diff --git a/pkcs7/sign_enveloped.go b/pkcs7/sign_enveloped.go
index 9727942..66e9eae 100644
--- a/pkcs7/sign_enveloped.go
+++ b/pkcs7/sign_enveloped.go
@@ -25,7 +25,7 @@ type signedEnvelopedData struct {
 	SignerInfos                []signerInfo           `asn1:"set"`
 }
 
-func (data signedEnvelopedData) GetRecipient(cert *smx509.Certificate) *recipientInfo {
+func (data signedEnvelopedData) findRecipient(cert *smx509.Certificate) *recipientInfo {
 	for _, recp := range data.RecipientInfos {
 		if isCertMatchForIssuerAndSerial(cert, recp.IssuerAndSerialNumber) {
 			return &recp
@@ -93,7 +93,7 @@ func (p7 *PKCS7) DecryptAndVerify(cert *smx509.Certificate, pkey crypto.PrivateK
 	if !ok {
 		return nil, errors.New("pkcs7: it's NOT SignedAndEvelopedData")
 	}
-	recipient := sed.GetRecipient(cert)
+	recipient := sed.findRecipient(cert)
 	if recipient == nil {
 		return nil, errors.New("pkcs7: no enveloped recipient for provided certificate")
 	}
diff --git a/pkcs7/sign_enveloped_test.go b/pkcs7/sign_enveloped_test.go
index 0b0e22f..a5b77a5 100644
--- a/pkcs7/sign_enveloped_test.go
+++ b/pkcs7/sign_enveloped_test.go
@@ -3,7 +3,6 @@ package pkcs7
 import (
 	"bytes"
 	"encoding/pem"
-	"fmt"
 	"math/big"
 	"testing"
 
@@ -188,14 +187,14 @@ func TestCreateSignedEvnvelopedData(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		fmt.Printf("%x\n", result)
+		// fmt.Printf("%x\n", result)
 
 		// parse, decrypt, verify
 		p7Data, err := Parse(result)
 		if err != nil {
 			t.Fatal(err)
 		}
-		encKeyBytes, err := p7Data.DecryptAndVerifyOnlyOne(*recipient.PrivateKey, func() error {
+		encKeyBytes, err := p7Data.DecryptAndVerify(recipient.Certificate, *recipient.PrivateKey, func() error {
 			return p7Data.Verify()
 		})
 		if err != nil {
diff --git a/pkcs7/verify_test_dsa.go b/pkcs7/verify_test_dsa.go
deleted file mode 100644
index d6e914e..0000000
--- a/pkcs7/verify_test_dsa.go
+++ /dev/null
@@ -1,183 +0,0 @@
-// +build go1.11 go1.12 go1.13 go1.14 go1.15
-
-package pkcs7
-
-import (
-	"encoding/pem"
-	"fmt"
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"testing"
-
-	"github.com/emmansun/gmsm/smx509"
-)
-
-func TestVerifyEC2(t *testing.T) {
-	fixture := UnmarshalDSATestFixture(EC2IdentityDocumentFixture)
-	p7, err := Parse(fixture.Input)
-	if err != nil {
-		t.Errorf("Parse encountered unexpected error: %v", err)
-	}
-	p7.Certificates = []*smx509.Certificate{fixture.Certificate}
-	if err := p7.Verify(); err != nil {
-		t.Errorf("Verify failed with error: %v", err)
-	}
-}
-
-var EC2IdentityDocumentFixture = `
------BEGIN PKCS7-----
-MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAaCA
-JIAEggGmewogICJwcml2YXRlSXAiIDogIjE3Mi4zMC4wLjI1MiIsCiAgImRldnBh
-eVByb2R1Y3RDb2RlcyIgOiBudWxsLAogICJhdmFpbGFiaWxpdHlab25lIiA6ICJ1
-cy1lYXN0LTFhIiwKICAidmVyc2lvbiIgOiAiMjAxMC0wOC0zMSIsCiAgImluc3Rh
-bmNlSWQiIDogImktZjc5ZmU1NmMiLAogICJiaWxsaW5nUHJvZHVjdHMiIDogbnVs
-bCwKICAiaW5zdGFuY2VUeXBlIiA6ICJ0Mi5taWNybyIsCiAgImFjY291bnRJZCIg
-OiAiMTIxNjU5MDE0MzM0IiwKICAiaW1hZ2VJZCIgOiAiYW1pLWZjZTNjNjk2IiwK
-ICAicGVuZGluZ1RpbWUiIDogIjIwMTYtMDQtMDhUMDM6MDE6MzhaIiwKICAiYXJj
-aGl0ZWN0dXJlIiA6ICJ4ODZfNjQiLAogICJrZXJuZWxJZCIgOiBudWxsLAogICJy
-YW1kaXNrSWQiIDogbnVsbCwKICAicmVnaW9uIiA6ICJ1cy1lYXN0LTEiCn0AAAAA
-AAAxggEYMIIBFAIBATBpMFwxCzAJBgNVBAYTAlVTMRkwFwYDVQQIExBXYXNoaW5n
-dG9uIFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYDVQQKExdBbWF6b24gV2Vi
-IFNlcnZpY2VzIExMQwIJAJa6SNnlXhpnMAkGBSsOAwIaBQCgXTAYBgkqhkiG9w0B
-CQMxCwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xNjA0MDgwMzAxNDRaMCMG
-CSqGSIb3DQEJBDEWBBTuUc28eBXmImAautC+wOjqcFCBVjAJBgcqhkjOOAQDBC8w
-LQIVAKA54NxGHWWCz5InboDmY/GHs33nAhQ6O/ZI86NwjA9Vz3RNMUJrUPU5tAAA
-AAAAAA==
------END PKCS7-----
------BEGIN CERTIFICATE-----
-MIIC7TCCAq0CCQCWukjZ5V4aZzAJBgcqhkjOOAQDMFwxCzAJBgNVBAYTAlVTMRkw
-FwYDVQQIExBXYXNoaW5ndG9uIFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYD
-VQQKExdBbWF6b24gV2ViIFNlcnZpY2VzIExMQzAeFw0xMjAxMDUxMjU2MTJaFw0z
-ODAxMDUxMjU2MTJaMFwxCzAJBgNVBAYTAlVTMRkwFwYDVQQIExBXYXNoaW5ndG9u
-IFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYDVQQKExdBbWF6b24gV2ViIFNl
-cnZpY2VzIExMQzCCAbcwggEsBgcqhkjOOAQBMIIBHwKBgQCjkvcS2bb1VQ4yt/5e
-ih5OO6kK/n1Lzllr7D8ZwtQP8fOEpp5E2ng+D6Ud1Z1gYipr58Kj3nssSNpI6bX3
-VyIQzK7wLclnd/YozqNNmgIyZecN7EglK9ITHJLP+x8FtUpt3QbyYXJdmVMegN6P
-hviYt5JH/nYl4hh3Pa1HJdskgQIVALVJ3ER11+Ko4tP6nwvHwh6+ERYRAoGBAI1j
-k+tkqMVHuAFcvAGKocTgsjJem6/5qomzJuKDmbJNu9Qxw3rAotXau8Qe+MBcJl/U
-hhy1KHVpCGl9fueQ2s6IL0CaO/buycU1CiYQk40KNHCcHfNiZbdlx1E9rpUp7bnF
-lRa2v1ntMX3caRVDdbtPEWmdxSCYsYFDk4mZrOLBA4GEAAKBgEbmeve5f8LIE/Gf
-MNmP9CM5eovQOGx5ho8WqD+aTebs+k2tn92BBPqeZqpWRa5P/+jrdKml1qx4llHW
-MXrs3IgIb6+hUIB+S8dz8/mmO0bpr76RoZVCXYab2CZedFut7qc3WUH9+EUAH5mw
-vSeDCOUMYQR7R9LINYwouHIziqQYMAkGByqGSM44BAMDLwAwLAIUWXBlk40xTwSw
-7HX32MxXYruse9ACFBNGmdX2ZBrVNGrN9N2f6ROk0k9K
------END CERTIFICATE-----`
-
-func TestDSASignWithOpenSSLAndVerify(t *testing.T) {
-	content := []byte(`
-A ship in port is safe,
-but that's not what ships are built for.
--- Grace Hopper`)
-	// write the content to a temp file
-	tmpContentFile, err := ioutil.TempFile("", "TestDSASignWithOpenSSLAndVerify_content")
-	if err != nil {
-		t.Fatal(err)
-	}
-	ioutil.WriteFile(tmpContentFile.Name(), content, 0755)
-
-	// write the signer cert to a temp file
-	tmpSignerCertFile, err := ioutil.TempFile("", "TestDSASignWithOpenSSLAndVerify_signer")
-	if err != nil {
-		t.Fatal(err)
-	}
-	ioutil.WriteFile(tmpSignerCertFile.Name(), dsaPublicCert, 0755)
-
-	// write the signer key to a temp file
-	tmpSignerKeyFile, err := ioutil.TempFile("", "TestDSASignWithOpenSSLAndVerify_key")
-	if err != nil {
-		t.Fatal(err)
-	}
-	ioutil.WriteFile(tmpSignerKeyFile.Name(), dsaPrivateKey, 0755)
-
-	tmpSignedFile, err := ioutil.TempFile("", "TestDSASignWithOpenSSLAndVerify_signature")
-	if err != nil {
-		t.Fatal(err)
-	}
-	// call openssl to sign the content
-	opensslCMD := exec.Command("openssl", "smime", "-sign", "-nodetach", "-md", "sha1",
-		"-in", tmpContentFile.Name(), "-out", tmpSignedFile.Name(),
-		"-signer", tmpSignerCertFile.Name(), "-inkey", tmpSignerKeyFile.Name(),
-		"-certfile", tmpSignerCertFile.Name(), "-outform", "PEM")
-	out, err := opensslCMD.CombinedOutput()
-	if err != nil {
-		t.Fatalf("openssl command failed with %s: %s", err, out)
-	}
-
-	// verify the signed content
-	pemSignature, err := ioutil.ReadFile(tmpSignedFile.Name())
-	if err != nil {
-		t.Fatal(err)
-	}
-	fmt.Printf("%s\n", pemSignature)
-	derBlock, _ := pem.Decode(pemSignature)
-	if derBlock == nil {
-		t.Fatalf("failed to read DER block from signature PEM %s", tmpSignedFile.Name())
-	}
-	p7, err := Parse(derBlock.Bytes)
-	if err != nil {
-		t.Fatalf("Parse encountered unexpected error: %v", err)
-	}
-	if err := p7.Verify(); err != nil {
-		t.Fatalf("Verify failed with error: %v", err)
-	}
-	os.Remove(tmpSignerCertFile.Name()) // clean up
-	os.Remove(tmpSignerKeyFile.Name())  // clean up
-	os.Remove(tmpContentFile.Name())    // clean up
-}
-
-var dsaPrivateKey = []byte(`-----BEGIN PRIVATE KEY-----
-MIIBSwIBADCCASwGByqGSM44BAEwggEfAoGBAP1/U4EddRIpUt9KnC7s5Of2EbdS
-PO9EAMMeP4C2USZpRV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7gB00b/JmYLdrmVCl
-pJ+f6AR7ECLCT7up1/63xhv4O1fnxqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith
-1yrv8iIDGZ3RSAHHAhUAl2BQjxUjC8yykrmCouuEC/BYHPUCgYEA9+GghdabPd7L
-vKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdRWVeOutRZT+ZxBxCBgLRJFnEj6EwoFhO3
-zwkyjMim4TwWeotUfI0o4KOuHiuzpnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImo
-g9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoEFgIUfW4aPdQBn9gJZp2KuNpzgHzvfsE=
------END PRIVATE KEY-----`)
-
-var dsaPublicCert = []byte(`-----BEGIN CERTIFICATE-----
-MIIDOjCCAvWgAwIBAgIEPCY/UDANBglghkgBZQMEAwIFADBsMRAwDgYDVQQGEwdV
-bmtub3duMRAwDgYDVQQIEwdVbmtub3duMRAwDgYDVQQHEwdVbmtub3duMRAwDgYD
-VQQKEwdVbmtub3duMRAwDgYDVQQLEwdVbmtub3duMRAwDgYDVQQDEwdVbmtub3du
-MB4XDTE4MTAyMjEzNDMwN1oXDTQ2MDMwOTEzNDMwN1owbDEQMA4GA1UEBhMHVW5r
-bm93bjEQMA4GA1UECBMHVW5rbm93bjEQMA4GA1UEBxMHVW5rbm93bjEQMA4GA1UE
-ChMHVW5rbm93bjEQMA4GA1UECxMHVW5rbm93bjEQMA4GA1UEAxMHVW5rbm93bjCC
-AbgwggEsBgcqhkjOOAQBMIIBHwKBgQD9f1OBHXUSKVLfSpwu7OTn9hG3UjzvRADD
-Hj+AtlEmaUVdQCJR+1k9jVj6v8X1ujD2y5tVbNeBO4AdNG/yZmC3a5lQpaSfn+gE
-exAiwk+7qdf+t8Yb+DtX58aophUPBPuD9tPFHsMCNVQTWhaRMvZ1864rYdcq7/Ii
-Axmd0UgBxwIVAJdgUI8VIwvMspK5gqLrhAvwWBz1AoGBAPfhoIXWmz3ey7yrXDa4
-V7l5lK+7+jrqgvlXTAs9B4JnUVlXjrrUWU/mcQcQgYC0SRZxI+hMKBYTt88JMozI
-puE8FnqLVHyNKOCjrh4rs6Z1kW6jfwv6ITVi8ftiegEkO8yk8b6oUZCJqIPf4Vrl
-nwaSi2ZegHtVJWQBTDv+z0kqA4GFAAKBgQDCriMPbEVBoRK4SOUeFwg7+VRf4TTp
-rcOQC9IVVoCjXzuWEGrp3ZI7YWJSpFnSch4lk29RH8O0HpI/NOzKnOBtnKr782pt
-1k/bJVMH9EaLd6MKnAVjrCDMYBB0MhebZ8QHY2elZZCWoqDYAcIDOsEx+m4NLErT
-ypPnjS5M0jm1PKMhMB8wHQYDVR0OBBYEFC0Yt5XdM0Kc95IX8NQ8XRssGPx7MA0G
-CWCGSAFlAwQDAgUAAzAAMC0CFQCIgQtrZZ9hdZG1ROhR5hc8nYEmbgIUAIlgC688
-qzy/7yePTlhlpj+ahMM=
------END CERTIFICATE-----`)
-
-type DSATestFixture struct {
-	Input       []byte
-	Certificate *smx509.Certificate
-}
-
-func UnmarshalDSATestFixture(testPEMBlock string) DSATestFixture {
-	var result DSATestFixture
-	var derBlock *pem.Block
-	var pemBlock = []byte(testPEMBlock)
-	for {
-		derBlock, pemBlock = pem.Decode(pemBlock)
-		if derBlock == nil {
-			break
-		}
-		switch derBlock.Type {
-		case "PKCS7":
-			result.Input = derBlock.Bytes
-		case "CERTIFICATE":
-			result.Certificate, _ = smx509.ParseCertificate(derBlock.Bytes)
-		}
-	}
-
-	return result
-}