[pbs-devel] [PATCH v6 proxmox-backup 0/3] add proxmox-backup-debug binary

[pbs-devel] [PATCH v6 proxmox-backup 0/3] add proxmox-backup-debug binary

[Hannes Laimer]

Adds a new proxmox-backup-debug binary for recovery or inspection of
index, blob and chunk files

v6(based on Wolfgang Bumiller <w.bumiller@proxmox.com>'s feedback):
  - removed unnecessary SCHEMA references
  - added few args with arg_param
  - removed unnecessary Result wrapping
  - moved logic for checking whether decode is to stdout into
    decode_blob function
  - improved argument description

v5:
  - improved some parts based on Dominik Csapak <d.csapak@proxmox.com>
    feedback on v4
  - changes are described in the patches themself

v4:
  - rewrote parts based on Wolfgang Bumiller <w.bumiller@proxmox.com>
    feedback on v3
  - check filetype mostly by magic number, except when
    looking for index files

v3:
  - move description into commit message

v2:
  - appiled suggestions + rewrote a few parts
  - renamed 'restore' to 'debug'<Paste>

Hannes Laimer (3):
  add chunk inspection to pb-debug
  add file inspection to pb-debug
  add index recovery to pb-debug

 Makefile                                |   3 +-
 src/bin/proxmox-backup-debug.rs         |  15 ++
 src/bin/proxmox_backup_debug/inspect.rs | 308 ++++++++++++++++++++++++
 src/bin/proxmox_backup_debug/mod.rs     |   4 +
 src/bin/proxmox_backup_debug/recover.rs | 119 +++++++++
 src/tools/mod.rs                        |  13 +
 6 files changed, 461 insertions(+), 1 deletion(-)
 create mode 100644 src/bin/proxmox-backup-debug.rs
 create mode 100644 src/bin/proxmox_backup_debug/inspect.rs
 create mode 100644 src/bin/proxmox_backup_debug/mod.rs
 create mode 100644 src/bin/proxmox_backup_debug/recover.rs

-- 
2.30.2

[pbs-devel] [PATCH v6 proxmox-backup 1/3] add chunk inspection to pb-debug

[Hannes Laimer]

Adds possibility to inspect chunks and find indexes that reference the
chunk. Options:
 - chunk: path to the chunk file
 - [opt] decode: path to a file or to stdout(-), if specified, the
   chunk will be decoded into the specified location
 - [opt] digest: needed when searching for references, if set, it will
   be used for verification when decoding
 - [opt] keyfile: path to a keyfile, needed if decode is specified and
   the data was encrypted
 - [opt] reference-filter: path in which indexes that reference the
   chunk should be searched, can be a group, snapshot or the whole
   datastore, if not specified no references will be searched
 - [default=true] use-filename-as-digest: use chunk-filename as digest,
   if no digest is specified

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
v6:
 - remove SCHEMA ref.
 - add "digest" and "use_filename_as_digest" arg
 - add "chunk" with .arg_param() 

v5:
 - compair digests directly
 - use KEYFILE_SCHEMA from proxmox_client_tools
 - outfile_out_stdout now returns something that is writebale, instead
   of writing directly

v4:
 - left the two schemas here since they are quite specific to this binary
 - output_or_stdout() directly outputs the data instead of returning
   stdout or an open file (could not find a type that allows to properly
   return either stdout or a file)

 Makefile                                |   3 +-
 src/bin/proxmox-backup-debug.rs         |  13 ++
 src/bin/proxmox_backup_debug/inspect.rs | 202 ++++++++++++++++++++++++
 src/bin/proxmox_backup_debug/mod.rs     |   2 +
 src/tools/mod.rs                        |  13 ++
 5 files changed, 232 insertions(+), 1 deletion(-)
 create mode 100644 src/bin/proxmox-backup-debug.rs
 create mode 100644 src/bin/proxmox_backup_debug/inspect.rs
 create mode 100644 src/bin/proxmox_backup_debug/mod.rs

diff --git a/Makefile b/Makefile
index d6c1acf5..14c07ca0 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,8 @@ USR_BIN := \
 
 # Binaries usable by admins
 USR_SBIN := \
-	proxmox-backup-manager
+	proxmox-backup-manager \
+	proxmox-backup-debug \
 
 # Binaries for services:
 SERVICE_BIN := \
diff --git a/src/bin/proxmox-backup-debug.rs b/src/bin/proxmox-backup-debug.rs
new file mode 100644
index 00000000..897fa221
--- /dev/null
+++ b/src/bin/proxmox-backup-debug.rs
@@ -0,0 +1,13 @@
+use proxmox::api::cli::*;
+
+mod proxmox_backup_debug;
+use proxmox_backup_debug::inspect_commands;
+
+fn main() {
+    proxmox_backup::tools::setup_safe_path_env();
+
+    let cmd_def = CliCommandMap::new().insert("inspect", inspect_commands());
+
+    let rpcenv = CliEnvironment::new();
+    run_cli_command(cmd_def, rpcenv, Some(|future| pbs_runtime::main(future)));
+}
diff --git a/src/bin/proxmox_backup_debug/inspect.rs b/src/bin/proxmox_backup_debug/inspect.rs
new file mode 100644
index 00000000..35f7dfa5
--- /dev/null
+++ b/src/bin/proxmox_backup_debug/inspect.rs
@@ -0,0 +1,202 @@
+use std::path::Path;
+
+use anyhow::{format_err, Error};
+use proxmox::api::cli::{
+    format_and_print_result, get_output_format, CliCommand, CliCommandMap, CommandLineInterface,
+};
+use proxmox::api::{api, cli::*};
+use serde_json::{json, Value};
+use walkdir::WalkDir;
+
+use proxmox_backup::backup::{
+    load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+};
+
+use pbs_client::tools::key_source::get_encryption_key_password;
+
+use proxmox_backup::tools::outfile_or_stdout;
+
+/// Decodes a blob and writes its content either to stdout or into a file
+fn decode_blob(
+    mut output_path: Option<&Path>,
+    key_file: Option<&Path>,
+    digest: Option<&[u8; 32]>,
+    blob: &DataBlob,
+) -> Result<(), Error> {
+    let mut crypt_conf_opt = None;
+    let crypt_conf;
+
+    if blob.is_encrypted() && key_file.is_some() {
+        let (key, _created, _fingerprint) =
+            load_and_decrypt_key(&key_file.unwrap(), &get_encryption_key_password)?;
+        crypt_conf = CryptConfig::new(key)?;
+        crypt_conf_opt = Some(&crypt_conf);
+    }
+
+    output_path = match output_path {
+        Some(path) if path.eq(Path::new("-")) => None,
+        _ => output_path,
+    };
+
+    outfile_or_stdout(output_path)?.write_all(blob.decode(crypt_conf_opt, digest)?.as_slice())?;
+    Ok(())
+}
+
+#[api(
+    input: {
+        properties: {
+            chunk: {
+                description: "The chunk file.",
+                type: String,
+            },
+            "reference-filter": {
+                description: "Path to the directory that should be searched for references.",
+                type: String,
+                optional: true,
+            },
+            "digest": {
+                description: "Needed when searching for references, if set, it will be used for verification when decoding.",
+                type: String,
+                optional: true,
+            },
+            "decode": {
+                description: "Path to the file to which the chunk should be decoded, '-' -> decode to stdout.",
+                type: String,
+                optional: true,
+            },
+            "keyfile": {
+                description: "Path to the keyfile with which the chunk was encrypted.",
+                type: String,
+                optional: true,
+            },
+            "use-filename-as-digest": {
+                description: "The filename should be used as digest for reference search and decode verification, if no digest is specified.",
+                type: bool,
+                optional: true,
+                default: true,
+            },
+            "output-format": {
+                schema: OUTPUT_FORMAT,
+                optional: true,
+            },
+        }
+    }
+)]
+/// Inspect a chunk
+fn inspect_chunk(
+    chunk: String,
+    reference_filter: Option<String>,
+    mut digest: Option<String>,
+    decode: Option<String>,
+    keyfile: Option<String>,
+    use_filename_as_digest: bool,
+    param: Value,
+) -> Result<(), Error> {
+    let output_format = get_output_format(&param);
+    let chunk_path = Path::new(&chunk);
+
+    if digest.is_none() && use_filename_as_digest {
+        digest = Some(if let Some((_, filename)) = chunk.rsplit_once("/") {
+            String::from(filename)
+        } else {
+            chunk.clone()
+        });
+    };
+
+    let digest_raw: Option<[u8; 32]> = digest
+        .map(|ref d| {
+            proxmox::tools::hex_to_digest(d)
+                .map_err(|e| format_err!("could not parse chunk - {}", e))
+        })
+        .map_or(Ok(None), |r| r.map(Some))?;
+
+    let search_path = reference_filter.as_ref().map(Path::new);
+    let key_file_path = keyfile.as_ref().map(Path::new);
+    let decode_output_path = decode.as_ref().map(Path::new);
+
+    let blob = DataBlob::load_from_reader(
+        &mut std::fs::File::open(&chunk_path)
+            .map_err(|e| format_err!("could not open chunk file - {}", e))?,
+    )?;
+
+    let referenced_by = if let (Some(search_path), Some(digest_raw)) = (search_path, digest_raw) {
+        let mut references = Vec::new();
+        for entry in WalkDir::new(search_path)
+            .follow_links(false)
+            .into_iter()
+            .filter_map(|e| e.ok())
+        {
+            use std::os::unix::ffi::OsStrExt;
+            let file_name = entry.file_name().as_bytes();
+
+            let index: Box<dyn IndexFile> = if file_name.ends_with(b".fidx") {
+                match FixedIndexReader::open(entry.path()) {
+                    Ok(index) => Box::new(index),
+                    Err(_) => continue,
+                }
+            } else if file_name.ends_with(b".didx") {
+                match DynamicIndexReader::open(entry.path()) {
+                    Ok(index) => Box::new(index),
+                    Err(_) => continue,
+                }
+            } else {
+                continue;
+            };
+
+            for pos in 0..index.index_count() {
+                if let Some(index_chunk_digest) = index.index_digest(pos) {
+                    if digest_raw.eq(index_chunk_digest) {
+                        references.push(entry.path().to_string_lossy().into_owned());
+                        break;
+                    }
+                }
+            }
+        }
+        if !references.is_empty() {
+            Some(references)
+        } else {
+            None
+        }
+    } else {
+        None
+    };
+
+    if decode_output_path.is_some() {
+        decode_blob(
+            decode_output_path,
+            key_file_path,
+            digest_raw.as_ref(),
+            &blob,
+        )?;
+    }
+
+    let crc_status = format!(
+        "{}({})",
+        blob.compute_crc(),
+        blob.verify_crc().map_or("NOK", |_| "OK")
+    );
+
+    let val = match referenced_by {
+        Some(references) => json!({
+            "crc": crc_status,
+            "encryption": blob.crypt_mode()?,
+            "referenced-by": references
+        }),
+        None => json!({
+             "crc": crc_status,
+             "encryption": blob.crypt_mode()?,
+        }),
+    };
+
+    format_and_print_result(&val, &output_format);
+    Ok(())
+}
+
+pub fn inspect_commands() -> CommandLineInterface {
+    let cmd_def = CliCommandMap::new().insert(
+        "chunk",
+        CliCommand::new(&API_METHOD_INSPECT_CHUNK).arg_param(&["chunk"]),
+    );
+
+    cmd_def.into()
+}
diff --git a/src/bin/proxmox_backup_debug/mod.rs b/src/bin/proxmox_backup_debug/mod.rs
new file mode 100644
index 00000000..644583db
--- /dev/null
+++ b/src/bin/proxmox_backup_debug/mod.rs
@@ -0,0 +1,2 @@
+mod inspect;
+pub use inspect::*;
diff --git a/src/tools/mod.rs b/src/tools/mod.rs
index b6c55ac2..dfff8c10 100644
--- a/src/tools/mod.rs
+++ b/src/tools/mod.rs
@@ -2,7 +2,10 @@
 //!
 //! This is a collection of small and useful tools.
 use std::any::Any;
+use std::fs::File;
+use std::io::{stdout, Write};
 use std::os::unix::io::RawFd;
+use std::path::Path;
 
 use anyhow::{bail, format_err, Error};
 use openssl::hash::{hash, DigestBytes, MessageDigest};
@@ -224,3 +227,13 @@ pub fn create_run_dir() -> Result<(), Error> {
     let _: bool = create_path(pbs_buildcfg::PROXMOX_BACKUP_RUN_DIR_M!(), None, Some(opts))?;
     Ok(())
 }
+
+/// Returns either a new file, if a path is given, or stdout, if no path is given.
+pub fn outfile_or_stdout<P: AsRef<Path>>(path: Option<P>) -> Result<Box<dyn Write>, Error> {
+    if let Some(path) = path {
+        let f = File::create(path)?;
+        Ok(Box::new(f) as Box<dyn Write>)
+    } else {
+        Ok(Box::new(stdout()) as Box<dyn Write>)
+    }
+}
-- 
2.30.2

[pbs-devel] [PATCH v6 proxmox-backup 2/3] add file inspection to pb-debug

[Hannes Laimer]

Adds possibility to inspect .blob, .fidx and .didx files. For index
files a list of the chunks referenced will be printed in addition to
some other inforation. .blob files can be decoded into file or directly
into stdout. Options:
 - file: path to the file
 - [opt] decode: path to a file or stdout(-), if specidied, the file will be
   decoded into the specified location [only for blob files, no effect
   with index files]
 - [opt] keyfile: path to a keyfile, needed if decode is specified and the
   data was encrypted

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
v6:
 - remove SCHEMA ref.
 - drop to_stdout variable
 - add "file" with .arg_param()

v5:
 - compair digests directly
 - use KEYFILE_SCHEMA from proxmox_client_tools
 - outfile_out_stdout now returns something that is writebale, instead
   of writing directly

v4:
 - left the two schemas here since they are quite specific to this binary
 - output_or_stdout() directly outputs the data instead of returning
   stdout or an open file (could not find a type that allows to properly
   return either stdout or a file)

 src/bin/proxmox_backup_debug/inspect.rs | 116 +++++++++++++++++++++++-
 1 file changed, 111 insertions(+), 5 deletions(-)

diff --git a/src/bin/proxmox_backup_debug/inspect.rs b/src/bin/proxmox_backup_debug/inspect.rs
index 35f7dfa5..1817efc7 100644
--- a/src/bin/proxmox_backup_debug/inspect.rs
+++ b/src/bin/proxmox_backup_debug/inspect.rs
@@ -1,6 +1,9 @@
+use std::collections::HashSet;
+use std::fs::File;
+use std::io::{Read, Seek, SeekFrom};
 use std::path::Path;
 
-use anyhow::{format_err, Error};
+use anyhow::{bail, format_err, Error};
 use proxmox::api::cli::{
     format_and_print_result, get_output_format, CliCommand, CliCommandMap, CommandLineInterface,
 };
@@ -10,6 +13,8 @@ use walkdir::WalkDir;
 
 use proxmox_backup::backup::{
     load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+    COMPRESSED_BLOB_MAGIC_1_0, DYNAMIC_SIZED_CHUNK_INDEX_1_0, ENCRYPTED_BLOB_MAGIC_1_0,
+    ENCR_COMPR_BLOB_MAGIC_1_0, FIXED_SIZED_CHUNK_INDEX_1_0, UNCOMPRESSED_BLOB_MAGIC_1_0,
 };
 
 use pbs_client::tools::key_source::get_encryption_key_password;
@@ -192,11 +197,112 @@ fn inspect_chunk(
     Ok(())
 }
 
+#[api(
+    input: {
+        properties: {
+            file: {
+                description: "Path to the file.",
+                type: String,
+            },
+            "decode": {
+                description: "Path to the file to which the file should be decoded, '-' -> decode to stdout.",
+                type: String,
+                optional: true,
+            },
+            "keyfile": {
+                description: "Path to the keyfile with which the file was encrypted.",
+                type: String,
+                optional: true,
+            },
+            "output-format": {
+                schema: OUTPUT_FORMAT,
+                optional: true,
+            },
+        }
+    }
+)]
+/// Inspect a file
+fn inspect_file(
+    file: String,
+    decode: Option<String>,
+    keyfile: Option<String>,
+    param: Value,
+) -> Result<(), Error> {
+    let output_format = get_output_format(&param);
+
+    let mut file = File::open(Path::new(&file))?;
+    let mut magic = [0; 8];
+    file.read_exact(&mut magic)?;
+    file.seek(SeekFrom::Start(0))?;
+    let val = match magic {
+        UNCOMPRESSED_BLOB_MAGIC_1_0
+        | COMPRESSED_BLOB_MAGIC_1_0
+        | ENCRYPTED_BLOB_MAGIC_1_0
+        | ENCR_COMPR_BLOB_MAGIC_1_0 => {
+            let data_blob = DataBlob::load_from_reader(&mut file)?;
+            let key_file_path = keyfile.as_ref().map(Path::new);
+
+            let decode_output_path = decode.as_ref().map(Path::new);
+
+            if decode_output_path.is_some() {
+                decode_blob(decode_output_path, key_file_path, None, &data_blob)?;
+            }
+
+            let crypt_mode = data_blob.crypt_mode()?;
+            json!({
+                "encryption": crypt_mode,
+                "raw_size": data_blob.raw_size(),
+            })
+        }
+        FIXED_SIZED_CHUNK_INDEX_1_0 | DYNAMIC_SIZED_CHUNK_INDEX_1_0 => {
+            let index: Box<dyn IndexFile> = match magic {
+                FIXED_SIZED_CHUNK_INDEX_1_0 => {
+                    Box::new(FixedIndexReader::new(file)?) as Box<dyn IndexFile>
+                }
+                DYNAMIC_SIZED_CHUNK_INDEX_1_0 => {
+                    Box::new(DynamicIndexReader::new(file)?) as Box<dyn IndexFile>
+                }
+                _ => bail!(format_err!("This is technically not possible")),
+            };
+
+            let mut ctime_str = index.index_ctime().to_string();
+            if let Ok(s) = proxmox::tools::time::strftime_local("%c", index.index_ctime()) {
+                ctime_str = s;
+            }
+
+            let mut chunk_digests = HashSet::new();
+
+            for pos in 0..index.index_count() {
+                let digest = index.index_digest(pos).unwrap();
+                chunk_digests.insert(proxmox::tools::digest_to_hex(digest));
+            }
+
+            json!({
+                "size": index.index_size(),
+                "ctime": ctime_str,
+                "chunk-digests": chunk_digests
+            })
+        }
+        _ => bail!(format_err!(
+            "Only .blob, .fidx and .didx files may be inspected"
+        )),
+    };
+
+    format_and_print_result(&val, &output_format);
+
+    Ok(())
+}
+
 pub fn inspect_commands() -> CommandLineInterface {
-    let cmd_def = CliCommandMap::new().insert(
-        "chunk",
-        CliCommand::new(&API_METHOD_INSPECT_CHUNK).arg_param(&["chunk"]),
-    );
+    let cmd_def = CliCommandMap::new()
+        .insert(
+            "chunk",
+            CliCommand::new(&API_METHOD_INSPECT_CHUNK).arg_param(&["chunk"]),
+        )
+        .insert(
+            "file",
+            CliCommand::new(&API_METHOD_INSPECT_FILE).arg_param(&["file"]),
+        );
 
     cmd_def.into()
 }
-- 
2.30.2

[pbs-devel] [PATCH v6 proxmox-backup 3/3] add index recovery to pb-debug

[Hannes Laimer]

Adds possibility to recover data from an index file. Options:
 - chunks: path to the directory where the chunks are saved
 - file: the index file that should be recovered(must be either .fidx or
   didx)
 - [opt] keyfile: path to a keyfile, if the data was encrypted, a keyfile is
   needed
 - [opt] skip-crc: boolean, if true, read chunks wont be verified with their
   crc-sum, increases the restore speed by a lot

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
v6:
 - remove SCHEMA ref.
 - add "file" and "chunks" with .arg_param() 
 - remove not needed Result wrapping

v5:
 - combine path for fixed and dynamic index fliles to avoid duplicate
   code

v4:
 - only the types of file that are passed by the user are check with the
   magic number, when looking for index files just the filename ending
   is checked -> don't have to open the file for that
 - not sure if a function for the magic nr reading, seek reset makes
   sense(?), it's just two lines

 src/bin/proxmox-backup-debug.rs         |   6 +-
 src/bin/proxmox_backup_debug/mod.rs     |   2 +
 src/bin/proxmox_backup_debug/recover.rs | 119 ++++++++++++++++++++++++
 3 files changed, 125 insertions(+), 2 deletions(-)
 create mode 100644 src/bin/proxmox_backup_debug/recover.rs

diff --git a/src/bin/proxmox-backup-debug.rs b/src/bin/proxmox-backup-debug.rs
index 897fa221..b3360c93 100644
--- a/src/bin/proxmox-backup-debug.rs
+++ b/src/bin/proxmox-backup-debug.rs
@@ -1,12 +1,14 @@
 use proxmox::api::cli::*;
 
 mod proxmox_backup_debug;
-use proxmox_backup_debug::inspect_commands;
+use proxmox_backup_debug::{inspect_commands, recover_commands};
 
 fn main() {
     proxmox_backup::tools::setup_safe_path_env();
 
-    let cmd_def = CliCommandMap::new().insert("inspect", inspect_commands());
+    let cmd_def = CliCommandMap::new()
+        .insert("inspect", inspect_commands())
+        .insert("recover", recover_commands());
 
     let rpcenv = CliEnvironment::new();
     run_cli_command(cmd_def, rpcenv, Some(|future| pbs_runtime::main(future)));
diff --git a/src/bin/proxmox_backup_debug/mod.rs b/src/bin/proxmox_backup_debug/mod.rs
index 644583db..62df7754 100644
--- a/src/bin/proxmox_backup_debug/mod.rs
+++ b/src/bin/proxmox_backup_debug/mod.rs
@@ -1,2 +1,4 @@
 mod inspect;
 pub use inspect::*;
+mod recover;
+pub use recover::*;
diff --git a/src/bin/proxmox_backup_debug/recover.rs b/src/bin/proxmox_backup_debug/recover.rs
new file mode 100644
index 00000000..706223b1
--- /dev/null
+++ b/src/bin/proxmox_backup_debug/recover.rs
@@ -0,0 +1,119 @@
+use std::fs::File;
+use std::io::{Read, Seek, SeekFrom, Write};
+use std::path::Path;
+
+use anyhow::{bail, format_err, Error};
+
+use proxmox::api::api;
+use proxmox::api::cli::{CliCommand, CliCommandMap, CommandLineInterface};
+use proxmox_backup::backup::{DYNAMIC_SIZED_CHUNK_INDEX_1_0, FIXED_SIZED_CHUNK_INDEX_1_0};
+use serde_json::Value;
+
+use proxmox_backup::backup::{
+    load_and_decrypt_key, CryptConfig, DataBlob, DynamicIndexReader, FixedIndexReader, IndexFile,
+};
+
+use pbs_client::tools::key_source::get_encryption_key_password;
+
+use proxmox::tools::digest_to_hex;
+
+#[api(
+    input: {
+        properties: {
+            file: {
+                description: "Path to the index file, either .fidx or .didx.",
+                type: String,
+            },
+            chunks: {
+                description: "Path to the directorty that contains the chunks, usually <datastore>/.chunks.",
+                type: String,
+            },
+            "keyfile": {
+                description: "Path to a keyfile, if the data was encrypted, a keyfile is needed for decryption.",
+                type: String,
+                optional: true,
+            },
+            "skip-crc": {
+                description: "Skip the crc verification, increases the restore speed by lot.",
+                type: Boolean,
+                optional: true,
+                default: false,
+            }
+        }
+    }
+)]
+/// Restore the data from an index file, given the directory of where chunks
+/// are saved, the index file and a keyfile, if needed for decryption.
+fn recover_index(
+    file: String,
+    chunks: String,
+    keyfile: Option<String>,
+    skip_crc: bool,
+    _param: Value,
+) -> Result<(), Error> {
+    let file_path = Path::new(&file);
+    let chunks_path = Path::new(&chunks);
+
+    let key_file_path = keyfile.as_ref().map(Path::new);
+
+    let mut file = File::open(Path::new(&file))?;
+    let mut magic = [0; 8];
+    file.read_exact(&mut magic)?;
+    file.seek(SeekFrom::Start(0))?;
+    let index: Box<dyn IndexFile> = match magic {
+        FIXED_SIZED_CHUNK_INDEX_1_0 => Box::new(FixedIndexReader::new(file)?) as Box<dyn IndexFile>,
+        DYNAMIC_SIZED_CHUNK_INDEX_1_0 => {
+            Box::new(DynamicIndexReader::new(file)?) as Box<dyn IndexFile>
+        }
+        _ => bail!(format_err!(
+            "index file must either be a .fidx or a .didx file"
+        )),
+    };
+
+    let crypt_conf_opt = if let Some(key_file_path) = key_file_path {
+        let (key, _created, _fingerprint) =
+            load_and_decrypt_key(&key_file_path, &get_encryption_key_password)?;
+        Some(CryptConfig::new(key)?)
+    } else {
+        None
+    };
+
+    let output_filename = file_path.file_stem().unwrap().to_str().unwrap();
+    let output_path = Path::new(output_filename);
+    let mut output_file = File::create(output_path)
+        .map_err(|e| format_err!("could not create output file - {}", e))?;
+
+    let mut data = Vec::with_capacity(4 * 1024 * 1024);
+    for pos in 0..index.index_count() {
+        let chunk_digest = index.index_digest(pos).unwrap();
+        let digest_str = digest_to_hex(chunk_digest);
+        let digest_prefix = &digest_str[0..4];
+        let chunk_path = chunks_path.join(digest_prefix).join(digest_str);
+        let mut chunk_file = std::fs::File::open(&chunk_path)
+            .map_err(|e| format_err!("could not open chunk file - {}", e))?;
+
+        data.clear();
+        chunk_file.read_to_end(&mut data)?;
+        let chunk_blob = DataBlob::from_raw(data.clone())?;
+
+        if !skip_crc {
+            chunk_blob.verify_crc()?;
+        }
+
+        output_file.write_all(
+            chunk_blob
+                .decode(crypt_conf_opt.as_ref(), Some(chunk_digest))?
+                .as_slice(),
+        )?;
+    }
+
+    Ok(())
+}
+
+pub fn recover_commands() -> CommandLineInterface {
+    let cmd_def = CliCommandMap::new().insert(
+        "index",
+        CliCommand::new(&API_METHOD_RECOVER_INDEX).arg_param(&["file", "chunks"]),
+    );
+    cmd_def.into()
+}
-- 
2.30.2