Adding upstream version 1:2.3.21+dfsg1.upstream/1%2.3.21+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 162 insertions, 0 deletions

diff --git a/src/lib-mail/qp-encoder.c b/src/lib-mail/qp-encoder.c
new file mode 100644
index 0000000..37a4412
--- /dev/null
+++ b/src/lib-mail/qp-encoder.c
@@ -0,0 +1,162 @@
+/* Copyright (c) 2017-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "str.h"
+#include "istream.h"
+#include "istream-private.h"
+#include "qp-encoder.h"
+#include <ctype.h>
+
+enum qp_encoder_last_char {
+	QP_ENCODER_LAST_ANY = 0,
+	QP_ENCODER_LAST_CR,
+	QP_ENCODER_LAST_WHITE_SPACE,
+};
+
+struct qp_encoder {
+	const char *linebreak;
+	string_t *dest;
+	size_t line_len;
+	size_t max_len;
+	enum qp_encoder_flag flags;
+	enum qp_encoder_last_char last_char;
+	bool add_header_preamble:1;
+};
+
+struct qp_encoder *
+qp_encoder_init(string_t *dest, unsigned int max_len, enum qp_encoder_flag flags)
+{
+	i_assert(max_len > 0);
+
+	if ((flags & QP_ENCODER_FLAG_HEADER_FORMAT) != 0 &&
+	    (flags & QP_ENCODER_FLAG_BINARY_DATA) != 0)
+		i_panic("qp encoder cannot do header format with binary data");
+
+	struct qp_encoder *qp = i_new(struct qp_encoder, 1);
+	qp->flags = flags;
+	qp->dest = dest;
+	qp->max_len = max_len;
+
+	if ((flags & QP_ENCODER_FLAG_HEADER_FORMAT) != 0) {
+		qp->linebreak = "?=\r\n =?utf-8?Q?";
+		qp->add_header_preamble = TRUE;
+	} else {
+		qp->linebreak = "=\r\n";
+	}
+	return qp;
+}
+
+void qp_encoder_deinit(struct qp_encoder **qp)
+{
+	i_free(*qp);
+}
+
+static inline void
+qp_encode_or_break(struct qp_encoder *qp, unsigned char c)
+{
+	bool encode = FALSE;
+
+	if ((qp->flags & QP_ENCODER_FLAG_HEADER_FORMAT) != 0) {
+		if (c == ' ')
+			c = '_';
+		else if (c != '\t' &&
+			 (c == '?' || c == '_' || c == '=' || c < 33 || c > 126))
+			encode = TRUE;
+	} else if (c != ' ' && c != '\t' &&
+		   (c == '=' || c < 33 || c > 126)) {
+		encode = TRUE;
+	}
+
+	/* Include terminating = as well */
+	if ((c == ' ' || c == '\t') && qp->line_len + 4 >= qp->max_len) {
+		const char *ptr = strchr(qp->linebreak, '\n');
+		str_printfa(qp->dest, "=%02X%s", c, qp->linebreak);
+		if (ptr != NULL)
+			qp->line_len = strlen(ptr+1);
+		else
+			qp->line_len = 0;
+		return;
+	}
+
+	/* Include terminating = as well */
+	if (qp->line_len + (encode?4:2) >= qp->max_len) {
+		str_append(qp->dest, qp->linebreak);
+		qp->line_len = 0;
+	}
+
+	if (encode) {
+		str_printfa(qp->dest, "=%02X", c);
+		qp->line_len += 3;
+	} else {
+		str_append_c(qp->dest, c);
+		qp->line_len += 1;
+	}
+}
+
+void qp_encoder_more(struct qp_encoder *qp, const void *_src, size_t src_size)
+{
+	const unsigned char *src = _src;
+	i_assert(_src != NULL || src_size == 0);
+	if (src_size == 0)
+		return;
+	if (qp->add_header_preamble) {
+		size_t used = qp->dest->used;
+		qp->add_header_preamble = FALSE;
+		str_append(qp->dest, "=?utf-8?Q?");
+		qp->line_len = qp->dest->used - used;
+	}
+	for(unsigned int i = 0; i < src_size; i++) {
+		unsigned char c = src[i];
+		/* if input is not binary data and we encounter newline
+		   convert it as crlf, or if the last byte was CR, preserve
+		   CRLF */
+		if (c == '\n' &&
+		    ((qp->flags & (QP_ENCODER_FLAG_BINARY_DATA|QP_ENCODER_FLAG_HEADER_FORMAT)) == 0 ||
+		      qp->last_char == QP_ENCODER_LAST_CR)) {
+			str_append_c(qp->dest, '\r');
+			str_append_c(qp->dest, '\n');
+			/* reset line length here */
+			qp->line_len = 0;
+			qp->last_char = QP_ENCODER_LAST_ANY;
+			continue;
+		} else if (qp->last_char == QP_ENCODER_LAST_CR) {
+			qp_encode_or_break(qp, '\r');
+			qp->last_char = QP_ENCODER_LAST_ANY;
+		}
+
+		if (c == ' ' || c == '\t')
+			qp->last_char = QP_ENCODER_LAST_WHITE_SPACE;
+		else if (c == '\r')
+			qp->last_char = QP_ENCODER_LAST_CR;
+		else
+			qp->last_char = QP_ENCODER_LAST_ANY;
+
+		if (c != '\r')
+			qp_encode_or_break(qp, c);
+	}
+}
+
+void qp_encoder_finish(struct qp_encoder *qp)
+{
+	switch (qp->last_char) {
+	case QP_ENCODER_LAST_CR:
+		/* Last char was CR which was not yet encoded */
+		qp_encode_or_break(qp, '\r');
+		break;
+	case QP_ENCODER_LAST_WHITE_SPACE:
+		/* Last char was a white space, it must be followed by
+		 * a printable char. */
+		str_append_c(qp->dest, '=');
+		break;
+	default:
+		break;
+	}
+
+	if ((qp->flags & QP_ENCODER_FLAG_HEADER_FORMAT) != 0 &&
+	    !qp->add_header_preamble)
+		str_append(qp->dest, "?=");
+	if ((qp->flags & QP_ENCODER_FLAG_HEADER_FORMAT) != 0)
+		qp->add_header_preamble = TRUE;
+	qp->line_len = 0;
+	qp->last_char = QP_ENCODER_LAST_ANY;
+}