crypto/cms: Add support for CAdES Basic Electronic Signatures (CAdES-BES)

A CAdES Basic Electronic Signature (CAdES-BES) contains, among other
specifications, a collection of  Signing Certificate reference attributes,
stored in the signedData ether as ESS signing-certificate or as
ESS signing-certificate-v2. These are described in detail in Section 5.7.2
of RFC 5126 - CMS Advanced Electronic Signatures (CAdES).

This patch adds support for adding  ESS signing-certificate[-v2] attributes
to CMS signedData. Although it implements only a small part of the RFC, it
is sufficient many cases to enable the `openssl cms` app to create signatures
which comply with legal requirements of some European States (e.g Italy).

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/7893)

5 files changed, 12 insertions, 386 deletions

diff --git a/crypto/ts/ts_asn1.c b/crypto/ts/ts_asn1.c
index 0db78b1e4f..5a588413bc 100644
--- a/crypto/ts/ts_asn1.c
+++ b/crypto/ts/ts_asn1.c
@@ -201,47 +201,6 @@ int i2d_TS_RESP_fp(FILE *fp, TS_RESP *a)
 }
 #endif
 
-ASN1_SEQUENCE(ESS_ISSUER_SERIAL) = {
-        ASN1_SEQUENCE_OF(ESS_ISSUER_SERIAL, issuer, GENERAL_NAME),
-        ASN1_SIMPLE(ESS_ISSUER_SERIAL, serial, ASN1_INTEGER)
-} static_ASN1_SEQUENCE_END(ESS_ISSUER_SERIAL)
-
-IMPLEMENT_ASN1_FUNCTIONS_const(ESS_ISSUER_SERIAL)
-IMPLEMENT_ASN1_DUP_FUNCTION(ESS_ISSUER_SERIAL)
-
-ASN1_SEQUENCE(ESS_CERT_ID) = {
-        ASN1_SIMPLE(ESS_CERT_ID, hash, ASN1_OCTET_STRING),
-        ASN1_OPT(ESS_CERT_ID, issuer_serial, ESS_ISSUER_SERIAL)
-} static_ASN1_SEQUENCE_END(ESS_CERT_ID)
-
-IMPLEMENT_ASN1_FUNCTIONS_const(ESS_CERT_ID)
-IMPLEMENT_ASN1_DUP_FUNCTION(ESS_CERT_ID)
-
-ASN1_SEQUENCE(ESS_SIGNING_CERT) = {
-        ASN1_SEQUENCE_OF(ESS_SIGNING_CERT, cert_ids, ESS_CERT_ID),
-        ASN1_SEQUENCE_OF_OPT(ESS_SIGNING_CERT, policy_info, POLICYINFO)
-} static_ASN1_SEQUENCE_END(ESS_SIGNING_CERT)
-
-IMPLEMENT_ASN1_FUNCTIONS_const(ESS_SIGNING_CERT)
-IMPLEMENT_ASN1_DUP_FUNCTION(ESS_SIGNING_CERT)
-
-ASN1_SEQUENCE(ESS_CERT_ID_V2) = {
-        ASN1_OPT(ESS_CERT_ID_V2, hash_alg, X509_ALGOR),
-        ASN1_SIMPLE(ESS_CERT_ID_V2, hash, ASN1_OCTET_STRING),
-        ASN1_OPT(ESS_CERT_ID_V2, issuer_serial, ESS_ISSUER_SERIAL)
-} static_ASN1_SEQUENCE_END(ESS_CERT_ID_V2)
-
-IMPLEMENT_ASN1_FUNCTIONS_const(ESS_CERT_ID_V2)
-IMPLEMENT_ASN1_DUP_FUNCTION(ESS_CERT_ID_V2)
-
-ASN1_SEQUENCE(ESS_SIGNING_CERT_V2) = {
-        ASN1_SEQUENCE_OF(ESS_SIGNING_CERT_V2, cert_ids, ESS_CERT_ID_V2),
-        ASN1_SEQUENCE_OF_OPT(ESS_SIGNING_CERT_V2, policy_info, POLICYINFO)
-} static_ASN1_SEQUENCE_END(ESS_SIGNING_CERT_V2)
-
-IMPLEMENT_ASN1_FUNCTIONS_const(ESS_SIGNING_CERT_V2)
-IMPLEMENT_ASN1_DUP_FUNCTION(ESS_SIGNING_CERT_V2)
-
 /* Getting encapsulated TS_TST_INFO object from PKCS7. */
 TS_TST_INFO *PKCS7_to_TS_TST_INFO(PKCS7 *token)
 {
diff --git a/crypto/ts/ts_err.c b/crypto/ts/ts_err.c
index cb89efb0d2..c971d477a6 100644
--- a/crypto/ts/ts_err.c
+++ b/crypto/ts/ts_err.c
@@ -1,6 +1,6 @@
 /*
  * Generated by util/mkerr.pl DO NOT EDIT
- * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -16,18 +16,6 @@
 static const ERR_STRING_DATA TS_str_functs[] = {
     {ERR_PACK(ERR_LIB_TS, TS_F_DEF_SERIAL_CB, 0), "def_serial_cb"},
     {ERR_PACK(ERR_LIB_TS, TS_F_DEF_TIME_CB, 0), "def_time_cb"},
-    {ERR_PACK(ERR_LIB_TS, TS_F_ESS_ADD_SIGNING_CERT, 0),
-     "ess_add_signing_cert"},
-    {ERR_PACK(ERR_LIB_TS, TS_F_ESS_ADD_SIGNING_CERT_V2, 0),
-     "ess_add_signing_cert_v2"},
-    {ERR_PACK(ERR_LIB_TS, TS_F_ESS_CERT_ID_NEW_INIT, 0),
-     "ess_CERT_ID_new_init"},
-    {ERR_PACK(ERR_LIB_TS, TS_F_ESS_CERT_ID_V2_NEW_INIT, 0),
-     "ess_cert_id_v2_new_init"},
-    {ERR_PACK(ERR_LIB_TS, TS_F_ESS_SIGNING_CERT_NEW_INIT, 0),
-     "ess_SIGNING_CERT_new_init"},
-    {ERR_PACK(ERR_LIB_TS, TS_F_ESS_SIGNING_CERT_V2_NEW_INIT, 0),
-     "ess_signing_cert_v2_new_init"},
     {ERR_PACK(ERR_LIB_TS, TS_F_INT_TS_RESP_VERIFY_TOKEN, 0),
      "int_ts_RESP_verify_token"},
     {ERR_PACK(ERR_LIB_TS, TS_F_PKCS7_TO_TS_TST_INFO, 0),
diff --git a/crypto/ts/ts_lcl.h b/crypto/ts/ts_lcl.h
index 967ea06943..320173376a 100644
--- a/crypto/ts/ts_lcl.h
+++ b/crypto/ts/ts_lcl.h
@@ -98,67 +98,6 @@ struct TS_status_info_st {
     ASN1_BIT_STRING *failure_info;
 };
 
-/*-
- * IssuerSerial ::= SEQUENCE {
- *         issuer                   GeneralNames,
- *         serialNumber             CertificateSerialNumber
- *         }
- */
-struct ESS_issuer_serial {
-    STACK_OF(GENERAL_NAME) *issuer;
-    ASN1_INTEGER *serial;
-};
-
-/*-
- * ESSCertID ::=  SEQUENCE {
- *         certHash                 Hash,
- *         issuerSerial             IssuerSerial OPTIONAL
- * }
- */
-struct ESS_cert_id {
-    ASN1_OCTET_STRING *hash;    /* Always SHA-1 digest. */
-    ESS_ISSUER_SERIAL *issuer_serial;
-};
-
-/*-
- * SigningCertificate ::=  SEQUENCE {
- *        certs        SEQUENCE OF ESSCertID,
- *        policies     SEQUENCE OF PolicyInformation OPTIONAL
- * }
- */
-struct ESS_signing_cert {
-    STACK_OF(ESS_CERT_ID) *cert_ids;
-    STACK_OF(POLICYINFO) *policy_info;
-};
-
-/*-
- * ESSCertIDv2 ::=  SEQUENCE {
- *        hashAlgorithm           AlgorithmIdentifier
- *                DEFAULT {algorithm id-sha256},
- *        certHash                Hash,
- *        issuerSerial            IssuerSerial OPTIONAL
- * }
- */
-
-struct ESS_cert_id_v2_st {
-    X509_ALGOR *hash_alg;       /* Default: SHA-256 */
-    ASN1_OCTET_STRING *hash;
-    ESS_ISSUER_SERIAL *issuer_serial;
-};
-
-/*-
- * SigningCertificateV2 ::= SEQUENCE {
- *        certs                   SEQUENCE OF ESSCertIDv2,
- *        policies                SEQUENCE OF PolicyInformation OPTIONAL
- * }
- */
-
-struct ESS_signing_cert_v2_st {
-    STACK_OF(ESS_CERT_ID_V2) *cert_ids;
-    STACK_OF(POLICYINFO) *policy_info;
-};
-
-
 struct TS_resp_ctx {
     X509 *signer_cert;
     EVP_PKEY *signer_key;
diff --git a/crypto/ts/ts_rsp_sign.c b/crypto/ts/ts_rsp_sign.c
index 27fa4f56b9..7791fc73c8 100644
--- a/crypto/ts/ts_rsp_sign.c
+++ b/crypto/ts/ts_rsp_sign.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2006-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -15,6 +15,7 @@
 #include <openssl/pkcs7.h>
 #include <openssl/crypto.h>
 #include "ts_lcl.h"
+#include "internal/ess_int.h"
 
 static ASN1_INTEGER *def_serial_cb(struct TS_resp_ctx *, void *);
 static int def_time_cb(struct TS_resp_ctx *, void *, long *sec, long *usec);
@@ -29,20 +30,7 @@ static TS_TST_INFO *ts_RESP_create_tst_info(TS_RESP_CTX *ctx,
 static int ts_RESP_process_extensions(TS_RESP_CTX *ctx);
 static int ts_RESP_sign(TS_RESP_CTX *ctx);
 
-static ESS_SIGNING_CERT *ess_SIGNING_CERT_new_init(X509 *signcert,
-                                                   STACK_OF(X509) *certs);
-static ESS_CERT_ID *ess_CERT_ID_new_init(X509 *cert, int issuer_needed);
 static int ts_TST_INFO_content_new(PKCS7 *p7);
-static int ess_add_signing_cert(PKCS7_SIGNER_INFO *si, ESS_SIGNING_CERT *sc);
-
-static ESS_SIGNING_CERT_V2 *ess_signing_cert_v2_new_init(const EVP_MD *hash_alg,
-                                                         X509 *signcert,
-                                                         STACK_OF(X509)
-                                                         *certs);
-static ESS_CERT_ID_V2 *ess_cert_id_v2_new_init(const EVP_MD *hash_alg,
-                                               X509 *cert, int issuer_needed);
-static int ess_add_signing_cert_v2(PKCS7_SIGNER_INFO *si,
-                                   ESS_SIGNING_CERT_V2 *sc);
 
 static ASN1_GENERALIZEDTIME
 *TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *, long, long,
@@ -681,20 +669,20 @@ static int ts_RESP_sign(TS_RESP_CTX *ctx)
     certs = ctx->flags & TS_ESS_CERT_ID_CHAIN ? ctx->certs : NULL;
     if (ctx->ess_cert_id_digest == NULL
         || ctx->ess_cert_id_digest == EVP_sha1()) {
-        if ((sc = ess_SIGNING_CERT_new_init(ctx->signer_cert, certs)) == NULL)
+        if ((sc = ESS_SIGNING_CERT_new_init(ctx->signer_cert, certs, 0)) == NULL)
             goto err;
 
-        if (!ess_add_signing_cert(si, sc)) {
+        if (!ESS_SIGNING_CERT_add(si, sc)) {
             TSerr(TS_F_TS_RESP_SIGN, TS_R_ESS_ADD_SIGNING_CERT_ERROR);
             goto err;
         }
     } else {
-        sc2 = ess_signing_cert_v2_new_init(ctx->ess_cert_id_digest,
-                                           ctx->signer_cert, certs);
+        sc2 = ESS_SIGNING_CERT_V2_new_init(ctx->ess_cert_id_digest,
+                                           ctx->signer_cert, certs, 0);
         if (sc2 == NULL)
             goto err;
 
-        if (!ess_add_signing_cert_v2(si, sc2)) {
+        if (!ESS_SIGNING_CERT_V2_add(si, sc2)) {
             TSerr(TS_F_TS_RESP_SIGN, TS_R_ESS_ADD_SIGNING_CERT_V2_ERROR);
             goto err;
         }
@@ -731,77 +719,6 @@ static int ts_RESP_sign(TS_RESP_CTX *ctx)
     return ret;
 }
 
-static ESS_SIGNING_CERT *ess_SIGNING_CERT_new_init(X509 *signcert,
-                                                   STACK_OF(X509) *certs)
-{
-    ESS_CERT_ID *cid;
-    ESS_SIGNING_CERT *sc = NULL;
-    int i;
-
-    if ((sc = ESS_SIGNING_CERT_new()) == NULL)
-        goto err;
-    if (sc->cert_ids == NULL
-        && (sc->cert_ids = sk_ESS_CERT_ID_new_null()) == NULL)
-        goto err;
-
-    if ((cid = ess_CERT_ID_new_init(signcert, 0)) == NULL
-        || !sk_ESS_CERT_ID_push(sc->cert_ids, cid))
-        goto err;
-    for (i = 0; i < sk_X509_num(certs); ++i) {
-        X509 *cert = sk_X509_value(certs, i);
-        if ((cid = ess_CERT_ID_new_init(cert, 1)) == NULL
-            || !sk_ESS_CERT_ID_push(sc->cert_ids, cid))
-            goto err;
-    }
-
-    return sc;
- err:
-    ESS_SIGNING_CERT_free(sc);
-    TSerr(TS_F_ESS_SIGNING_CERT_NEW_INIT, ERR_R_MALLOC_FAILURE);
-    return NULL;
-}
-
-static ESS_CERT_ID *ess_CERT_ID_new_init(X509 *cert, int issuer_needed)
-{
-    ESS_CERT_ID *cid = NULL;
-    GENERAL_NAME *name = NULL;
-    unsigned char cert_sha1[SHA_DIGEST_LENGTH];
-
-    /* Call for side-effect of computing hash and caching extensions */
-    X509_check_purpose(cert, -1, 0);
-    if ((cid = ESS_CERT_ID_new()) == NULL)
-        goto err;
-    X509_digest(cert, EVP_sha1(), cert_sha1, NULL);
-    if (!ASN1_OCTET_STRING_set(cid->hash, cert_sha1, SHA_DIGEST_LENGTH))
-        goto err;
-
-    /* Setting the issuer/serial if requested. */
-    if (issuer_needed) {
-        if (cid->issuer_serial == NULL
-            && (cid->issuer_serial = ESS_ISSUER_SERIAL_new()) == NULL)
-            goto err;
-        if ((name = GENERAL_NAME_new()) == NULL)
-            goto err;
-        name->type = GEN_DIRNAME;
-        if ((name->d.dirn = X509_NAME_dup(X509_get_issuer_name(cert))) == NULL)
-            goto err;
-        if (!sk_GENERAL_NAME_push(cid->issuer_serial->issuer, name))
-            goto err;
-        name = NULL;            /* Ownership is lost. */
-        ASN1_INTEGER_free(cid->issuer_serial->serial);
-        if (!(cid->issuer_serial->serial =
-              ASN1_INTEGER_dup(X509_get_serialNumber(cert))))
-            goto err;
-    }
-
-    return cid;
- err:
-    GENERAL_NAME_free(name);
-    ESS_CERT_ID_free(cid);
-    TSerr(TS_F_ESS_CERT_ID_NEW_INIT, ERR_R_MALLOC_FAILURE);
-    return NULL;
-}
-
 static int ts_TST_INFO_content_new(PKCS7 *p7)
 {
     PKCS7 *ret = NULL;
@@ -829,159 +746,6 @@ static int ts_TST_INFO_content_new(PKCS7 *p7)
     return 0;
 }
 
-static int ess_add_signing_cert(PKCS7_SIGNER_INFO *si, ESS_SIGNING_CERT *sc)
-{
-    ASN1_STRING *seq = NULL;
-    unsigned char *p, *pp = NULL;
-    int len;
-
-    len = i2d_ESS_SIGNING_CERT(sc, NULL);
-    if ((pp = OPENSSL_malloc(len)) == NULL) {
-        TSerr(TS_F_ESS_ADD_SIGNING_CERT, ERR_R_MALLOC_FAILURE);
-        goto err;
-    }
-    p = pp;
-    i2d_ESS_SIGNING_CERT(sc, &p);
-    if ((seq = ASN1_STRING_new()) == NULL || !ASN1_STRING_set(seq, pp, len)) {
-        TSerr(TS_F_ESS_ADD_SIGNING_CERT, ERR_R_MALLOC_FAILURE);
-        goto err;
-    }
-    OPENSSL_free(pp);
-    pp = NULL;
-    return PKCS7_add_signed_attribute(si,
-                                      NID_id_smime_aa_signingCertificate,
-                                      V_ASN1_SEQUENCE, seq);
- err:
-    ASN1_STRING_free(seq);
-    OPENSSL_free(pp);
-
-    return 0;
-}
-
-static ESS_SIGNING_CERT_V2 *ess_signing_cert_v2_new_init(const EVP_MD *hash_alg,
-                                                         X509 *signcert,
-                                                         STACK_OF(X509) *certs)
-{
-    ESS_CERT_ID_V2 *cid = NULL;
-    ESS_SIGNING_CERT_V2 *sc = NULL;
-    int i;
-
-    if ((sc = ESS_SIGNING_CERT_V2_new()) == NULL)
-        goto err;
-    if ((cid = ess_cert_id_v2_new_init(hash_alg, signcert, 0)) == NULL)
-        goto err;
-    if (!sk_ESS_CERT_ID_V2_push(sc->cert_ids, cid))
-        goto err;
-    cid = NULL;
-
-    for (i = 0; i < sk_X509_num(certs); ++i) {
-        X509 *cert = sk_X509_value(certs, i);
-
-        if ((cid = ess_cert_id_v2_new_init(hash_alg, cert, 1)) == NULL)
-            goto err;
-        if (!sk_ESS_CERT_ID_V2_push(sc->cert_ids, cid))
-            goto err;
-        cid = NULL;
-    }
-
-    return sc;
- err:
-    ESS_SIGNING_CERT_V2_free(sc);
-    ESS_CERT_ID_V2_free(cid);
-    TSerr(TS_F_ESS_SIGNING_CERT_V2_NEW_INIT, ERR_R_MALLOC_FAILURE);
-    return NULL;
-}
-
-static ESS_CERT_ID_V2 *ess_cert_id_v2_new_init(const EVP_MD *hash_alg,
-                                               X509 *cert, int issuer_needed)
-{
-    ESS_CERT_ID_V2 *cid = NULL;
-    GENERAL_NAME *name = NULL;
-    unsigned char hash[EVP_MAX_MD_SIZE];
-    unsigned int hash_len = sizeof(hash);
-    X509_ALGOR *alg = NULL;
-
-    memset(hash, 0, sizeof(hash));
-
-    if ((cid = ESS_CERT_ID_V2_new()) == NULL)
-        goto err;
-
-    if (hash_alg != EVP_sha256()) {
-        alg = X509_ALGOR_new();
-        if (alg == NULL)
-            goto err;
-        X509_ALGOR_set_md(alg, hash_alg);
-        if (alg->algorithm == NULL)
-            goto err;
-        cid->hash_alg = alg;
-        alg = NULL;
-    } else {
-        cid->hash_alg = NULL;
-    }
-
-    if (!X509_digest(cert, hash_alg, hash, &hash_len))
-        goto err;
-
-    if (!ASN1_OCTET_STRING_set(cid->hash, hash, hash_len))
-        goto err;
-
-    if (issuer_needed) {
-        if ((cid->issuer_serial = ESS_ISSUER_SERIAL_new()) == NULL)
-            goto err;
-        if ((name = GENERAL_NAME_new()) == NULL)
-            goto err;
-        name->type = GEN_DIRNAME;
-        if ((name->d.dirn = X509_NAME_dup(X509_get_issuer_name(cert))) == NULL)
-            goto err;
-        if (!sk_GENERAL_NAME_push(cid->issuer_serial->issuer, name))
-            goto err;
-        name = NULL;            /* Ownership is lost. */
-        ASN1_INTEGER_free(cid->issuer_serial->serial);
-        cid->issuer_serial->serial =
-                ASN1_INTEGER_dup(X509_get_serialNumber(cert));
-        if (cid->issuer_serial->serial == NULL)
-            goto err;
-    }
-
-    return cid;
- err:
-    X509_ALGOR_free(alg);
-    GENERAL_NAME_free(name);
-    ESS_CERT_ID_V2_free(cid);
-    TSerr(TS_F_ESS_CERT_ID_V2_NEW_INIT, ERR_R_MALLOC_FAILURE);
-    return NULL;
-}
-
-static int ess_add_signing_cert_v2(PKCS7_SIGNER_INFO *si,
-                                   ESS_SIGNING_CERT_V2 *sc)
-{
-    ASN1_STRING *seq = NULL;
-    unsigned char *p, *pp = NULL;
-    int len = i2d_ESS_SIGNING_CERT_V2(sc, NULL);
-
-    if ((pp = OPENSSL_malloc(len)) == NULL) {
-        TSerr(TS_F_ESS_ADD_SIGNING_CERT_V2, ERR_R_MALLOC_FAILURE);
-        goto err;
-    }
-
-    p = pp;
-    i2d_ESS_SIGNING_CERT_V2(sc, &p);
-    if ((seq = ASN1_STRING_new()) == NULL || !ASN1_STRING_set(seq, pp, len)) {
-        TSerr(TS_F_ESS_ADD_SIGNING_CERT_V2, ERR_R_MALLOC_FAILURE);
-        goto err;
-    }
-
-    OPENSSL_free(pp);
-    pp = NULL;
-    return PKCS7_add_signed_attribute(si,
-                                      NID_id_smime_aa_signingCertificateV2,
-                                      V_ASN1_SEQUENCE, seq);
- err:
-    ASN1_STRING_free(seq);
-    OPENSSL_free(pp);
-    return 0;
-}
-
 static ASN1_GENERALIZEDTIME *TS_RESP_set_genTime_with_precision(
         ASN1_GENERALIZEDTIME *asn1_time, long sec, long usec,
         unsigned precision)
diff --git a/crypto/ts/ts_rsp_verify.c b/crypto/ts/ts_rsp_verify.c
index facc4b580a..e658354eb3 100644
--- a/crypto/ts/ts_rsp_verify.c
+++ b/crypto/ts/ts_rsp_verify.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2006-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -13,12 +13,12 @@
 #include <openssl/ts.h>
 #include <openssl/pkcs7.h>
 #include "ts_lcl.h"
+#include "internal/ess_int.h"
 
 static int ts_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
                           X509 *signer, STACK_OF(X509) **chain);
 static int ts_check_signing_certs(PKCS7_SIGNER_INFO *si,
                                   STACK_OF(X509) *chain);
-static ESS_SIGNING_CERT *ess_get_signing_cert(PKCS7_SIGNER_INFO *si);
 static int ts_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert);
 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert);
 static int int_ts_RESP_verify_token(TS_VERIFY_CTX *ctx,
@@ -38,7 +38,6 @@ static int ts_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer);
 static int ts_find_name(STACK_OF(GENERAL_NAME) *gen_names,
                         GENERAL_NAME *name);
 static int ts_find_cert_v2(STACK_OF(ESS_CERT_ID_V2) *cert_ids, X509 *cert);
-static ESS_SIGNING_CERT_V2 *ess_get_signing_cert_v2(PKCS7_SIGNER_INFO *si);
 
 /*
  * This must be large enough to hold all values in ts_status_text (with
@@ -201,9 +200,9 @@ end:
 static int ts_check_signing_certs(PKCS7_SIGNER_INFO *si,
                                   STACK_OF(X509) *chain)
 {
-    ESS_SIGNING_CERT *ss = ess_get_signing_cert(si);
+    ESS_SIGNING_CERT *ss = ESS_SIGNING_CERT_get(si);
     STACK_OF(ESS_CERT_ID) *cert_ids = NULL;
-    ESS_SIGNING_CERT_V2 *ssv2 = ess_get_signing_cert_v2(si);
+    ESS_SIGNING_CERT_V2 *ssv2 = ESS_SIGNING_CERT_V2_get(si);
     STACK_OF(ESS_CERT_ID_V2) *cert_ids_v2 = NULL;
     X509 *cert;
     int i = 0;
@@ -257,29 +256,6 @@ static int ts_check_signing_certs(PKCS7_SIGNER_INFO *si,
     return ret;
 }
 
-static ESS_SIGNING_CERT *ess_get_signing_cert(PKCS7_SIGNER_INFO *si)
-{
-    ASN1_TYPE *attr;
-    const unsigned char *p;
-    attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificate);
-    if (!attr)
-        return NULL;
-    p = attr->value.sequence->data;
-    return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length);
-}
-
-static ESS_SIGNING_CERT_V2 *ess_get_signing_cert_v2(PKCS7_SIGNER_INFO *si)
-{
-    ASN1_TYPE *attr;
-    const unsigned char *p;
-
-    attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificateV2);
-    if (attr == NULL)
-        return NULL;
-    p = attr->value.sequence->data;
-    return d2i_ESS_SIGNING_CERT_V2(NULL, &p, attr->value.sequence->length);
-}
-
 /* Returns < 0 if certificate is not found, certificate index otherwise. */
 static int ts_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert)
 {