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diff --git a/third_party/libwebrtc/rtc_base/openssl_digest.h b/third_party/libwebrtc/rtc_base/openssl_digest.h
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+++ b/third_party/libwebrtc/rtc_base/openssl_digest.h
@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef RTC_BASE_OPENSSL_DIGEST_H_
+#define RTC_BASE_OPENSSL_DIGEST_H_
+
+#include <openssl/ossl_typ.h>
+#include <stddef.h>
+
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/message_digest.h"
+
+namespace rtc {
+
+// An implementation of the digest class that uses OpenSSL.
+class OpenSSLDigest final : public MessageDigest {
+ public:
+  // Creates an OpenSSLDigest with `algorithm` as the hash algorithm.
+  explicit OpenSSLDigest(absl::string_view algorithm);
+  ~OpenSSLDigest() override;
+  // Returns the digest output size (e.g. 16 bytes for MD5).
+  size_t Size() const override;
+  // Updates the digest with `len` bytes from `buf`.
+  void Update(const void* buf, size_t len) override;
+  // Outputs the digest value to `buf` with length `len`.
+  size_t Finish(void* buf, size_t len) override;
+
+  // Helper function to look up a digest's EVP by name.
+  static bool GetDigestEVP(absl::string_view algorithm, const EVP_MD** md);
+  // Helper function to look up a digest's name by EVP.
+  static bool GetDigestName(const EVP_MD* md, std::string* algorithm);
+  // Helper function to get the length of a digest.
+  static bool GetDigestSize(absl::string_view algorithm, size_t* len);
+
+ private:
+  EVP_MD_CTX* ctx_ = nullptr;
+  const EVP_MD* md_;
+};
+
+}  // namespace rtc
+
+#endif  // RTC_BASE_OPENSSL_DIGEST_H_