cipher: Support internal generation of IV for AEAD cipher mode.

* cipher/cipher-gcm.c (_gcry_cipher_gcm_setiv_zero): New.
(_gcry_cipher_gcm_encrypt, _gcry_cipher_gcm_decrypt)
(_gcry_cipher_gcm_authenticate): Use _gcry_cipher_gcm_setiv_zero.
* cipher/cipher-internal.h (struct gcry_cipher_handle): Add aead field.
* cipher/cipher.c (_gcry_cipher_setiv): Check calling setiv to reject
direct invocation in FIPS mode.
(_gcry_cipher_setup_geniv, _gcry_cipher_geniv): New.
* doc/gcrypt.texi: Add explanation for two new functions.
* src/gcrypt-int.h (_gcry_cipher_setup_geniv, _gcry_cipher_geniv): New.
* src/gcrypt.h.in (enum gcry_cipher_geniv_methods): New.
(gcry_cipher_setup_geniv, gcry_cipher_geniv): New.
* src/libgcrypt.def (gcry_cipher_setup_geniv, gcry_cipher_geniv): Add.
* src/libgcrypt.vers: Likewise.
* src/visibility.c (gcry_cipher_setup_geniv, gcry_cipher_geniv): Add.
* src/visibility.h: Likewise.

--

GnuPG-bug-id: 4873
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

6 files changed, 48 insertions, 0 deletions

diff --git a/src/gcrypt-int.h b/src/gcrypt-int.h
index 04953ffc..c3ca5d71 100644
--- a/src/gcrypt-int.h
+++ b/src/gcrypt-int.h
@@ -69,6 +69,12 @@ gcry_err_code_t _gcry_cipher_setkey (gcry_cipher_hd_t hd,
                                      const void *key, size_t keylen);
 gcry_err_code_t _gcry_cipher_setiv (gcry_cipher_hd_t hd,
                                     const void *iv, size_t ivlen);
+gcry_err_code_t _gcry_cipher_setup_geniv (gcry_cipher_hd_t hd, int method,
+                                          const void *fixed_iv,
+                                          size_t fixed_ivlen,
+                                          const void *dyn_iv, size_t dyn_ivlen);
+gcry_err_code_t _gcry_cipher_geniv (gcry_cipher_hd_t hd,
+                                    void *iv, size_t ivlen);
 gpg_err_code_t _gcry_cipher_authenticate (gcry_cipher_hd_t hd, const void *abuf,
                                           size_t abuflen);
 gpg_err_code_t _gcry_cipher_gettag (gcry_cipher_hd_t hd, void *outtag,
diff --git a/src/gcrypt.h.in b/src/gcrypt.h.in
index 60bcb6d1..8451a4ce 100644
--- a/src/gcrypt.h.in
+++ b/src/gcrypt.h.in
@@ -986,6 +986,13 @@ enum gcry_cipher_flags
     GCRY_CIPHER_EXTENDED    = 16  /* Enable extended AES-WRAP.  */
   };
 
+/* Methods used for AEAD IV generation. */
+enum gcry_cipher_geniv_methods
+  {
+    GCRY_CIPHER_GENIV_METHOD_CONCAT = 1,
+    GCRY_CIPHER_GENIV_METHOD_XOR = 2
+  };
+
 /* GCM works only with blocks of 128 bits */
 #define GCRY_GCM_BLOCK_LEN  (128 / 8)
 
@@ -1057,6 +1064,15 @@ gcry_error_t gcry_cipher_setkey (gcry_cipher_hd_t hd,
 gcry_error_t gcry_cipher_setiv (gcry_cipher_hd_t hd,
                                 const void *iv, size_t ivlen);
 
+/* Initialization vector generation setup for AEAD modes/ciphers.  */
+gcry_error_t gcry_cipher_setup_geniv (gcry_cipher_hd_t hd, int method,
+                                      const void *fixed_iv, size_t fixed_ivlen,
+                                      const void *dyn_iv, size_t dyn_ivlen);
+
+/* Initialization vector generation for AEAD modes/ciphers.  */
+gcry_error_t gcry_cipher_geniv (gcry_cipher_hd_t hd,
+                                void *iv, size_t ivlen);
+
 /* Provide additional authentication data for AEAD modes/ciphers.  */
 gcry_error_t gcry_cipher_authenticate (gcry_cipher_hd_t hd, const void *abuf,
                                        size_t abuflen);
diff --git a/src/libgcrypt.def b/src/libgcrypt.def
index d6de731f..a66511c8 100644
--- a/src/libgcrypt.def
+++ b/src/libgcrypt.def
@@ -298,4 +298,7 @@ EXPORTS
       gcry_kdf_final            @260
       gcry_kdf_close            @261
 
+      gcry_cipher_setup_geniv   @262
+      gcry_cipher_geniv         @263
+
 ;; end of file with public symbols for Windows.
diff --git a/src/libgcrypt.vers b/src/libgcrypt.vers
index 2e274f60..62b0e4ee 100644
--- a/src/libgcrypt.vers
+++ b/src/libgcrypt.vers
@@ -125,6 +125,9 @@ GCRYPT_1.6 {
     gcry_pk_hash_sign; gcry_pk_hash_verify; gcry_pk_random_override_new;
 
     gcry_kdf_open; gcry_kdf_compute; gcry_kdf_final; gcry_kdf_close;
+
+    gcry_cipher_setup_geniv; gcry_cipher_geniv;
+
   local:
     *;
 
diff --git a/src/visibility.c b/src/visibility.c
index daaf4033..150b197d 100644
--- a/src/visibility.c
+++ b/src/visibility.c
@@ -774,6 +774,22 @@ gcry_cipher_setctr (gcry_cipher_hd_t hd, const void *ctr, size_t ctrlen)
 }
 
 gcry_error_t
+gcry_cipher_setup_geniv (gcry_cipher_hd_t hd, int method,
+                         const void *fixed_iv, size_t fixed_iv_len,
+                         const void *dyn_iv, size_t dyn_iv_len)
+{
+  return gcry_error (_gcry_cipher_setup_geniv (hd, method,
+                                               fixed_iv, fixed_iv_len,
+                                               dyn_iv, dyn_iv_len));
+}
+
+gcry_error_t
+gcry_cipher_geniv (gcry_cipher_hd_t hd, void *iv, size_t iv_len)
+{
+  return gcry_error (_gcry_cipher_geniv (hd, iv, iv_len));
+}
+
+gcry_error_t
 gcry_cipher_authenticate (gcry_cipher_hd_t hd, const void *abuf, size_t abuflen)
 {
   if (!fips_is_operational ())
diff --git a/src/visibility.h b/src/visibility.h
index 14bf6248..6aef3278 100644
--- a/src/visibility.h
+++ b/src/visibility.h
@@ -122,6 +122,8 @@ MARK_VISIBLEX (gcry_cipher_close)
 MARK_VISIBLEX (gcry_cipher_setkey)
 MARK_VISIBLEX (gcry_cipher_setiv)
 MARK_VISIBLEX (gcry_cipher_setctr)
+MARK_VISIBLEX (gcry_cipher_setup_geniv)
+MARK_VISIBLEX (gcry_cipher_geniv)
 MARK_VISIBLEX (gcry_cipher_authenticate)
 MARK_VISIBLEX (gcry_cipher_checktag)
 MARK_VISIBLEX (gcry_cipher_gettag)
@@ -344,6 +346,8 @@ MARK_VISIBLEX (_gcry_mpi_get_const)
 #define gcry_cipher_setctr          _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_cipher_algo_info       _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_cipher_algo_name       _gcry_USE_THE_UNDERSCORED_FUNCTION
+#define gcry_cipher_setup_geniv     _gcry_USE_THE_UNDERSCORED_FUNCTION
+#define gcry_cipher_geniv           _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_cipher_authenticate    _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_cipher_checktag        _gcry_USE_THE_UNDERSCORED_FUNCTION
 #define gcry_cipher_gettag          _gcry_USE_THE_UNDERSCORED_FUNCTION