UCLIBC_HAS_CRYPT_IMPL enabled as well. Signed-off-by: William Pitcock <nenolod@dereferenced.org> Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
-rw-r--r--extra/Configs/Config.in7
-rw-r--r--libcrypt/Makefile.in1
-rw-r--r--libcrypt/crypt.c3
-rw-r--r--libcrypt/libcrypt.h2
-rw-r--r--libcrypt/sha256-crypt.c326
-rw-r--r--libcrypt/sha256.c294
-rw-r--r--libcrypt/sha256.h58
7 files changed, 691 insertions, 0 deletions
diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in
index bbde976d0..d4960fbbf 100644
--- a/extra/Configs/Config.in
+++ b/extra/Configs/Config.in
@@ -1174,6 +1174,13 @@ config UCLIBC_HAS_CRYPT_IMPL
help
libcrypt contains crypt(), setkey() and encrypt()
+config UCLIBC_HAS_SHA256_CRYPT_IMPL
+ bool "libcrypt SHA256 support"
+ depends on UCLIBC_HAS_CRYPT_IMPL
+ help
+ This adds support for SHA256 password hashing via the crypt() function.
+ Say N here if you do not need SHA256 crypt support.
+
config UCLIBC_HAS_SHA512_CRYPT_IMPL
bool "libcrypt SHA512 support"
depends on UCLIBC_HAS_CRYPT_IMPL
diff --git a/libcrypt/Makefile.in b/libcrypt/Makefile.in
index 2fceaedb9..94753f4ad 100644
--- a/libcrypt/Makefile.in
+++ b/libcrypt/Makefile.in
@@ -21,6 +21,7 @@ libcrypt_OUT := $(top_builddir)libcrypt
libcrypt_SRC-y :=
libcrypt_SRC-$(UCLIBC_HAS_CRYPT_IMPL) += crypt.c des.c md5.c
+libcrypt_SRC-$(UCLIBC_HAS_SHA256_CRYPT_IMPL) += sha256.c sha256-crypt.c
libcrypt_SRC-$(UCLIBC_HAS_SHA512_CRYPT_IMPL) += sha512.c sha512-crypt.c
libcrypt_SRC-$(UCLIBC_HAS_CRYPT_STUB) += crypt_stub.c
diff --git a/libcrypt/crypt.c b/libcrypt/crypt.c
index b5bf9ee0f..188a6a081 100644
--- a/libcrypt/crypt.c
+++ b/libcrypt/crypt.c
@@ -19,6 +19,9 @@ static const struct {
const crypt_impl_f crypt_impl;
} crypt_impl_tab[] = {
{ "$1$", __md5_crypt },
+#ifdef __UCLIBC_HAS_SHA256_CRYPT_IMPL__
+ { "$5$", __sha256_crypt },
+#endif
#ifdef __UCLIBC_HAS_SHA512_CRYPT_IMPL__
{ "$6$", __sha512_crypt },
#endif
diff --git a/libcrypt/libcrypt.h b/libcrypt/libcrypt.h
index fcad6aed0..67733d17f 100644
--- a/libcrypt/libcrypt.h
+++ b/libcrypt/libcrypt.h
@@ -9,9 +9,11 @@
#define __LIBCRYPT_H__
extern char *__md5_crypt(const unsigned char *pw, const unsigned char *salt) attribute_hidden;
+extern char *__sha256_crypt(const unsigned char *pw, const unsigned char *salt) attribute_hidden;
extern char *__sha512_crypt(const unsigned char *pw, const unsigned char *salt) attribute_hidden;
extern char *__des_crypt(const unsigned char *pw, const unsigned char *salt) attribute_hidden;
+extern char *__sha256_crypt_r (const char *key, const char *salt, char *buffer, int buflen) attribute_hidden;
extern char *__sha512_crypt_r (const char *key, const char *salt, char *buffer, int buflen) attribute_hidden;
/* shut up gcc-4.x signed warnings */
diff --git a/libcrypt/sha256-crypt.c b/libcrypt/sha256-crypt.c
new file mode 100644
index 000000000..44221482f
--- /dev/null
+++ b/libcrypt/sha256-crypt.c
@@ -0,0 +1,326 @@
+/* One way encryption based on SHA256 sum.
+ Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2007.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/param.h>
+
+#include "sha256.h"
+#include "libcrypt.h"
+
+/* Define our magic string to mark salt for SHA256 "encryption"
+ replacement. */
+static const char sha256_salt_prefix[] = "$5$";
+
+/* Prefix for optional rounds specification. */
+static const char sha256_rounds_prefix[] = "rounds=";
+
+/* Maximum salt string length. */
+#define SALT_LEN_MAX 16
+/* Default number of rounds if not explicitly specified. */
+#define ROUNDS_DEFAULT 5000
+/* Minimum number of rounds. */
+#define ROUNDS_MIN 1000
+/* Maximum number of rounds. */
+#define ROUNDS_MAX 999999999
+
+/* Table with characters for base64 transformation. */
+static const char b64t[64] =
+"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+#define B64_FROM_24BIT(b2, b1, b0, steps) \
+ { \
+ int n = (steps); \
+ unsigned int w = ((b2) << 16) | ((b1) << 8) | (b0); \
+ while (n-- > 0 && buflen > 0) \
+ { \
+ *cp++ = b64t[w & 0x3f]; \
+ --buflen; \
+ w >>= 6; \
+ } \
+ }
+
+char *
+__sha256_crypt_r (const char *key,
+ const char *salt,
+ char *buffer,
+ int buflen)
+{
+ unsigned char alt_result[32]
+ __attribute__ ((__aligned__ (__alignof__ (uint32_t))));
+ unsigned char temp_result[32]
+ __attribute__ ((__aligned__ (__alignof__ (uint32_t))));
+ size_t salt_len;
+ size_t key_len;
+ size_t cnt;
+ char *cp;
+ char *copied_key = NULL;
+ char *copied_salt = NULL;
+ char *p_bytes;
+ char *s_bytes;
+ /* Default number of rounds. */
+ size_t rounds = ROUNDS_DEFAULT;
+ bool rounds_custom = false;
+
+ /* Find beginning of salt string. The prefix should normally always
+ be present. Just in case it is not. */
+ if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
+ /* Skip salt prefix. */
+ salt += sizeof (sha256_salt_prefix) - 1;
+
+ if (strncmp (salt, sha256_rounds_prefix, sizeof (sha256_rounds_prefix) - 1)
+ == 0)
+ {
+ const char *num = salt + sizeof (sha256_rounds_prefix) - 1;
+ char *endp;
+ unsigned long int srounds = strtoul (num, &endp, 10);
+ if (*endp == '$')
+ {
+ salt = endp + 1;
+ rounds = MAX (ROUNDS_MIN, MIN (srounds, ROUNDS_MAX));
+ rounds_custom = true;
+ }
+ }
+
+ salt_len = MIN (strcspn (salt, "$"), SALT_LEN_MAX);
+ key_len = strlen (key);
+
+ if ((key - (char *) 0) % __alignof__ (uint32_t) != 0)
+ {
+ char *tmp = (char *) alloca (key_len + __alignof__ (uint32_t));
+ key = copied_key =
+ memcpy (tmp + __alignof__ (uint32_t)
+ - (tmp - (char *) 0) % __alignof__ (uint32_t),
+ key, key_len);
+ assert ((key - (char *) 0) % __alignof__ (uint32_t) == 0);
+ }
+
+ if ((salt - (char *) 0) % __alignof__ (uint32_t) != 0)
+ {
+ char *tmp = (char *) alloca (salt_len + __alignof__ (uint32_t));
+ salt = copied_salt =
+ memcpy (tmp + __alignof__ (uint32_t)
+ - (tmp - (char *) 0) % __alignof__ (uint32_t),
+ salt, salt_len);
+ assert ((salt - (char *) 0) % __alignof__ (uint32_t) == 0);
+ }
+
+ struct sha256_ctx ctx;
+ struct sha256_ctx alt_ctx;
+
+ /* Prepare for the real work. */
+ __sha256_init_ctx (&ctx);
+
+ /* Add the key string. */
+ __sha256_process_bytes (key, key_len, &ctx);
+
+ /* The last part is the salt string. This must be at most 16
+ characters and it ends at the first `$' character. */
+ __sha256_process_bytes (salt, salt_len, &ctx);
+
+
+ /* Compute alternate SHA256 sum with input KEY, SALT, and KEY. The
+ final result will be added to the first context. */
+ __sha256_init_ctx (&alt_ctx);
+
+ /* Add key. */
+ __sha256_process_bytes (key, key_len, &alt_ctx);
+
+ /* Add salt. */
+ __sha256_process_bytes (salt, salt_len, &alt_ctx);
+
+ /* Add key again. */
+ __sha256_process_bytes (key, key_len, &alt_ctx);
+
+ /* Now get result of this (32 bytes) and add it to the other
+ context. */
+ __sha256_finish_ctx (&alt_ctx, alt_result);
+
+ /* Add for any character in the key one byte of the alternate sum. */
+ for (cnt = key_len; cnt > 32; cnt -= 32)
+ __sha256_process_bytes (alt_result, 32, &ctx);
+ __sha256_process_bytes (alt_result, cnt, &ctx);
+
+ /* Take the binary representation of the length of the key and for every
+ 1 add the alternate sum, for every 0 the key. */
+ for (cnt = key_len; cnt > 0; cnt >>= 1)
+ if ((cnt & 1) != 0)
+ __sha256_process_bytes (alt_result, 32, &ctx);
+ else
+ __sha256_process_bytes (key, key_len, &ctx);
+
+ /* Create intermediate result. */
+ __sha256_finish_ctx (&ctx, alt_result);
+
+ /* Start computation of P byte sequence. */
+ __sha256_init_ctx (&alt_ctx);
+
+ /* For every character in the password add the entire password. */
+ for (cnt = 0; cnt < key_len; ++cnt)
+ __sha256_process_bytes (key, key_len, &alt_ctx);
+
+ /* Finish the digest. */
+ __sha256_finish_ctx (&alt_ctx, temp_result);
+
+ /* Create byte sequence P. */
+ cp = p_bytes = alloca (key_len);
+ for (cnt = key_len; cnt >= 32; cnt -= 32)
+ cp = mempcpy (cp, temp_result, 32);
+ memcpy (cp, temp_result, cnt);
+
+ /* Start computation of S byte sequence. */
+ __sha256_init_ctx (&alt_ctx);
+
+ /* For every character in the password add the entire password. */
+ for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt)
+ __sha256_process_bytes (salt, salt_len, &alt_ctx);
+
+ /* Finish the digest. */
+ __sha256_finish_ctx (&alt_ctx, temp_result);
+
+ /* Create byte sequence S. */
+ cp = s_bytes = alloca (salt_len);
+ for (cnt = salt_len; cnt >= 32; cnt -= 32)
+ cp = mempcpy (cp, temp_result, 32);
+ memcpy (cp, temp_result, cnt);
+
+ /* Repeatedly run the collected hash value through SHA256 to burn
+ CPU cycles. */
+ for (cnt = 0; cnt < rounds; ++cnt)
+ {
+ /* New context. */
+ __sha256_init_ctx (&ctx);
+
+ /* Add key or last result. */
+ if ((cnt & 1) != 0)
+ __sha256_process_bytes (p_bytes, key_len, &ctx);
+ else
+ __sha256_process_bytes (alt_result, 32, &ctx);
+
+ /* Add salt for numbers not divisible by 3. */
+ if (cnt % 3 != 0)
+ __sha256_process_bytes (s_bytes, salt_len, &ctx);
+
+ /* Add key for numbers not divisible by 7. */
+ if (cnt % 7 != 0)
+ __sha256_process_bytes (p_bytes, key_len, &ctx);
+
+ /* Add key or last result. */
+ if ((cnt & 1) != 0)
+ __sha256_process_bytes (alt_result, 32, &ctx);
+ else
+ __sha256_process_bytes (p_bytes, key_len, &ctx);
+
+ /* Create intermediate result. */
+ __sha256_finish_ctx (&ctx, alt_result);
+ }
+
+ /* Now we can construct the result string. It consists of three
+ parts. */
+ cp = stpncpy (buffer, sha256_salt_prefix, MAX (0, buflen));
+ buflen -= sizeof (sha256_salt_prefix) - 1;
+
+ if (rounds_custom)
+ {
+ int n = snprintf (cp, MAX (0, buflen), "%s%zu$",
+ sha256_rounds_prefix, rounds);
+ cp += n;
+ buflen -= n;
+ }
+
+ cp = stpncpy (cp, salt, MIN ((size_t) MAX (0, buflen), salt_len));
+ buflen -= MIN ((size_t) MAX (0, buflen), salt_len);
+
+ if (buflen > 0)
+ {
+ *cp++ = '$';
+ --buflen;
+ }
+
+ B64_FROM_24BIT (alt_result[0], alt_result[10], alt_result[20], 4);
+ B64_FROM_24BIT (alt_result[21], alt_result[1], alt_result[11], 4);
+ B64_FROM_24BIT (alt_result[12], alt_result[22], alt_result[2], 4);
+ B64_FROM_24BIT (alt_result[3], alt_result[13], alt_result[23], 4);
+ B64_FROM_24BIT (alt_result[24], alt_result[4], alt_result[14], 4);
+ B64_FROM_24BIT (alt_result[15], alt_result[25], alt_result[5], 4);
+ B64_FROM_24BIT (alt_result[6], alt_result[16], alt_result[26], 4);
+ B64_FROM_24BIT (alt_result[27], alt_result[7], alt_result[17], 4);
+ B64_FROM_24BIT (alt_result[18], alt_result[28], alt_result[8], 4);
+ B64_FROM_24BIT (alt_result[9], alt_result[19], alt_result[29], 4);
+ B64_FROM_24BIT (0, alt_result[31], alt_result[30], 3);
+ if (buflen <= 0)
+ {
+ __set_errno (ERANGE);
+ buffer = NULL;
+ }
+ else
+ *cp = '\0'; /* Terminate the string. */
+
+ /* Clear the buffer for the intermediate result so that people
+ attaching to processes or reading core dumps cannot get any
+ information. We do it in this way to clear correct_words[]
+ inside the SHA256 implementation as well. */
+ __sha256_init_ctx (&ctx);
+ __sha256_finish_ctx (&ctx, alt_result);
+ memset (&ctx, '\0', sizeof (ctx));
+ memset (&alt_ctx, '\0', sizeof (alt_ctx));
+
+ memset (temp_result, '\0', sizeof (temp_result));
+ memset (p_bytes, '\0', key_len);
+ memset (s_bytes, '\0', salt_len);
+ if (copied_key != NULL)
+ memset (copied_key, '\0', key_len);
+ if (copied_salt != NULL)
+ memset (copied_salt, '\0', salt_len);
+
+ return buffer;
+}
+
+static char *buffer;
+
+/* This entry point is equivalent to the `crypt' function in Unix
+ libcs. */
+char *
+__sha256_crypt (const unsigned char *key, const unsigned char *salt)
+{
+ /* We don't want to have an arbitrary limit in the size of the
+ password. We can compute an upper bound for the size of the
+ result in advance and so we can prepare the buffer we pass to
+ `sha256_crypt_r'. */
+ static int buflen;
+ int needed = (sizeof (sha256_salt_prefix) - 1
+ + sizeof (sha256_rounds_prefix) + 9 + 1
+ + strlen (salt) + 1 + 43 + 1);
+
+ if (buflen < needed)
+ {
+ char *new_buffer = (char *) realloc (buffer, needed);
+ if (new_buffer == NULL)
+ return NULL;
+
+ buffer = new_buffer;
+ buflen = needed;
+ }
+
+ return __sha256_crypt_r ((const char *) key, (const char *) salt, buffer, buflen);
+}
diff --git a/libcrypt/sha256.c b/libcrypt/sha256.c
new file mode 100644
index 000000000..e652a6705
--- /dev/null
+++ b/libcrypt/sha256.c
@@ -0,0 +1,294 @@
+/* Functions to compute SHA256 message digest of files or memory blocks.
+ according to the definition of SHA256 in FIPS 180-2.
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* Written by Ulrich Drepper <drepper@redhat.com>, 2007. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <endian.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "sha256.h"
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# ifdef _LIBC
+# include <byteswap.h>
+# define SWAP(n) bswap_32 (n)
+# else
+# define SWAP(n) \
+ (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+# endif
+#else
+# define SWAP(n) (n)
+#endif
+
+
+/* This array contains the bytes used to pad the buffer to the next
+ 64-byte boundary. (FIPS 180-2:5.1.1) */
+static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
+
+
+/* Constants for SHA256 from FIPS 180-2:4.2.2. */
+static const uint32_t K[64] =
+ {
+ 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+ 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+ 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+ 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+ 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+ 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+ 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+ 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+ 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+ 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+ 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+ 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+ 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+ 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+ 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+ 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+ };
+
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+ It is assumed that LEN % 64 == 0. */
+static void
+sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx)
+{
+ const uint32_t *words = buffer;
+ size_t nwords = len / sizeof (uint32_t);
+ uint32_t a = ctx->H[0];
+ uint32_t b = ctx->H[1];
+ uint32_t c = ctx->H[2];
+ uint32_t d = ctx->H[3];
+ uint32_t e = ctx->H[4];
+ uint32_t f = ctx->H[5];
+ uint32_t g = ctx->H[6];
+ uint32_t h = ctx->H[7];
+
+ /* First increment the byte count. FIPS 180-2 specifies the possible
+ length of the file up to 2^64 bits. Here we only compute the
+ number of bytes. Do a double word increment. */
+ ctx->total[0] += len;
+ if (ctx->total[0] < len)
+ ++ctx->total[1];
+
+ /* Process all bytes in the buffer with 64 bytes in each round of
+ the loop. */
+ while (nwords > 0)
+ {
+ uint32_t W[64];
+ uint32_t a_save = a;
+ uint32_t b_save = b;
+ uint32_t c_save = c;
+ uint32_t d_save = d;
+ uint32_t e_save = e;
+ uint32_t f_save = f;
+ uint32_t g_save = g;
+ uint32_t h_save = h;
+
+ /* Operators defined in FIPS 180-2:4.1.2. */
+#define Ch(x, y, z) ((x & y) ^ (~x & z))
+#define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
+#define S0(x) (CYCLIC (x, 2) ^ CYCLIC (x, 13) ^ CYCLIC (x, 22))
+#define S1(x) (CYCLIC (x, 6) ^ CYCLIC (x, 11) ^ CYCLIC (x, 25))
+#define R0(x) (CYCLIC (x, 7) ^ CYCLIC (x, 18) ^ (x >> 3))
+#define R1(x) (CYCLIC (x, 17) ^ CYCLIC (x, 19) ^ (x >> 10))
+
+ /* It is unfortunate that C does not provide an operator for
+ cyclic rotation. Hope the C compiler is smart enough. */
+#define CYCLIC(w, s) ((w >> s) | (w << (32 - s)))
+
+ /* Compute the message schedule according to FIPS 180-2:6.2.2 step 2. */
+ for (unsigned int t = 0; t < 16; ++t)
+ {
+ W[t] = SWAP (*words);
+ ++words;
+ }
+ for (unsigned int t = 16; t < 64; ++t)
+ W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
+
+ /* The actual computation according to FIPS 180-2:6.2.2 step 3. */
+ for (unsigned int t = 0; t < 64; ++t)
+ {
+ uint32_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
+ uint32_t T2 = S0 (a) + Maj (a, b, c);
+ h = g;
+ g = f;
+ f = e;
+ e = d + T1;
+ d = c;
+ c = b;
+ b = a;
+ a = T1 + T2;
+ }
+
+ /* Add the starting values of the context according to FIPS 180-2:6.2.2
+ step 4. */
+ a += a_save;
+ b += b_save;
+ c += c_save;
+ d += d_save;
+ e += e_save;
+ f += f_save;
+ g += g_save;
+ h += h_save;
+
+ /* Prepare for the next round. */
+ nwords -= 16;
+ }
+
+ /* Put checksum in context given as argument. */
+ ctx->H[0] = a;
+ ctx->H[1] = b;
+ ctx->H[2] = c;
+ ctx->H[3] = d;
+ ctx->H[4] = e;
+ ctx->H[5] = f;
+ ctx->H[6] = g;
+ ctx->H[7] = h;
+}
+
+
+/* Initialize structure containing state of computation.
+ (FIPS 180-2:5.3.2) */
+void
+__sha256_init_ctx (struct sha256_ctx *ctx)
+{
+ ctx->H[0] = 0x6a09e667;
+ ctx->H[1] = 0xbb67ae85;
+ ctx->H[2] = 0x3c6ef372;
+ ctx->H[3] = 0xa54ff53a;
+ ctx->H[4] = 0x510e527f;
+ ctx->H[5] = 0x9b05688c;
+ ctx->H[6] = 0x1f83d9ab;
+ ctx->H[7] = 0x5be0cd19;
+
+ ctx->total[0] = ctx->total[1] = 0;
+ ctx->buflen = 0;
+}
+
+
+/* Process the remaining bytes in the internal buffer and the usual
+ prolog according to the standard and write the result to RESBUF.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32 bits value. */
+void *
+__sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
+{
+ /* Take yet unprocessed bytes into account. */
+ uint32_t bytes = ctx->buflen;
+ size_t pad;
+
+ /* Now count remaining bytes. */
+ ctx->total[0] += bytes;
+ if (ctx->total[0] < bytes)
+ ++ctx->total[1];
+
+ pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
+ memcpy (&ctx->buffer[bytes], fillbuf, pad);
+
+ /* Put the 64-bit file length in *bits* at the end of the buffer. */
+ *(uint32_t *) &ctx->buffer[bytes + pad + 4] = SWAP (ctx->total[0] << 3);
+ *(uint32_t *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
+ (ctx->total[0] >> 29));
+
+ /* Process last bytes. */
+ sha256_process_block (ctx->buffer, bytes + pad + 8, ctx);
+
+ /* Put result from CTX in first 32 bytes following RESBUF. */
+ for (unsigned int i = 0; i < 8; ++i)
+ ((uint32_t *) resbuf)[i] = SWAP (ctx->H[i]);
+
+ return resbuf;
+}
+
+
+void
+__sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx)
+{
+ /* When we already have some bits in our internal buffer concatenate
+ both inputs first. */
+ if (ctx->buflen != 0)
+ {
+ size_t left_over = ctx->buflen;
+ size_t add = 128 - left_over > len ? len : 128 - left_over;
+
+ memcpy (&ctx->buffer[left_over], buffer, add);
+ ctx->buflen += add;
+
+ if (ctx->buflen > 64)
+ {
+ sha256_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
+
+ ctx->buflen &= 63;
+ /* The regions in the following copy operation cannot overlap. */
+ memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+ ctx->buflen);
+ }
+
+ buffer = (const char *) buffer + add;
+ len -= add;
+ }
+
+ /* Process available complete blocks. */
+ if (len >= 64)
+ {
+#if __GNUC__ >= 2
+# define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint32_t) != 0)
+#else
+# define UNALIGNED_P(p) (((uintptr_t) p) % sizeof (uint32_t) != 0)
+#endif
+ if (UNALIGNED_P (buffer))
+ while (len > 64)
+ {
+ sha256_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+ buffer = (const char *) buffer + 64;
+ len -= 64;
+ }
+ else
+ {
+ sha256_process_block (buffer, len & ~63, ctx);
+ buffer = (const char *) buffer + (len & ~63);
+ len &= 63;
+ }
+ }
+
+ /* Move remaining bytes into internal buffer. */
+ if (len > 0)
+ {
+ size_t left_over = ctx->buflen;
+
+ memcpy (&ctx->buffer[left_over], buffer, len);
+ left_over += len;
+ if (left_over >= 64)
+ {
+ sha256_process_block (ctx->buffer, 64, ctx);
+ left_over -= 64;
+ memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+ }
+ ctx->buflen = left_over;
+ }
+}
diff --git a/libcrypt/sha256.h b/libcrypt/sha256.h
new file mode 100644
index 000000000..291674f35
--- /dev/null
+++ b/libcrypt/sha256.h
@@ -0,0 +1,58 @@
+/* Declaration of functions and data types used for SHA256 sum computing
+ library functions.
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#ifndef _SHA256_H
+#define _SHA256_H 1
+
+#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+
+
+/* Structure to save state of computation between the single steps. */
+struct sha256_ctx
+{
+ uint32_t H[8];
+
+ uint32_t total[2];
+ uint32_t buflen;
+ char buffer[128] __attribute__ ((__aligned__ (__alignof__ (uint32_t))));
+};
+
+/* Initialize structure containing state of computation.
+ (FIPS 180-2: 5.3.2) */
+extern void __sha256_init_ctx (struct sha256_ctx *ctx) attribute_hidden;
+
+/* Starting with the result of former calls of this function (or the
+ initialization function update the context for the next LEN bytes
+ starting at BUFFER.
+ It is NOT required that LEN is a multiple of 64. */
+extern void __sha256_process_bytes (const void *buffer, size_t len,
+ struct sha256_ctx *ctx) attribute_hidden;
+
+/* Process the remaining bytes in the buffer and put result from CTX
+ in first 32 bytes following RESBUF.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32 bits value. */
+extern void *__sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
+ attribute_hidden;
+
+#endif /* sha256.h */