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- #include <assert.h>
- #include <errno.h>
- #include <stdbool.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/param.h>
- #include "sha512.h"
- #include "libcrypt.h"
- static const char sha512_salt_prefix[] = "$6$";
- static const char sha512_rounds_prefix[] = "rounds=";
- #define SALT_LEN_MAX 16
- #define ROUNDS_DEFAULT 5000
- #define ROUNDS_MIN 1000
- #define ROUNDS_MAX 999999999
- 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 *
- __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))));
- 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;
-
- size_t rounds = ROUNDS_DEFAULT;
- bool rounds_custom = false;
-
- if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
-
- 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 ((uintptr_t)key % __alignof__ (uint64_t) != 0)
- {
- char *tmp = (char *) alloca (key_len + __alignof__ (uint64_t));
- key = copied_key =
- memcpy (tmp + __alignof__ (uint64_t)
- - (uintptr_t)tmp % __alignof__ (uint64_t),
- key, key_len);
- assert ((key - (char *) 0) % __alignof__ (uint64_t) == 0);
- }
- if ((uintptr_t)salt % __alignof__ (uint64_t) != 0)
- {
- char *tmp = (char *) alloca (salt_len + __alignof__ (uint64_t));
- salt = copied_salt =
- memcpy (tmp + __alignof__ (uint64_t)
- - (uintptr_t)tmp % __alignof__ (uint64_t),
- salt, salt_len);
- assert ((uintptr_t)salt % __alignof__ (uint64_t) == 0);
- }
- struct sha512_ctx ctx;
- struct sha512_ctx alt_ctx;
-
- __sha512_init_ctx (&ctx);
-
- __sha512_process_bytes (key, key_len, &ctx);
-
- __sha512_process_bytes (salt, salt_len, &ctx);
-
- __sha512_init_ctx (&alt_ctx);
-
- __sha512_process_bytes (key, key_len, &alt_ctx);
-
- __sha512_process_bytes (salt, salt_len, &alt_ctx);
-
- __sha512_process_bytes (key, key_len, &alt_ctx);
-
- __sha512_finish_ctx (&alt_ctx, alt_result);
-
- for (cnt = key_len; cnt > 64; cnt -= 64)
- __sha512_process_bytes (alt_result, 64, &ctx);
- __sha512_process_bytes (alt_result, cnt, &ctx);
-
- 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);
-
- __sha512_finish_ctx (&ctx, alt_result);
-
- __sha512_init_ctx (&alt_ctx);
-
- for (cnt = 0; cnt < key_len; ++cnt)
- __sha512_process_bytes (key, key_len, &alt_ctx);
-
- __sha512_finish_ctx (&alt_ctx, temp_result);
-
- cp = p_bytes = alloca (key_len);
- for (cnt = key_len; cnt >= 64; cnt -= 64)
- cp = mempcpy (cp, temp_result, 64);
- memcpy (cp, temp_result, cnt);
-
- __sha512_init_ctx (&alt_ctx);
-
- for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt)
- __sha512_process_bytes (salt, salt_len, &alt_ctx);
-
- __sha512_finish_ctx (&alt_ctx, temp_result);
-
- cp = s_bytes = alloca (salt_len);
- for (cnt = salt_len; cnt >= 64; cnt -= 64)
- cp = mempcpy (cp, temp_result, 64);
- memcpy (cp, temp_result, cnt);
-
- for (cnt = 0; cnt < rounds; ++cnt)
- {
-
- __sha512_init_ctx (&ctx);
-
- if ((cnt & 1) != 0)
- __sha512_process_bytes (p_bytes, key_len, &ctx);
- else
- __sha512_process_bytes (alt_result, 64, &ctx);
-
- if (cnt % 3 != 0)
- __sha512_process_bytes (s_bytes, salt_len, &ctx);
-
- if (cnt % 7 != 0)
- __sha512_process_bytes (p_bytes, key_len, &ctx);
-
- if ((cnt & 1) != 0)
- __sha512_process_bytes (alt_result, 64, &ctx);
- else
- __sha512_process_bytes (p_bytes, key_len, &ctx);
-
- __sha512_finish_ctx (&ctx, alt_result);
- }
-
- 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;
- }
- 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)
- {
- __set_errno (ERANGE);
- buffer = NULL;
- }
- else
- *cp = '\0';
-
- __sha512_init_ctx (&ctx);
- __sha512_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;
- char *
- __sha512_crypt (const unsigned char *key, const unsigned char *salt)
- {
-
- static int buflen;
- 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 ((const char *) key, (const char *) salt, buffer, buflen);
- }
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