[nrf noup] zephyr: Add support for compressed image updates

Adds support for LZMA-compressed firmware updates

Signed-off-by: Jamie McCrae <[email protected]>
(cherry picked from commit a242e91)

Author: nordicjm

boot/bootutil/src/image_validate.c

@@ -40,6 +40,15 @@
 
 #include "mcuboot_config/mcuboot_config.h"
 
+#if defined(MCUBOOT_DECOMPRESS_IMAGES)
+#include <nrf_compress/implementation.h>
+#include <compression/decompression.h>
+#endif
+
+#include "bootutil/bootutil_log.h"
+
+BOOT_LOG_MODULE_DECLARE(mcuboot);
+
 #ifdef MCUBOOT_ENC_IMAGES
 #include "bootutil/enc_key.h"
 #endif
@@ -416,6 +425,68 @@ bootutil_img_validate(struct enc_key_data *enc_state, int image_index,
     FIH_DECLARE(security_counter_valid, FIH_FAILURE);
 #endif
 
+#ifdef MCUBOOT_DECOMPRESS_IMAGES
+    /* If the image is compressed, the integrity of the image must also be validated */
+    if (MUST_DECOMPRESS(fap, image_index, hdr)) {
+        bool found_decompressed_size = false;
+        bool found_decompressed_sha = false;
+        bool found_decompressed_signature = false;
+
+        rc = bootutil_tlv_iter_begin(&it, hdr, fap, IMAGE_TLV_ANY, true);
+        if (rc) {
+            goto out;
+        }
+
+        if (it.tlv_end > bootutil_max_image_size(fap)) {
+            rc = -1;
+            goto out;
+        }
+
+        while (true) {
+            uint16_t expected_size = 0;
+            bool *found_flag = NULL;
+
+            rc = bootutil_tlv_iter_next(&it, &off, &len, &type);
+            if (rc < 0) {
+                goto out;
+            } else if (rc > 0) {
+                break;
+            }
+
+            switch (type) {
+            case IMAGE_TLV_DECOMP_SIZE:
+                expected_size = sizeof(size_t);
+                found_flag = &found_decompressed_size;
+                break;
+            case IMAGE_TLV_DECOMP_SHA:
+                expected_size = IMAGE_HASH_SIZE;
+                found_flag = &found_decompressed_sha;
+                break;
+            case IMAGE_TLV_DECOMP_SIGNATURE:
+                found_flag = &found_decompressed_signature;
+                break;
+            default:
+                continue;
+            };
+
+            if (type == IMAGE_TLV_DECOMP_SIGNATURE && !EXPECTED_SIG_LEN(len)) {
+                rc = -1;
+                goto out;
+            } else if (type != IMAGE_TLV_DECOMP_SIGNATURE && len != expected_size) {
+                rc = -1;
+                goto out;
+            }
+
+            *found_flag = true;
+        }
+
+        rc = (!found_decompressed_size || !found_decompressed_sha || !found_decompressed_signature);
+        if (rc) {
+            goto out;
+        }
+    }
+#endif
+
     rc = bootutil_img_hash(enc_state, image_index, hdr, fap, tmp_buf,
             tmp_buf_sz, hash, seed, seed_len);
     if (rc) {
@@ -587,6 +658,161 @@ bootutil_img_validate(struct enc_key_data *enc_state, int image_index,
     }
 #endif
 
+#ifdef MCUBOOT_DECOMPRESS_IMAGES
+    /* Only after all previous verifications have passed, perform a dry-run of the decompression
+     * and ensure the image is valid
+     */
+    if (!rc && MUST_DECOMPRESS(fap, image_index, hdr)) {
+        image_hash_valid = 0;
+        FIH_SET(valid_signature, FIH_FAILURE);
+
+        rc = bootutil_img_hash_decompress(enc_state, image_index, hdr, fap, tmp_buf, tmp_buf_sz,
+                                          hash, seed, seed_len);
+        if (rc) {
+            goto out;
+        }
+
+        rc = bootutil_tlv_iter_begin(&it, hdr, fap, IMAGE_TLV_DECOMP_SHA, true);
+        if (rc) {
+            goto out;
+        }
+
+        if (it.tlv_end > bootutil_max_image_size(fap)) {
+            rc = -1;
+            goto out;
+        }
+
+        while (true) {
+            rc = bootutil_tlv_iter_next(&it, &off, &len, &type);
+            if (rc < 0) {
+                goto out;
+            } else if (rc > 0) {
+                break;
+            }
+
+            if (type == IMAGE_TLV_DECOMP_SHA) {
+                /* Verify the image hash. This must always be present. */
+                if (len != sizeof(hash)) {
+                    rc = -1;
+                    goto out;
+                }
+                rc = LOAD_IMAGE_DATA(hdr, fap, off, buf, sizeof(hash));
+                if (rc) {
+                    goto out;
+                }
+
+                FIH_CALL(boot_fih_memequal, fih_rc, hash, buf, sizeof(hash));
+                if (FIH_NOT_EQ(fih_rc, FIH_SUCCESS)) {
+                    FIH_SET(fih_rc, FIH_FAILURE);
+                    goto out;
+                }
+
+                image_hash_valid = 1;
+            }
+        }
+
+        rc = !image_hash_valid;
+        if (rc) {
+            goto out;
+        }
+
+#ifdef EXPECTED_SIG_TLV
+#ifdef EXPECTED_KEY_TLV
+        rc = bootutil_tlv_iter_begin(&it, hdr, fap, EXPECTED_KEY_TLV, false);
+        if (rc) {
+            goto out;
+        }
+
+        if (it.tlv_end > bootutil_max_image_size(fap)) {
+            rc = -1;
+            goto out;
+        }
+
+        while (true) {
+            rc = bootutil_tlv_iter_next(&it, &off, &len, &type);
+            if (rc < 0) {
+                goto out;
+            } else if (rc > 0) {
+                break;
+            }
+
+            if (type == EXPECTED_KEY_TLV) {
+                /*
+                 * Determine which key we should be checking.
+                 */
+                if (len > KEY_BUF_SIZE) {
+                    rc = -1;
+                    goto out;
+                 }
+#ifndef MCUBOOT_HW_KEY
+                rc = LOAD_IMAGE_DATA(hdr, fap, off, buf, len);
+                if (rc) {
+                    goto out;
+                }
+                key_id = bootutil_find_key(buf, len);
+#else
+                rc = LOAD_IMAGE_DATA(hdr, fap, off, key_buf, len);
+                if (rc) {
+                    goto out;
+                }
+                key_id = bootutil_find_key(image_index, key_buf, len);
+#endif /* !MCUBOOT_HW_KEY */
+                /*
+                 * The key may not be found, which is acceptable.  There
+                 * can be multiple signatures, each preceded by a key.
+                 */
+            }
+        }
+#endif /* EXPECTED_KEY_TLV */
+
+        rc = bootutil_tlv_iter_begin(&it, hdr, fap, IMAGE_TLV_DECOMP_SIGNATURE, true);
+        if (rc) {
+            goto out;
+        }
+
+        if (it.tlv_end > bootutil_max_image_size(fap)) {
+            rc = -1;
+            goto out;
+        }
+
+        while (true) {
+            rc = bootutil_tlv_iter_next(&it, &off, &len, &type);
+            if (rc < 0) {
+                goto out;
+            } else if (rc > 0) {
+                rc = 0;
+                break;
+            }
+
+            if (type == IMAGE_TLV_DECOMP_SIGNATURE) {
+                /* Ignore this signature if it is out of bounds. */
+                if (key_id < 0 || key_id >= bootutil_key_cnt) {
+                    key_id = -1;
+                    continue;
+                }
+
+                if (!EXPECTED_SIG_LEN(len) || len > sizeof(buf)) {
+                    rc = -1;
+                    goto out;
+                }
+                rc = LOAD_IMAGE_DATA(hdr, fap, off, buf, len);
+                if (rc) {
+                    goto out;
+                }
+
+                FIH_CALL(bootutil_verify_sig, valid_signature, hash, sizeof(hash),
+                                                               buf, len, key_id);
+                key_id = -1;
+            }
+        }
+#endif /* EXPECTED_SIG_TLV */
+    }
+#endif
+
+#ifdef EXPECTED_SIG_TLV
+    FIH_SET(fih_rc, valid_signature);
+#endif
+
 out:
     if (rc) {
         FIH_SET(fih_rc, FIH_FAILURE);