media/cdm: drop deps on SymmetricKey, 3/n

This change drops dependencies on crypto::SymmetricKey in the cdm
decryptor fuzzers, and removes the decrypt function variants that accept
SymmetricKeys. A subsequent CL will remove SymmetricKey use from
AesDecryptor, which will require a larger cleanup.

Bug: 372283556
Change-Id: If5878cd82590b5bf03f6916a4f30d9ad19e6299e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6091303
Commit-Queue: Elly FJ <ellyjones@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1401557}

media/cdm/aes_decryptor.cc

@@ -159,10 +159,10 @@ static scoped_refptr<DecoderBuffer> DecryptData(
   CHECK(input.decrypt_config());
 
   if (input.decrypt_config()->encryption_scheme() == EncryptionScheme::kCenc)
-    return DecryptCencBuffer(input, key);
+    return DecryptCencBuffer(input, base::as_byte_span(key.key()));
 
   if (input.decrypt_config()->encryption_scheme() == EncryptionScheme::kCbcs)
-    return DecryptCbcsBuffer(input, key);
+    return DecryptCbcsBuffer(input, base::as_byte_span(key.key()));
 
   DVLOG(1) << "Only 'cenc' and 'cbcs' modes supported.";
   return nullptr;

media/cdm/cbcs_decryptor.cc

@@ -19,7 +19,6 @@
 #include "base/logging.h"
 #include "base/memory/scoped_refptr.h"
 #include "base/numerics/checked_math.h"
-#include "crypto/symmetric_key.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 #include "media/base/encryption_pattern.h"
@@ -123,12 +122,6 @@ bool DecryptWithPattern(base::span<const uint8_t> key,
 
 }  // namespace
 
-scoped_refptr<DecoderBuffer> DecryptCbcsBuffer(
-    const DecoderBuffer& input,
-    const crypto::SymmetricKey& key) {
-  return DecryptCbcsBuffer(input, base::as_byte_span(key.key()));
-}
-
 scoped_refptr<DecoderBuffer> DecryptCbcsBuffer(const DecoderBuffer& input,
                                                base::span<const uint8_t> key) {
   const size_t sample_size = input.size();

media/cdm/cbcs_decryptor.h

@@ -9,10 +9,6 @@
 #include "base/memory/scoped_refptr.h"
 #include "media/base/media_export.h"
 
-namespace crypto {
-class SymmetricKey;
-}
-
 namespace media {
 class DecoderBuffer;
 
@@ -47,9 +43,6 @@ class DecoderBuffer;
 
 // Decrypts the encrypted buffer |input| using |key| and values found in
 // |input|->DecryptConfig. The key size must be 128 bits.
-MEDIA_EXPORT scoped_refptr<DecoderBuffer> DecryptCbcsBuffer(
-    const DecoderBuffer& input,
-    const crypto::SymmetricKey& key);
 MEDIA_EXPORT scoped_refptr<DecoderBuffer> DecryptCbcsBuffer(
     const DecoderBuffer& input,
     base::span<const uint8_t> key);

media/cdm/cbcs_decryptor_fuzzer.cc

@@ -50,11 +50,6 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data_ptr, size_t size) {
   const uint8_t encryption_pattern = data[1];
   data = data.subspan<2>();
 
-  static std::unique_ptr<crypto::SymmetricKey> key =
-      crypto::SymmetricKey::Import(
-          crypto::SymmetricKey::AES,
-          std::string(std::begin(kKey), std::end(kKey)));
-
   // |clear_bytes| is used to determine how much of the buffer is "clear".
   // Since the code checks SubsampleEntries, use |clear_bytes| as the actual
   // number of bytes clear, and the rest as encrypted. To avoid size_t problems,
@@ -75,9 +70,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data_ptr, size_t size) {
 
   // Key_ID is never used.
   encrypted_buffer->set_decrypt_config(media::DecryptConfig::CreateCbcsConfig(
-      "key_id", std::string(std::begin(kIv), std::end(kIv)), subsamples,
-      pattern));
+      "key_id", std::string(base::as_string_view(kIv)), subsamples, pattern));
 
-  media::DecryptCbcsBuffer(*encrypted_buffer, *key);
+  media::DecryptCbcsBuffer(*encrypted_buffer, kKey);
   return 0;
 }

media/cdm/cenc_decryptor.cc

@@ -15,7 +15,6 @@
 #include "base/containers/span.h"
 #include "base/logging.h"
 #include "crypto/aes_ctr.h"
-#include "crypto/symmetric_key.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 #include "media/base/subsample_entry.h"
@@ -69,12 +68,6 @@ void CopyExtraSettings(const DecoderBuffer& input, DecoderBuffer* output) {
 
 }  // namespace
 
-scoped_refptr<DecoderBuffer> DecryptCencBuffer(
-    const DecoderBuffer& input,
-    const crypto::SymmetricKey& wrapped_key) {
-  return DecryptCencBuffer(input, base::as_byte_span(wrapped_key.key()));
-}
-
 scoped_refptr<DecoderBuffer> DecryptCencBuffer(const DecoderBuffer& input,
                                                base::span<const uint8_t> key) {
   base::span<const uint8_t> sample = input;

media/cdm/cenc_decryptor.h

@@ -9,10 +9,6 @@
 #include "base/memory/scoped_refptr.h"
 #include "media/base/media_export.h"
 
-namespace crypto {
-class SymmetricKey;
-}
-
 namespace media {
 class DecoderBuffer;
 
@@ -38,9 +34,6 @@ class DecoderBuffer;
 
 // Decrypts the encrypted buffer |input| using |key| and values found in
 // |input|->DecryptConfig. The key size must be 128 bits.
-MEDIA_EXPORT scoped_refptr<DecoderBuffer> DecryptCencBuffer(
-    const DecoderBuffer& input,
-    const crypto::SymmetricKey& key);
 MEDIA_EXPORT scoped_refptr<DecoderBuffer> DecryptCencBuffer(
     const DecoderBuffer& input,
     base::span<const uint8_t> key);

media/cdm/cenc_decryptor_fuzzer.cc

@@ -14,7 +14,6 @@
 #include "base/compiler_specific.h"
 #include "base/containers/span.h"
 #include "base/logging.h"
-#include "crypto/symmetric_key.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/subsample_entry.h"
 
@@ -48,11 +47,6 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data_ptr, size_t size) {
   const uint8_t clear_bytes = data[0];
   data = data.subspan<1>();
 
-  static std::unique_ptr<crypto::SymmetricKey> key =
-      crypto::SymmetricKey::Import(
-          crypto::SymmetricKey::AES,
-          std::string(std::begin(kKey), std::end(kKey)));
-
   // |clear_bytes| is used to determine how much of the buffer is "clear".
   // Since the code checks SubsampleEntries, use |clear_bytes| as the actual
   // number of bytes clear, and the rest as encrypted. To avoid size_t problems,
@@ -70,6 +64,6 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data_ptr, size_t size) {
   encrypted_buffer->set_decrypt_config(media::DecryptConfig::CreateCencConfig(
       "key_id", std::string(base::as_string_view(kIv)), subsamples));
 
-  media::DecryptCencBuffer(*encrypted_buffer, *key);
+  media::DecryptCencBuffer(*encrypted_buffer, kKey);
   return 0;
 }