diff options
| -rw-r--r-- | include/qpdf/QPDFWriter.hh | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/include/qpdf/QPDFWriter.hh b/include/qpdf/QPDFWriter.hh index e8b744d2..e2f731d3 100644 --- a/include/qpdf/QPDFWriter.hh +++ b/include/qpdf/QPDFWriter.hh @@ -219,13 +219,20 @@ class QPDFWriter QPDF_DLL void copyEncryptionParameters(QPDF&); - // Set up for encrypted output. Disables stream prefiltering and - // content normalization. Note that setting R2 encryption - // parameters sets the PDF version to at least 1.3, setting R3 - // encryption parameters pushes the PDF version number to at least - // 1.4, setting R4 parameters pushes the version to at least 1.5, - // or if AES is used, 1.6, and setting R5 or R6 parameters pushes - // the version to at least 1.7 with extension level 3. + // Set up for encrypted output. User and owner password both must + // be specified. Either or both may be the empty string. Note + // that qpdf does not apply any special treatment to the empty + // string, which makes it possible to create encrypted files with + // empty owner passwords and non-empty user passwords or with the + // same password for both user and owner. Some PDF reading + // products don't handle such files very well. Enabling + // encryption disables stream prefiltering and content + // normalization. Note that setting R2 encryption parameters sets + // the PDF version to at least 1.3, setting R3 encryption + // parameters pushes the PDF version number to at least 1.4, + // setting R4 parameters pushes the version to at least 1.5, or if + // AES is used, 1.6, and setting R5 or R6 parameters pushes the + // version to at least 1.7 with extension level 3. QPDF_DLL void setR2EncryptionParameters( char const* user_password, char const* owner_password, |