From: René Scharfe Date: Sat, 3 Sep 2016 15:59:20 +0000 (+0200) Subject: introduce hex2chr() for converting two hexadecimal digits to a character X-Git-Tag: v2.10.1~34^2 X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/d23309733a5b2a9e1adc304ee50c5a5ed7a087c2?hp=e0c1ceafc5bece92d35773a75fff59497e1d9bd5 introduce hex2chr() for converting two hexadecimal digits to a character 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 Signed-off-by: Junio C Hamano --- diff --git a/cache.h b/cache.h index c141b3ca0d..81af2c2a6b 100644 --- a/cache.h +++ b/cache.h @@ -1133,6 +1133,16 @@ 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 0519f853b2..60541c9d4b 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 62fdb37079..30489c60b1 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 b27165603a..37e74cbb83 100644 --- a/pretty.c +++ b/pretty.c @@ -1063,7 +1063,7 @@ 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]) { @@ -1087,14 +1087,11 @@ 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 bc551a752c..9adbb8af3e 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 2d89ad190c..eaf4f07081 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;