Bug 50733 - Add font-file hash?

Add "hash" object which contains SHA256 hash value (so far) computed from the font file.

fontconfig/fontconfig.h

@@ -115,6 +115,7 @@ typedef int		FcBool;
 #define FC_FONT_FEATURES    "fontfeatures"	/* String */
 #define FC_NAMELANG	    "namelang"		/* String RFC 3866 langs */
 #define FC_PRGNAME	    "prgname"		/* String */
+#define FC_HASH		    "hash"		/* String */
 
 #define FC_CACHE_SUFFIX		    ".cache-" FC_CACHE_VERSION
 #define FC_DIR_CACHE_FILE	    "fonts.cache-" FC_CACHE_VERSION

src/Makefile.am

@@ -139,6 +139,7 @@ libfontconfig_la_SOURCES = \
 	fcformat.c \
 	fcfreetype.c \
 	fcfs.c \
+	fchash.c \
 	fcinit.c \
 	fclang.c \
 	fclist.c \

src/fcfreetype.c

@@ -1123,6 +1123,8 @@ FcFreeTypeQueryFace (const FT_Face  face,
     FcChar8	    *style = 0;
     int		    st;
 
+    FcChar8	    *hashstr;
+
     pat = FcPatternCreate ();
     if (!pat)
 	goto bail0;
@@ -1634,6 +1636,13 @@ FcFreeTypeQueryFace (const FT_Face  face,
     if (!FcPatternAddBool (pat, FC_DECORATIVE, decorative))
 	goto bail1;
 
+    hashstr = FcHashGetSHA256DigestFromFile (file);
+    if (!hashstr)
+	goto bail1;
+    if (!FcPatternAddString (pat, FC_HASH, hashstr))
+	goto bail1;
+    free (hashstr);
+
     /*
      * Compute the unicode coverage for the font
      */

src/fchash.c

@@ -0,0 +1,265 @@
+/*
+ * fontconfig/src/fchash.c
+ *
+ * Copyright © 2003 Keith Packard
+ * Copyright © 2013 Red Hat, Inc.
+ * Red Hat Author(s): Akira TAGOH
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the author(s) not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission.  The authors make no
+ * representations about the suitability of this software for any purpose.  It
+ * is provided "as is" without express or implied warranty.
+ *
+ * THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "fcint.h"
+#include <stdio.h>
+#include <string.h>
+
+#define ROTRN(w, v, n)	((((FcChar32)v) >> n) | (((FcChar32)v) << (w - n)))
+#define ROTR32(v, n)	ROTRN(32, v, n)
+#define SHR(v, n)	(v >> n)
+#define Ch(x, y, z)	((x & y) ^ (~x & z))
+#define Maj(x, y, z)	((x & y) ^ (x & z) ^ (y & z))
+#define SS0(x)		(ROTR32(x, 2) ^ ROTR32(x, 13) ^ ROTR32(x, 22))
+#define SS1(x)		(ROTR32(x, 6) ^ ROTR32(x, 11) ^ ROTR32(x, 25))
+#define ss0(x)		(ROTR32(x, 7) ^ ROTR32(x, 18) ^ SHR(x, 3))
+#define ss1(x)		(ROTR32(x, 17) ^ ROTR32(x, 19) ^ SHR(x, 10))
+
+
+static FcChar32 *
+FcHashInitSHA256Digest (void)
+{
+    int i;
+    static const FcChar32 h[] = {
+	0x6a09e667UL, 0xbb67ae85UL, 0x3c6ef372UL, 0xa54ff53aUL,
+	0x510e527fUL, 0x9b05688cUL, 0x1f83d9abUL, 0x5be0cd19UL
+    };
+    FcChar32 *ret = malloc (sizeof (FcChar32) * 8);
+
+    if (!ret)
+	return NULL;
+
+    for (i = 0; i < 8; i++)
+	ret[i] = h[i];
+
+    return ret;
+}
+
+static void
+FcHashComputeSHA256Digest (FcChar32   *hash,
+			   const char *block)
+{
+    static const FcChar32 k[] = {
+	0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
+	0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
+	0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
+	0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
+	0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+	0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
+	0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
+	0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
+	0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
+	0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+	0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
+	0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
+	0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
+	0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
+	0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+	0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+    };
+    FcChar32 w[64], i, j, t1, t2;
+    FcChar32 a, b, c, d, e, f, g, h;
+
+#define H(n)	(hash[n])
+
+    a = H(0);
+    b = H(1);
+    c = H(2);
+    d = H(3);
+    e = H(4);
+    f = H(5);
+    g = H(6);
+    h = H(7);
+
+    for (i = 0; i < 16; i++)
+    {
+	j =  (block[(i * 4) + 0] & 0xff) << (8 * 3);
+	j |= (block[(i * 4) + 1] & 0xff) << (8 * 2);
+	j |= (block[(i * 4) + 2] & 0xff) << (8 * 1);
+	j |= (block[(i * 4) + 3] & 0xff);
+	w[i] = j;
+    }
+    for (i = 16; i < 64; i++)
+	w[i] = ss1(w[i - 2]) + w[i - 7] + ss0(w[i - 15]) + w[i - 16];
+
+    for (i = 0; i < 64; i++)
+    {
+	t1 = h + SS1(e) + Ch(e, f, g) + k[i] + w[i];
+	t2 = SS0(a) + Maj(a, b, c);
+	h = g;
+	g = f;
+	f = e;
+	e = d + t1;
+	d = c;
+	c = b;
+	b = a;
+	a = t1 + t2;
+    }
+
+    H(0) += a;
+    H(1) += b;
+    H(2) += c;
+    H(3) += d;
+    H(4) += e;
+    H(5) += f;
+    H(6) += g;
+    H(7) += h;
+
+#undef H
+}
+
+static FcChar8 *
+FcHashSHA256ToString (FcChar32 *hash)
+{
+    FcChar8 *ret = NULL;
+    static const char hex[] = "0123456789abcdef";
+    int i, j;
+
+    if (hash)
+    {
+	ret = malloc (sizeof (FcChar8) * (8 * 8 + 7 + 1));
+	if (!ret)
+	    return NULL;
+	memcpy (ret, "sha256:", 7);
+#define H(n)	hash[n]
+	for (i = 0; i < 8; i++)
+	{
+	    FcChar32 v = H(i);
+
+	    for (j = 0; j < 8; j++)
+		ret[7 + (i * 8) + j] = hex[(v >> (28 - j * 4)) & 0xf];
+	}
+	ret[7 + i * 8] = 0;
+#undef H
+	free (hash);
+    }
+
+    return ret;
+}
+
+FcChar8 *
+FcHashGetSHA256Digest (const FcChar8 *input_strings,
+		       size_t         len)
+{
+    size_t i, round_len = len / 64;
+    char block[64];
+    FcChar32 *ret = FcHashInitSHA256Digest ();
+
+    if (!ret)
+	return NULL;
+
+    for (i = 0; i < round_len; i++)
+    {
+	FcHashComputeSHA256Digest (ret, (const char *)&input_strings[i * 64]);
+    }
+    /* padding */
+    if ((len % 64) != 0)
+	memcpy (block, &input_strings[len / 64], len % 64);
+    memset (&block[len % 64], 0, 64 - (len % 64));
+    block[len % 64] = 0x80;
+    if ((64 - (len % 64)) < 9)
+    {
+	/* process a block once */
+	FcHashComputeSHA256Digest (ret, block);
+	memset (block, 0, 64);
+    }
+    /* set input size at the end */
+    len *= 8;
+    block[63 - 0] =  len        & 0xff;
+    block[63 - 1] = (len >>  8) & 0xff;
+    block[63 - 2] = (len >> 16) & 0xff;
+    block[63 - 3] = (len >> 24) & 0xff;
+    block[63 - 4] = (len >> 32) & 0xff;
+    block[63 - 5] = (len >> 40) & 0xff;
+    block[63 - 6] = (len >> 48) & 0xff;
+    block[63 - 7] = (len >> 56) & 0xff;
+    FcHashComputeSHA256Digest (ret, block);
+
+    return FcHashSHA256ToString (ret);
+}
+
+FcChar8 *
+FcHashGetSHA256DigestFromFile (const FcChar8 *filename)
+{
+    FILE *fp = fopen ((const char *)filename, "rb");
+    char ibuf[64];
+    FcChar32 *ret;
+    size_t len;
+    struct stat st;
+
+    if (!fp)
+	return NULL;
+
+    if (FcStat (filename, &st))
+	goto bail0;
+
+    ret = FcHashInitSHA256Digest ();
+    if (!ret)
+	return NULL;
+
+    while (!feof (fp))
+    {
+	if ((len = fread (ibuf, sizeof (char), 64, fp)) < 64)
+	{
+	    long v;
+
+	    /* add a padding */
+	    memset (&ibuf[len], 0, 64 - len);
+	    ibuf[len] = 0x80;
+	    if ((64 - len) < 9)
+	    {
+		/* process a block once */
+		FcHashComputeSHA256Digest (ret, ibuf);
+		memset (ibuf, 0, 64);
+	    }
+	    /* set input size at the end */
+	    v = (long)st.st_size * 8;
+	    ibuf[63 - 0] =  v        & 0xff;
+	    ibuf[63 - 1] = (v >>  8) & 0xff;
+	    ibuf[63 - 2] = (v >> 16) & 0xff;
+	    ibuf[63 - 3] = (v >> 24) & 0xff;
+	    ibuf[63 - 4] = (v >> 32) & 0xff;
+	    ibuf[63 - 5] = (v >> 40) & 0xff;
+	    ibuf[63 - 6] = (v >> 48) & 0xff;
+	    ibuf[63 - 7] = (v >> 56) & 0xff;
+	    FcHashComputeSHA256Digest (ret, ibuf);
+	    break;
+	}
+	else
+	{
+	    FcHashComputeSHA256Digest (ret, ibuf);
+	}
+    }
+    fclose (fp);
+
+    return FcHashSHA256ToString (ret);
+
+bail0:
+    fclose (fp);
+    return NULL;
+}

src/fcint.h

@@ -812,6 +812,13 @@ FcFontSetSerializeAlloc (FcSerialize *serialize, const FcFontSet *s);
 FcPrivate FcFontSet *
 FcFontSetSerialize (FcSerialize *serialize, const FcFontSet * s);
 
+/* fchash.c */
+FcPrivate FcChar8 *
+FcHashGetSHA256Digest (const FcChar8 *input_strings,
+		       size_t         len);
+FcPrivate FcChar8 *
+FcHashGetSHA256DigestFromFile (const FcChar8 *filename);
+
 /* fcxml.c */
 FcPrivate void
 FcTestDestroy (FcTest *test);

src/fcobjs.h

@@ -43,4 +43,5 @@ FC_OBJECT (LCD_FILTER,		FcTypeInteger)
 FC_OBJECT (NAMELANG,		FcTypeString)
 FC_OBJECT (FONT_FEATURES,	FcTypeString)
 FC_OBJECT (PRGNAME,		FcTypeString)
+FC_OBJECT (HASH,		FcTypeString)
 /* ^-------------- Add new objects here. */