Try to detect if cipherText is plainText.

In some situations, the cipherText that was passed in is actually
plainText.  Old mpsites files used to store the login name as plain text
even though the file was redacted.  Newer versions of the file store the
login name as ciphertext.  There is no clear way to distinguish between
the two cases.

platform-independent/c/core/src/mpw-algorithm_v0.c

@@ -166,6 +166,11 @@ const char *mpw_site_crypted_password_v0(
         err( "Missing encrypted state." );
         return NULL;
     }
+    if (strlen( cipherText ) % 4 != 0) {
+        wrn( "Malformed encrypted state, not base64." );
+        // This can happen if state was stored in a non-encrypted form, eg. login in old mpsites.
+        return strdup( cipherText );
+    }
 
     // Base64-decode
     uint8_t *cipherBuf = calloc( 1, mpw_base64_decode_max( cipherText ) );
@@ -184,8 +189,10 @@ const char *mpw_site_crypted_password_v0(
     mpw_free( &plainBytes, bufSize );
     if (!plainText)
         err( "AES decryption error: %s", strerror( errno ) );
+    else if (!mpw_utf8_strchars( plainText ))
+        wrn( "decrypted -> plainText: %zu bytes = illegal UTF-8 = %s", strlen( plainText ), mpw_hex( plainText, bufSize ) );
     else
-        trc( "decrypted -> plainText: %zu bytes = %s = %s", strlen( plainText ), plainText, mpw_hex( plainText, strlen( plainText ) ) );
+        trc( "decrypted -> plainText: %zu bytes = %s = %s", strlen( plainText ), plainText, mpw_hex( plainText, bufSize ) );
 
     return plainText;
 }

platform-independent/c/core/src/mpw-marshal.c

@@ -980,7 +980,7 @@ static void mpw_marshal_read_flat(
                     str_counter = mpw_strdup( strtok( NULL, "" ) );
                     mpw_free_string( &typeAndVersionAndCounter );
                 }
-                siteLoginState = mpw_get_token( &positionInLine, endOfLine, "\t\n" ); // TODO: Needs to be encoded if redacted?
+                siteLoginState = mpw_get_token( &positionInLine, endOfLine, "\t\n" );
                 siteName = mpw_get_token( &positionInLine, endOfLine, "\t\n" );
                 siteResultState = mpw_get_token( &positionInLine, endOfLine, "\n" );
                 break;
@@ -1019,11 +1019,9 @@ static void mpw_marshal_read_flat(
             mpw_marshal_data_set_num( siteCounter, file->data, "sites", siteName, "counter", NULL );
             mpw_marshal_data_set_num( siteAlgorithm, file->data, "sites", siteName, "algorithm", NULL );
             mpw_marshal_data_set_num( siteType, file->data, "sites", siteName, "type", NULL );
-            mpw_marshal_data_set_str( siteResultState && strlen( siteResultState )? siteResultState: NULL, file->data, "sites", siteName,
-                    "password", NULL );
+            mpw_marshal_data_set_str( siteResultState, file->data, "sites", siteName, "password", NULL );
             mpw_marshal_data_set_num( MPResultTypeDefault, file->data, "sites", siteName, "login_type", NULL );
-            mpw_marshal_data_set_str( siteLoginState && strlen( siteLoginState )? siteLoginState: NULL, file->data, "sites", siteName,
-                    "login_name", NULL );
+            mpw_marshal_data_set_str( siteLoginState, file->data, "sites", siteName, "login_name", NULL );
             mpw_marshal_data_set_num( strtol( str_uses, NULL, 10 ), file->data, "sites", siteName, "uses", NULL );
             if (strftime( dateString, sizeof( dateString ), "%FT%TZ", gmtime( &siteLastUsed ) ))
                 mpw_marshal_data_set_str( dateString, file->data, "sites", siteName, "last_used", NULL );

platform-independent/c/core/src/mpw-util.c

@@ -607,6 +607,9 @@ const uint8_t *mpw_unhex(const char *hex, size_t *length) {
 
 size_t mpw_utf8_charlen(const char *utf8String) {
 
+    if (!utf8String)
+        return 0;
+
     // Legal UTF-8 byte sequences: <http://www.unicode.org/unicode/uni2errata/UTF-8_Corrigendum.html>
     unsigned char utf8Char = (unsigned char)*utf8String;
     if (utf8Char >= 0x00 && utf8Char <= 0x7F)
@@ -624,8 +627,9 @@ size_t mpw_utf8_charlen(const char *utf8String) {
 size_t mpw_utf8_strchars(const char *utf8String) {
 
     size_t strchars = 0, charlen;
-    for (char *remaining = (char *)utf8String; (charlen = mpw_utf8_charlen( remaining )); remaining += charlen)
-        ++strchars;
+    for (char *remaining = (char *)utf8String; remaining && *remaining; remaining += charlen, ++strchars)
+        if (!(charlen = mpw_utf8_charlen( remaining )))
+            return 0;
 
     return strchars;
 }

platform-independent/c/core/src/mpw-util.h

@@ -256,9 +256,9 @@ bool mpw_id_buf_equals(MPKeyID id1, MPKeyID id2);
 
 //// String utilities.
 
-/** @return The byte length of the UTF-8 character at the start of the given string. */
+/** @return The byte length of the UTF-8 character at the start of the given string or 0 if it is NULL, empty or not a legal UTF-8 character. */
 size_t mpw_utf8_charlen(const char *utf8String);
-/** @return The amount of UTF-8 characters in the given string. */
+/** @return The amount of UTF-8 characters in the given string or 0 if it is NULL, empty, or contains bytes that are not legal in UTF-8. */
 size_t mpw_utf8_strchars(const char *utf8String);
 /** Drop-in for memdup(3).
  * @return A buffer (allocated, len) with len bytes copied from src or NULL if src is missing or the buffer could not be allocated. */