base64dec: don't read out of bounds (0b2eb9)

This commit is contained in:
bakkeby 2020-03-24 14:21:08 +01:00
parent 63b2d856cf
commit 5f311ddc78
1 changed files with 5 additions and 1 deletions

6
st.c
View File

@ -388,7 +388,7 @@ char
base64dec_getc(const char **src)
{
while (**src && !isprint(**src)) (*src)++;
return *((*src)++);
return **src ? *((*src)++) : '='; /* emulate padding if string ends */
}
char *
@ -406,6 +406,10 @@ base64dec(const char *src)
int c = base64_digits[(unsigned char) base64dec_getc(&src)];
int d = base64_digits[(unsigned char) base64dec_getc(&src)];
/* invalid input. 'a' can be -1, e.g. if src is "\n" (c-str) */
if (a == -1 || b == -1)
break;
*dst++ = (a << 2) | ((b & 0x30) >> 4);
if (c == -1)
break;