225 lines
8.6 KiB
Go
225 lines
8.6 KiB
Go
package getproviders
|
|
|
|
import (
|
|
"crypto/sha256"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"path/filepath"
|
|
"strings"
|
|
|
|
"golang.org/x/mod/sumdb/dirhash"
|
|
)
|
|
|
|
const h1Prefix = "h1:"
|
|
const zipHashPrefix = "zh:"
|
|
|
|
// PackageHash computes a hash of the contents of the package at the given
|
|
// location, using whichever hash algorithm is the current default.
|
|
//
|
|
// Currently, this method returns version 1 hashes as produced by the
|
|
// function PackageHashV1, but this function may switch to other versions in
|
|
// later releases. Call PackageHashV1 directly if you specifically need a V1
|
|
// hash.
|
|
//
|
|
// PackageHash can be used only with the two local package location types
|
|
// PackageLocalDir and PackageLocalArchive, because it needs to access the
|
|
// contents of the indicated package in order to compute the hash. If given
|
|
// a non-local location this function will always return an error.
|
|
func PackageHash(loc PackageLocation) (string, error) {
|
|
return PackageHashV1(loc)
|
|
}
|
|
|
|
// PackageMatchesHash returns true if the package at the given location matches
|
|
// the given hash, or false otherwise.
|
|
//
|
|
// If it cannot read from the given location, or if the given hash is in an
|
|
// unsupported format, PackageMatchesHash returns an error.
|
|
//
|
|
// There is currently only one hash format, as implemented by HashV1. However,
|
|
// if others are introduced in future PackageMatchesHash may accept multiple
|
|
// formats, and may generate errors for any formats that become obsolete.
|
|
//
|
|
// PackageMatchesHash can be used only with the two local package location types
|
|
// PackageLocalDir and PackageLocalArchive, because it needs to access the
|
|
// contents of the indicated package in order to compute the hash. If given
|
|
// a non-local location this function will always return an error.
|
|
func PackageMatchesHash(loc PackageLocation, want string) (bool, error) {
|
|
switch {
|
|
case strings.HasPrefix(want, h1Prefix):
|
|
got, err := PackageHashV1(loc)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
return got == want, nil
|
|
default:
|
|
return false, fmt.Errorf("unsupported hash format (this may require a newer version of Terraform)")
|
|
}
|
|
}
|
|
|
|
// PreferredHashes examines all of the given hash strings and returns the one
|
|
// that the current version of Terraform considers to provide the strongest
|
|
// verification.
|
|
//
|
|
// Returns an empty string if none of the given hashes are of a supported
|
|
// format. If PreferredHash returns a non-empty string then it will be one
|
|
// of the hash strings in "given", and that hash is the one that must pass
|
|
// verification in order for a package to be considered valid.
|
|
func PreferredHashes(given []string) []string {
|
|
var ret []string
|
|
for _, s := range given {
|
|
if strings.HasPrefix(s, h1Prefix) {
|
|
return append(ret, s)
|
|
}
|
|
}
|
|
return ret
|
|
}
|
|
|
|
// PackageHashLegacyZipSHA implements the old provider package hashing scheme
|
|
// of taking a SHA256 hash of the containing .zip archive itself, rather than
|
|
// of the contents of the archive.
|
|
//
|
|
// The result is a hash string with the "zh:" prefix, which is intended to
|
|
// represent "zip hash". After the prefix is a lowercase-hex encoded SHA256
|
|
// checksum, intended to exactly match the formatting used in the registry
|
|
// API (apart from the prefix) so that checksums can be more conveniently
|
|
// compared by humans.
|
|
//
|
|
// Because this hashing scheme uses the official provider .zip file as its
|
|
// input, it accepts only PackageLocalArchive locations.
|
|
func PackageHashLegacyZipSHA(loc PackageLocalArchive) (string, error) {
|
|
archivePath, err := filepath.EvalSymlinks(string(loc))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
f, err := os.Open(archivePath)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer f.Close()
|
|
|
|
h := sha256.New()
|
|
_, err = io.Copy(h, f)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
gotHash := h.Sum(nil)
|
|
return fmt.Sprintf("%s%x", zipHashPrefix, gotHash), nil
|
|
}
|
|
|
|
// HashLegacyZipSHAFromSHA is a convenience method to produce the schemed-string
|
|
// hash format from an already-calculated hash of a provider .zip archive.
|
|
//
|
|
// This just adds the "zh:" prefix and encodes the string in hex, so that the
|
|
// result is in the same format as PackageHashLegacyZipSHA.
|
|
func HashLegacyZipSHAFromSHA(sum [sha256.Size]byte) string {
|
|
return fmt.Sprintf("%s%x", zipHashPrefix, sum[:])
|
|
}
|
|
|
|
// PackageHashV1 computes a hash of the contents of the package at the given
|
|
// location using hash algorithm 1.
|
|
//
|
|
// The hash covers the paths to files in the directory and the contents of
|
|
// those files. It does not cover other metadata about the files, such as
|
|
// permissions.
|
|
//
|
|
// This function is named "PackageHashV1" in anticipation of other hashing
|
|
// algorithms being added in a backward-compatible way in future. The result
|
|
// from PackageHashV1 always begins with the prefix "h1:" so that callers can
|
|
// distinguish the results of potentially multiple different hash algorithms in
|
|
// future.
|
|
//
|
|
// PackageHashV1 can be used only with the two local package location types
|
|
// PackageLocalDir and PackageLocalArchive, because it needs to access the
|
|
// contents of the indicated package in order to compute the hash. If given
|
|
// a non-local location this function will always return an error.
|
|
func PackageHashV1(loc PackageLocation) (string, error) {
|
|
// Our HashV1 is really just the Go Modules hash version 1, which is
|
|
// sufficient for our needs and already well-used for identity of
|
|
// Go Modules distribution packages. It is also blocked from incompatible
|
|
// changes by being used in a wide array of go.sum files already.
|
|
//
|
|
// In particular, it also supports computing an equivalent hash from
|
|
// an unpacked zip file, which is not important for Terraform workflow
|
|
// today but is likely to become so in future if we adopt a top-level
|
|
// lockfile mechanism that is intended to be checked in to version control,
|
|
// rather than just a transient lock for a particular local cache directory.
|
|
// (In that case we'd need to check hashes of _packed_ packages, too.)
|
|
//
|
|
// Internally, dirhash.Hash1 produces a string containing a sequence of
|
|
// newline-separated path+filehash pairs for all of the files in the
|
|
// directory, and then finally produces a hash of that string to return.
|
|
// In both cases, the hash algorithm is SHA256.
|
|
|
|
switch loc := loc.(type) {
|
|
|
|
case PackageLocalDir:
|
|
// We'll first dereference a possible symlink at our PackageDir location,
|
|
// as would be created if this package were linked in from another cache.
|
|
packageDir, err := filepath.EvalSymlinks(string(loc))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
return dirhash.HashDir(packageDir, "", dirhash.Hash1)
|
|
|
|
case PackageLocalArchive:
|
|
archivePath, err := filepath.EvalSymlinks(string(loc))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
return dirhash.HashZip(archivePath, dirhash.Hash1)
|
|
|
|
default:
|
|
return "", fmt.Errorf("cannot hash package at %s", loc.String())
|
|
}
|
|
}
|
|
|
|
// Hash computes a hash of the contents of the package at the location
|
|
// associated with the reciever, using whichever hash algorithm is the current
|
|
// default.
|
|
//
|
|
// This method will change to use new hash versions as they are introduced
|
|
// in future. If you need a specific hash version, call the method for that
|
|
// version directly instead, such as HashV1.
|
|
//
|
|
// Hash can be used only with the two local package location types
|
|
// PackageLocalDir and PackageLocalArchive, because it needs to access the
|
|
// contents of the indicated package in order to compute the hash. If given
|
|
// a non-local location this function will always return an error.
|
|
func (m PackageMeta) Hash() (string, error) {
|
|
return PackageHash(m.Location)
|
|
}
|
|
|
|
// MatchesHash returns true if the package at the location associated with
|
|
// the receiver matches the given hash, or false otherwise.
|
|
//
|
|
// If it cannot read from the given location, or if the given hash is in an
|
|
// unsupported format, MatchesHash returns an error.
|
|
//
|
|
// MatchesHash can be used only with the two local package location types
|
|
// PackageLocalDir and PackageLocalArchive, because it needs to access the
|
|
// contents of the indicated package in order to compute the hash. If given
|
|
// a non-local location this function will always return an error.
|
|
func (m PackageMeta) MatchesHash(want string) (bool, error) {
|
|
return PackageMatchesHash(m.Location, want)
|
|
}
|
|
|
|
// HashV1 computes a hash of the contents of the package at the location
|
|
// associated with the receiver using hash algorithm 1.
|
|
//
|
|
// The hash covers the paths to files in the directory and the contents of
|
|
// those files. It does not cover other metadata about the files, such as
|
|
// permissions.
|
|
//
|
|
// HashV1 can be used only with the two local package location types
|
|
// PackageLocalDir and PackageLocalArchive, because it needs to access the
|
|
// contents of the indicated package in order to compute the hash. If given
|
|
// a non-local location this function will always return an error.
|
|
func (m PackageMeta) HashV1() (string, error) {
|
|
return PackageHashV1(m.Location)
|
|
}
|