[dice][refactor] Remove unused library libdiced_utils and tests

As all its callers have been migrated to the well maintained
crate ciborium in the previous cls (aosp/2459709, aosp/2462175),
we can now remove the library libdiced_utils safely.

Test: N/A.
Bug: 268322533
Change-Id: I91d014570a37782fdb3ec9ecdc9cb701c5374f4b
diff --git a/diced/Android.bp b/diced/Android.bp
index 3e15ed7..26a1c4d 100644
--- a/diced/Android.bp
+++ b/diced/Android.bp
@@ -22,26 +22,6 @@
 }
 
 rust_library {
-    name: "libdiced_utils",
-    crate_name: "diced_utils",
-    srcs: ["src/utils.rs"],
-    rustlibs: [
-        "libanyhow",
-    ],
-}
-
-rust_test {
-    name: "diced_utils_test",
-    crate_name: "diced_utils_test",
-    srcs: ["src/utils.rs"],
-    test_suites: ["general-tests"],
-    auto_gen_config: true,
-    rustlibs: [
-        "libanyhow",
-    ],
-}
-
-rust_library {
     name: "libdiced_sample_inputs",
     crate_name: "diced_sample_inputs",
     srcs: ["src/sample_inputs.rs"],
diff --git a/diced/TEST_MAPPING b/diced/TEST_MAPPING
index 1b078a4..674b448 100644
--- a/diced/TEST_MAPPING
+++ b/diced/TEST_MAPPING
@@ -13,9 +13,6 @@
       "name": "libopen_dice_bcc_bindgen_test"
     },
     {
-      "name": "diced_utils_test"
-    },
-    {
       "name": "diced_sample_inputs_test"
     }
   ]
diff --git a/diced/src/utils.rs b/diced/src/utils.rs
deleted file mode 100644
index 0931e68..0000000
--- a/diced/src/utils.rs
+++ /dev/null
@@ -1,169 +0,0 @@
-// Copyright 2021, The Android Open Source Project
-//
-// 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.
-
-//! Implements utility functions and types for diced and the dice HAL.
-
-/// This submodule implements a limited set of CBOR generation functionality. Essentially,
-/// a cbor header generator and some convenience functions for number and BSTR encoding.
-pub mod cbor {
-    use anyhow::{anyhow, Context, Result};
-    use std::convert::TryInto;
-    use std::io::Write;
-
-    /// CBOR encodes a positive number.
-    pub fn encode_number(n: u64, buffer: &mut dyn Write) -> Result<()> {
-        encode_header(0, n, buffer)
-    }
-
-    /// CBOR encodes a binary string.
-    pub fn encode_bstr(bstr: &[u8], buffer: &mut dyn Write) -> Result<()> {
-        encode_header(
-            2,
-            bstr.len().try_into().context("In encode_bstr: Failed to convert usize to u64.")?,
-            buffer,
-        )
-        .context("In encode_bstr: While writing header.")?;
-        let written = buffer.write(bstr).context("In encode_bstr: While writing payload.")?;
-        if written != bstr.len() {
-            return Err(anyhow!("In encode_bstr: Buffer too small. ({}, {})", written, bstr.len()));
-        }
-        Ok(())
-    }
-
-    /// Formats a CBOR header. `t` is the type, and n is the header argument.
-    pub fn encode_header(t: u8, n: u64, buffer: &mut dyn Write) -> Result<()> {
-        match n {
-            n if n < 24 => {
-                let written =
-                    buffer.write(&u8::to_be_bytes((t << 5) | (n as u8 & 0x1F))).with_context(
-                        || format!("In encode_header: Failed to write header ({}, {})", t, n),
-                    )?;
-                if written != 1 {
-                    return Err(anyhow!("In encode_header: Buffer to small. ({}, {})", t, n));
-                }
-            }
-            n if n <= 0xFF => {
-                let written =
-                    buffer.write(&u8::to_be_bytes((t << 5) | (24u8 & 0x1F))).with_context(
-                        || format!("In encode_header: Failed to write header ({}, {})", t, n),
-                    )?;
-                if written != 1 {
-                    return Err(anyhow!("In encode_header: Buffer to small. ({}, {})", t, n));
-                }
-                let written = buffer.write(&u8::to_be_bytes(n as u8)).with_context(|| {
-                    format!("In encode_header: Failed to write size ({}, {})", t, n)
-                })?;
-                if written != 1 {
-                    return Err(anyhow!(
-                        "In encode_header while writing size: Buffer to small. ({}, {})",
-                        t,
-                        n
-                    ));
-                }
-            }
-            n if n <= 0xFFFF => {
-                let written =
-                    buffer.write(&u8::to_be_bytes((t << 5) | (25u8 & 0x1F))).with_context(
-                        || format!("In encode_header: Failed to write header ({}, {})", t, n),
-                    )?;
-                if written != 1 {
-                    return Err(anyhow!("In encode_header: Buffer to small. ({}, {})", t, n));
-                }
-                let written = buffer.write(&u16::to_be_bytes(n as u16)).with_context(|| {
-                    format!("In encode_header: Failed to write size ({}, {})", t, n)
-                })?;
-                if written != 2 {
-                    return Err(anyhow!(
-                        "In encode_header while writing size: Buffer to small. ({}, {})",
-                        t,
-                        n
-                    ));
-                }
-            }
-            n if n <= 0xFFFFFFFF => {
-                let written =
-                    buffer.write(&u8::to_be_bytes((t << 5) | (26u8 & 0x1F))).with_context(
-                        || format!("In encode_header: Failed to write header ({}, {})", t, n),
-                    )?;
-                if written != 1 {
-                    return Err(anyhow!("In encode_header: Buffer to small. ({}, {})", t, n));
-                }
-                let written = buffer.write(&u32::to_be_bytes(n as u32)).with_context(|| {
-                    format!("In encode_header: Failed to write size ({}, {})", t, n)
-                })?;
-                if written != 4 {
-                    return Err(anyhow!(
-                        "In encode_header while writing size: Buffer to small. ({}, {})",
-                        t,
-                        n
-                    ));
-                }
-            }
-            n => {
-                let written =
-                    buffer.write(&u8::to_be_bytes((t << 5) | (27u8 & 0x1F))).with_context(
-                        || format!("In encode_header: Failed to write header ({}, {})", t, n),
-                    )?;
-                if written != 1 {
-                    return Err(anyhow!("In encode_header: Buffer to small. ({}, {})", t, n));
-                }
-                let written = buffer.write(&u64::to_be_bytes(n)).with_context(|| {
-                    format!("In encode_header: Failed to write size ({}, {})", t, n)
-                })?;
-                if written != 8 {
-                    return Err(anyhow!(
-                        "In encode_header while writing size: Buffer to small. ({}, {})",
-                        t,
-                        n
-                    ));
-                }
-            }
-        }
-        Ok(())
-    }
-
-    #[cfg(test)]
-    mod test {
-        use super::*;
-
-        fn encode_header_helper(t: u8, n: u64) -> Vec<u8> {
-            let mut b: Vec<u8> = vec![];
-            encode_header(t, n, &mut b).unwrap();
-            b
-        }
-
-        #[test]
-        fn encode_header_test() {
-            assert_eq!(&encode_header_helper(0, 0), &[0b000_00000]);
-            assert_eq!(&encode_header_helper(0, 23), &[0b000_10111]);
-            assert_eq!(&encode_header_helper(0, 24), &[0b000_11000, 24]);
-            assert_eq!(&encode_header_helper(0, 0xff), &[0b000_11000, 0xff]);
-            assert_eq!(&encode_header_helper(0, 0x100), &[0b000_11001, 0x01, 0x00]);
-            assert_eq!(&encode_header_helper(0, 0xffff), &[0b000_11001, 0xff, 0xff]);
-            assert_eq!(&encode_header_helper(0, 0x10000), &[0b000_11010, 0x00, 0x01, 0x00, 0x00]);
-            assert_eq!(
-                &encode_header_helper(0, 0xffffffff),
-                &[0b000_11010, 0xff, 0xff, 0xff, 0xff]
-            );
-            assert_eq!(
-                &encode_header_helper(0, 0x100000000),
-                &[0b000_11011, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00]
-            );
-            assert_eq!(
-                &encode_header_helper(0, 0xffffffffffffffff),
-                &[0b000_11011, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff]
-            );
-        }
-    }
-}