[FFmpeg-cvslog] avutil/aes_ctr: Add method to set 16-byte IV.

[Jacob Trimble]

ffmpeg | branch: master | Jacob Trimble <modmaker-at-google.com at ffmpeg.org> | Mon Jan  8 14:12:43 2018 -0800| [9f07cf7c00f3a87669c27aec947daf0f3d33b01f] | committer: Michael Niedermayer

avutil/aes_ctr: Add method to set 16-byte IV.

Signed-off-by: Jacob Trimble <modmaker at google.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9f07cf7c00f3a87669c27aec947daf0f3d33b01f
---

 doc/APIchanges            | 3 +++
 libavutil/aes_ctr.c       | 6 ++++++
 libavutil/aes_ctr.h       | 7 ++++++-
 libavutil/tests/aes_ctr.c | 2 +-
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index 7699365879..c27f104c95 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,9 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2018-xx-xx - xxxxxxx - lavu 56.9.100 - aes_ctr.h
+  Add method to set the 16-byte IV.
+
 2018-01-xx - xxxxxxx - lavf 58.5.100 - avformat.h
   Explicitly make avformat_network_init() and avformat_network_deinit() optional.
   If these are not called, network initialization and deinitialization is
diff --git a/libavutil/aes_ctr.c b/libavutil/aes_ctr.c
index e9c568fe0d..0c2e86785f 100644
--- a/libavutil/aes_ctr.c
+++ b/libavutil/aes_ctr.c
@@ -45,6 +45,12 @@ void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t* iv)
     a->block_offset = 0;
 }
 
+void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t* iv)
+{
+    memcpy(a->counter, iv, sizeof(a->counter));
+    a->block_offset = 0;
+}
+
 const uint8_t* av_aes_ctr_get_iv(struct AVAESCTR *a)
 {
     return a->counter;
diff --git a/libavutil/aes_ctr.h b/libavutil/aes_ctr.h
index f596fa6a46..e4aae126a7 100644
--- a/libavutil/aes_ctr.h
+++ b/libavutil/aes_ctr.h
@@ -67,11 +67,16 @@ const uint8_t* av_aes_ctr_get_iv(struct AVAESCTR *a);
 void av_aes_ctr_set_random_iv(struct AVAESCTR *a);
 
 /**
- * Forcefully change the iv
+ * Forcefully change the 8-byte iv
  */
 void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t* iv);
 
 /**
+ * Forcefully change the "full" 16-byte iv, including the counter
+ */
+void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t* iv);
+
+/**
  * Increment the top 64 bit of the iv (performed after each frame)
  */
 void av_aes_ctr_increment_iv(struct AVAESCTR *a);
diff --git a/libavutil/tests/aes_ctr.c b/libavutil/tests/aes_ctr.c
index c5ebeda7ac..00fdb05d13 100644
--- a/libavutil/tests/aes_ctr.c
+++ b/libavutil/tests/aes_ctr.c
@@ -45,7 +45,7 @@ int main (void)
 
     av_aes_ctr_set_random_iv(ae);
     iv =   av_aes_ctr_get_iv(ae);
-    av_aes_ctr_set_iv(ad, iv);
+    av_aes_ctr_set_full_iv(ad, iv);
 
     av_aes_ctr_crypt(ae, tmp, plain, sizeof(tmp));
     av_aes_ctr_crypt(ad, tmp, tmp,   sizeof(tmp));