diff options
| -rw-r--r-- | extra/Configs/Config.in | 7 | ||||
| -rw-r--r-- | libcrypt/Makefile.in | 1 | ||||
| -rw-r--r-- | libcrypt/crypt.c | 3 | ||||
| -rw-r--r-- | libcrypt/libcrypt.h | 2 | ||||
| -rw-r--r-- | libcrypt/sha256-crypt.c | 326 | ||||
| -rw-r--r-- | libcrypt/sha256.c | 294 | ||||
| -rw-r--r-- | libcrypt/sha256.h | 58 |
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 */ |