Switch to HMAC_DRBG for all RNG generation.

Add support and tests for additional_data param to HMAC_DRBG

Add Stateful_RNG class which has fork detection and periodic reseeding.

AutoSeeded_RNG passes the current pid and time as additional_data

2 files changed, 11 insertions, 4 deletions

diff --git a/src/lib/pubkey/rfc6979/rfc6979.cpp b/src/lib/pubkey/rfc6979/rfc6979.cpp
index 0b26aadb5..1173eefee 100644
--- a/src/lib/pubkey/rfc6979/rfc6979.cpp
+++ b/src/lib/pubkey/rfc6979/rfc6979.cpp
@@ -17,18 +17,23 @@ RFC6979_Nonce_Generator::RFC6979_Nonce_Generator(const std::string& hash,
    m_order(order),
    m_qlen(m_order.bits()),
    m_rlen(m_qlen / 8 + (m_qlen % 8 ? 1 : 0)),
-   m_hmac_drbg(new HMAC_DRBG(MessageAuthenticationCode::create("HMAC(" + hash + ")").release())),
+   m_hmac_drbg(new HMAC_DRBG(hash, 0)),
    m_rng_in(m_rlen * 2),
    m_rng_out(m_rlen)
    {
    BigInt::encode_1363(m_rng_in.data(), m_rlen, x);
    }
 
+RFC6979_Nonce_Generator::~RFC6979_Nonce_Generator()
+   {
+   // for ~unique_ptr
+   }
+
 const BigInt& RFC6979_Nonce_Generator::nonce_for(const BigInt& m)
    {
    BigInt::encode_1363(&m_rng_in[m_rlen], m_rlen, m);
    m_hmac_drbg->clear();
-   m_hmac_drbg->add_entropy(m_rng_in.data(), m_rng_in.size());
+   m_hmac_drbg->initialize_with(m_rng_in.data(), m_rng_in.size());
 
    do
       {
diff --git a/src/lib/pubkey/rfc6979/rfc6979.h b/src/lib/pubkey/rfc6979/rfc6979.h
index 32728befb..2518535f7 100644
--- a/src/lib/pubkey/rfc6979/rfc6979.h
+++ b/src/lib/pubkey/rfc6979/rfc6979.h
@@ -14,7 +14,7 @@
 
 namespace Botan {
 
-class RandomNumberGenerator;
+class HMAC_DRBG;
 
 class BOTAN_DLL RFC6979_Nonce_Generator
    {
@@ -26,12 +26,14 @@ class BOTAN_DLL RFC6979_Nonce_Generator
                               const BigInt& order,
                               const BigInt& x);
 
+      ~RFC6979_Nonce_Generator();
+
       const BigInt& nonce_for(const BigInt& m);
    private:
       const BigInt& m_order;
       BigInt m_k;
       size_t m_qlen, m_rlen;
-      std::unique_ptr<RandomNumberGenerator> m_hmac_drbg;
+      std::unique_ptr<HMAC_DRBG> m_hmac_drbg;
       secure_vector<byte> m_rng_in, m_rng_out;
    };