/*
* Unwrap PKCS#7 data and decrypt if necessary
*/
int pkcs7_unwrap(struct scep *s, struct sscep_ctx *ctx, struct sscep_operation_info *op_info, char* data, int datalen)
{
BIO *memorybio = NULL;
BIO *outbio = NULL;
BIO *pkcs7bio = NULL;
int i, bytes, used;
STACK_OF(PKCS7_SIGNER_INFO) *sk;
PKCS7 *p7enc = NULL;
PKCS7_SIGNER_INFO *si;
STACK_OF(X509_ATTRIBUTE) *attribs;
char *p = NULL;
unsigned char buffer[1024];
X509 *recipientcert;
EVP_PKEY *recipientkey;
int ret = SCEP_PKISTATUS_P7;
/* Create new memory BIO for outer PKCS#7 */
memorybio = BIO_new(BIO_s_mem());
/* Read in data */
if (ctx->verbose){
qeo_log_i("reading outer PKCS#7");
}
if (BIO_write(memorybio, data, datalen) <= 0) {
qeo_log_e("error reading PKCS#7 data");
goto error;
}
if (ctx->verbose){
qeo_log_i("PKCS#7 payload size: %d bytes", datalen);
}
s->reply_p7 = d2i_PKCS7_bio(memorybio, NULL );
if (s->reply_p7 == NULL ) {
qeo_log_e("error retrieving PKCS#7 data");
goto error;
}
if (ctx->debug) {
qeo_log_i("printing PEM fomatted PKCS#7");
PEM_write_PKCS7(stdout, s->reply_p7);
}
/* Make sure this is a signed PKCS#7 */
if (!PKCS7_type_is_signed(s->reply_p7)) {
qeo_log_e("PKCS#7 is not signed!");
goto error;
}
/* Create BIO for content data */
pkcs7bio = PKCS7_dataInit(s->reply_p7, NULL );
if (pkcs7bio == NULL ) {
qeo_log_e("cannot get PKCS#7 data");
goto error;
}
/* Copy enveloped data from PKCS#7 */
outbio = BIO_new(BIO_s_mem());
used = 0;
for (;;) {
bytes = BIO_read(pkcs7bio, buffer, sizeof(buffer));
used += bytes;
if (bytes <= 0)
break;
BIO_write(outbio, buffer, bytes);
}
(void)BIO_flush(outbio);
if (ctx->verbose){
qeo_log_i("PKCS#7 contains %d bytes of enveloped data", used);
}
/* Get signer */
sk = PKCS7_get_signer_info(s->reply_p7);
if (sk == NULL ) {
qeo_log_e("cannot get signer info!");
goto error;
}
/* Verify signature */
if (ctx->verbose){
qeo_log_i("verifying signature");
}
si = sk_PKCS7_SIGNER_INFO_value(sk, 0);
if (PKCS7_signatureVerify(pkcs7bio, s->reply_p7, si, op_info->racert) <= 0) {
qeo_log_e("error verifying signature");
goto error;
}
if (ctx->verbose){
qeo_log_i("signature ok");
}
/* Get signed attributes */
if (ctx->verbose){
qeo_log_i("finding signed attributes");
}
attribs = PKCS7_get_signed_attributes(si);
if (attribs == NULL ) {
qeo_log_e("no attributes found");
goto error;
}
/* Transaction id */
if ((get_signed_attribute(attribs, ctx->nid_transId, V_ASN1_PRINTABLESTRING, &p, ctx)) == 1) {
qeo_log_e("cannot find transId");
goto error;
}
if (ctx->verbose){
qeo_log_i("reply transaction id: %s", p);
}
if (strncmp(s->transaction_id, p, strlen(p))) {
qeo_log_e("transaction id mismatch");
goto error;
}
free(p);
p=NULL;
/* Message type, should be of type CertRep */
if (get_signed_attribute(attribs, ctx->nid_messageType, V_ASN1_PRINTABLESTRING, &p, ctx) == 1) {
qeo_log_e("cannot find messageType");
goto error;
}
if (atoi(p) != 3) {
qeo_log_e("wrong message type in reply");
goto error;
}
if (ctx->verbose){
qeo_log_i("reply message type is good");
}
free(p);
p=NULL;
/* Recipient nonces: */
if (get_signed_attribute(attribs, ctx->nid_recipientNonce, V_ASN1_OCTET_STRING, &p, ctx) == 1) {
qeo_log_e("cannot find recipientNonce");
goto error;
}
s->reply_recipient_nonce = p;
p = NULL;
if (ctx->verbose) {
qeo_log_i("recipientNonce in reply");
}
/*
* Compare recipient nonce to original sender nonce
* The draft says nothing about this, but it makes sense to me..
* XXXXXXXXXXXXXX check
*/
for (i = 0; i < 16; i++) {
if (s->sender_nonce[i] != s->reply_recipient_nonce[i]) {
if (ctx->verbose)
qeo_log_e("corrupted nonce received");
/* Instead of exit, break out */
break;
}
}
/* Get pkiStatus */
if (get_signed_attribute(attribs, ctx->nid_pkiStatus, V_ASN1_PRINTABLESTRING, &p, ctx) == 1) {
qeo_log_e("cannot find pkiStatus");
/* This is a mandatory attribute.. */
goto error;
}
switch (atoi(p)) {
case SCEP_PKISTATUS_SUCCESS:
qeo_log_i("pkistatus: SUCCESS");
s->pki_status = SCEP_PKISTATUS_SUCCESS;
break;
case SCEP_PKISTATUS_FAILURE:
qeo_log_i("pkistatus: FAILURE");
s->pki_status = SCEP_PKISTATUS_FAILURE;
break;
case SCEP_PKISTATUS_PENDING:
qeo_log_i("pkistatus: PENDING");
s->pki_status = SCEP_PKISTATUS_PENDING;
break;
default:
qeo_log_e("wrong pkistatus in reply");
goto error;
}
free(p);
p=NULL;
/* Get failInfo */
if (s->pki_status == SCEP_PKISTATUS_FAILURE) {
if (get_signed_attribute(attribs, ctx->nid_failInfo, V_ASN1_PRINTABLESTRING, &p, ctx) == 1) {
qeo_log_e("cannot find failInfo");
goto error;
}
switch (atoi(p)) {
case SCEP_FAILINFO_BADALG:
s->fail_info = SCEP_FAILINFO_BADALG;
qeo_log_i("reason: %s", SCEP_FAILINFO_BADALG_STR);
break;
case SCEP_FAILINFO_BADMSGCHK:
s->fail_info = SCEP_FAILINFO_BADMSGCHK;
qeo_log_i("reason: %s", SCEP_FAILINFO_BADMSGCHK_STR);
break;
case SCEP_FAILINFO_BADREQ:
s->fail_info = SCEP_FAILINFO_BADREQ;
qeo_log_i("reason: %s", SCEP_FAILINFO_BADREQ_STR);
break;
case SCEP_FAILINFO_BADTIME:
s->fail_info = SCEP_FAILINFO_BADTIME;
qeo_log_i("reason: %s", SCEP_FAILINFO_BADTIME_STR);
break;
case SCEP_FAILINFO_BADCERTID:
s->fail_info = SCEP_FAILINFO_BADCERTID;
qeo_log_i("reason: %s", SCEP_FAILINFO_BADCERTID_STR);
break;
default:
qeo_log_e("wrong failInfo in " "reply");
goto error;
}
free(p);
p=NULL;
}
/* If FAILURE or PENDING, we can return */
if (s->pki_status != SCEP_PKISTATUS_SUCCESS) {
/* There shouldn't be any more data... */
if (ctx->verbose && (used != 0)) {
qeo_log_e("illegal size of payload");
}
return (0);
}
/* We got success and expect data */
if (used == 0) {
qeo_log_e("illegal size of payload");
goto error;
}
/* Decrypt the inner PKCS#7 */
recipientcert = s->signercert;
recipientkey = s->signerkey;
if (ctx->verbose){
qeo_log_i("reading inner PKCS#7");
}
p7enc = d2i_PKCS7_bio(outbio, NULL );
if (p7enc == NULL ) {
qeo_log_e("cannot read inner PKCS#7");
goto error;
}
BIO_free(outbio);/* No longer need it */
outbio = NULL;
if (ctx->debug) {
qeo_log_i("printing PEM fomatted PKCS#7");
PEM_write_PKCS7(stdout, p7enc);
}
/* Decrypt the data */
outbio = BIO_new(BIO_s_mem());
if (ctx->verbose){
qeo_log_i("decrypting inner PKCS#7");
}
if (PKCS7_decrypt(p7enc, recipientkey, recipientcert, outbio, 0) == 0) {
qeo_log_e("error decrypting inner PKCS#7");
goto error;
}
(void)BIO_flush(outbio);
/* Write decrypted data */
PKCS7_free(s->reply_p7);
s->reply_p7 = d2i_PKCS7_bio(outbio, NULL );
ret = 0;
error:
free(p);
BIO_free(outbio);
BIO_free_all(pkcs7bio);
BIO_free(memorybio);
PKCS7_free(p7enc);
return ret;
}
/*
* Unwrap PKCS#7 data and decrypt if necessary
*/
int pkcs7_unwrap(struct scep *s) {
BIO *memorybio;
BIO *outbio;
BIO *pkcs7bio;
int i, len, bytes, used;
STACK_OF(PKCS7_SIGNER_INFO) *sk;
PKCS7 *p7enc;
PKCS7_SIGNER_INFO *si;
STACK_OF(X509_ATTRIBUTE) *attribs;
char *p;
unsigned char buffer[1024];
X509 *recipientcert;
EVP_PKEY *recipientkey;
/* Create new memory BIO for outer PKCS#7 */
memorybio = BIO_new(BIO_s_mem());
/* Read in data */
if (v_flag)
printf("%s: reading outer PKCS#7\n",pname);
if ((len = BIO_write(memorybio, s->reply_payload, s->reply_len)) <= 0) {
fprintf(stderr, "%s: error reading PKCS#7 data\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
if (v_flag)
printf("%s: PKCS#7 payload size: %d bytes\n", pname, len);
BIO_set_flags(memorybio, BIO_FLAGS_MEM_RDONLY);
s->reply_p7 = d2i_PKCS7_bio(memorybio, NULL);
if (d_flag) {
printf("%s: printing PEM fomatted PKCS#7\n", pname);
PEM_write_PKCS7(stdout, s->reply_p7);
}
/* Make sure this is a signed PKCS#7 */
if (!PKCS7_type_is_signed(s->reply_p7)) {
fprintf(stderr, "%s: PKCS#7 is not signed!\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
/* Create BIO for content data */
pkcs7bio = PKCS7_dataInit(s->reply_p7, NULL);
if (pkcs7bio == NULL) {
fprintf(stderr, "%s: cannot get PKCS#7 data\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
/* Copy enveloped data from PKCS#7 */
outbio = BIO_new(BIO_s_mem());
used = 0;
for (;;) {
bytes = BIO_read(pkcs7bio, buffer, sizeof(buffer));
used += bytes;
if (bytes <= 0) break;
BIO_write(outbio, buffer, bytes);
}
BIO_flush(outbio);
if (v_flag)
printf("%s: PKCS#7 contains %d bytes of enveloped data\n",
pname, used);
/* Get signer */
sk = PKCS7_get_signer_info(s->reply_p7);
if (sk == NULL) {
fprintf(stderr, "%s: cannot get signer info!\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
/* Verify signature */
if (v_flag)
printf("%s: verifying signature\n", pname);
si = sk_PKCS7_SIGNER_INFO_value(sk, 0);
if (PKCS7_signatureVerify(pkcs7bio, s->reply_p7, si, cacert) <= 0) {
fprintf(stderr, "%s: error verifying signature\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
if (v_flag)
printf("%s: signature ok\n", pname);
/* Get signed attributes */
if (v_flag)
printf("%s: finding signed attributes\n", pname);
attribs = PKCS7_get_signed_attributes(si);
if (attribs == NULL) {
fprintf(stderr, "%s: no attributes found\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
/* Transaction id */
if ((get_signed_attribute(attribs, nid_transId,
V_ASN1_PRINTABLESTRING, &p)) == 1) {
fprintf(stderr, "%s: cannot find transId\n", pname);
exit (SCEP_PKISTATUS_P7);
}
if (v_flag)
printf("%s: reply transaction id: %s\n", pname, p);
if (strncmp(s->transaction_id, p, strlen(p))) {
fprintf(stderr, "%s: transaction id mismatch\n", pname);
exit (SCEP_PKISTATUS_P7);
}
/* Message type, should be of type CertRep */
if ((i = get_signed_attribute(attribs, nid_messageType,
V_ASN1_PRINTABLESTRING, &p)) == 1) {
fprintf(stderr, "%s: cannot find messageType\n", pname);
exit (SCEP_PKISTATUS_P7);
}
if (atoi(p) != 3) {
fprintf(stderr, "%s: wrong message type in reply\n", pname);
exit (SCEP_PKISTATUS_P7);
}
if (v_flag)
printf("%s: reply message type is good\n", pname);
/* Sender and recipient nonces: */
if ((i = get_signed_attribute(attribs, nid_senderNonce,
V_ASN1_OCTET_STRING, &p)) == 1) {
if (v_flag)
fprintf(stderr, "%s: cannot find senderNonce\n", pname);
/* Some implementations don't put in on reply */
/* XXXXXXXXXXXXXXXXXXXXXXXXXXXXX
exit (SCEP_PKISTATUS_P7); */
}
s->reply_sender_nonce = p;
if (v_flag) {
printf("%s: senderNonce in reply: ", pname);
for (i = 0; i < 16; i++) {
printf("%02X", s->reply_sender_nonce[i]);
}
printf("\n");
}
if (( i = get_signed_attribute(attribs, nid_recipientNonce,
V_ASN1_OCTET_STRING, &p)) == 1) {
fprintf(stderr, "%s: cannot find recipientNonce\n", pname);
exit (SCEP_PKISTATUS_P7);
}
s->reply_recipient_nonce = p;
if (v_flag) {
printf("%s: recipientNonce in reply: ", pname);
for (i = 0; i < 16; i++) {
printf("%02X", s->reply_recipient_nonce[i]);
}
printf("\n");
}
/*
* Compare recipient nonce to original sender nonce
* The draft says nothing about this, but it makes sense to me..
* XXXXXXXXXXXXXX check
*/
for (i = 0; i < 16; i++) {
if (s->sender_nonce[i] != s->reply_recipient_nonce[i]) {
if (v_flag)
fprintf(stderr, "%s: corrupted nonce "
"received\n", pname);
/* Instead of exit, break out */
break;
}
}
/* Get pkiStatus */
if ((i = get_signed_attribute(attribs, nid_pkiStatus,
V_ASN1_PRINTABLESTRING, &p)) == 1) {
fprintf(stderr, "%s: cannot find pkiStatus\n", pname);
/* This is a mandatory attribute.. */
exit (SCEP_PKISTATUS_P7);
}
switch (atoi(p)) {
case SCEP_PKISTATUS_SUCCESS:
printf("%s: pkistatus: SUCCESS\n",pname);
s->pki_status = SCEP_PKISTATUS_SUCCESS;
break;
case SCEP_PKISTATUS_FAILURE:
printf("%s: pkistatus: FAILURE\n",pname);
s->pki_status = SCEP_PKISTATUS_FAILURE;
break;
case SCEP_PKISTATUS_PENDING:
printf("%s: pkistatus: PENDING\n",pname);
s->pki_status = SCEP_PKISTATUS_PENDING;
break;
default:
fprintf(stderr, "%s: wrong pkistatus in reply\n",pname);
exit (SCEP_PKISTATUS_P7);
}
/* Get failInfo */
if (s->pki_status == SCEP_PKISTATUS_FAILURE) {
if ((i = get_signed_attribute(attribs, nid_failInfo,
V_ASN1_PRINTABLESTRING, &p)) == 1) {
fprintf(stderr, "%s: cannot find failInfo\n",
pname);
exit (SCEP_PKISTATUS_P7);
}
switch (atoi(p)) {
case SCEP_FAILINFO_BADALG:
s->fail_info = SCEP_FAILINFO_BADALG;
printf("%s: reason: %s\n", pname,
SCEP_FAILINFO_BADALG_STR);
break;
case SCEP_FAILINFO_BADMSGCHK:
s->fail_info = SCEP_FAILINFO_BADMSGCHK;
printf("%s: reason: %s\n", pname,
SCEP_FAILINFO_BADMSGCHK_STR);
break;
case SCEP_FAILINFO_BADREQ:
s->fail_info = SCEP_FAILINFO_BADREQ;
printf("%s: reason: %s\n", pname,
SCEP_FAILINFO_BADREQ_STR);
break;
case SCEP_FAILINFO_BADTIME:
s->fail_info = SCEP_FAILINFO_BADTIME;
printf("%s: reason: %s\n", pname,
SCEP_FAILINFO_BADTIME_STR);
break;
case SCEP_FAILINFO_BADCERTID:
s->fail_info = SCEP_FAILINFO_BADCERTID;
printf("%s: reason: %s\n", pname,
SCEP_FAILINFO_BADCERTID_STR);
break;
default:
fprintf(stderr, "%s: wrong failInfo in " "reply\n",pname);
exit (SCEP_PKISTATUS_P7);
}
}
/* If FAILURE or PENDING, we can return */
if (s->pki_status != SCEP_PKISTATUS_SUCCESS) {
/* There shouldn't be any more data... */
if (v_flag && (used != 0)) {
fprintf(stderr, "%s: illegal size of payload\n", pname);
}
return (0);
}
/* We got success and expect data */
if (used == 0) {
fprintf(stderr, "%s: illegal size of payload\n", pname);
exit (SCEP_PKISTATUS_P7);
}
/* Decrypt the inner PKCS#7 */
if ((s->request_type == SCEP_REQUEST_PKCSREQ) ||
(s->request_type == SCEP_REQUEST_GETCERTINIT)) {
recipientcert = s->signercert;
recipientkey = s->signerkey;
}
else {
recipientcert = localcert;
recipientkey = rsa;
}
if (v_flag)
printf("%s: reading inner PKCS#7\n",pname);
p7enc = d2i_PKCS7_bio(outbio, NULL);
if (p7enc == NULL) {
fprintf(stderr, "%s: cannot read inner PKCS#7\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
if (d_flag) {
printf("%s: printing PEM fomatted PKCS#7\n", pname);
PEM_write_PKCS7(stdout, p7enc);
}
/* Decrypt the data */
outbio = BIO_new(BIO_s_mem());
if (v_flag)
printf("%s: decrypting inner PKCS#7\n",pname);
if (PKCS7_decrypt(p7enc, recipientkey, recipientcert, outbio, 0) == 0) {
fprintf(stderr, "%s: error decrypting inner PKCS#7\n", pname);
ERR_print_errors_fp(stderr);
exit (SCEP_PKISTATUS_P7);
}
BIO_flush(outbio);
/* Write decrypted data */
s->reply_len = BIO_get_mem_data(outbio, &s->reply_payload);
if (v_flag)
printf("%s: PKCS#7 payload size: %d bytes\n", pname,
s->reply_len);
BIO_set_flags(outbio, BIO_FLAGS_MEM_RDONLY);
s->reply_p7 = d2i_PKCS7_bio(outbio, NULL);
return (0);
}
