622 lines
20 KiB
C++
622 lines
20 KiB
C++
/* SHA512-based Unix crypt implementation.
|
|
Released into the Public Domain by Ulrich Drepper <drepper@redhat.com>. */
|
|
|
|
#include <endian.h>
|
|
#include <errno.h>
|
|
#include <limits.h>
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/param.h>
|
|
#include <sys/types.h>
|
|
|
|
|
|
/* Structure to save state of computation between the single steps. */
|
|
struct sha512_ctx
|
|
{
|
|
uint64_t H[8];
|
|
|
|
uint64_t total[2];
|
|
uint64_t buflen;
|
|
char buffer[256]; /* NB: always correctly aligned for uint64_t. */
|
|
};
|
|
|
|
|
|
#if __BYTE_ORDER == __LITTLE_ENDIAN
|
|
# define SWAP(n) \
|
|
(((n) << 56) \
|
|
| (((n) & 0xff00) << 40) \
|
|
| (((n) & 0xff0000) << 24) \
|
|
| (((n) & 0xff000000) << 8) \
|
|
| (((n) >> 8) & 0xff000000) \
|
|
| (((n) >> 24) & 0xff0000) \
|
|
| (((n) >> 40) & 0xff00) \
|
|
| ((n) >> 56))
|
|
#else
|
|
# define SWAP(n) (n)
|
|
#endif
|
|
|
|
|
|
/* This array contains the bytes used to pad the buffer to the next
|
|
64-byte boundary. (FIPS 180-2:5.1.2) */
|
|
static const unsigned char fillbuf[128] = { 0x80, 0 /* , 0, 0, ... */ };
|
|
|
|
|
|
/* Constants for SHA512 from FIPS 180-2:4.2.3. */
|
|
static const uint64_t K[80] =
|
|
{
|
|
UINT64_C (0x428a2f98d728ae22), UINT64_C (0x7137449123ef65cd),
|
|
UINT64_C (0xb5c0fbcfec4d3b2f), UINT64_C (0xe9b5dba58189dbbc),
|
|
UINT64_C (0x3956c25bf348b538), UINT64_C (0x59f111f1b605d019),
|
|
UINT64_C (0x923f82a4af194f9b), UINT64_C (0xab1c5ed5da6d8118),
|
|
UINT64_C (0xd807aa98a3030242), UINT64_C (0x12835b0145706fbe),
|
|
UINT64_C (0x243185be4ee4b28c), UINT64_C (0x550c7dc3d5ffb4e2),
|
|
UINT64_C (0x72be5d74f27b896f), UINT64_C (0x80deb1fe3b1696b1),
|
|
UINT64_C (0x9bdc06a725c71235), UINT64_C (0xc19bf174cf692694),
|
|
UINT64_C (0xe49b69c19ef14ad2), UINT64_C (0xefbe4786384f25e3),
|
|
UINT64_C (0x0fc19dc68b8cd5b5), UINT64_C (0x240ca1cc77ac9c65),
|
|
UINT64_C (0x2de92c6f592b0275), UINT64_C (0x4a7484aa6ea6e483),
|
|
UINT64_C (0x5cb0a9dcbd41fbd4), UINT64_C (0x76f988da831153b5),
|
|
UINT64_C (0x983e5152ee66dfab), UINT64_C (0xa831c66d2db43210),
|
|
UINT64_C (0xb00327c898fb213f), UINT64_C (0xbf597fc7beef0ee4),
|
|
UINT64_C (0xc6e00bf33da88fc2), UINT64_C (0xd5a79147930aa725),
|
|
UINT64_C (0x06ca6351e003826f), UINT64_C (0x142929670a0e6e70),
|
|
UINT64_C (0x27b70a8546d22ffc), UINT64_C (0x2e1b21385c26c926),
|
|
UINT64_C (0x4d2c6dfc5ac42aed), UINT64_C (0x53380d139d95b3df),
|
|
UINT64_C (0x650a73548baf63de), UINT64_C (0x766a0abb3c77b2a8),
|
|
UINT64_C (0x81c2c92e47edaee6), UINT64_C (0x92722c851482353b),
|
|
UINT64_C (0xa2bfe8a14cf10364), UINT64_C (0xa81a664bbc423001),
|
|
UINT64_C (0xc24b8b70d0f89791), UINT64_C (0xc76c51a30654be30),
|
|
UINT64_C (0xd192e819d6ef5218), UINT64_C (0xd69906245565a910),
|
|
UINT64_C (0xf40e35855771202a), UINT64_C (0x106aa07032bbd1b8),
|
|
UINT64_C (0x19a4c116b8d2d0c8), UINT64_C (0x1e376c085141ab53),
|
|
UINT64_C (0x2748774cdf8eeb99), UINT64_C (0x34b0bcb5e19b48a8),
|
|
UINT64_C (0x391c0cb3c5c95a63), UINT64_C (0x4ed8aa4ae3418acb),
|
|
UINT64_C (0x5b9cca4f7763e373), UINT64_C (0x682e6ff3d6b2b8a3),
|
|
UINT64_C (0x748f82ee5defb2fc), UINT64_C (0x78a5636f43172f60),
|
|
UINT64_C (0x84c87814a1f0ab72), UINT64_C (0x8cc702081a6439ec),
|
|
UINT64_C (0x90befffa23631e28), UINT64_C (0xa4506cebde82bde9),
|
|
UINT64_C (0xbef9a3f7b2c67915), UINT64_C (0xc67178f2e372532b),
|
|
UINT64_C (0xca273eceea26619c), UINT64_C (0xd186b8c721c0c207),
|
|
UINT64_C (0xeada7dd6cde0eb1e), UINT64_C (0xf57d4f7fee6ed178),
|
|
UINT64_C (0x06f067aa72176fba), UINT64_C (0x0a637dc5a2c898a6),
|
|
UINT64_C (0x113f9804bef90dae), UINT64_C (0x1b710b35131c471b),
|
|
UINT64_C (0x28db77f523047d84), UINT64_C (0x32caab7b40c72493),
|
|
UINT64_C (0x3c9ebe0a15c9bebc), UINT64_C (0x431d67c49c100d4c),
|
|
UINT64_C (0x4cc5d4becb3e42b6), UINT64_C (0x597f299cfc657e2a),
|
|
UINT64_C (0x5fcb6fab3ad6faec), UINT64_C (0x6c44198c4a475817)
|
|
};
|
|
|
|
|
|
/* Process LEN bytes of BUFFER, accumulating context into CTX.
|
|
It is assumed that LEN % 128 == 0. */
|
|
static void
|
|
sha512_process_block (const void *buffer, size_t len, struct sha512_ctx *ctx)
|
|
{
|
|
const uint64_t *words = (uint64_t *)buffer;
|
|
size_t nwords = len / sizeof (uint64_t);
|
|
uint64_t a = ctx->H[0];
|
|
uint64_t b = ctx->H[1];
|
|
uint64_t c = ctx->H[2];
|
|
uint64_t d = ctx->H[3];
|
|
uint64_t e = ctx->H[4];
|
|
uint64_t f = ctx->H[5];
|
|
uint64_t g = ctx->H[6];
|
|
uint64_t h = ctx->H[7];
|
|
|
|
/* First increment the byte count. FIPS 180-2 specifies the possible
|
|
length of the file up to 2^128 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 128 bytes in each round of
|
|
the loop. */
|
|
while (nwords > 0)
|
|
{
|
|
uint64_t W[80];
|
|
uint64_t a_save = a;
|
|
uint64_t b_save = b;
|
|
uint64_t c_save = c;
|
|
uint64_t d_save = d;
|
|
uint64_t e_save = e;
|
|
uint64_t f_save = f;
|
|
uint64_t g_save = g;
|
|
uint64_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, 28) ^ CYCLIC (x, 34) ^ CYCLIC (x, 39))
|
|
#define S1(x) (CYCLIC (x, 14) ^ CYCLIC (x, 18) ^ CYCLIC (x, 41))
|
|
#define R0(x) (CYCLIC (x, 1) ^ CYCLIC (x, 8) ^ (x >> 7))
|
|
#define R1(x) (CYCLIC (x, 19) ^ CYCLIC (x, 61) ^ (x >> 6))
|
|
|
|
/* 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 << (64 - s)))
|
|
|
|
/* Compute the message schedule according to FIPS 180-2:6.3.2 step 2. */
|
|
for (unsigned int t = 0; t < 16; ++t)
|
|
{
|
|
W[t] = SWAP (*words);
|
|
++words;
|
|
}
|
|
for (unsigned int t = 16; t < 80; ++t)
|
|
W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
|
|
|
|
/* The actual computation according to FIPS 180-2:6.3.2 step 3. */
|
|
for (unsigned int t = 0; t < 80; ++t)
|
|
{
|
|
uint64_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
|
|
uint64_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 180-2:6.3.2
|
|
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 180-2:5.3.3) */
|
|
static void
|
|
sha512_init_ctx (struct sha512_ctx *ctx)
|
|
{
|
|
ctx->H[0] = UINT64_C (0x6a09e667f3bcc908);
|
|
ctx->H[1] = UINT64_C (0xbb67ae8584caa73b);
|
|
ctx->H[2] = UINT64_C (0x3c6ef372fe94f82b);
|
|
ctx->H[3] = UINT64_C (0xa54ff53a5f1d36f1);
|
|
ctx->H[4] = UINT64_C (0x510e527fade682d1);
|
|
ctx->H[5] = UINT64_C (0x9b05688c2b3e6c1f);
|
|
ctx->H[6] = UINT64_C (0x1f83d9abfb41bd6b);
|
|
ctx->H[7] = UINT64_C (0x5be0cd19137e2179);
|
|
|
|
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. */
|
|
static void *
|
|
sha512_finish_ctx (struct sha512_ctx *ctx, void *resbuf)
|
|
{
|
|
/* Take yet unprocessed bytes into account. */
|
|
uint64_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 >= 112 ? 128 + 112 - bytes : 112 - bytes;
|
|
memcpy (&ctx->buffer[bytes], fillbuf, pad);
|
|
|
|
/* Put the 128-bit file length in *bits* at the end of the buffer. */
|
|
*(uint64_t *) &ctx->buffer[bytes + pad + 8] = SWAP (ctx->total[0] << 3);
|
|
*(uint64_t *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
|
|
(ctx->total[0] >> 61));
|
|
|
|
/* Process last bytes. */
|
|
sha512_process_block (ctx->buffer, bytes + pad + 16, ctx);
|
|
|
|
/* Put result from CTX in first 64 bytes following RESBUF. */
|
|
for (unsigned int i = 0; i < 8; ++i)
|
|
((uint64_t *) resbuf)[i] = SWAP (ctx->H[i]);
|
|
|
|
return resbuf;
|
|
}
|
|
|
|
|
|
static void
|
|
sha512_process_bytes (const void *buffer, size_t len, struct sha512_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 = 256 - left_over > len ? len : 256 - left_over;
|
|
|
|
memcpy (&ctx->buffer[left_over], buffer, add);
|
|
ctx->buflen += add;
|
|
|
|
if (ctx->buflen > 128)
|
|
{
|
|
sha512_process_block (ctx->buffer, ctx->buflen & ~127, ctx);
|
|
|
|
ctx->buflen &= 127;
|
|
/* The regions in the following copy operation cannot overlap. */
|
|
memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~127],
|
|
ctx->buflen);
|
|
}
|
|
|
|
buffer = (const char *) buffer + add;
|
|
len -= add;
|
|
}
|
|
|
|
/* Process available complete blocks. */
|
|
if (len >= 128)
|
|
{
|
|
#if !_STRING_ARCH_unaligned
|
|
/* To check alignment gcc has an appropriate operator. Other
|
|
compilers don't. */
|
|
# if __GNUC__ >= 2
|
|
# define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint64_t) != 0)
|
|
# else
|
|
# define UNALIGNED_P(p) (((uintptr_t) p) % sizeof (uint64_t) != 0)
|
|
# endif
|
|
if (UNALIGNED_P (buffer))
|
|
while (len > 128)
|
|
{
|
|
sha512_process_block (memcpy (ctx->buffer, buffer, 128), 128,
|
|
ctx);
|
|
buffer = (const char *) buffer + 128;
|
|
len -= 128;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sha512_process_block (buffer, len & ~127, ctx);
|
|
buffer = (const char *) buffer + (len & ~127);
|
|
len &= 127;
|
|
}
|
|
}
|
|
|
|
/* 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 >= 128)
|
|
{
|
|
sha512_process_block (ctx->buffer, 128, ctx);
|
|
left_over -= 128;
|
|
memcpy (ctx->buffer, &ctx->buffer[128], left_over);
|
|
}
|
|
ctx->buflen = left_over;
|
|
}
|
|
}
|
|
|
|
|
|
/* Define our magic string to mark salt for SHA512 "encryption"
|
|
replacement. */
|
|
static const char sha512_salt_prefix[] = "$6$";
|
|
|
|
/* Prefix for optional rounds specification. */
|
|
static const char sha512_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[65] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
|
|
|
|
static char *
|
|
sha512_crypt_r (const char *key, const char *salt, char *buffer, int buflen)
|
|
{
|
|
unsigned char alt_result[64]
|
|
__attribute__ ((__aligned__ (__alignof__ (uint64_t))));
|
|
unsigned char temp_result[64]
|
|
__attribute__ ((__aligned__ (__alignof__ (uint64_t))));
|
|
struct sha512_ctx ctx;
|
|
struct sha512_ctx alt_ctx;
|
|
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 (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
|
|
/* Skip salt prefix. */
|
|
salt += sizeof (sha512_salt_prefix) - 1;
|
|
|
|
if (strncmp (salt, sha512_rounds_prefix, sizeof (sha512_rounds_prefix) - 1)
|
|
== 0)
|
|
{
|
|
const char *num = salt + sizeof (sha512_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__ (uint64_t) != 0)
|
|
{
|
|
char *tmp = (char *) alloca (key_len + __alignof__ (uint64_t));
|
|
key = copied_key = (char *)
|
|
memcpy (tmp + __alignof__ (uint64_t)
|
|
- (tmp - (char *) 0) % __alignof__ (uint64_t),
|
|
key, key_len);
|
|
}
|
|
|
|
if ((salt - (char *) 0) % __alignof__ (uint64_t) != 0)
|
|
{
|
|
char *tmp = (char *) alloca (salt_len + __alignof__ (uint64_t));
|
|
salt = copied_salt = (char *)
|
|
memcpy (tmp + __alignof__ (uint64_t)
|
|
- (tmp - (char *) 0) % __alignof__ (uint64_t),
|
|
salt, salt_len);
|
|
}
|
|
|
|
/* Prepare for the real work. */
|
|
sha512_init_ctx (&ctx);
|
|
|
|
/* Add the key string. */
|
|
sha512_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 (for
|
|
compatibility with existing implementations). */
|
|
sha512_process_bytes (salt, salt_len, &ctx);
|
|
|
|
|
|
/* Compute alternate SHA512 sum with input KEY, SALT, and KEY. The
|
|
final result will be added to the first context. */
|
|
sha512_init_ctx (&alt_ctx);
|
|
|
|
/* Add key. */
|
|
sha512_process_bytes (key, key_len, &alt_ctx);
|
|
|
|
/* Add salt. */
|
|
sha512_process_bytes (salt, salt_len, &alt_ctx);
|
|
|
|
/* Add key again. */
|
|
sha512_process_bytes (key, key_len, &alt_ctx);
|
|
|
|
/* Now get result of this (64 bytes) and add it to the other
|
|
context. */
|
|
sha512_finish_ctx (&alt_ctx, alt_result);
|
|
|
|
/* Add for any character in the key one byte of the alternate sum. */
|
|
for (cnt = key_len; cnt > 64; cnt -= 64)
|
|
sha512_process_bytes (alt_result, 64, &ctx);
|
|
sha512_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)
|
|
sha512_process_bytes (alt_result, 64, &ctx);
|
|
else
|
|
sha512_process_bytes (key, key_len, &ctx);
|
|
|
|
/* Create intermediate result. */
|
|
sha512_finish_ctx (&ctx, alt_result);
|
|
|
|
/* Start computation of P byte sequence. */
|
|
sha512_init_ctx (&alt_ctx);
|
|
|
|
/* For every character in the password add the entire password. */
|
|
for (cnt = 0; cnt < key_len; ++cnt)
|
|
sha512_process_bytes (key, key_len, &alt_ctx);
|
|
|
|
/* Finish the digest. */
|
|
sha512_finish_ctx (&alt_ctx, temp_result);
|
|
|
|
/* Create byte sequence P. */
|
|
cp = p_bytes = (char *)alloca (key_len);
|
|
for (cnt = key_len; cnt >= 64; cnt -= 64)
|
|
cp = (char *)mempcpy (cp, temp_result, 64);
|
|
memcpy (cp, temp_result, cnt);
|
|
|
|
/* Start computation of S byte sequence. */
|
|
sha512_init_ctx (&alt_ctx);
|
|
|
|
/* For every character in the password add the entire password. */
|
|
for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt)
|
|
sha512_process_bytes (salt, salt_len, &alt_ctx);
|
|
|
|
/* Finish the digest. */
|
|
sha512_finish_ctx (&alt_ctx, temp_result);
|
|
|
|
/* Create byte sequence S. */
|
|
cp = s_bytes = (char *)alloca (salt_len);
|
|
for (cnt = salt_len; cnt >= 64; cnt -= 64)
|
|
cp = (char *)mempcpy ( cp, temp_result, 64);
|
|
memcpy (cp, temp_result, cnt);
|
|
|
|
/* Repeatedly run the collected hash value through SHA512 to burn
|
|
CPU cycles. */
|
|
for (cnt = 0; cnt < rounds; ++cnt)
|
|
{
|
|
/* New context. */
|
|
sha512_init_ctx (&ctx);
|
|
|
|
/* Add key or last result. */
|
|
if ((cnt & 1) != 0)
|
|
sha512_process_bytes (p_bytes, key_len, &ctx);
|
|
else
|
|
sha512_process_bytes (alt_result, 64, &ctx);
|
|
|
|
/* Add salt for numbers not divisible by 3. */
|
|
if (cnt % 3 != 0)
|
|
sha512_process_bytes (s_bytes, salt_len, &ctx);
|
|
|
|
/* Add key for numbers not divisible by 7. */
|
|
if (cnt % 7 != 0)
|
|
sha512_process_bytes (p_bytes, key_len, &ctx);
|
|
|
|
/* Add key or last result. */
|
|
if ((cnt & 1) != 0)
|
|
sha512_process_bytes (alt_result, 64, &ctx);
|
|
else
|
|
sha512_process_bytes (p_bytes, key_len, &ctx);
|
|
|
|
/* Create intermediate result. */
|
|
sha512_finish_ctx (&ctx, alt_result);
|
|
}
|
|
|
|
/* Now we can construct the result string. It consists of three
|
|
parts. */
|
|
cp = __stpncpy (buffer, sha512_salt_prefix, MAX (0, buflen));
|
|
buflen -= sizeof (sha512_salt_prefix) - 1;
|
|
|
|
if (rounds_custom)
|
|
{
|
|
int n = snprintf (cp, MAX (0, buflen), "%s%zu$",
|
|
sha512_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;
|
|
}
|
|
|
|
#define b64_from_24bit(B2, B1, B0, N) \
|
|
do { \
|
|
unsigned int w = ((B2) << 16) | ((B1) << 8) | (B0); \
|
|
int n = (N); \
|
|
while (n-- > 0 && buflen > 0) \
|
|
{ \
|
|
*cp++ = b64t[w & 0x3f]; \
|
|
--buflen; \
|
|
w >>= 6; \
|
|
} \
|
|
} while (0)
|
|
|
|
b64_from_24bit (alt_result[0], alt_result[21], alt_result[42], 4);
|
|
b64_from_24bit (alt_result[22], alt_result[43], alt_result[1], 4);
|
|
b64_from_24bit (alt_result[44], alt_result[2], alt_result[23], 4);
|
|
b64_from_24bit (alt_result[3], alt_result[24], alt_result[45], 4);
|
|
b64_from_24bit (alt_result[25], alt_result[46], alt_result[4], 4);
|
|
b64_from_24bit (alt_result[47], alt_result[5], alt_result[26], 4);
|
|
b64_from_24bit (alt_result[6], alt_result[27], alt_result[48], 4);
|
|
b64_from_24bit (alt_result[28], alt_result[49], alt_result[7], 4);
|
|
b64_from_24bit (alt_result[50], alt_result[8], alt_result[29], 4);
|
|
b64_from_24bit (alt_result[9], alt_result[30], alt_result[51], 4);
|
|
b64_from_24bit (alt_result[31], alt_result[52], alt_result[10], 4);
|
|
b64_from_24bit (alt_result[53], alt_result[11], alt_result[32], 4);
|
|
b64_from_24bit (alt_result[12], alt_result[33], alt_result[54], 4);
|
|
b64_from_24bit (alt_result[34], alt_result[55], alt_result[13], 4);
|
|
b64_from_24bit (alt_result[56], alt_result[14], alt_result[35], 4);
|
|
b64_from_24bit (alt_result[15], alt_result[36], alt_result[57], 4);
|
|
b64_from_24bit (alt_result[37], alt_result[58], alt_result[16], 4);
|
|
b64_from_24bit (alt_result[59], alt_result[17], alt_result[38], 4);
|
|
b64_from_24bit (alt_result[18], alt_result[39], alt_result[60], 4);
|
|
b64_from_24bit (alt_result[40], alt_result[61], alt_result[19], 4);
|
|
b64_from_24bit (alt_result[62], alt_result[20], alt_result[41], 4);
|
|
b64_from_24bit (0, 0, alt_result[63], 2);
|
|
|
|
if (buflen <= 0)
|
|
{
|
|
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 SHA512 implementation as well. */
|
|
sha512_init_ctx (&ctx);
|
|
sha512_finish_ctx (&ctx, alt_result);
|
|
memset (temp_result, '\0', sizeof (temp_result));
|
|
memset (p_bytes, '\0', key_len);
|
|
memset (s_bytes, '\0', salt_len);
|
|
memset (&ctx, '\0', sizeof (ctx));
|
|
memset (&alt_ctx, '\0', sizeof (alt_ctx));
|
|
if (copied_key != NULL)
|
|
memset (copied_key, '\0', key_len);
|
|
if (copied_salt != NULL)
|
|
memset (copied_salt, '\0', salt_len);
|
|
|
|
return buffer;
|
|
}
|
|
|
|
|
|
/* This entry point is equivalent to the `crypt' function in Unix
|
|
libcs. */
|
|
char *
|
|
sha512_crypt (const char *key, const 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
|
|
`sha512_crypt_r'. */
|
|
static char *buffer = NULL;
|
|
static int buflen = 0;
|
|
int needed = (sizeof (sha512_salt_prefix) - 1
|
|
+ sizeof (sha512_rounds_prefix) + 9 + 1
|
|
+ strlen (salt) + 1 + 86 + 1);
|
|
|
|
if (buflen < needed)
|
|
{
|
|
char *new_buffer = (char *) realloc (buffer, needed);
|
|
if (new_buffer == NULL)
|
|
return NULL;
|
|
|
|
buffer = new_buffer;
|
|
buflen = needed;
|
|
}
|
|
|
|
return sha512_crypt_r (key, salt, buffer, buflen);
|
|
}
|
|
|