mirror of
https://github.com/sheumann/hush.git
synced 2024-12-23 05:29:58 +00:00
287 lines
9.2 KiB
C
287 lines
9.2 KiB
C
/* SHA256 and SHA512-based Unix crypt implementation.
|
|
* Released into the Public Domain by Ulrich Drepper <drepper@redhat.com>.
|
|
*/
|
|
|
|
/* Prefix for optional rounds specification. */
|
|
static const char str_rounds[] ALIGN1 = "rounds=%u$";
|
|
|
|
/* Maximum salt string length. */
|
|
#define SALT_LEN_MAX 16
|
|
/* Default number of rounds if not explicitly specified. */
|
|
#define ROUNDS_DEFAULT 5000
|
|
/* Minimum number of rounds. */
|
|
#define ROUNDS_MIN 1000
|
|
/* Maximum number of rounds. */
|
|
#define ROUNDS_MAX 999999999
|
|
|
|
static char *
|
|
NOINLINE
|
|
sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data)
|
|
{
|
|
void (*sha_begin)(void *ctx) FAST_FUNC;
|
|
void (*sha_hash)(void *ctx, const void *buffer, size_t len) FAST_FUNC;
|
|
void (*sha_end)(void *ctx, void *resbuf) FAST_FUNC;
|
|
int _32or64;
|
|
|
|
char *result, *resptr;
|
|
|
|
/* btw, sha256 needs [32] and uint32_t only */
|
|
struct {
|
|
unsigned char alt_result[64];
|
|
unsigned char temp_result[64];
|
|
union {
|
|
sha256_ctx_t x;
|
|
sha512_ctx_t y;
|
|
} ctx;
|
|
union {
|
|
sha256_ctx_t x;
|
|
sha512_ctx_t y;
|
|
} alt_ctx;
|
|
} L __attribute__((__aligned__(__alignof__(uint64_t))));
|
|
#define alt_result (L.alt_result )
|
|
#define temp_result (L.temp_result)
|
|
#define ctx (L.ctx )
|
|
#define alt_ctx (L.alt_ctx )
|
|
unsigned salt_len;
|
|
unsigned key_len;
|
|
unsigned cnt;
|
|
unsigned rounds;
|
|
char *cp;
|
|
char is_sha512;
|
|
|
|
/* Analyze salt, construct already known part of result */
|
|
cnt = strlen(salt_data) + 1 + 43 + 1;
|
|
is_sha512 = salt_data[1];
|
|
if (is_sha512 == '6')
|
|
cnt += 43;
|
|
result = resptr = xzalloc(cnt); /* will provide NUL terminator */
|
|
*resptr++ = '$';
|
|
*resptr++ = is_sha512;
|
|
*resptr++ = '$';
|
|
rounds = ROUNDS_DEFAULT;
|
|
salt_data += 3;
|
|
if (strncmp(salt_data, str_rounds, 7) == 0) {
|
|
/* 7 == strlen("rounds=") */
|
|
char *endp;
|
|
cnt = bb_strtou(salt_data + 7, &endp, 10);
|
|
if (*endp == '$') {
|
|
salt_data = endp + 1;
|
|
rounds = cnt;
|
|
if (rounds < ROUNDS_MIN)
|
|
rounds = ROUNDS_MIN;
|
|
if (rounds > ROUNDS_MAX)
|
|
rounds = ROUNDS_MAX;
|
|
/* add "rounds=NNNNN$" to result */
|
|
resptr += sprintf(resptr, str_rounds, rounds);
|
|
}
|
|
}
|
|
salt_len = strchrnul(salt_data, '$') - salt_data;
|
|
if (salt_len > SALT_LEN_MAX)
|
|
salt_len = SALT_LEN_MAX;
|
|
/* xstrdup assures suitable alignment; also we will use it
|
|
as a scratch space later. */
|
|
salt_data = xstrndup(salt_data, salt_len);
|
|
/* add "salt$" to result */
|
|
strcpy(resptr, salt_data);
|
|
resptr += salt_len;
|
|
*resptr++ = '$';
|
|
/* key data doesn't need much processing */
|
|
key_len = strlen(key_data);
|
|
key_data = xstrdup(key_data);
|
|
|
|
/* Which flavor of SHAnnn ops to use? */
|
|
sha_begin = (void*)sha256_begin;
|
|
sha_hash = (void*)sha256_hash;
|
|
sha_end = (void*)sha256_end;
|
|
_32or64 = 32;
|
|
if (is_sha512 == '6') {
|
|
sha_begin = (void*)sha512_begin;
|
|
sha_hash = (void*)sha512_hash;
|
|
sha_end = (void*)sha512_end;
|
|
_32or64 = 64;
|
|
}
|
|
|
|
/* Add KEY, SALT. */
|
|
sha_begin(&ctx);
|
|
sha_hash(&ctx, key_data, key_len);
|
|
sha_hash(&ctx, salt_data, salt_len);
|
|
|
|
/* Compute alternate SHA sum with input KEY, SALT, and KEY.
|
|
The final result will be added to the first context. */
|
|
sha_begin(&alt_ctx);
|
|
sha_hash(&alt_ctx, key_data, key_len);
|
|
sha_hash(&alt_ctx, salt_data, salt_len);
|
|
sha_hash(&alt_ctx, key_data, key_len);
|
|
sha_end(&alt_ctx, alt_result);
|
|
|
|
/* Add result of this to the other context. */
|
|
/* Add for any character in the key one byte of the alternate sum. */
|
|
for (cnt = key_len; cnt > _32or64; cnt -= _32or64)
|
|
sha_hash(&ctx, alt_result, _32or64);
|
|
sha_hash(&ctx, alt_result, cnt);
|
|
|
|
/* 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)
|
|
sha_hash(&ctx, alt_result, _32or64);
|
|
else
|
|
sha_hash(&ctx, key_data, key_len);
|
|
|
|
/* Create intermediate result. */
|
|
sha_end(&ctx, alt_result);
|
|
|
|
/* Start computation of P byte sequence. */
|
|
/* For every character in the password add the entire password. */
|
|
sha_begin(&alt_ctx);
|
|
for (cnt = 0; cnt < key_len; ++cnt)
|
|
sha_hash(&alt_ctx, key_data, key_len);
|
|
sha_end(&alt_ctx, temp_result);
|
|
|
|
/* NB: past this point, raw key_data is not used anymore */
|
|
|
|
/* Create byte sequence P. */
|
|
#define p_bytes key_data /* reuse the buffer as it is of the key_len size */
|
|
cp = p_bytes; /* was: ... = alloca(key_len); */
|
|
for (cnt = key_len; cnt >= _32or64; cnt -= _32or64) {
|
|
cp = memcpy(cp, temp_result, _32or64);
|
|
cp += _32or64;
|
|
}
|
|
memcpy(cp, temp_result, cnt);
|
|
|
|
/* Start computation of S byte sequence. */
|
|
/* For every character in the password add the entire password. */
|
|
sha_begin(&alt_ctx);
|
|
for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt)
|
|
sha_hash(&alt_ctx, salt_data, salt_len);
|
|
sha_end(&alt_ctx, temp_result);
|
|
|
|
/* NB: past this point, raw salt_data is not used anymore */
|
|
|
|
/* Create byte sequence S. */
|
|
#define s_bytes salt_data /* reuse the buffer as it is of the salt_len size */
|
|
cp = s_bytes; /* was: ... = alloca(salt_len); */
|
|
for (cnt = salt_len; cnt >= _32or64; cnt -= _32or64) {
|
|
cp = memcpy(cp, temp_result, _32or64);
|
|
cp += _32or64;
|
|
}
|
|
memcpy(cp, temp_result, cnt);
|
|
|
|
/* Repeatedly run the collected hash value through SHA to burn
|
|
CPU cycles. */
|
|
for (cnt = 0; cnt < rounds; ++cnt) {
|
|
sha_begin(&ctx);
|
|
|
|
/* Add key or last result. */
|
|
if ((cnt & 1) != 0)
|
|
sha_hash(&ctx, p_bytes, key_len);
|
|
else
|
|
sha_hash(&ctx, alt_result, _32or64);
|
|
/* Add salt for numbers not divisible by 3. */
|
|
if (cnt % 3 != 0)
|
|
sha_hash(&ctx, s_bytes, salt_len);
|
|
/* Add key for numbers not divisible by 7. */
|
|
if (cnt % 7 != 0)
|
|
sha_hash(&ctx, p_bytes, key_len);
|
|
/* Add key or last result. */
|
|
if ((cnt & 1) != 0)
|
|
sha_hash(&ctx, alt_result, _32or64);
|
|
else
|
|
sha_hash(&ctx, p_bytes, key_len);
|
|
|
|
sha_end(&ctx, alt_result);
|
|
}
|
|
|
|
/* Append encrypted password to result buffer */
|
|
//TODO: replace with something like
|
|
// bb_uuencode(cp, src, length, bb_uuenc_tbl_XXXbase64);
|
|
#define b64_from_24bit(B2, B1, B0, N) \
|
|
do { \
|
|
unsigned w = ((B2) << 16) | ((B1) << 8) | (B0); \
|
|
resptr = to64(resptr, w, N); \
|
|
} while (0)
|
|
if (is_sha512 == '5') {
|
|
unsigned i = 0;
|
|
while (1) {
|
|
unsigned j = i + 10;
|
|
unsigned k = i + 20;
|
|
if (j >= 30) j -= 30;
|
|
if (k >= 30) k -= 30;
|
|
b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4);
|
|
if (k == 29)
|
|
break;
|
|
i = k + 1;
|
|
}
|
|
b64_from_24bit(0, alt_result[31], alt_result[30], 3);
|
|
/* was:
|
|
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);
|
|
*/
|
|
} else {
|
|
unsigned i = 0;
|
|
while (1) {
|
|
unsigned j = i + 21;
|
|
unsigned k = i + 42;
|
|
if (j >= 63) j -= 63;
|
|
if (k >= 63) k -= 63;
|
|
b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4);
|
|
if (j == 20)
|
|
break;
|
|
i = j + 1;
|
|
}
|
|
b64_from_24bit(0, 0, alt_result[63], 2);
|
|
/* was:
|
|
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);
|
|
*/
|
|
}
|
|
/* *resptr = '\0'; - xzalloc did it */
|
|
#undef b64_from_24bit
|
|
|
|
/* Clear the buffer for the intermediate result so that people
|
|
attaching to processes or reading core dumps cannot get any
|
|
information. */
|
|
memset(&L, 0, sizeof(L)); /* [alt]_ctx and XXX_result buffers */
|
|
memset(key_data, 0, key_len); /* also p_bytes */
|
|
memset(salt_data, 0, salt_len); /* also s_bytes */
|
|
free(key_data);
|
|
free(salt_data);
|
|
#undef p_bytes
|
|
#undef s_bytes
|
|
|
|
return result;
|
|
#undef alt_result
|
|
#undef temp_result
|
|
#undef ctx
|
|
#undef alt_ctx
|
|
}
|