Create CRT API for accessing symmetric cipher state

Create CRT API for creating dynamically sized byte buf
awslabs · May 17, 2024 · 6950b76 · 6950b76
1 parent cac7ca5
commit 6950b76
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Showing 5 changed files with 42 additions and 1 deletion.
diff --git a/crt/aws-c-cal b/crt/aws-c-cal
diff --git a/include/aws/crt/Types.h b/include/aws/crt/Types.h
@@ -57,6 +57,7 @@ namespace Aws
         AWS_CRT_CPP_API ByteBuf ByteBufFromEmptyArray(const uint8_t *array, size_t len) noexcept;
         AWS_CRT_CPP_API ByteBuf ByteBufFromArray(const uint8_t *array, size_t capacity) noexcept;
         AWS_CRT_CPP_API ByteBuf ByteBufNewCopy(Allocator *alloc, const uint8_t *array, size_t len);
+        AWS_CRT_CPP_API ByteBuf ByteBufInit(Allocator *alloc, size_t len);
         AWS_CRT_CPP_API void ByteBufDelete(ByteBuf &);
 
         AWS_CRT_CPP_API ByteCursor ByteCursorFromCString(const char *str) noexcept;

diff --git a/include/aws/crt/crypto/SymmetricCipher.h b/include/aws/crt/crypto/SymmetricCipher.h
@@ -3,6 +3,7 @@
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0.
  */
+#include <aws/cal/symmetric_cipher.h>
 #include <aws/crt/Exports.h>
 #include <aws/crt/Types.h>
 
@@ -17,6 +18,13 @@ namespace Aws
             static const size_t AES_256_CIPHER_BLOCK_SIZE = 16u;
             static const size_t AES_256_KEY_SIZE_BYTES = 32u;
 
+            enum class SymmetricCipherState
+            {
+                READY,
+                FINALIZED,
+                ERROR,
+            };
+
             class AWS_CRT_CPP_API SymmetricCipher final
             {
               public:
@@ -71,6 +79,12 @@ namespace Aws
                  */
                 operator bool() const noexcept;
 
+                /**
+                 * Returns current stat of the cipher instance. ready to be used, finalized, or in a error state.
+                 * If the cipher is in a finalized or error state it may not be used anymore
+                 **/
+                SymmetricCipherState GetState() const noexcept;
+
                 /**
                  * Returns the value of the last aws error encountered by operations on this instance.
                  */

diff --git a/source/Types.cpp b/source/Types.cpp
@@ -30,6 +30,13 @@ namespace Aws
             return retVal;
         }
 
+        ByteBuf ByteBufInit(Allocator *alloc, size_t len)
+        {
+            ByteBuf buff;
+            aws_byte_buf_init(&buff, alloc, len);
+            return buff;
+        }
+
         void ByteBufDelete(ByteBuf &buf) { aws_byte_buf_clean_up(&buf); }
 
         ByteCursor ByteCursorFromCString(const char *str) noexcept { return aws_byte_cursor_from_c_str(str); }

diff --git a/source/crypto/SymmetricCipher.cpp b/source/crypto/SymmetricCipher.cpp
@@ -6,6 +6,7 @@
 #include <aws/crt/crypto/SymmetricCipher.h>
 
 #include <aws/cal/symmetric_cipher.h>
+#include <sys/stat.h>
 
 namespace Aws
 {
@@ -27,6 +28,24 @@ namespace Aws
                 return m_cipher != nullptr ? aws_symmetric_cipher_is_good(m_cipher.get()) : false;
             }
 
+            SymmetricCipherState SymmetricCipher::GetState() const noexcept
+            {
+                if (m_cipher == nullptr)
+                {
+                    return SymmetricCipherState::ERROR;
+                }
+                const auto state = aws_symmetric_cipher_get_state(m_cipher.get());
+                switch (state)
+                {
+                    case AWS_SYMMETRIC_CIPHER_READY:
+                        return SymmetricCipherState::READY;
+                    case AWS_SYMMETRIC_CIPHER_FINALIZED:
+                        return SymmetricCipherState::FINALIZED;
+                    default:
+                        return SymmetricCipherState::ERROR;
+                }
+            }
+
             bool SymmetricCipher::Encrypt(const ByteCursor &toEncrypt, ByteBuf &out) noexcept
             {
                 if (!*this)