From 525243c689b1bc0d04a3a6904c243bdae63f9d8d Mon Sep 17 00:00:00 2001
From: Nick Parker <nparker@zetetic.net>
Date: Thu, 17 May 2012 07:59:43 -0500
Subject: [PATCH] Adding PRAGMA cipher_version to identify the current
 SQLCipher version, also including test.

---
 src/crypto.c     | 10 ++++++++++
 src/crypto.h     |  4 ++++
 src/pragma.c     |  4 ++++
 test/crypto.test | 12 ++++++++++++
 4 files changed, 30 insertions(+)

diff --git a/src/crypto.c b/src/crypto.c
index 3b1bfbf7..8928fb9d 100644
--- a/src/crypto.c
+++ b/src/crypto.c
@@ -38,6 +38,16 @@
 #include "btreeInt.h"
 #include "crypto.h"
 
+/* Generate code to return a string value */
+void codec_vdbe_return_static_string(Parse *pParse, const char *zLabel, const char *value){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  int mem = ++pParse->nMem;
+  sqlite3VdbeAddOp4(v, OP_String, 0, mem, 0, (char*)value, P4_STATIC);
+  sqlite3VdbeSetNumCols(v, 1);
+  sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, SQLITE_STATIC);
+  sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
+}
+
 int codec_set_kdf_iter(sqlite3* db, int nDb, int kdf_iter, int for_ctx) {
   struct Db *pDb = &db->aDb[nDb];
   CODEC_TRACE(("codec_set_kdf_iter: entered db=%p nDb=%d kdf_iter=%d for_ctx=%d\n", db, nDb, kdf_iter, for_ctx));
diff --git a/src/crypto.h b/src/crypto.h
index 6074907f..6485c968 100644
--- a/src/crypto.h
+++ b/src/crypto.h
@@ -37,6 +37,10 @@
 
 #define FILE_HEADER_SZ 16
 
+#ifndef CIPHER_VERSION
+#define CIPHER_VERSION "2.0.5"
+#endif
+
 #ifndef CIPHER
 #define CIPHER "aes-256-cbc"
 #endif
diff --git a/src/pragma.c b/src/pragma.c
index 1b23bc61..09282a73 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -1535,6 +1535,10 @@ void sqlite3Pragma(
     }
   }else
 /** BEGIN CRYPTO **/
+  if( sqlite3StrICmp(zLeft, "cipher_version")==0 && !zRight ){
+    extern void codec_vdbe_return_static_string(Parse *pParse, const char *zLabel, const char *value);
+    codec_vdbe_return_static_string(pParse, "cipher_version", CIPHER_VERSION);
+  }else
   if( sqlite3StrICmp(zLeft, "cipher")==0 && zRight ){
     extern int codec_set_cipher_name(sqlite3*, int, const char *, int);
     codec_set_cipher_name(db, iDb, zRight, 2); // change cipher for both
diff --git a/test/crypto.test b/test/crypto.test
index 78240561..cefe533a 100644
--- a/test/crypto.test
+++ b/test/crypto.test
@@ -1205,4 +1205,16 @@ do_test change-default-use-hmac-attach {
 db close
 file delete -force test.db
 
+# verify the pragma cipher_version
+# returns the currently configured
+# sqlcipher version
+do_test verify-pragma-cipher-version {
+    sqlite_orig db test.db
+    execsql {
+        PRAGMA cipher_version;
+    }
+} {2.0.5}
+db close
+file delete -force test.db
+
 finish_test