/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/x509.h>
#include <assert.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/pem.h>
#include <openssl/stack.h>
#include "../bytestring/internal.h"
/* pkcs7_parse_header reads the non-certificate/non-CRL prefix of a PKCS#7
* SignedData blob from |cbs| and sets |*out| to point to the rest of the
* input. If the input is in BER format, then |*der_bytes| will be set to a
* pointer that needs to be freed by the caller once they have finished
* processing |*out| (which will be pointing into |*der_bytes|).
*
* It returns one on success or zero on error. On error, |*der_bytes| is
* NULL. */
static int pkcs7_parse_header(uint8_t **der_bytes, CBS *out, CBS *cbs) {
size_t der_len;
CBS in, content_info, content_type, wrapped_signed_data, signed_data;
uint64_t version;
/* The input may be in BER format. */
*der_bytes = NULL;
if (!CBS_asn1_ber_to_der(cbs, der_bytes, &der_len)) {
return 0;
}
if (*der_bytes != NULL) {
CBS_init(&in, *der_bytes, der_len);
} else {
CBS_init(&in, CBS_data(cbs), CBS_len(cbs));
}
/* See https://tools.ietf.org/html/rfc2315#section-7 */
if (!CBS_get_asn1(&in, &content_info, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&content_info, &content_type, CBS_ASN1_OBJECT)) {
goto err;
}
if (OBJ_cbs2nid(&content_type) != NID_pkcs7_signed) {
OPENSSL_PUT_ERROR(X509, pkcs7_parse_header,
X509_R_NOT_PKCS7_SIGNED_DATA);
goto err;
}
/* See https://tools.ietf.org/html/rfc2315#section-9.1 */
if (!CBS_get_asn1(&content_info, &wrapped_signed_data,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
!CBS_get_asn1(&wrapped_signed_data, &signed_data, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1_uint64(&signed_data, &version) ||
!CBS_get_asn1(&signed_data, NULL /* digests */, CBS_ASN1_SET) ||
!CBS_get_asn1(&signed_data, NULL /* content */, CBS_ASN1_SEQUENCE)) {
goto err;
}
if (version < 1) {
OPENSSL_PUT_ERROR(X509, pkcs7_parse_header,
X509_R_BAD_PKCS7_VERSION);
goto err;
}
CBS_init(out, CBS_data(&signed_data), CBS_len(&signed_data));
return 1;
err:
if (*der_bytes) {
OPENSSL_free(*der_bytes);
*der_bytes = NULL;
}
return 0;
}
int PKCS7_get_certificates(STACK_OF(X509) *out_certs, CBS *cbs) {
CBS signed_data, certificates;
uint8_t *der_bytes = NULL;
int ret = 0;
const size_t initial_certs_len = sk_X509_num(out_certs);
if (!pkcs7_parse_header(&der_bytes, &signed_data, cbs)) {
return 0;
}
/* See https://tools.ietf.org/html/rfc2315#section-9.1 */
if (!CBS_get_asn1(&signed_data, &certificates,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
OPENSSL_PUT_ERROR(X509, PKCS7_get_certificates,
X509_R_NO_CERTIFICATES_INCLUDED);
goto err;
}
while (CBS_len(&certificates) > 0) {
CBS cert;
X509 *x509;
const uint8_t *inp;
if (!CBS_get_asn1_element(&certificates, &cert, CBS_ASN1_SEQUENCE)) {
goto err;
}
inp = CBS_data(&cert);
x509 = d2i_X509(NULL, &inp, CBS_len(&cert));
if (!x509) {
goto err;
}
assert(inp == CBS_data(&cert) + CBS_len(&cert));
if (sk_X509_push(out_certs, x509) == 0) {
X509_free(x509);
goto err;
}
}
ret = 1;
err:
if (der_bytes) {
OPENSSL_free(der_bytes);
}
if (!ret) {
while (sk_X509_num(out_certs) != initial_certs_len) {
X509 *x509 = sk_X509_pop(out_certs);
X509_free(x509);
}
}
return ret;
}
int PKCS7_get_CRLs(STACK_OF(X509_CRL) *out_crls, CBS *cbs) {
CBS signed_data, crls;
uint8_t *der_bytes = NULL;
int ret = 0;
const size_t initial_crls_len = sk_X509_CRL_num(out_crls);
if (!pkcs7_parse_header(&der_bytes, &signed_data, cbs)) {
return 0;
}
/* See https://tools.ietf.org/html/rfc2315#section-9.1 */
/* Even if only CRLs are included, there may be an empty certificates block.
* OpenSSL does this, for example. */
if (CBS_peek_asn1_tag(&signed_data,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) &&
!CBS_get_asn1(&signed_data, NULL /* certificates */,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
goto err;
}
if (!CBS_get_asn1(&signed_data, &crls,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 1)) {
OPENSSL_PUT_ERROR(X509, PKCS7_get_CRLs,
X509_R_NO_CRLS_INCLUDED);
goto err;
}
while (CBS_len(&crls) > 0) {
CBS crl_data;
X509_CRL *crl;
const uint8_t *inp;
if (!CBS_get_asn1_element(&crls, &crl_data, CBS_ASN1_SEQUENCE)) {
goto err;
}
inp = CBS_data(&crl_data);
crl = d2i_X509_CRL(NULL, &inp, CBS_len(&crl_data));
if (!crl) {
goto err;
}
assert(inp == CBS_data(&crl_data) + CBS_len(&crl_data));
if (sk_X509_CRL_push(out_crls, crl) == 0) {
X509_CRL_free(crl);
goto err;
}
}
ret = 1;
err:
if (der_bytes) {
OPENSSL_free(der_bytes);
}
if (!ret) {
while (sk_X509_CRL_num(out_crls) != initial_crls_len) {
X509_CRL_free(sk_X509_CRL_pop(out_crls));
}
}
return ret;
}
int PKCS7_get_PEM_certificates(STACK_OF(X509) *out_certs, BIO *pem_bio) {
uint8_t *data;
long len;
int ret;
/* Even though we pass PEM_STRING_PKCS7 as the expected PEM type here, PEM
* internally will actually allow several other values too, including
* "CERTIFICATE". */
if (!PEM_bytes_read_bio(&data, &len, NULL /* PEM type output */,
PEM_STRING_PKCS7, pem_bio,
NULL /* password callback */,
NULL /* password callback argument */)) {
return 0;
}
CBS cbs;
CBS_init(&cbs, data, len);
ret = PKCS7_get_certificates(out_certs, &cbs);
OPENSSL_free(data);
return ret;
}
int PKCS7_get_PEM_CRLs(STACK_OF(X509_CRL) *out_crls, BIO *pem_bio) {
uint8_t *data;
long len;
int ret;
/* Even though we pass PEM_STRING_PKCS7 as the expected PEM type here, PEM
* internally will actually allow several other values too, including
* "CERTIFICATE". */
if (!PEM_bytes_read_bio(&data, &len, NULL /* PEM type output */,
PEM_STRING_PKCS7, pem_bio,
NULL /* password callback */,
NULL /* password callback argument */)) {
return 0;
}
CBS cbs;
CBS_init(&cbs, data, len);
ret = PKCS7_get_CRLs(out_crls, &cbs);
OPENSSL_free(data);
return ret;
}
/* pkcs7_bundle writes a PKCS#7, SignedData structure to |out| and then calls
* |cb| with a CBB to which certificate or CRL data can be written, and the
* opaque context pointer, |arg|. The callback can return zero to indicate an
* error.
*
* pkcs7_bundle returns one on success or zero on error. */
static int pkcs7_bundle(CBB *out, int (*cb)(CBB *out, const void *arg),
const void *arg) {
CBB outer_seq, wrapped_seq, seq, version_bytes, digest_algos_set,
content_info;
/* See https://tools.ietf.org/html/rfc2315#section-7 */
if (!CBB_add_asn1(out, &outer_seq, CBS_ASN1_SEQUENCE) ||
!OBJ_nid2cbb(&outer_seq, NID_pkcs7_signed) ||
!CBB_add_asn1(&outer_seq, &wrapped_seq,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
/* See https://tools.ietf.org/html/rfc2315#section-9.1 */
!CBB_add_asn1(&wrapped_seq, &seq, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1(&seq, &version_bytes, CBS_ASN1_INTEGER) ||
!CBB_add_u8(&version_bytes, 1) ||
!CBB_add_asn1(&seq, &digest_algos_set, CBS_ASN1_SET) ||
!CBB_add_asn1(&seq, &content_info, CBS_ASN1_SEQUENCE) ||
!OBJ_nid2cbb(&content_info, NID_pkcs7_data) ||
!cb(&seq, arg)) {
return 0;
}
return CBB_flush(out);
}
static int pkcs7_bundle_certificates_cb(CBB *out, const void *arg) {
const STACK_OF(X509) *certs = arg;
size_t i;
CBB certificates;
/* See https://tools.ietf.org/html/rfc2315#section-9.1 */
if (!CBB_add_asn1(out, &certificates,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
return 0;
}
for (i = 0; i < sk_X509_num(certs); i++) {
X509 *x509 = sk_X509_value(certs, i);
uint8_t *buf;
int len = i2d_X509(x509, NULL);
if (len < 0 ||
!CBB_add_space(&certificates, &buf, len) ||
i2d_X509(x509, &buf) < 0) {
return 0;
}
}
return CBB_flush(out);
}
int PKCS7_bundle_certificates(CBB *out, const STACK_OF(X509) *certs) {
return pkcs7_bundle(out, pkcs7_bundle_certificates_cb, certs);
}
static int pkcs7_bundle_crls_cb(CBB *out, const void *arg) {
const STACK_OF(X509_CRL) *crls = arg;
size_t i;
CBB crl_data;
/* See https://tools.ietf.org/html/rfc2315#section-9.1 */
if (!CBB_add_asn1(out, &crl_data,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 1)) {
return 0;
}
for (i = 0; i < sk_X509_CRL_num(crls); i++) {
X509_CRL *crl = sk_X509_CRL_value(crls, i);
uint8_t *buf;
int len = i2d_X509_CRL(crl, NULL);
if (len < 0 ||
!CBB_add_space(&crl_data, &buf, len) ||
i2d_X509_CRL(crl, &buf) < 0) {
return 0;
}
}
return CBB_flush(out);
}
int PKCS7_bundle_CRLs(CBB *out, const STACK_OF(X509_CRL) *crls) {
return pkcs7_bundle(out, pkcs7_bundle_crls_cb, crls);
}