overflow in b64_encode

[tim-napoli]

Hi,

in your function you're writing this:

enc = realloc(size);
enc[size++] = something;

This is wrong. If you allocates n byte, you cannot access the nth first bytes of the allocated array (think using size = 1).
You need to allocate n + 1. And check the end of the function, you have another invalid write there
(just use b64_encode with valgrind).

Have fix that using static strings.

I prefer a function with this signature :

/*
 * Encode some data in b64.
 * @param src Pointer to the content to encode
 * @param len Content's length
 * @param dst Pointer to the encoded result string (NULL-terminated)
 * @param dst_size Maximal size of the dst content.
 * @return Some error if `dst_size` is lower than the required decoded content length.
 */
int b64_encode(const char* src, size_t len, char* dst, size_t dst_size);

This way your implementation doesn't allocate anything by itself, discharging this responsibility to the caller.

[tim-napoli]

NVM, the problem is only present in the sources I pulled using clib ?