Function mime_state_downgrade

lib_acl_cpp/src/mime/internal/mime_state_parse.cpp:293–340

/* mime_state_downgrade - convert 8-bit data to quoted-printable */

void mime_state_downgrade(MIME_STATE *state, int rec_type,
	const char *text, ssize_t len)
{
	static char hexchars[] = "0123456789ABCDEF";
	const unsigned char *cp;
	MIME_NODE *node = state->curr_node;
	int     ch;

#define CU_CHAR_PTR(x)	((const unsigned char *) (x))
#define QP_ENCODE(buffer, ch) { \
	buffer += '='; \
	buffer += (char) hexchars[(ch >> 4) & 0xff]; \
	buffer += (char) hexchars[ch & 0xf]; \
}

	/*
	 * Insert a soft line break when the output reaches a critical length
	 * before we reach a hard line break.
	 */
	for (cp = CU_CHAR_PTR(text); cp < CU_CHAR_PTR(text + len); cp++) {
		/* Critical length before hard line break. */
		if (LEN(node->buffer) > 72) {
			node->buffer += '=';
		}
		/* Append the next character. */
		ch = *cp;
		if ((ch < 32 && ch != '\t') || ch == '=' || ch > 126) {
			QP_ENCODE(node->buffer, ch);
		} else {
			ADDCH(node->buffer, ch);
		}
	}

	/*
	 * Flush output after a hard line break (i.e. the end of a REC_TYPE_NORM
	 * record). Fix trailing whitespace as per the RFC: in the worst case,
	 * the output length will grow from 73 characters to 75 characters.
	 */
	if (rec_type == REC_TYPE_NORM) {
		if (LEN(node->buffer) > 0
			&& ((ch = END(node->buffer)[-1]) == ' ' || ch == '\t'))
		{
			acl_vstring_truncate(node->buffer, LEN(node->buffer) - 1);
			QP_ENCODE(node->buffer, ch);
		}
		ACL_VSTRING_TERMINATE(node->buffer);
	}
}

static ACL_FIFO *mail_addr_add(ACL_FIFO *addr_list, const char *addr)
{