[avb][test] Move test util methods to a separate module

Bug: 256148034
Test: atest libpvmfw_avb.integration_test
Change-Id: Ibd24eadd1d8d8d6007dab9f63a28c963790a8563
diff --git a/pvmfw/avb/Android.bp b/pvmfw/avb/Android.bp
index 0527dfb..837f747 100644
--- a/pvmfw/avb/Android.bp
+++ b/pvmfw/avb/Android.bp
@@ -27,7 +27,7 @@
 rust_test {
     name: "libpvmfw_avb.integration_test",
     crate_name: "pvmfw_avb_test",
-    srcs: ["tests/*_test.rs"],
+    srcs: ["tests/*.rs"],
     test_suites: ["general-tests"],
     data: [
         ":avb_testkey_rsa2048_pub_bin",
diff --git a/pvmfw/avb/tests/api_test.rs b/pvmfw/avb/tests/api_test.rs
index 872ad63..2bd46d5 100644
--- a/pvmfw/avb/tests/api_test.rs
+++ b/pvmfw/avb/tests/api_test.rs
@@ -14,54 +14,48 @@
  * limitations under the License.
  */
 
-use anyhow::Result;
-use avb_bindgen::{
-    avb_footer_validate_and_byteswap, avb_vbmeta_image_header_to_host_byte_order, AvbFooter,
-    AvbVBMetaImageHeader,
-};
-use pvmfw_avb::{verify_payload, AvbSlotVerifyError};
-use std::{
-    fs,
-    mem::{size_of, transmute, MaybeUninit},
-    ptr,
-};
+mod utils;
 
-const MICRODROID_KERNEL_IMG_PATH: &str = "microdroid_kernel";
-const INITRD_NORMAL_IMG_PATH: &str = "microdroid_initrd_normal.img";
-const INITRD_DEBUG_IMG_PATH: &str = "microdroid_initrd_debuggable.img";
+use anyhow::Result;
+use avb_bindgen::{AvbFooter, AvbVBMetaImageHeader};
+use pvmfw_avb::AvbSlotVerifyError;
+use std::{fs, mem::size_of, ptr};
+use utils::*;
+
 const TEST_IMG_WITH_ONE_HASHDESC_PATH: &str = "test_image_with_one_hashdesc.img";
 const TEST_IMG_WITH_PROP_DESC_PATH: &str = "test_image_with_prop_desc.img";
 const TEST_IMG_WITH_NON_INITRD_HASHDESC_PATH: &str = "test_image_with_non_initrd_hashdesc.img";
 const UNSIGNED_TEST_IMG_PATH: &str = "unsigned_test.img";
 
-const PUBLIC_KEY_RSA2048_PATH: &str = "data/testkey_rsa2048_pub.bin";
-const PUBLIC_KEY_RSA4096_PATH: &str = "data/testkey_rsa4096_pub.bin";
 const RANDOM_FOOTER_POS: usize = 30;
 
 /// This test uses the Microdroid payload compiled on the fly to check that
 /// the latest payload can be verified successfully.
 #[test]
 fn latest_normal_payload_passes_verification() -> Result<()> {
-    assert_payload_verification_succeeds(
+    assert_payload_verification_with_initrd_eq(
         &load_latest_signed_kernel()?,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
+        Ok(()),
     )
 }
 
 #[test]
 fn latest_debug_payload_passes_verification() -> Result<()> {
-    assert_payload_verification_succeeds(
+    assert_payload_verification_with_initrd_eq(
         &load_latest_signed_kernel()?,
         &load_latest_initrd_debug()?,
         &load_trusted_public_key()?,
+        Ok(()),
     )
 }
 
 #[test]
 fn payload_expecting_no_initrd_passes_verification_with_no_initrd() -> Result<()> {
-    assert_payload_verification_with_no_initrd_eq(
+    assert_payload_verification_eq(
         &fs::read(TEST_IMG_WITH_ONE_HASHDESC_PATH)?,
+        /*initrd=*/ None,
         &load_trusted_public_key()?,
         Ok(()),
     )
@@ -69,8 +63,9 @@
 
 #[test]
 fn payload_with_non_initrd_descriptor_passes_verification_with_no_initrd() -> Result<()> {
-    assert_payload_verification_with_no_initrd_eq(
+    assert_payload_verification_eq(
         &fs::read(TEST_IMG_WITH_NON_INITRD_HASHDESC_PATH)?,
+        /*initrd=*/ None,
         &load_trusted_public_key()?,
         Ok(()),
     )
@@ -78,8 +73,9 @@
 
 #[test]
 fn payload_with_prop_descriptor_fails_verification_with_no_initrd() -> Result<()> {
-    assert_payload_verification_with_no_initrd_eq(
+    assert_payload_verification_eq(
         &fs::read(TEST_IMG_WITH_PROP_DESC_PATH)?,
+        /*initrd=*/ None,
         &load_trusted_public_key()?,
         Err(AvbSlotVerifyError::InvalidMetadata),
     )
@@ -87,8 +83,9 @@
 
 #[test]
 fn payload_expecting_initrd_fails_verification_with_no_initrd() -> Result<()> {
-    assert_payload_verification_with_no_initrd_eq(
+    assert_payload_verification_eq(
         &load_latest_signed_kernel()?,
+        /*initrd=*/ None,
         &load_trusted_public_key()?,
         Err(AvbSlotVerifyError::InvalidMetadata),
     )
@@ -96,41 +93,41 @@
 
 #[test]
 fn payload_with_empty_public_key_fails_verification() -> Result<()> {
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &load_latest_signed_kernel()?,
         &load_latest_initrd_normal()?,
         /*trusted_public_key=*/ &[0u8; 0],
-        AvbSlotVerifyError::PublicKeyRejected,
+        Err(AvbSlotVerifyError::PublicKeyRejected),
     )
 }
 
 #[test]
 fn payload_with_an_invalid_public_key_fails_verification() -> Result<()> {
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &load_latest_signed_kernel()?,
         &load_latest_initrd_normal()?,
         /*trusted_public_key=*/ &[0u8; 512],
-        AvbSlotVerifyError::PublicKeyRejected,
+        Err(AvbSlotVerifyError::PublicKeyRejected),
     )
 }
 
 #[test]
 fn payload_with_a_different_valid_public_key_fails_verification() -> Result<()> {
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &load_latest_signed_kernel()?,
         &load_latest_initrd_normal()?,
         &fs::read(PUBLIC_KEY_RSA2048_PATH)?,
-        AvbSlotVerifyError::PublicKeyRejected,
+        Err(AvbSlotVerifyError::PublicKeyRejected),
     )
 }
 
 #[test]
 fn unsigned_kernel_fails_verification() -> Result<()> {
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &fs::read(UNSIGNED_TEST_IMG_PATH)?,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
-        AvbSlotVerifyError::Io,
+        Err(AvbSlotVerifyError::Io),
     )
 }
 
@@ -139,11 +136,11 @@
     let mut kernel = load_latest_signed_kernel()?;
     kernel[1] = !kernel[1]; // Flip the bits
 
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &kernel,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
-        AvbSlotVerifyError::Verification,
+        Err(AvbSlotVerifyError::Verification),
     )
 }
 
@@ -153,11 +150,11 @@
     let avb_footer_index = kernel.len() - size_of::<AvbFooter>() + RANDOM_FOOTER_POS;
     kernel[avb_footer_index] = !kernel[avb_footer_index];
 
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &kernel,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
-        AvbSlotVerifyError::InvalidMetadata,
+        Err(AvbSlotVerifyError::InvalidMetadata),
     )
 }
 
@@ -169,11 +166,11 @@
 
     kernel[vbmeta_index] = !kernel[vbmeta_index]; // Flip the bits
 
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &kernel,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
-        AvbSlotVerifyError::InvalidMetadata,
+        Err(AvbSlotVerifyError::InvalidMetadata),
     )
 }
 
@@ -192,17 +189,17 @@
     kernel[public_key_offset..(public_key_offset + public_key_size)]
         .copy_from_slice(&empty_public_key);
 
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &kernel,
         &load_latest_initrd_normal()?,
         &empty_public_key,
-        AvbSlotVerifyError::Verification,
+        Err(AvbSlotVerifyError::Verification),
     )?;
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &kernel,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
-        AvbSlotVerifyError::Verification,
+        Err(AvbSlotVerifyError::Verification),
     )
 }
 
@@ -234,81 +231,10 @@
         AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED, vbmeta_header.flags as u32,
         "VBMeta verification flag should be disabled now."
     );
-    assert_payload_verification_fails(
+    assert_payload_verification_with_initrd_eq(
         &kernel,
         &load_latest_initrd_normal()?,
         &load_trusted_public_key()?,
-        AvbSlotVerifyError::Verification,
+        Err(AvbSlotVerifyError::Verification),
     )
 }
-
-fn extract_avb_footer(kernel: &[u8]) -> Result<AvbFooter> {
-    let footer_start = kernel.len() - size_of::<AvbFooter>();
-    // SAFETY: The slice is the same size as the struct which only contains simple data types.
-    let mut footer = unsafe {
-        transmute::<[u8; size_of::<AvbFooter>()], AvbFooter>(kernel[footer_start..].try_into()?)
-    };
-    // SAFETY: The function updates the struct in-place.
-    unsafe {
-        avb_footer_validate_and_byteswap(&footer, &mut footer);
-    }
-    Ok(footer)
-}
-
-fn extract_vbmeta_header(kernel: &[u8], footer: &AvbFooter) -> Result<AvbVBMetaImageHeader> {
-    let vbmeta_offset: usize = footer.vbmeta_offset.try_into()?;
-    let vbmeta_size: usize = footer.vbmeta_size.try_into()?;
-    let vbmeta_src = &kernel[vbmeta_offset..(vbmeta_offset + vbmeta_size)];
-    // SAFETY: The latest kernel has a valid VBMeta header at the position specified in footer.
-    let vbmeta_header = unsafe {
-        let mut header = MaybeUninit::uninit();
-        let src = vbmeta_src.as_ptr() as *const _ as *const AvbVBMetaImageHeader;
-        avb_vbmeta_image_header_to_host_byte_order(src, header.as_mut_ptr());
-        header.assume_init()
-    };
-    Ok(vbmeta_header)
-}
-
-fn assert_payload_verification_with_no_initrd_eq(
-    kernel: &[u8],
-    trusted_public_key: &[u8],
-    expected_result: Result<(), AvbSlotVerifyError>,
-) -> Result<()> {
-    assert_eq!(expected_result, verify_payload(kernel, /*initrd=*/ None, trusted_public_key));
-    Ok(())
-}
-
-fn assert_payload_verification_fails(
-    kernel: &[u8],
-    initrd: &[u8],
-    trusted_public_key: &[u8],
-    expected_error: AvbSlotVerifyError,
-) -> Result<()> {
-    assert_eq!(Err(expected_error), verify_payload(kernel, Some(initrd), trusted_public_key));
-    Ok(())
-}
-
-fn assert_payload_verification_succeeds(
-    kernel: &[u8],
-    initrd: &[u8],
-    trusted_public_key: &[u8],
-) -> Result<()> {
-    assert_eq!(Ok(()), verify_payload(kernel, Some(initrd), trusted_public_key));
-    Ok(())
-}
-
-fn load_latest_signed_kernel() -> Result<Vec<u8>> {
-    Ok(fs::read(MICRODROID_KERNEL_IMG_PATH)?)
-}
-
-fn load_latest_initrd_normal() -> Result<Vec<u8>> {
-    Ok(fs::read(INITRD_NORMAL_IMG_PATH)?)
-}
-
-fn load_latest_initrd_debug() -> Result<Vec<u8>> {
-    Ok(fs::read(INITRD_DEBUG_IMG_PATH)?)
-}
-
-fn load_trusted_public_key() -> Result<Vec<u8>> {
-    Ok(fs::read(PUBLIC_KEY_RSA4096_PATH)?)
-}
diff --git a/pvmfw/avb/tests/utils.rs b/pvmfw/avb/tests/utils.rs
new file mode 100644
index 0000000..aa40bb8
--- /dev/null
+++ b/pvmfw/avb/tests/utils.rs
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+//! Utility methods used by API tests.
+
+use anyhow::Result;
+use avb_bindgen::{
+    avb_footer_validate_and_byteswap, avb_vbmeta_image_header_to_host_byte_order, AvbFooter,
+    AvbVBMetaImageHeader,
+};
+use pvmfw_avb::{verify_payload, AvbSlotVerifyError};
+use std::{
+    fs,
+    mem::{size_of, transmute, MaybeUninit},
+};
+
+const MICRODROID_KERNEL_IMG_PATH: &str = "microdroid_kernel";
+const INITRD_NORMAL_IMG_PATH: &str = "microdroid_initrd_normal.img";
+const INITRD_DEBUG_IMG_PATH: &str = "microdroid_initrd_debuggable.img";
+const PUBLIC_KEY_RSA4096_PATH: &str = "data/testkey_rsa4096_pub.bin";
+
+pub const PUBLIC_KEY_RSA2048_PATH: &str = "data/testkey_rsa2048_pub.bin";
+
+pub fn assert_payload_verification_with_initrd_eq(
+    kernel: &[u8],
+    initrd: &[u8],
+    trusted_public_key: &[u8],
+    expected_result: Result<(), AvbSlotVerifyError>,
+) -> Result<()> {
+    assert_payload_verification_eq(kernel, Some(initrd), trusted_public_key, expected_result)
+}
+
+pub fn assert_payload_verification_eq(
+    kernel: &[u8],
+    initrd: Option<&[u8]>,
+    trusted_public_key: &[u8],
+    expected_result: Result<(), AvbSlotVerifyError>,
+) -> Result<()> {
+    assert_eq!(expected_result, verify_payload(kernel, initrd, trusted_public_key));
+    Ok(())
+}
+
+pub fn load_latest_signed_kernel() -> Result<Vec<u8>> {
+    Ok(fs::read(MICRODROID_KERNEL_IMG_PATH)?)
+}
+
+pub fn load_latest_initrd_normal() -> Result<Vec<u8>> {
+    Ok(fs::read(INITRD_NORMAL_IMG_PATH)?)
+}
+
+pub fn load_latest_initrd_debug() -> Result<Vec<u8>> {
+    Ok(fs::read(INITRD_DEBUG_IMG_PATH)?)
+}
+
+pub fn load_trusted_public_key() -> Result<Vec<u8>> {
+    Ok(fs::read(PUBLIC_KEY_RSA4096_PATH)?)
+}
+
+pub fn extract_avb_footer(kernel: &[u8]) -> Result<AvbFooter> {
+    let footer_start = kernel.len() - size_of::<AvbFooter>();
+    // SAFETY: The slice is the same size as the struct which only contains simple data types.
+    let mut footer = unsafe {
+        transmute::<[u8; size_of::<AvbFooter>()], AvbFooter>(kernel[footer_start..].try_into()?)
+    };
+    // SAFETY: The function updates the struct in-place.
+    unsafe {
+        avb_footer_validate_and_byteswap(&footer, &mut footer);
+    }
+    Ok(footer)
+}
+
+pub fn extract_vbmeta_header(kernel: &[u8], footer: &AvbFooter) -> Result<AvbVBMetaImageHeader> {
+    let vbmeta_offset: usize = footer.vbmeta_offset.try_into()?;
+    let vbmeta_size: usize = footer.vbmeta_size.try_into()?;
+    let vbmeta_src = &kernel[vbmeta_offset..(vbmeta_offset + vbmeta_size)];
+    // SAFETY: The latest kernel has a valid VBMeta header at the position specified in footer.
+    let vbmeta_header = unsafe {
+        let mut header = MaybeUninit::uninit();
+        let src = vbmeta_src.as_ptr() as *const _ as *const AvbVBMetaImageHeader;
+        avb_vbmeta_image_header_to_host_byte_order(src, header.as_mut_ptr());
+        header.assume_init()
+    };
+    Ok(vbmeta_header)
+}