Roll forward to cl/338482889

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: I9850950db8bd84f0904ea1a413151887f52098cf

cpp/platform/impl/g3/crypto.cc

@@ -0,0 +1,39 @@
+#include "platform/api/crypto.h"
+
+#include <cstdint>
+#include <string>
+
+#include "platform/base/byte_array.h"
+#include "absl/strings/string_view.h"
+#include "openssl/digest.h"
+
+namespace location {
+namespace nearby {
+
+// Initialize global crypto state.
+void Crypto::Init() {}
+
+static ByteArray Hash(absl::string_view input, const EVP_MD* algo) {
+  unsigned int md_out_size = EVP_MAX_MD_SIZE;
+  uint8_t digest_buffer[EVP_MAX_MD_SIZE];
+  if (input.empty()) return {};
+
+  if (!EVP_Digest(input.data(), input.size(), digest_buffer, &md_out_size, algo,
+                  nullptr))
+    return {};
+
+  return ByteArray{reinterpret_cast<char*>(digest_buffer), md_out_size};
+}
+
+// Return MD5 hash of input.
+ByteArray Crypto::Md5(absl::string_view input) {
+  return Hash(input, EVP_md5());
+}
+
+// Return SHA256 hash of input.
+ByteArray Crypto::Sha256(absl::string_view input) {
+  return Hash(input, EVP_sha256());
+}
+
+}  // namespace nearby
+}  // namespace location