gpg: First take on PKT_ENCRYPTED_AEAD.

* common/openpgpdefs.h (PKT_ENCRYPTED_AEAD): New const.
* g10/dek.h (DEK): Increase size of use_aead to 4 bits.
* g10/filter.h (cipher_filter_context_t):  Add new fields for AEAD.
* g10/packet.h (PKT_encrypted): Add fields aead_algo, cipher_algo, and
chunkbyte.
* g10/build-packet.c (do_encrypted_aead): New.
(build_packet): Call it.
* g10/parse-packet.c (dump_sig_subpkt): Handle SIGSUBPKT_PREF_AEAD.
(parse_one_sig_subpkt, can_handle_critical): Ditto.
(parse_encrypted): Clear new PKT_ENCRYPTED fields.
(parse_encrypted_aead): New.
(parse): Call it.
* g10/gpg.c (main): Take care of --rfc4880bis option when checking
compliance.
* g10/cipher-aead.c: Replace the stub by real code.
* g10/decrypt-data.c (decode_filter_ctx_t): Add fields for use with
AEAD.
(aead_set_nonce): New.
(aead_set_ad): New.
(decrypt_data): Support AEAD.
(aead_underflow): New.
(aead_decode_filter): New.
* g10/encrypt.c (use_aead): Make that new fucntion work.
(encrypt_simple): Use default_aead_algo() instead of EAX.
* g10/mainproc.c (proc_encrypted): Support AEAD.
(do_proc_packets): Support PKT_ENCRYPTED_AEAD.
--

This code has seen only a very few manual tests.  Encrypting always
uses a 64k chunks and decryption has not been tested with larger
chunks.  Those small chunks make debugging much faster.

Tests can be done using:

  gpg --rfc4880bis --pinentry-mode=loopback --passphrase abc \
      --force-aead --aead-algo ocb --s2k-mode 0 --cipher AES \
      -v -z 0 --status-fd 2 -c <INFILE >OUTFILE

and

  gpg --rfc4880bis --pinentry-mode=loopback --passphrase=abc \
      --status-fd 2 -v -d <INFILE >OUTFILE

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 46 insertions, 9 deletions

diff --git a/g10/filter.h b/g10/filter.h
index 29243556e..cd177f4a4 100644
--- a/g10/filter.h
+++ b/g10/filter.h
@@ -88,15 +88,52 @@ struct compress_filter_context_s {
 typedef struct compress_filter_context_s compress_filter_context_t;
 
 
-typedef struct {
-    DEK *dek;
-    u32 datalen;
-    gcry_cipher_hd_t cipher_hd;
-    unsigned int wrote_header : 1;
-    unsigned int short_blklen_warn : 1;
-    unsigned long short_blklen_count;
-    gcry_md_hd_t mdc_hash;
-    byte enchash[20];
+typedef struct
+{
+  /* Object with the key and algo */
+  DEK *dek;
+
+  /* Length of the data to encrypt if known - 32 bit because OpenPGP
+   * requires partial encoding for a larger data size.  */
+  u32 datalen;
+
+  /* The current cipher handle.  */
+  gcry_cipher_hd_t cipher_hd;
+
+  /* Various processing flags.  */
+  unsigned int wrote_header : 1;
+  unsigned int short_blklen_warn : 1;
+  unsigned long short_blklen_count;
+
+  /* The encoded chunk byte for AEAD.  */
+  byte chunkbyte;
+
+  /* The decoded CHUNKBYTE.  */
+  uint64_t chunksize;
+
+  /* The chunk index for AEAD.  */
+  uint64_t chunkindex;
+
+  /* The number of bytes in the current chunk.  */
+  uint64_t chunklen;
+
+  /* The total count of encrypted plaintext octets.  Note that we
+   * don't care about encrypting more than 16 Exabyte. */
+  uint64_t total;
+
+  /* The hash context and a buffer used for MDC.  */
+  gcry_md_hd_t mdc_hash;
+  byte enchash[20];
+
+  /* The start IV for AEAD encryption.   */
+  byte startiv[16];
+
+  /* Using a large buffer for encryption makes processing easier and
+   * also makes sure the data is well aligned.  */
+  char *buffer;
+  size_t bufsize;  /* Allocated length.  */
+  size_t buflen;   /* Used length.       */
+
 } cipher_filter_context_t;