error out if key_sz is ever 0 due to context corruption

sjlombardo · sjlombardo · commit f09f9f908ab8 · 2012-05-15T20:48:10.000-04:00
diff --git a/src/crypto.h b/src/crypto.h
@@ -79,8 +79,7 @@
 #endif
 
 
-/* extensions defined in pragma.c */ 
-   
+/* extensions defined in pager.c */ 
 void sqlite3pager_get_codec(Pager *pPager, void **ctx);
 int sqlite3pager_is_mj_pgno(Pager *pPager, Pgno pgno);
 sqlite3_file *sqlite3Pager_get_fd(Pager *pPager);
@@ -91,7 +90,8 @@ void sqlite3pager_sqlite3PagerSetCodec(
   void (*xCodecFree)(void*),
   void *pCodec
 );
-/* end extensions defined in pragma.c */
+void sqlite3pager_sqlite3PagerSetError(Pager *pPager, int error);
+/* end extensions defined in pager.c */
  
 /*
 **  Simple shared routines for converting hex char strings to binary data
diff --git a/src/crypto_impl.c b/src/crypto_impl.c
@@ -353,7 +353,9 @@ int sqlcipher_codec_ctx_set_use_hmac(codec_ctx *ctx, int use) {
 }
 
 void sqlcipher_codec_ctx_set_error(codec_ctx *ctx, int error) {
-  ctx->pBt->db->errCode = error;
+  CODEC_TRACE(("sqlcipher_codec_ctx_set_error: ctx=%p, error=%d\n", ctx, error));
+  sqlite3pager_sqlite3PagerSetError(ctx->pBt->pBt->pPager, error);
+  ctx->pBt->pBt->db->errCode = error;
 }
 
 int sqlcipher_codec_ctx_get_pagesize(codec_ctx *ctx) {
@@ -502,11 +504,11 @@ int sqlcipher_page_cipher(codec_ctx *ctx, int for_ctx, Pgno pgno, int mode, int
 
   CODEC_TRACE(("codec_cipher:entered pgno=%d, mode=%d, size=%d\n", pgno, mode, size));
 
-  /* just copy raw data from in to out when key size is 0
-   * i.e. during a rekey of a plaintext database */ 
+  /* the key size should never be zero. If it is, error out. */
   if(c_ctx->key_sz == 0) {
-    memcpy(out, in, size);
-    return SQLITE_OK;
+    CODEC_TRACE(("codec_cipher: error possible context corruption, key_sz is zero for pgno=%d\n", pgno));
+    memset(out, 0, page_sz); 
+    return SQLITE_ERROR;
   } 
 
   if(mode == CIPHER_ENCRYPT) {
diff --git a/src/pager.c b/src/pager.c
@@ -6920,6 +6920,9 @@ void sqlite3pager_sqlite3PagerSetCodec(
   sqlite3PagerSetCodec(pPager, xCodec, xCodecSizeChng, xCodecFree, pCodec); 
 }
 
+void sqlite3pager_sqlite3PagerSetError( Pager *pPager, int error) {
+  pPager->errCode = error;
+}
 
 #endif
 /* END CRYPTO */

Original file line number	Diff line number	Diff line change
`@@ -6920,6 +6920,9 @@ void sqlite3pager_sqlite3PagerSetCodec(`
`6920`	`6920`	`sqlite3PagerSetCodec(pPager, xCodec, xCodecSizeChng, xCodecFree, pCodec);`
`6921`	`6921`	`}`
`6922`	`6922`
	`6923`	`+void sqlite3pager_sqlite3PagerSetError( Pager *pPager, int error) {`
	`6924`	`+ pPager->errCode = error;`
	`6925`	`+}`
`6923`	`6926`
`6924`	`6927`	`#endif`
`6925`	`6928`	`/* END CRYPTO */`