// Assume that *out is large enough to contain the output. // Theoretically it should be 4/3 the length of src. const uint8_t *s = (const uint8_t *) src; uint8_t *o = (uint8_t *) out; // Use local temporaries to avoid cache thrashing: size_t olen = 0; size_t slen = srclen; struct base64_state st; st.bytes = state->bytes; st.carry = state->carry; // Turn three bytes into four 6-bit numbers: // in[0] = 00111111 // in[1] = 00112222 // in[2] = 00222233 // in[3] = 00333333 // Duff's device, a for() loop inside a switch() statement. Legal! switch (st.bytes) { for (;;) { case 0: