Function plain_base64

imap-send.c:879–909

#define ENCODED_SIZE(n) (4 * DIV_ROUND_UP((n), 3))
static char *plain_base64(const char *user, const char *pass)
{
	struct strbuf raw = STRBUF_INIT;
	int b64_len;
	char *b64;

	/*
	 * Compose the PLAIN string
	 *
	 * The username and password are combined to one string and base64 encoded.
	 * "\0user\0pass"
	 *
	 * The method has been described in RFC4616.
	 *
	 * https://datatracker.ietf.org/doc/html/rfc4616
	 */
	strbuf_addch(&raw, '\0');
	strbuf_addstr(&raw, user);
	strbuf_addch(&raw, '\0');
	strbuf_addstr(&raw, pass);

	b64 = xmallocz(ENCODED_SIZE(raw.len));
	b64_len = EVP_EncodeBlock((unsigned char *)b64, (unsigned char *)raw.buf, raw.len);
	strbuf_release(&raw);

	if (b64_len < 0) {
		free(b64);
		return NULL;
	}
	return b64;
}

static char *cram(const char *challenge_64, const char *user, const char *pass)
{