    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152

    //! Shared download logic between [`HttpRegistry`] and [`RemoteRegistry`].
    //!
    //! [`HttpRegistry`]: super::http_remote::HttpRegistry
    //! [`RemoteRegistry`]: super::remote::RemoteRegistry

    use anyhow::Context;
    use cargo_credential::Operation;
    use cargo_util::registry::make_dep_path;
    use cargo_util::Sha256;

    use crate::core::PackageId;
    use crate::sources::registry::MaybeLock;
    use crate::sources::registry::RegistryConfig;
    use crate::util::auth;
    use crate::util::errors::CargoResult;
    use crate::util::{Config, Filesystem};
    use std::fmt::Write as FmtWrite;
    use std::fs::{self, File, OpenOptions};
    use std::io::prelude::*;
    use std::io::SeekFrom;
    use std::str;

    const CRATE_TEMPLATE: &str = "{crate}";
    const VERSION_TEMPLATE: &str = "{version}";
    const PREFIX_TEMPLATE: &str = "{prefix}";
    const LOWER_PREFIX_TEMPLATE: &str = "{lowerprefix}";
    const CHECKSUM_TEMPLATE: &str = "{sha256-checksum}";

    /// Checks if `pkg` is downloaded and ready under the directory at `cache_path`.
    /// If not, returns a URL to download it from.
    ///
    /// This is primarily called by [`RegistryData::download`](super::RegistryData::download).
    pub(super) fn download(
        cache_path: &Filesystem,
        config: &Config,
        pkg: PackageId,
        checksum: &str,
        registry_config: RegistryConfig,
    ) -> CargoResult<MaybeLock> {
        let path = cache_path.join(&pkg.tarball_name());
        let path = config.assert_package_cache_locked(&path);

        // Attempt to open a read-only copy first to avoid an exclusive write
        // lock and also work with read-only filesystems. Note that we check the
        // length of the file like below to handle interrupted downloads.
        //
        // If this fails then we fall through to the exclusive path where we may
        // have to redownload the file.
        if let Ok(dst) = File::open(path) {
            let meta = dst.metadata()?;
            if meta.len() > 0 {
                return Ok(MaybeLock::Ready(dst));
            }
        }

        let mut url = registry_config.dl;
        if !url.contains(CRATE_TEMPLATE)
            && !url.contains(VERSION_TEMPLATE)
            && !url.contains(PREFIX_TEMPLATE)
            && !url.contains(LOWER_PREFIX_TEMPLATE)
            && !url.contains(CHECKSUM_TEMPLATE)
        {
            // Original format before customizing the download URL was supported.
            write!(
                url,
                "/{}/{}/download",
                pkg.name(),
                pkg.version().to_string()
            )
            .unwrap();
        } else {
            let prefix = make_dep_path(&pkg.name(), true);
            url = url
                .replace(CRATE_TEMPLATE, &*pkg.name())
                .replace(VERSION_TEMPLATE, &pkg.version().to_string())
                .replace(PREFIX_TEMPLATE, &prefix)
                .replace(LOWER_PREFIX_TEMPLATE, &prefix.to_lowercase())
                .replace(CHECKSUM_TEMPLATE, checksum);
        }

        let authorization = if registry_config.auth_required {
            Some(auth::auth_token(
                config,
                &pkg.source_id(),
                None,
                Operation::Read,
                vec![],
                true,
            )?)
        } else {
            None
        };

        Ok(MaybeLock::Download {
            url,
            descriptor: pkg.to_string(),
            authorization: authorization,
        })
    }

    /// Verifies the integrity of `data` with `checksum` and persists it under the
    /// directory at `cache_path`.
    ///
    /// This is primarily called by [`RegistryData::finish_download`](super::RegistryData::finish_download).
    pub(super) fn finish_download(
        cache_path: &Filesystem,
        config: &Config,
        pkg: PackageId,
        checksum: &str,
        data: &[u8],
    ) -> CargoResult<File> {
        // Verify what we just downloaded
        let actual = Sha256::new().update(data).finish_hex();
        if actual != checksum {
            anyhow::bail!("failed to verify the checksum of `{}`", pkg)
        }

        cache_path.create_dir()?;
        let path = cache_path.join(&pkg.tarball_name());
        let path = config.assert_package_cache_locked(&path);
        let mut dst = OpenOptions::new()
            .create(true)
            .read(true)
            .write(true)
            .open(&path)
            .with_context(|| format!("failed to open `{}`", path.display()))?;
        let meta = dst.metadata()?;
        if meta.len() > 0 {
            return Ok(dst);
        }

        dst.write_all(data)?;
        dst.seek(SeekFrom::Start(0))?;
        Ok(dst)
    }

    /// Checks if a tarball of `pkg` has been already downloaded under the
    /// directory at `cache_path`.
    ///
    /// This is primarily called by [`RegistryData::is_crate_downloaded`](super::RegistryData::is_crate_downloaded).
    pub(super) fn is_crate_downloaded(
        cache_path: &Filesystem,
        config: &Config,
        pkg: PackageId,
    ) -> bool {
        let path = cache_path.join(pkg.tarball_name());
        let path = config.assert_package_cache_locked(&path);
        if let Ok(meta) = fs::metadata(path) {
            return meta.len() > 0;
        }
        false
    }