file_util: consolidate hex/unhex routines

Consolidate the various copies of the bin2hex table into one global variant
and replace the broken hex() define with a static helper function to prevent
accidential multiple expression evaluation.

This also fixes bug when converting hexadecimal checksums into binary forms
where the letters a..f/A..F where incorrectly converted into 0..5 instead
of 10..15 .

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/libopkg/file_util.c b/libopkg/file_util.c
index 14ca02e30a727f0daa00a4d23353c9af1e1bd98a..759c21b3ae76d206f717022c38dc8538fecf0d52 100644 (file)
--- a/libopkg/file_util.c
+++ b/libopkg/file_util.c
@@ -125,18 +125,31 @@ int file_mkdir_hier(const char *path, long mode)
        return make_directory(path, mode, FILEUTILS_RECUR);
 }
 
+
+static int hex2bin(unsigned char x)
+{
+       if (x >= 'a' && x <= 'f')
+               return x - 'a' + 10;
+       else if (x >= 'A' && x <= 'F')
+               return x - 'A' + 10;
+       else if (x >= '0' && x <= '9')
+               return x - '0';
+       else
+               return 0;
+}
+
+static const unsigned char bin2hex[16] = {
+       '0', '1', '2', '3',
+       '4', '5', '6', '7',
+       '8', '9', 'a', 'b',
+       'c', 'd', 'e', 'f'
+};
+
 char *file_md5sum_alloc(const char *file_name)
 {
        static const int md5sum_bin_len = 16;
        static const int md5sum_hex_len = 32;
 
-       static const unsigned char bin2hex[16] = {
-               '0', '1', '2', '3',
-               '4', '5', '6', '7',
-               '8', '9', 'a', 'b',
-               'c', 'd', 'e', 'f'
-       };
-
        int i, len;
        char *md5sum_hex;
        unsigned char md5sum_bin[md5sum_bin_len];
@@ -165,13 +178,6 @@ char *file_sha256sum_alloc(const char *file_name)
        static const int sha256sum_bin_len = 32;
        static const int sha256sum_hex_len = 64;
 
-       static const unsigned char bin2hex[16] = {
-               '0', '1', '2', '3',
-               '4', '5', '6', '7',
-               '8', '9', 'a', 'b',
-               'c', 'd', 'e', 'f'
-       };
-
        int i, err;
        FILE *file;
        char *sha256sum_hex;
@@ -212,13 +218,6 @@ char *checksum_bin2hex(const char *src, size_t len)
        unsigned char *p;
        static unsigned char buf[65];
        const unsigned char *s = (unsigned char *)src;
-       static const unsigned char bin2hex[16] = {
-               '0', '1', '2', '3',
-               '4', '5', '6', '7',
-               '8', '9', 'a', 'b',
-               'c', 'd', 'e', 'f'
-       };
-
        if (!s || len > 32)
                return NULL;
 
@@ -254,13 +253,10 @@ char *checksum_hex2bin(const char *src, size_t *len)
                return NULL;
        }
 
-#define hex(c) \
-       (c >= 'a' ? (c - 'a') : (c >= 'A' ? (c - 'A') : (c - '0')))
-
        for (p = buf, *len = 0;
             slen > 0 && isxdigit(s[0]) && isxdigit(s[1]);
             slen--, s += 2, (*len)++)
-               *p++ = hex(s[0]) * 16 + hex(s[1]);
+               *p++ = hex2bin(s[0]) * 16 + hex2bin(s[1]);
 
        return (char *)buf;
 }
@@ -377,23 +373,16 @@ static int urlencode_is_specialchar(char c)
 
 char *urlencode_path(const char *filename)
 {
-       static const char bin2hex[16] = {
-               '0', '1', '2', '3',
-               '4', '5', '6', '7',
-               '8', '9', 'a', 'b',
-               'c', 'd', 'e', 'f'
-       };
-
        size_t len = 0;
-       const char *in;
-       char *copy, *out;
+       const unsigned char *in;
+       unsigned char *copy, *out;
 
-       for (in = filename; *in != 0; in++)
+       for (in = (unsigned char *)filename; *in != 0; in++)
                len += urlencode_is_specialchar(*in) ? 3 : 1;
 
        copy = xcalloc(1, len + 1);
 
-       for (in = filename, out = copy; *in != 0; in++) {
+       for (in = (unsigned char *)filename, out = copy; *in != 0; in++) {
                if (urlencode_is_specialchar(*in)) {
                        *out++ = '%';
                        *out++ = bin2hex[*in / 16];
@@ -404,5 +393,5 @@ char *urlencode_path(const char *filename)
                }
        }
 
-       return copy;
+       return (char *)copy;
 }