Remove internal step package

This commit removes the use of the step package and the use of STEPPATH
as the base directory for relative paths  in template files, as well as
the location of the tpmkms storage directory.

kms/tpmkms/tpmkms.go

@@ -13,10 +13,8 @@ import (
 	"errors"
 	"fmt"
 	"net/url"
-	"path/filepath"
 	"time"
 
-	"go.step.sm/crypto/internal/step"
 	"go.step.sm/crypto/kms/apiv1"
 	"go.step.sm/crypto/kms/uri"
 	"go.step.sm/crypto/tpm"
@@ -93,7 +91,7 @@ var signatureAlgorithmMapping = map[apiv1.SignatureAlgorithm]algorithmAttributes
 //	})
 //
 // The default storage location for serialized TPM objects when
-// an instance of TPMKMS is created, is $STEPPATH/tpm.
+// an instance of TPMKMS is created, is the relative path "tpm".
 //
 // The system default TPM device will be used when not configured. A
 // specific TPM device can be selected by setting the device:
@@ -146,7 +144,7 @@ func New(ctx context.Context, opts apiv1.Options) (kms *TPMKMS, err error) {
 		identityEarlyRenewalEnabled:     true,
 		identityRenewalPeriodPercentage: 60, // default to AK certificate renewal at 60% of lifetime
 	}
-	storageDirectory := filepath.Join(step.Path(), "tpm") // store TPM objects in $STEPPATH/tpm by default
+	storageDirectory := "tpm" // store TPM objects in a relative tpm directory by default.
 	if opts.StorageDirectory != "" {
 		storageDirectory = opts.StorageDirectory
 	}

sshutil/options.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/pkg/errors"
 
-	"go.step.sm/crypto/internal/step"
 	"go.step.sm/crypto/internal/templates"
 )
 
@@ -71,8 +70,7 @@ func WithTemplateBase64(s string, data TemplateData) Option {
 // with the given data.
 func WithTemplateFile(path string, data TemplateData) Option {
 	return func(cr CertificateRequest, o *Options) error {
-		filename := step.Abs(path)
-		b, err := os.ReadFile(filename)
+		b, err := os.ReadFile(path)
 		if err != nil {
 			return errors.Wrapf(err, "error reading %s", path)
 		}

x509util/options.go

@@ -13,7 +13,6 @@ import (
 	"golang.org/x/crypto/cryptobyte"
 	"golang.org/x/crypto/cryptobyte/asn1"
 
-	"go.step.sm/crypto/internal/step"
 	"go.step.sm/crypto/internal/templates"
 )
 
@@ -82,8 +81,7 @@ func WithTemplateBase64(s string, data TemplateData) Option {
 // with the given data.
 func WithTemplateFile(path string, data TemplateData) Option {
 	return func(cr *x509.CertificateRequest, o *Options) error {
-		filename := step.Abs(path)
-		b, err := os.ReadFile(filename)
+		b, err := os.ReadFile(path)
 		if err != nil {
 			return errors.Wrapf(err, "error reading %s", path)
 		}