support for large and file-backed custom TLVs

.github/workflows/test-custom-tlv-simulator.yml

@@ -48,3 +48,51 @@ jobs:
       - name: Run get_tlv simulator test
         run: |
           [ x`./wolfboot.elf get_tlv 2>/dev/null| tail -1` =  xAABBCCDDEEFF0011223344 ]
+
+  custom_tlv_large_simulator_tests:
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/wolfssl/wolfboot-ci-sim:v1.0
+    timeout-minutes: 15
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Trust workspace
+        run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
+
+      - name: make clean
+        run: |
+          make distclean
+
+      - name: Select config
+        run: |
+          cp config/examples/sim.config .config
+
+      - name: Build tools
+        run: |
+          make -C tools/keytools && make -C tools/bin-assemble
+
+      - name: Build wolfboot.elf and test-app/image.elf with a 2KB header
+        run: |
+          make clean && make IMAGE_HEADER_SIZE=2048
+
+      - name: Sign the image with 300-byte buffer and file custom TLVs
+        run: |
+          VAL=`printf 'A5%.0s' $(seq 1 300)`
+          head -c 300 /dev/zero | tr '\0' '\245' > large_tlv.bin
+          IMAGE_HEADER_SIZE=2048 tools/keytools/sign --ed25519 --custom-tlv-buffer 0x0034 $VAL --custom-tlv-file 0x0035 large_tlv.bin test-app/image.elf wolfboot_signing_private_key.der 1
+
+      - name: Re-assemble the internal_flash.dd image file
+        run: |
+          make assemble_internal_flash.dd IMAGE_HEADER_SIZE=2048
+
+      - name: Run get_tlv simulator test on the 300-byte buffer TLV
+        run: |
+          [ x`./wolfboot.elf get_tlv 2>/dev/null| tail -1` = x`printf 'A5%.0s' $(seq 1 300)` ]
+
+      - name: Run get_tlv simulator test on the 300-byte file TLV (tag 0x35)
+        run: |
+          [ x`./wolfboot.elf get_tlv=53 2>/dev/null| tail -1` = x`printf 'A5%.0s' $(seq 1 300)` ]

docs/Signing.md

@@ -255,17 +255,30 @@ Provides a value to be set with a custom tag
    * `--custom-tlv-buffer tag value`: Adds a TLV entry with arbitrary length to the manifest
    header, corresponding to the type identified by `tag`, and assigns the value `value`. The
    tag is a 16-bit number. Valid tags are in the range between 0x0030 and 0xFEFE. The length
-   is implicit, and is the length of the value.
+   is implicit, and is the length of the value. The maximum length is 65535 bytes.
    Value argument is in the form of a hex string, e.g. `--custom-tlv-buffer 0x0030 AABBCCDDEE`
    will add a TLV entry with tag 0x0030, length 5 and value 0xAABBCCDDEE.
 
    * `--custom-tlv-string tag ascii-string`: Adds a TLV entry with arbitrary length to the manifest
    header, corresponding to the type identified by `tag`, and assigns the value of `ascii-string`. The
    tag is a 16-bit number. Valid tags are in the range between 0x0030 and 0xFEFE. The length
-   is implicit, and is the length of the `ascii-string`. `ascii-string` argument is in the form of a string,
+   is implicit, and is the length of the `ascii-string`. The maximum length is 65535 bytes.
+   `ascii-string` argument is in the form of a string,
    e.g. `--custom-tlv-string 0x0030 "Version-1"` will add a TLV entry with tag 0x0030,
    length 9 and value Version-1.
 
+   * `--custom-tlv-file tag filename`: Adds a TLV entry with arbitrary length to the manifest
+   header, corresponding to the type identified by `tag`, with the value read as raw bytes
+   from the file `filename`. The tag is a 16-bit number. Valid tags are in the range between
+   0x0030 and 0xFEFE. The length is implicit, and is the size of the file. The maximum length
+   is 65535 bytes. Unlike `--custom-tlv-buffer`, the value is not passed on the command line,
+   so large binary values are not subject to the OS argument length limits.
+
+   If the custom TLVs do not fit in the configured header size, the sign tool automatically
+   increases the size of the manifest header, rounding up to the next power of two. wolfBoot
+   must be built with a matching `IMAGE_HEADER_SIZE`, or it will fail to locate the firmware
+   image at boot.
+
 #### Three-steps signing using external provisioning tools
 
 If the private key is not accessible, while it's possible to sign payloads using