1 files changed, 9 insertions, 1 deletions
diff --git a/src/kdf/prf_tls/prf_tls.cpp b/src/kdf/prf_tls/prf_tls.cpp
index 2b57cdd25..3790650b0 100644
--- a/src/kdf/prf_tls/prf_tls.cpp
+++ b/src/kdf/prf_tls/prf_tls.cpp
@@ -23,7 +23,15 @@ void P_hash(MemoryRegion<byte>& output,
             const byte secret[], size_t secret_len,
             const byte seed[], size_t seed_len)
    {
-   mac->set_key(secret, secret_len);
+   try
+      {
+      mac->set_key(secret, secret_len);
+      }
+   catch(Invalid_Key_Length)
+      {
+      throw Internal_Error("The premaster secret of " + to_string(secret_len) +
+                           " bytes is too long for the PRF");
+      }
 
    SecureVector<byte> A(seed, seed_len);