commit 7578f3f0dea091a3392f0be3216989bdc7355ad2
author Adam Langley <agl@chromium.org> Thu Jul 24 17:42:11 2014 -0700
committer Adam Langley <agl@chromium.org> Mon Jul 28 17:05:13 2014 -0700
tree 0c3eaf9664635e32c9800935d84f8d8503b2ae85
parent 3e1488555806d7fd78ae75a585161bc7cb15f096

Make EVP_CIPHER_CTX_copy work in GCM mode.

PR#3272

(Imported from upstream's 14183e50e75f54c44df6be69670180860ac19550 and
802fdcda1ebc4241a8e02af0046ba2f5264f71f6)

Change-Id: Ied6183d938e320f953a18f6616890d88b74def3f

crypto/cipher/cipher.c

diff --git a/crypto/cipher/cipher.c b/crypto/cipher/cipher.c
index bf5c559..c6572b8 100644
--- a/crypto/cipher/cipher.c
+++ b/crypto/cipher/cipher.c
@@ -140,6 +140,10 @@
     memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
   }
 
+  if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY) {
+    return in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out);
+  }
+
   return 1;
 }
 

crypto/cipher/e_aes.c

diff --git a/crypto/cipher/e_aes.c b/crypto/cipher/e_aes.c
index 6e3fafb..8caac70 100644
--- a/crypto/cipher/e_aes.c
+++ b/crypto/cipher/e_aes.c
@@ -480,6 +480,27 @@
       gctx->iv_set = 1;
       return 1;
 
+    case EVP_CTRL_COPY: {
+      EVP_CIPHER_CTX *out = ptr;
+      EVP_AES_GCM_CTX *gctx_out = out->cipher_data;
+      if (gctx->gcm.key) {
+        if (gctx->gcm.key != &gctx->ks) {
+          return 0;
+        }
+        gctx_out->gcm.key = &gctx_out->ks;
+      }
+      if (gctx->iv == c->iv) {
+        gctx_out->iv = out->iv;
+      } else {
+        gctx_out->iv = OPENSSL_malloc(gctx->ivlen);
+        if (!gctx_out->iv) {
+          return 0;
+        }
+        memcpy(gctx_out->iv, gctx->iv, gctx->ivlen);
+      }
+      return 1;
+    }
+
     default:
       return -1;
   }
@@ -775,7 +796,7 @@
     NID_aes_256_gcm, 1 /* block_size */, 32 /* key_size */, 12 /* iv_len */,
     sizeof(EVP_AES_GCM_CTX),
     EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER |
-        EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT |
+        EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT | EVP_CIPH_CUSTOM_COPY |
         EVP_CIPH_FLAG_AEAD_CIPHER,
     NULL /* app_data */, aesni_gcm_init_key, aes_gcm_cipher, aes_gcm_cleanup,
     aes_gcm_ctrl};

include/openssl/cipher.h

diff --git a/include/openssl/cipher.h b/include/openssl/cipher.h
index 191d44a..19988aa 100644
--- a/include/openssl/cipher.h
+++ b/include/openssl/cipher.h
@@ -325,6 +325,11 @@
  * one. */
 #define EVP_CIPH_FLAG_AEAD_CIPHER 0x800
 
+/* EVP_CIPH_CUSTOM_COPY indicates that the |ctrl| callback should be called
+ * with |EVP_CTRL_COPY| at the end of normal |EVP_CIPHER_CTX_copy|
+ * processing. */
+#define EVP_CIPH_CUSTOM_COPY 0x1000
+
 
 /* Private functions. */