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-rw-r--r--com32/elflink/modules/sha512crypt.c606
1 files changed, 606 insertions, 0 deletions
diff --git a/com32/elflink/modules/sha512crypt.c b/com32/elflink/modules/sha512crypt.c
new file mode 100644
index 00000000..617423c2
--- /dev/null
+++ b/com32/elflink/modules/sha512crypt.c
@@ -0,0 +1,606 @@
+/* SHA512-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 <stdbool.h>
+#include <stdint.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 sha512crypt_init()
+{
+ 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 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)
+{
+ unsigned int t;
+ const uint64_t *words = 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 (t = 0; t < 16; ++t) {
+ W[t] = SWAP(*words);
+ ++words;
+ }
+ for (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 (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)
+{
+ unsigned int i;
+ /* 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 (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[64] =
+ "./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 = 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 = 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 8
+ 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 = alloca(key_len);
+ for (cnt = key_len; cnt >= 64; cnt -= 64)
+ cp = 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 = alloca(salt_len);
+ for (cnt = salt_len; cnt >= 64; cnt -= 64)
+ cp = 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;
+ 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(key, salt, buffer, buflen);
+}
+
+static void sha512crypt_exit()
+{
+ // Nothing to do
+}
+
+// Define entry and exit points.
+MODULE_INIT(sha512crypt_init);
+MODULE_EXIT(sha512crypt_exit);