Give SHA256 functions C bindings

2 files changed, 70 insertions, 32 deletions

diff --git a/include/olm/crypto.h b/include/olm/crypto.h
new file mode 100644
index 0000000..1357834
--- /dev/null
+++ b/include/olm/crypto.h
@@ -0,0 +1,65 @@
+/* Copyright 2015 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* C-compatible crpyto utility functions. At some point all of crypto.hh will
+ * move here.
+ */
+
+#ifndef OLM_CRYPTO_H_
+#define OLM_CRYPTO_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+const size_t SHA256_OUTPUT_LENGTH = 32;
+
+/** Computes SHA-256 of the input. The output buffer must be a least 32
+ * bytes long. */
+void crypto_sha256(
+    uint8_t const * input, size_t input_length,
+    uint8_t * output
+);
+
+/** HMAC: Keyed-Hashing for Message Authentication
+ * http://tools.ietf.org/html/rfc2104
+ * Computes HMAC-SHA-256 of the input for the key. The output buffer must
+ * be at least 32 bytes long. */
+void crypto_hmac_sha256(
+    uint8_t const * key, size_t key_length,
+    uint8_t const * input, size_t input_length,
+    uint8_t * output
+);
+
+
+/** HMAC-based Key Derivation Function (HKDF)
+ * https://tools.ietf.org/html/rfc5869
+ * Derives key material from the input bytes. */
+void crypto_hkdf_sha256(
+    uint8_t const * input, size_t input_length,
+    uint8_t const * info, size_t info_length,
+    uint8_t const * salt, size_t salt_length,
+    uint8_t * output, size_t output_length
+);
+
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif /* OLM_CRYPTO_H_ */
diff --git a/include/olm/crypto.hh b/include/olm/crypto.hh
index 7a05f8d..64e8f7d 100644
--- a/include/olm/crypto.hh
+++ b/include/olm/crypto.hh
@@ -18,6 +18,11 @@
 #include <cstdint>
 #include <cstddef>
 
+// eventually all of this needs to move into crypto.h, and everything should
+// use that. For now, include crypto.h here.
+
+#include "olm/crypto.h"
+
 namespace olm {
 
 static const std::size_t KEY_LENGTH = 32;
@@ -142,38 +147,6 @@ std::size_t aes_decrypt_cbc(
 );
 
 
-/** Computes SHA-256 of the input. The output buffer must be a least 32
- * bytes long. */
-void sha256(
-    std::uint8_t const * input, std::size_t input_length,
-    std::uint8_t * output
-);
-
-
-const std::size_t SHA256_OUTPUT_LENGTH = 32;
-
-
-/** HMAC: Keyed-Hashing for Message Authentication
- * http://tools.ietf.org/html/rfc2104
- * Computes HMAC-SHA-256 of the input for the key. The output buffer must
- * be at least 32 bytes long. */
-void hmac_sha256(
-    std::uint8_t const * key, std::size_t key_length,
-    std::uint8_t const * input, std::size_t input_length,
-    std::uint8_t * output
-);
-
-
-/** HMAC-based Key Derivation Function (HKDF)
- * https://tools.ietf.org/html/rfc5869
- * Derives key material from the input bytes. */
-void hkdf_sha256(
-    std::uint8_t const * input, std::size_t input_length,
-    std::uint8_t const * info, std::size_t info_length,
-    std::uint8_t const * salt, std::size_t salt_length,
-    std::uint8_t * output, std::size_t output_length
-);
-
 } // namespace olm
 
 #endif /* OLM_CRYPTO_HH_ */