Add and use a helper function that decodes the char value of two
hexadecimal digits. It returns a negative number on error, avoids
running over the end of the given string and doesn't shift negative
values.
Signed-off-by: Rene Scharfe <l.s.r@xxxxxx>
---
cache.h | 10 ++++++++++
hex.c | 12 ++----------
pkt-line.c | 23 ++---------------------
pretty.c | 13 +++++--------
ref-filter.c | 20 +-------------------
url.c | 21 +--------------------
6 files changed, 21 insertions(+), 78 deletions(-)
diff --git a/cache.h b/cache.h
index b780a91..b0dae4b 100644
--- a/cache.h
+++ b/cache.h
@@ -1139,6 +1139,16 @@ static inline unsigned int hexval(unsigned char c)
return hexval_table[c];
}
+/*
+ * Convert two consecutive hexadecimal digits into a char. Return a
+ * negative value on error. Don't run over the end of short strings.
+ */
+static inline int hex2chr(const char *s)
+{
+ int val = hexval(s[0]);
+ return (val < 0) ? val : (val << 4) | hexval(s[1]);
+}
+
/* Convert to/from hex/sha1 representation */
#define MINIMUM_ABBREV minimum_abbrev
#define DEFAULT_ABBREV default_abbrev
diff --git a/hex.c b/hex.c
index 9619b67..ab2610e 100644
--- a/hex.c
+++ b/hex.c
@@ -39,16 +39,8 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
{
int i;
for (i = 0; i < GIT_SHA1_RAWSZ; i++) {
- unsigned int val;
- /*
- * hex[1]=='\0' is caught when val is checked below,
- * but if hex[0] is NUL we have to avoid reading
- * past the end of the string:
- */
- if (!hex[0])
- return -1;
- val = (hexval(hex[0]) << 4) | hexval(hex[1]);
- if (val & ~0xff)
+ int val = hex2chr(hex);
+ if (val < 0)
return -1;
*sha1++ = val;
hex += 2;
diff --git a/pkt-line.c b/pkt-line.c
index 62fdb37..30489c6 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -172,27 +172,8 @@ static int get_packet_data(int fd, char **src_buf, size_t *src_size,
static int packet_length(const char *linelen)
{
- int n;
- int len = 0;
-
- for (n = 0; n < 4; n++) {
- unsigned char c = linelen[n];
- len <<= 4;
- if (c >= '0' && c <= '9') {
- len += c - '0';
- continue;
- }
- if (c >= 'a' && c <= 'f') {
- len += c - 'a' + 10;
- continue;
- }
- if (c >= 'A' && c <= 'F') {
- len += c - 'A' + 10;
- continue;
- }
- return -1;
- }
- return len;
+ int val = hex2chr(linelen);
+ return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
}
int packet_read(int fd, char **src_buf, size_t *src_len,
diff --git a/pretty.c b/pretty.c
index 9609afb..9788bd8 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1065,7 +1065,7 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
const struct commit *commit = c->commit;
const char *msg = c->message;
struct commit_list *p;
- int h1, h2;
+ int ch;
/* these are independent of the commit */
switch (placeholder[0]) {
@@ -1089,14 +1089,11 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
return 1;
case 'x':
/* %x00 == NUL, %x0a == LF, etc. */
- if (0 <= (h1 = hexval_table[0xff & placeholder[1]]) &&
- h1 <= 16 &&
- 0 <= (h2 = hexval_table[0xff & placeholder[2]]) &&
- h2 <= 16) {
- strbuf_addch(sb, (h1<<4)|h2);
- return 3;
- } else
+ ch = hex2chr(placeholder + 1);
+ if (ch < 0)
return 0;
+ strbuf_addch(sb, ch);
+ return 3;
case 'w':
if (placeholder[1] == '(') {
unsigned long width = 0, indent1 = 0, indent2 = 0;
diff --git a/ref-filter.c b/ref-filter.c
index bc551a7..9adbb8a 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1576,24 +1576,6 @@ void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
qsort(array->items, array->nr, sizeof(struct ref_array_item *), compare_refs);
}
-static int hex1(char ch)
-{
- if ('0' <= ch && ch <= '9')
- return ch - '0';
- else if ('a' <= ch && ch <= 'f')
- return ch - 'a' + 10;
- else if ('A' <= ch && ch <= 'F')
- return ch - 'A' + 10;
- return -1;
-}
-static int hex2(const char *cp)
-{
- if (cp[0] && cp[1])
- return (hex1(cp[0]) << 4) | hex1(cp[1]);
- else
- return -1;
-}
-
static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
{
struct strbuf *s = &state->stack->output;
@@ -1603,7 +1585,7 @@ static void append_literal(const char *cp, const char *ep, struct ref_formatting
if (cp[1] == '%')
cp++;
else {
- int ch = hex2(cp + 1);
+ int ch = hex2chr(cp + 1);
if (0 <= ch) {
strbuf_addch(s, ch);
cp += 3;
diff --git a/url.c b/url.c
index 2d89ad1..eaf4f07 100644
--- a/url.c
+++ b/url.c
@@ -29,25 +29,6 @@ int is_url(const char *url)
return (url[0] == ':' && url[1] == '/' && url[2] == '/');
}
-static int url_decode_char(const char *q)
-{
- int i;
- unsigned char val = 0;
- for (i = 0; i < 2; i++) {
- unsigned char c = *q++;
- val <<= 4;
- if (c >= '0' && c <= '9')
- val += c - '0';
- else if (c >= 'a' && c <= 'f')
- val += c - 'a' + 10;
- else if (c >= 'A' && c <= 'F')
- val += c - 'A' + 10;
- else
- return -1;
- }
- return val;
-}
-
static char *url_decode_internal(const char **query, int len,
const char *stop_at, struct strbuf *out,
int decode_plus)
@@ -66,7 +47,7 @@ static char *url_decode_internal(const char **query, int len,
}
if (c == '%') {
- int val = url_decode_char(q + 1);
+ int val = hex2chr(q + 1);
if (0 <= val) {
strbuf_addch(out, val);
q += 3;
--
2.10.0