Files
trivy/pkg/dependency/parser/python/packaging/parse.go

100 lines
3.2 KiB
Go

package packaging
import (
"bufio"
"errors"
"io"
"net/textproto"
"strings"
"sync"
"golang.org/x/xerrors"
ftypes "github.com/aquasecurity/trivy/pkg/fanal/types"
"github.com/aquasecurity/trivy/pkg/licensing"
"github.com/aquasecurity/trivy/pkg/log"
xio "github.com/aquasecurity/trivy/pkg/x/io"
)
var licenseMetadataInfoOnce sync.Once
type Parser struct {
logger *log.Logger
}
func NewParser() *Parser {
return &Parser{
logger: log.WithPrefix("python"),
}
}
// Parse parses egg and wheel metadata.
// e.g. .egg-info/PKG-INFO and dist-info/METADATA
func (p *Parser) Parse(r xio.ReadSeekerAt) ([]ftypes.Package, []ftypes.Dependency, error) {
rd := textproto.NewReader(bufio.NewReader(r))
h, err := rd.ReadMIMEHeader()
if e := textproto.ProtocolError(""); errors.As(err, &e) {
// A MIME header may contain bytes in the key or value outside the set allowed by RFC 7230.
// cf. https://cs.opensource.google/go/go/+/a6642e67e16b9d769a0c08e486ba08408064df19
// However, our required key/value could have been correctly parsed,
// so we continue with the subsequent process.
p.logger.Debug("MIME protocol error", log.Err(err))
} else if err != nil && err != io.EOF {
return nil, nil, xerrors.Errorf("read MIME error: %w", err)
}
name, version := h.Get("name"), h.Get("version")
if name == "" || version == "" {
return nil, nil, xerrors.New("name or version is empty")
}
// "License-Expression" takes precedence in accordance with https://peps.python.org/pep-0639/#deprecate-license-field
// Although keep in mind that pep-0639 is still in draft.
var license string
if le := h.Get("License-Expression"); le != "" {
license = le
} else {
// Get possible multiple occurrences of licenses from "Classifier: License" field
// When present it should define the license whereas "License" would define any additional exceptions or modifications
// ref. https://packaging.python.org/en/latest/specifications/core-metadata/#license
var licenses []string
for _, classifier := range h.Values("Classifier") {
if strings.HasPrefix(classifier, "License :: ") {
values := strings.Split(classifier, " :: ")
licenseName := values[len(values)-1]
// According to the classifier list https://pypi.org/classifiers/ there is one classifier which seems more like a grouping
// It has no specific license definition (Classifier: License :: OSI Approved) - it is skipped
if licenseName != "OSI Approved" {
licenses = append(licenses, licenseName)
}
}
}
license = strings.Join(licenses, ", ")
if l := h.Get("License"); l != "" {
if len(licenses) != 0 {
licenseMetadataInfoOnce.Do(func() {
p.logger.Info("Licenses acquired from one or more METADATA files may be subject to additional terms. Use `--debug` flag to see all affected packages.")
})
p.logger.Debug("License acquired from METADATA classifiers may be subject to additional terms",
log.String("name", name), log.String("version", version))
} else {
license = l
}
}
}
if license == "" && h.Get("License-File") != "" {
license = licensing.LicenseFilePrefix + h.Get("License-File")
}
return []ftypes.Package{
{
Name: name,
Version: version,
Licenses: licensing.SplitLicenses(license),
},
}, nil, nil
}