tdf#105844 offapi,package,sfx2,xmlsecurity: add AEAD w/ AES GCM

... and use it in the new experimental ODF encryption mode.

https://www.w3.org/TR/xmlenc-core1/#sec-AES-GCM

Unfortunately it turned out that NSS PK11_CipherOp() does not work with
CKM_AES_GCM because it is initialized with "context->multi = PR_FALSE"
in sftk_CryptInit(), so the one-step functions PK11_Encrypt() and
PK11_Decrypt() have to be used.

NSS 3.52 also changed a parameter struct definition - see
https://fedoraproject.org/wiki/Changes/NssGCMParams - which is not a
problem for RHEL or SUSE system NSS since those are rebased, but it
is likely a problem for less well maintained Ubuntu LTS, so use
the old struct definition which evidently still works with NSS 3.94.

NSS 3.52 also added a new PK11_AEADOp() API but it looks like this
doesn't support incremental encryption either.

Change-Id: Ibd4a672db74b65b1218926ba35ff8d2f70444c7e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/160505
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>
(cherry picked from commit f0fda7ad2236f478fea396a23d4f982e5fc37e68)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/160581

1 files changed, 13 insertions, 0 deletions

diff --git a/offapi/com/sun/star/xml/crypto/CipherID.idl b/offapi/com/sun/star/xml/crypto/CipherID.idl
index 80d64a995a93..c1ecd297a741 100644
--- a/offapi/com/sun/star/xml/crypto/CipherID.idl
+++ b/offapi/com/sun/star/xml/crypto/CipherID.idl
@@ -30,12 +30,25 @@ module com { module sun { module star { module xml { module crypto {
 constants CipherID
 {
     /** identifier of AES algorithm in CBC mode with W3C padding
+
+        @see https://www.w3.org/TR/xmlenc-core1/#sec-Padding
+        @see https://www.w3.org/TR/xmlenc-core1/#sec-AES
      */
     const long AES_CBC_W3C_PADDING = 1;
 
     /** identifier of the Blowfish algorithm in 8-bit CFB mode
      */
     const long BLOWFISH_CFB_8 = 2;
+
+    /** identifier of AES algorithm in GCM mode with 96-bit IV prefixed,
+        128 bit authentication tag, and no padding, as specified in
+        [XMLENC-CORE1] 5.2.4 AES-GCM.
+
+        @see https://www.w3.org/TR/xmlenc-core1/#sec-AES-GCM
+
+        @since LO 24.2
+     */
+    const long AES_GCM_W3C = 3;
 };