diff options
| -rwxr-xr-x | src/base64.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/src/base64.c b/src/base64.c index 496f697..6407a0e 100755 --- a/src/base64.c +++ b/src/base64.c @@ -104,9 +104,18 @@ #include <string.h> #include "base64.h" +/* Useful for encoding */ static char base64_chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +/* For constant time lookups */ +static int +is_base64_char(char c) +{ + return (('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z') || + ('0' <= c && c <= '9') || (c == '+' || c == '/')); +} + static int pos(char c) { @@ -156,16 +165,16 @@ base64_encode(const void *data, int size, char **str) return strlen(s); } -#define DECODE_ERROR 0xffffffff +#define DECODE_ERROR ((unsigned) -1) static unsigned int -token_decode(const char *token) +token_decode(const char *token, const size_t size) { int i; unsigned int val = 0; int marker = 0; - if (strlen(token) < 4) + if (size < 4) return DECODE_ERROR; for (i = 0; i < 4; i++) { @@ -185,13 +194,15 @@ token_decode(const char *token) int base64_decode(const char *str, void *data) { - const char *p; - unsigned char *q; + const char *p; + unsigned char *q; + unsigned int size; q = data; - for (p = str; *p && (*p == '=' || strchr(base64_chars, *p)); p += 4) + size = strlen(str); + for (p = str; *p && (*p == '=' || is_base64_char(*p)); p += 4, size -= 4) { - unsigned int val = token_decode(p); + unsigned int val = token_decode(p, size); unsigned int marker = (val >> 24) & 0xff; if (val == DECODE_ERROR) @@ -204,3 +215,4 @@ base64_decode(const char *str, void *data) } return q - (unsigned char *) data; } + |