aboutsummaryrefslogtreecommitdiffstats
path: root/com32/elflink/modules/sha256crypt.c
diff options
context:
space:
mode:
Diffstat (limited to 'com32/elflink/modules/sha256crypt.c')
-rw-r--r--com32/elflink/modules/sha256crypt.c559
1 files changed, 0 insertions, 559 deletions
diff --git a/com32/elflink/modules/sha256crypt.c b/com32/elflink/modules/sha256crypt.c
deleted file mode 100644
index 61b23f2a..00000000
--- a/com32/elflink/modules/sha256crypt.c
+++ /dev/null
@@ -1,559 +0,0 @@
-/* SHA256-based Unix crypt implementation.
- Released into the Public Domain by Ulrich Drepper <drepper@redhat.com>. */
-
-#include <alloca.h>
-#include <endian.h>
-#include <errno.h>
-#include <limits.h>
-#include <stdint.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <minmax.h>
-#include <sys/types.h>
-#include <sys/module.h>
-
-#include "xcrypt.h"
-
-static int sha256crypt_init(void)
-{
- return 0; // Nothing to do; return success
-}
-
-#define MIN(x,y) min(x,y)
-#define MAX(x,y) max(x,y)
-
-/* 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]; /* NB: always correctly aligned for uint32_t. */
-};
-
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-# define SWAP(n) \
- (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
-#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)
-{
- unsigned int t;
- 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 (t = 0; t < 16; ++t) {
- W[t] = SWAP(*words);
- ++words;
- }
- for (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 (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) */
-static 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. */
-static void *sha256_finish_ctx(struct sha256_ctx *ctx, void *resbuf)
-{
- unsigned int i;
- /* 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 (i = 0; i < 8; ++i)
- ((uint32_t *) resbuf)[i] = SWAP(ctx->H[i]);
-
- return resbuf;
-}
-
-static 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) {
-/* To check alignment gcc has an appropriate operator. Other
- compilers don't. */
-#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;
- }
-}
-
-/* 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";
-
-static 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))));
- struct sha256_ctx ctx;
- struct sha256_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(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);
- }
-
- 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);
- }
-
- /* 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 8
- characters and it ends at the first `$' character (for
- compatibility with existing implementations). */
- 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;
- }
-#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[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) {
- 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(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 *sha256_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
- `sha256_crypt_r'. */
- static char *buffer;
- 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(key, salt, buffer, buflen);
-}
-
-static void sha256crypt_exit(void)
-{
- // Nothing to do
-}
-
-// Define entry and exit points.
-MODULE_INIT(sha256crypt_init);
-MODULE_EXIT(sha256crypt_exit);