apc-p15-tool/pkg/app/pem_to_p15.go
2025-06-23 20:01:41 -04:00

170 lines
6 KiB
Go

package app
import (
"apc-p15-tool/pkg/pkcs15"
"crypto/x509"
"encoding/asn1"
"fmt"
"slices"
"time"
)
// list of keys supported by the NMC2
var nmc2SupportedKeyTypes = []pkcs15.KeyType{
pkcs15.KeyTypeRSA1024,
pkcs15.KeyTypeRSA2048,
pkcs15.KeyTypeRSA3072, // officially not supported but works
}
// known good signing algorithms
var knownSupportedNMC2SigningAlgs = []x509.SignatureAlgorithm{
x509.SHA256WithRSA,
}
var knownSupportedNMC3SigningAlgs = append(knownSupportedNMC2SigningAlgs, []x509.SignatureAlgorithm{
x509.ECDSAWithSHA384,
}...)
// known supported cert extensions
var knownSupportedCriticalOIDs = []asn1.ObjectIdentifier{
{2, 5, 29, 15}, // keyUsage
{2, 5, 29, 19}, // basicConstraints
{2, 5, 29, 17}, // subjectAltName
}
var knownSupportedOIDs = append(knownSupportedCriticalOIDs, []asn1.ObjectIdentifier{
{2, 5, 29, 37}, // extKeyUsage
{2, 5, 29, 14}, // subjectKeyIdentifier
{2, 5, 29, 35}, // authorityKeyIdentifier
{1, 3, 6, 1, 5, 5, 7, 1, 1}, // authorityInfoAccess
{2, 5, 29, 32}, // certificatePolicies
{1, 3, 6, 1, 4, 1, 11129, 2, 4, 2}, // googleSignedCertificateTimestamp
{2, 5, 29, 31}, // cRLDistributionPoints
}...)
// pemToAPCP15 reads the specified pem files and returns the apc p15 file(s). If the
// key type of the key is not supported by NMC2, the combined key+cert file is not
// generated and nil is returned instead for that file. If the key IS supported by
// NMC2, the key+cert file is generated and the proper header is prepended.
func (app *app) pemToAPCP15(keyPem, certPem []byte, parentCmdName string) (keyFile []byte, apcKeyCertFile []byte, err error) {
app.stdLogger.Printf("%s: making apc p15 file(s) content from pem", parentCmdName)
// make p15 struct
p15, err := pkcs15.ParsePEMToPKCS15(keyPem, certPem)
if err != nil {
return nil, nil, fmt.Errorf("%s: failed to parse pem files (%w)", parentCmdName, err)
}
app.stdLogger.Printf("%s: successfully parsed pem files", parentCmdName)
// make key file (always)
keyFile, err = p15.ToP15Key()
if err != nil {
return nil, nil, fmt.Errorf("%s: failed to make p15 key file (%w)", parentCmdName, err)
}
app.stdLogger.Printf("%s: successfully generated p15 key file content", parentCmdName)
// check key type for compat with NMC2
nmc2KeyType := false
if slices.Contains(nmc2SupportedKeyTypes, p15.KeyType()) {
nmc2KeyType = true
app.stdLogger.Printf("%s: key type is supported by NMC2, generating p15 key+cert file content...", parentCmdName)
// make file bytes
keyCertFile, err := p15.ToP15KeyCert()
if err != nil {
return nil, nil, fmt.Errorf("%s: failed to make p15 key+cert file content (%w)", parentCmdName, err)
}
// make header for file bytes
apcHeader, err := makeFileHeader(keyCertFile)
if err != nil {
return nil, nil, fmt.Errorf("%s: failed to make p15 key+cert file header (%w)", parentCmdName, err)
}
// combine header with file
apcKeyCertFile = append(apcHeader, keyCertFile...)
}
// check various parts of cert and log compatibility warnings
warned := false
// key not supported for NMC2
if !nmc2KeyType {
app.stdLogger.Printf("WARNING: %s: key type is %s and is not supported by NMC2.", parentCmdName, p15.KeyType().String())
warned = true
}
// signature algorithm (see: https://github.com/gregtwallace/apc-p15-tool/issues/18)
if !nmc2KeyType {
// definitely not for NMC2
if !slices.Contains(knownSupportedNMC3SigningAlgs, p15.Cert.SignatureAlgorithm) {
app.stdLogger.Printf("WARNING: %s: Certificate signing algorithm is %s and it is not known if NMC3 supports this algorithm.", parentCmdName, p15.Cert.SignatureAlgorithm.String())
warned = true
}
} else {
// could be for either NMC2 or NMC3
if !slices.Contains(knownSupportedNMC2SigningAlgs, p15.Cert.SignatureAlgorithm) {
if !slices.Contains(knownSupportedNMC3SigningAlgs, p15.Cert.SignatureAlgorithm) {
// not in NMC2 or NMC3 list
app.stdLogger.Printf("WARNING: %s: Certificate signing algorithm is %s and is not supported by NMC2. It is also not known if NMC3 supports this algorithm.", parentCmdName, p15.Cert.SignatureAlgorithm.String())
} else {
// not in NMC2 list, but is in NMC3 list
app.stdLogger.Printf("WARNING: %s: Certificate signing algorithm is %s and it does not support NMC2.", parentCmdName, p15.Cert.SignatureAlgorithm.String())
}
warned = true
}
}
// check validity dates
if time.Now().Before(p15.Cert.NotBefore) {
app.stdLogger.Printf("WARNING: %s: Current time (%s) is before certificate's NotBefore time (%s).",
parentCmdName, time.Now().Format(timeLoggingFormat), p15.Cert.NotBefore.Format(timeLoggingFormat))
warned = true
}
if time.Now().After(p15.Cert.NotAfter) {
app.stdLogger.Printf("WARNING: %s: Current time (%s) is after certificate's NotAfter time (%s).",
parentCmdName, time.Now().Format(timeLoggingFormat), p15.Cert.NotAfter.Format(timeLoggingFormat))
warned = true
}
// check extensions against known working extensions
for _, extension := range p15.Cert.Extensions {
// critical or not?
okOIDs := knownSupportedCriticalOIDs
criticalLogMsg := "Critical "
if !extension.Critical {
okOIDs = knownSupportedOIDs
criticalLogMsg = ""
}
// validate OIDs
ok := false
for _, okOID := range okOIDs {
if okOID.Equal(extension.Id) {
ok = true
break
}
}
if !ok {
app.stdLogger.Printf("WARNING: %s: %sExtension %s may not be supported by NMC.", parentCmdName, criticalLogMsg, extension.Id.String())
}
}
// log a message about possible failure
if warned {
app.stdLogger.Printf("WARNING: %s: Possible certificate compatibility issues were detected. If the resulting p15 file "+
"does not work with your NMC (e.g., a self-signed certificate is regenerated after you try to install the p15), "+
"modify your certificate to resolve the warnings and try again.", parentCmdName)
}
// end compatibility warnings
app.stdLogger.Printf("%s: apc p15 file(s) data succesfully generated", parentCmdName)
return keyFile, apcKeyCertFile, nil
}