RSA encrypt and decrypt using OpenSSL

1 files changed, 148 insertions, 0 deletions

diff --git a/src/lib/vendor/openssl/openssl_rsa.cpp b/src/lib/vendor/openssl/openssl_rsa.cpp
new file mode 100644
index 000000000..42298621e
--- /dev/null
+++ b/src/lib/vendor/openssl/openssl_rsa.cpp
@@ -0,0 +1,148 @@
+/*
+* OpenSSL RSA interface
+* (C) 2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/rsa.h>
+#include <botan/internal/pk_utils.h>
+#include <functional>
+#include <memory>
+
+#include <openssl/rsa.h>
+#include <openssl/x509.h>
+#include <openssl/err.h>
+
+namespace Botan {
+
+namespace {
+
+std::pair<int, size_t> get_openssl_enc_pad(const std::string& eme)
+   {
+   if(eme == "Raw")
+      return std::make_pair(RSA_NO_PADDING, 0);
+   else if(eme == "EME-PKCS1-v1_5")
+      return std::make_pair(RSA_PKCS1_PADDING, 11);
+   else if(eme == "EME1(SHA-1)")
+      return std::make_pair(RSA_PKCS1_OAEP_PADDING, 41);
+   else
+      throw Lookup_Error("OpenSSL RSA does not support EME " + eme);
+   }
+
+class OpenSSL_Error : public Exception
+   {
+   public:
+      OpenSSL_Error(const std::string& what) :
+         Exception(what + " failed: " + ERR_error_string(ERR_get_error(), nullptr)) {}
+   };
+
+class OpenSSL_RSA_Encryption_Operation : public PK_Ops::Encryption
+   {
+   public:
+      typedef RSA_PublicKey Key_Type;
+
+      static OpenSSL_RSA_Encryption_Operation* make(const Spec& spec)
+         {
+         try
+            {
+            if(auto* key = dynamic_cast<const RSA_PublicKey*>(&spec.key()))
+               {
+               auto pad_info = get_openssl_enc_pad(spec.padding());
+               return new OpenSSL_RSA_Encryption_Operation(*key, pad_info.first, pad_info.second);
+               }
+            }
+         catch(...) {}
+
+         return nullptr;
+         }
+
+      OpenSSL_RSA_Encryption_Operation(const RSA_PublicKey& rsa, int pad, size_t pad_overhead) :
+         m_openssl_rsa(nullptr, ::RSA_free), m_padding(pad)
+         {
+         const std::vector<byte> der = rsa.x509_subject_public_key();
+         const byte* der_ptr = &der[0];
+         m_openssl_rsa.reset(d2i_RSAPublicKey(nullptr, &der_ptr, der.size()));
+         if(!m_openssl_rsa)
+            throw OpenSSL_Error("d2i_RSAPublicKey");
+
+         m_bits = 8 * (RSA_size(m_openssl_rsa.get()) - pad_overhead);
+         }
+
+      size_t max_input_bits() const override { return m_bits; };
+
+      secure_vector<byte> encrypt(const byte msg[], size_t msg_len,
+                                  RandomNumberGenerator&) override
+         {
+
+         secure_vector<byte> buf(::RSA_size(m_openssl_rsa.get()));
+         int rc = ::RSA_public_encrypt(msg_len, msg, &buf[0], m_openssl_rsa.get(), m_padding);
+         if(rc < 0)
+            throw OpenSSL_Error("RSA_public_encrypt");
+         return buf;
+         }
+
+   private:
+      std::unique_ptr<RSA, std::function<void (RSA*)>> m_openssl_rsa;
+      size_t m_bits = 0;
+      int m_padding = 0;
+   };
+
+class OpenSSL_RSA_Decryption_Operation : public PK_Ops::Decryption
+   {
+   public:
+      typedef RSA_PrivateKey Key_Type;
+
+      static OpenSSL_RSA_Decryption_Operation* make(const Spec& spec)
+         {
+         try
+            {
+            if(auto* key = dynamic_cast<const RSA_PrivateKey*>(&spec.key()))
+               {
+               auto pad_info = get_openssl_enc_pad(spec.padding());
+               return new OpenSSL_RSA_Decryption_Operation(*key, pad_info.first);
+               }
+            }
+         catch(...) {}
+
+         return nullptr;
+         }
+
+      OpenSSL_RSA_Decryption_Operation(const RSA_PrivateKey& rsa, int pad) :
+         m_openssl_rsa(nullptr, ::RSA_free), m_padding(pad)
+         {
+         const secure_vector<byte> der = rsa.pkcs8_private_key();
+         const byte* der_ptr = &der[0];
+         m_openssl_rsa.reset(d2i_RSAPrivateKey(nullptr, &der_ptr, der.size()));
+         if(!m_openssl_rsa)
+            throw OpenSSL_Error("d2i_RSAPrivateKey");
+
+         m_bits = 8 * RSA_size(m_openssl_rsa.get());
+         }
+
+      size_t max_input_bits() const override { return m_bits; };
+
+      secure_vector<byte> decrypt(const byte msg[], size_t msg_len) override
+         {
+         secure_vector<byte> buf(::RSA_size(m_openssl_rsa.get()));
+         int rc = ::RSA_private_decrypt(msg_len, msg, &buf[0], m_openssl_rsa.get(), m_padding);
+         if(rc < 0 || static_cast<size_t>(rc) > buf.size())
+            throw OpenSSL_Error("RSA_private_decrypt");
+         buf.resize(rc);
+         return buf;
+         }
+
+   private:
+      std::unique_ptr<RSA, std::function<void (RSA*)>> m_openssl_rsa;
+      size_t m_bits = 0;
+      int m_padding = 0;
+   };
+
+BOTAN_REGISTER_TYPE(PK_Ops::Encryption, OpenSSL_RSA_Encryption_Operation, "RSA",
+                    OpenSSL_RSA_Encryption_Operation::make, "openssl", 96);
+BOTAN_REGISTER_TYPE(PK_Ops::Decryption, OpenSSL_RSA_Decryption_Operation, "RSA",
+                    OpenSSL_RSA_Decryption_Operation::make, "openssl", 96);
+
+}
+
+}