- #50334, crypt ignores sha512 and add support for sha256/512 to php's crypt [DOC]

1 files changed, 831 insertions, 0 deletions

diff --git a/ext/standard/crypt_sha512.c b/ext/standard/crypt_sha512.c
new file mode 100644
index 0000000000..7bc648d7fa
--- /dev/null
+++ b/ext/standard/crypt_sha512.c
@@ -0,0 +1,831 @@
+/* SHA512-based Unix crypt implementation.
+   Released into the Public Domain by Ulrich Drepper <drepper@redhat.com>.  */
+/* Windows VC++ port by Pierre Joye <pierre@php.net> */
+
+#ifndef PHP_WIN32
+# include <endian.h>
+# include "php.h"
+# include "php_main.h"
+#endif
+
+#include <errno.h>
+#include <limits.h>
+#ifdef PHP_WIN32
+# include "win32/php_stdint.h"
+# include "win32/php_stdbool.h"
+# define __alignof__ __alignof
+# define alloca _alloca
+#else
+# if HAVE_INTTYPES_H
+#  include <inttypes.h>
+# elif HAVE_STDINT_H
+#  include <stdint.h>
+# endif
+# include <stdbool.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef PHP_WIN32
+# include <string.h>
+#else
+# include <sys/param.h>
+# include <sys/types.h>
+# if HAVE_STRING_H
+#  define __USE_GNU 
+#  include <string.h>
+# else
+#  include <strings.h>
+# endif
+#endif
+#if 0
+#ifndef stpncpy
+char * stpncpy(char *dst, const char *src, size_t len)
+{
+	size_t n = strlen(src);
+	if (n > len) {
+		n = len;
+	}
+	return strncpy(dst, src, len) + n;
+}
+#endif
+
+#ifndef mempcpy
+void * mempcpy(void * dst, const void * src, size_t len)
+{
+	return (((char *)memcpy(dst, src, len)) + len);
+}
+#endif
+#endif
+
+#ifndef MIN
+# define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
+#ifndef MAX
+# define MAX(a, b) (((a) > (b)) ? (a) : (b))
+#endif
+
+/* 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 PHP_WIN32 || (__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 = 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;
+		unsigned int t;
+
+/* 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) {
+	/* Take yet unprocessed bytes into account.  */
+	uint64_t bytes = ctx->buflen;
+	size_t pad;
+	unsigned int i;
+
+	/* Now count remaining bytes.  */
+	ctx->total[0] += bytes;
+	if (ctx->total[0] < bytes) {
+		++ctx->total[1];
+	}
+
+	pad = bytes >= 112 ? 128 + 112 - (size_t)bytes : 112 - (size_t)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, (size_t)(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 = (size_t)ctx->buflen;
+		size_t add = (size_t)(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],
+					(size_t)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 = (size_t)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";
+
+
+char *
+php_sha512_crypt_r(const char *key, const char *salt, char *buffer, int buflen) {
+#ifdef PHP_WIN32
+	__declspec(align(64)) unsigned char alt_result[64];
+	__declspec(align(64)) unsigned char temp_result[64];
+#else
+	unsigned char alt_result[64]
+		__attribute__ ((__aligned__ (__alignof__ (uint64_t))));
+	unsigned char temp_result[64]
+		__attribute__ ((__aligned__ (__alignof__ (uint64_t))));
+#endif
+	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 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 = alloca(key_len);
+	for (cnt = key_len; cnt >= 64; cnt -= 64) {
+		cp = mempcpy((void *) cp, (const void *)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) {
+#ifdef PHP_WIN32
+	  int n = _snprintf(cp, MAX(0, buflen), "%s%u$", sha512_rounds_prefix, rounds);
+#else
+	  int n = snprintf(cp, MAX(0, buflen), "%s%zu$", sha512_rounds_prefix, rounds);
+#endif
+	  cp += n;
+	  buflen -= n;
+	}
+
+	cp = stpncpy(cp, salt, MIN((size_t) MAX(0, buflen), salt_len));
+	buflen -= (int) MIN((size_t) MAX(0, buflen), salt_len);
+
+	if (buflen > 0) {
+		*cp++ = '$';
+		--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 *
+php_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 = (int)(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 php_sha512_crypt_r (key, salt, buffer, buflen);
+}
+
+#ifdef TEST
+static const struct {
+	const char *input;
+	const char result[64];
+} tests[] =
+	{
+	/* Test vectors from FIPS 180-2: appendix C.1.  */
+	{ "abc",
+	  "\xdd\xaf\x35\xa1\x93\x61\x7a\xba\xcc\x41\x73\x49\xae\x20\x41\x31"
+	  "\x12\xe6\xfa\x4e\x89\xa9\x7e\xa2\x0a\x9e\xee\xe6\x4b\x55\xd3\x9a"
+	  "\x21\x92\x99\x2a\x27\x4f\xc1\xa8\x36\xba\x3c\x23\xa3\xfe\xeb\xbd"
+	  "\x45\x4d\x44\x23\x64\x3c\xe8\x0e\x2a\x9a\xc9\x4f\xa5\x4c\xa4\x9f" },
+	/* Test vectors from FIPS 180-2: appendix C.2.  */
+	{ "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
+	  "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
+	  "\x8e\x95\x9b\x75\xda\xe3\x13\xda\x8c\xf4\xf7\x28\x14\xfc\x14\x3f"
+	  "\x8f\x77\x79\xc6\xeb\x9f\x7f\xa1\x72\x99\xae\xad\xb6\x88\x90\x18"
+	  "\x50\x1d\x28\x9e\x49\x00\xf7\xe4\x33\x1b\x99\xde\xc4\xb5\x43\x3a"
+	  "\xc7\xd3\x29\xee\xb6\xdd\x26\x54\x5e\x96\xe5\x5b\x87\x4b\xe9\x09" },
+	/* Test vectors from the NESSIE project.  */
+	{ "",
+	  "\xcf\x83\xe1\x35\x7e\xef\xb8\xbd\xf1\x54\x28\x50\xd6\x6d\x80\x07"
+	  "\xd6\x20\xe4\x05\x0b\x57\x15\xdc\x83\xf4\xa9\x21\xd3\x6c\xe9\xce"
+	  "\x47\xd0\xd1\x3c\x5d\x85\xf2\xb0\xff\x83\x18\xd2\x87\x7e\xec\x2f"
+	  "\x63\xb9\x31\xbd\x47\x41\x7a\x81\xa5\x38\x32\x7a\xf9\x27\xda\x3e" },
+	{ "a",
+	  "\x1f\x40\xfc\x92\xda\x24\x16\x94\x75\x09\x79\xee\x6c\xf5\x82\xf2"
+	  "\xd5\xd7\xd2\x8e\x18\x33\x5d\xe0\x5a\xbc\x54\xd0\x56\x0e\x0f\x53"
+	  "\x02\x86\x0c\x65\x2b\xf0\x8d\x56\x02\x52\xaa\x5e\x74\x21\x05\x46"
+	  "\xf3\x69\xfb\xbb\xce\x8c\x12\xcf\xc7\x95\x7b\x26\x52\xfe\x9a\x75" },
+	{ "message digest",
+	  "\x10\x7d\xbf\x38\x9d\x9e\x9f\x71\xa3\xa9\x5f\x6c\x05\x5b\x92\x51"
+	  "\xbc\x52\x68\xc2\xbe\x16\xd6\xc1\x34\x92\xea\x45\xb0\x19\x9f\x33"
+	  "\x09\xe1\x64\x55\xab\x1e\x96\x11\x8e\x8a\x90\x5d\x55\x97\xb7\x20"
+	  "\x38\xdd\xb3\x72\xa8\x98\x26\x04\x6d\xe6\x66\x87\xbb\x42\x0e\x7c" },
+	{ "abcdefghijklmnopqrstuvwxyz",
+	  "\x4d\xbf\xf8\x6c\xc2\xca\x1b\xae\x1e\x16\x46\x8a\x05\xcb\x98\x81"
+	  "\xc9\x7f\x17\x53\xbc\xe3\x61\x90\x34\x89\x8f\xaa\x1a\xab\xe4\x29"
+	  "\x95\x5a\x1b\xf8\xec\x48\x3d\x74\x21\xfe\x3c\x16\x46\x61\x3a\x59"
+	  "\xed\x54\x41\xfb\x0f\x32\x13\x89\xf7\x7f\x48\xa8\x79\xc7\xb1\xf1" },
+	{ "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
+	  "\x20\x4a\x8f\xc6\xdd\xa8\x2f\x0a\x0c\xed\x7b\xeb\x8e\x08\xa4\x16"
+	  "\x57\xc1\x6e\xf4\x68\xb2\x28\xa8\x27\x9b\xe3\x31\xa7\x03\xc3\x35"
+	  "\x96\xfd\x15\xc1\x3b\x1b\x07\xf9\xaa\x1d\x3b\xea\x57\x78\x9c\xa0"
+	  "\x31\xad\x85\xc7\xa7\x1d\xd7\x03\x54\xec\x63\x12\x38\xca\x34\x45" },
+	{ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
+	  "\x1e\x07\xbe\x23\xc2\x6a\x86\xea\x37\xea\x81\x0c\x8e\xc7\x80\x93"
+	  "\x52\x51\x5a\x97\x0e\x92\x53\xc2\x6f\x53\x6c\xfc\x7a\x99\x96\xc4"
+	  "\x5c\x83\x70\x58\x3e\x0a\x78\xfa\x4a\x90\x04\x1d\x71\xa4\xce\xab"
+	  "\x74\x23\xf1\x9c\x71\xb9\xd5\xa3\xe0\x12\x49\xf0\xbe\xbd\x58\x94" },
+	{ "123456789012345678901234567890123456789012345678901234567890"
+	  "12345678901234567890",
+	  "\x72\xec\x1e\xf1\x12\x4a\x45\xb0\x47\xe8\xb7\xc7\x5a\x93\x21\x95"
+	  "\x13\x5b\xb6\x1d\xe2\x4e\xc0\xd1\x91\x40\x42\x24\x6e\x0a\xec\x3a"
+	  "\x23\x54\xe0\x93\xd7\x6f\x30\x48\xb4\x56\x76\x43\x46\x90\x0c\xb1"
+	  "\x30\xd2\xa4\xfd\x5d\xd1\x6a\xbb\x5e\x30\xbc\xb8\x50\xde\xe8\x43" }
+  };
+#define ntests (sizeof (tests) / sizeof (tests[0]))
+
+
+static const struct
+{
+	const char *salt;
+	const char *input;
+	const char *expected;
+} tests2[] = {
+	{ "$6$saltstring", "Hello world!",
+	"$6$saltstring$svn8UoSVapNtMuq1ukKS4tPQd8iKwSMHWjl/O817G3uBnIFNjnQJu"
+	"esI68u4OTLiBFdcbYEdFCoEOfaS35inz1"},
+	{ "$6$rounds=10000$saltstringsaltstring", "Hello world!",
+	"$6$rounds=10000$saltstringsaltst$OW1/O6BYHV6BcXZu8QVeXbDWra3Oeqh0sb"
+	"HbbMCVNSnCM/UrjmM0Dp8vOuZeHBy/YTBmSK6H9qs/y3RnOaw5v." },
+	{ "$6$rounds=5000$toolongsaltstring", "This is just a test",
+	"$6$rounds=5000$toolongsaltstrin$lQ8jolhgVRVhY4b5pZKaysCLi0QBxGoNeKQ"
+	"zQ3glMhwllF7oGDZxUhx1yxdYcz/e1JSbq3y6JMxxl8audkUEm0" },
+	{ "$6$rounds=1400$anotherlongsaltstring",
+	"a very much longer text to encrypt.  This one even stretches over more"
+	"than one line.",
+	"$6$rounds=1400$anotherlongsalts$POfYwTEok97VWcjxIiSOjiykti.o/pQs.wP"
+	"vMxQ6Fm7I6IoYN3CmLs66x9t0oSwbtEW7o7UmJEiDwGqd8p4ur1" },
+	{ "$6$rounds=77777$short",
+	"we have a short salt string but not a short password",
+	"$6$rounds=77777$short$WuQyW2YR.hBNpjjRhpYD/ifIw05xdfeEyQoMxIXbkvr0g"
+	"ge1a1x3yRULJ5CCaUeOxFmtlcGZelFl5CxtgfiAc0" },
+	{ "$6$rounds=123456$asaltof16chars..", "a short string",
+	"$6$rounds=123456$asaltof16chars..$BtCwjqMJGx5hrJhZywWvt0RLE8uZ4oPwc"
+	"elCjmw2kSYu.Ec6ycULevoBK25fs2xXgMNrCzIMVcgEJAstJeonj1" },
+	{ "$6$rounds=10$roundstoolow", "the minimum number is still observed",
+	"$6$rounds=1000$roundstoolow$kUMsbe306n21p9R.FRkW3IGn.S9NPN0x50YhH1x"
+	"hLsPuWGsUSklZt58jaTfF4ZEQpyUNGc0dqbpBYYBaHHrsX." },
+};
+#define ntests2 (sizeof (tests2) / sizeof (tests2[0]))
+
+
+int main (void) {
+	struct sha512_ctx ctx;
+	char sum[64];
+	int result = 0;
+	int cnt;
+	int i;
+	char buf[1000];
+	static const char expected[64] =
+		"\xe7\x18\x48\x3d\x0c\xe7\x69\x64\x4e\x2e\x42\xc7\xbc\x15\xb4\x63"
+		"\x8e\x1f\x98\xb1\x3b\x20\x44\x28\x56\x32\xa8\x03\xaf\xa9\x73\xeb"
+		"\xde\x0f\xf2\x44\x87\x7e\xa6\x0a\x4c\xb0\x43\x2c\xe5\x77\xc3\x1b"
+		"\xeb\x00\x9c\x5c\x2c\x49\xaa\x2e\x4e\xad\xb2\x17\xad\x8c\xc0\x9b";
+
+	for (cnt = 0; cnt < (int) ntests; ++cnt) {
+		sha512_init_ctx (&ctx);
+		sha512_process_bytes (tests[cnt].input, strlen (tests[cnt].input), &ctx);
+		sha512_finish_ctx (&ctx, sum);
+		if (memcmp (tests[cnt].result, sum, 64) != 0) {
+			printf ("test %d run %d failed\n", cnt, 1);
+			result = 1;
+		}
+
+		sha512_init_ctx (&ctx);
+		for (i = 0; tests[cnt].input[i] != '\0'; ++i) {
+			sha512_process_bytes (&tests[cnt].input[i], 1, &ctx);
+		}
+		sha512_finish_ctx (&ctx, sum);
+		if (memcmp (tests[cnt].result, sum, 64) != 0) {
+			printf ("test %d run %d failed\n", cnt, 2);
+			result = 1;
+		}
+	}
+
+	/* Test vector from FIPS 180-2: appendix C.3.  */
+
+	memset (buf, 'a', sizeof (buf));
+	sha512_init_ctx (&ctx);
+	for (i = 0; i < 1000; ++i) {
+		sha512_process_bytes (buf, sizeof (buf), &ctx);
+	}
+
+	sha512_finish_ctx (&ctx, sum);
+	if (memcmp (expected, sum, 64) != 0) {
+		printf ("test %d failed\n", cnt);
+		result = 1;
+	}
+
+	for (cnt = 0; cnt < ntests2; ++cnt) {
+		char *cp = php_sha512_crypt(tests2[cnt].input, tests2[cnt].salt);
+
+		if (strcmp (cp, tests2[cnt].expected) != 0) {
+			printf ("test %d: expected \"%s\", got \"%s\"\n",
+					cnt, tests2[cnt].expected, cp);
+			result = 1;
+		}
+	}
+
+	if (result == 0) {
+		puts ("all tests OK");
+	}
+
+	return result;
+}
+#endif