[mbed-tls] mbedtls_base64_encode reports different olen's when used for size checking and when encoding

Hi,

I don't understand why mbedtls_base64_encode returns different olen's for the same source buffer. See example below:

uint8_t s[10]; uint8_t d[17]; size_t sz; int ret; ret = mbedtls_base64_encode(NULL, 0, &sz, s, 10); // returns sz == 17 ret = mbedtls_base64_encode(d, 17, &sz, s, 10); // returns sz == 16

Shouldn't it be the same?

Regards, Frederik