Add T::provider() to allow user to inquire about implementation used

For block ciphers, stream ciphers, hashes, MACs, and cipher modes.
Cipher_Mode already had it, with a slightly different usage.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/lib/block/block_cipher.h b/src/lib/block/block_cipher.h
index 0f4c2c1c5..68fc0f487 100644
--- a/src/lib/block/block_cipher.h
+++ b/src/lib/block/block_cipher.h
@@ -10,6 +10,7 @@
 
 #include <botan/scan_name.h>
 #include <botan/sym_algo.h>
+#include <string>
 
 namespace Botan {
 
@@ -53,6 +54,13 @@ class BOTAN_DLL BlockCipher : public SymmetricAlgorithm
          }
 
       /**
+      * @return provider information about this implementation. Default is "base",
+      * might also return "sse2", "avx2", "openssl", or some other arbitrary string.
+      * The return value is guaranteed to point to a string literal constant.
+      */
+      virtual const char* provider() const { return "base"; }
+
+      /**
       * Encrypt a block.
       * @param in The plaintext block to be encrypted as a byte array.
       * Must be of length block_size().