pop3-migration: Convert all non-ASCII in headers to '?'

diff --git a/src/plugins/pop3-migration/pop3-migration-plugin.c b/src/plugins/pop3-migration/pop3-migration-plugin.c
index 941fb6aa8bdc165f7e6997a95137dc3003a3ad09..fbebb79645a5754c3d44937a085a657a12c57464 100644 (file)
--- a/src/plugins/pop3-migration/pop3-migration-plugin.c
+++ b/src/plugins/pop3-migration/pop3-migration-plugin.c
@@ -154,8 +154,8 @@ int pop3_migration_get_hdr_sha1(uint32_t mail_seq, struct istream *input,
                                bool *have_eoh_r)
 {
        struct istream *input2;
-       const unsigned char *data, *p;
-       size_t size, idx;
+       const unsigned char *data;
+       size_t i, start, size;
        struct sha1_ctxt sha1_ctx;
        struct pop3_hdr_context hdr_ctx;
 
@@ -171,18 +171,25 @@ int pop3_migration_get_hdr_sha1(uint32_t mail_seq, struct istream *input,
 
        sha1_init(&sha1_ctx);
        while (i_stream_read_data(input, &data, &size, 0) > 0) {
-               /* if there are NULs in header, replace them with 0x80
-                  character. This is done by at least Dovecot IMAP and also
-                  POP3 with outlook-no-nuls workaround. */
-               while ((p = memchr(data, '\0', size)) != NULL) {
-                       idx = p - data;
-                       sha1_loop(&sha1_ctx, data, idx);
-                       sha1_loop(&sha1_ctx, "\x80", 1);
-                       i_assert(size > idx);
-                       data += idx + 1;
-                       size -= idx + 1;
+               /* - Dovecot IMAP replaces NULs with 0x80 character.
+                  - Dovecot POP3 with outlook-no-nuls workaround replaces NULs
+                  with 0x80 character.
+                  - Zimbra replaces 8bit chars with '?' in header fetches,
+                  but not body fetches.
+                  - Yahoo replaces 8bit chars with '?' in partial header
+                  fetches, but not POP3 TOP.
+
+                  So we'll just replace all control and 8bit chars with '?',
+                  which hopefully will satisfy everybody.
+               */
+               for (i = start = 0; i < size; i++) {
+                       if (data[i] < 0x20 || data[i] >= 0x80) {
+                               sha1_loop(&sha1_ctx, data + start, i-start);
+                               sha1_loop(&sha1_ctx, "?", 1);
+                               start = i+1;
+                       }
                }
-               sha1_loop(&sha1_ctx, data, size);
+               sha1_loop(&sha1_ctx, data + start, i-start);
                i_stream_skip(input, size);
        }
        if (input->stream_errno != 0) {