diff options
| -rw-r--r-- | cache.h | 9 | ||||
| -rw-r--r-- | hex.c | 10 |
2 files changed, 18 insertions, 1 deletions
@@ -819,7 +819,16 @@ static inline int get_sha1_with_context(const char *str, unsigned char *sha1, st { return get_sha1_with_context_1(str, sha1, orc, 0, NULL); } + +/* + * Try to read a SHA1 in hexadecimal format from the 40 characters + * starting at hex. Write the 20-byte result to sha1 in binary form. + * Return 0 on success. Reading stops if a NUL is encountered in the + * input, so it is safe to pass this function an arbitrary + * null-terminated string. + */ extern int get_sha1_hex(const char *hex, unsigned char *sha1); + extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */ extern int read_ref(const char *filename, unsigned char *sha1); extern const char *resolve_ref(const char *path, unsigned char *sha1, int, int *); @@ -39,7 +39,15 @@ int get_sha1_hex(const char *hex, unsigned char *sha1) { int i; for (i = 0; i < 20; i++) { - unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]); + 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) return -1; *sha1++ = val; |