ref: 2bbc75bddc6f2a07056ff017108e35f14061041b
dir: /third_party/boringssl/src/crypto/pkcs7/pkcs7_x509.c/
/* Copyright (c) 2017, 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/pkcs7.h>
#include <assert.h>
#include <limits.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/pem.h>
#include <openssl/pool.h>
#include <openssl/stack.h>
#include <openssl/x509.h>
#include "internal.h"
#include "../internal.h"
int PKCS7_get_certificates(STACK_OF(X509) *out_certs, CBS *cbs) {
int ret = 0;
const size_t initial_certs_len = sk_X509_num(out_certs);
STACK_OF(CRYPTO_BUFFER) *raw = sk_CRYPTO_BUFFER_new_null();
if (raw == NULL ||
!PKCS7_get_raw_certificates(raw, cbs, NULL)) {
goto err;
}
for (size_t i = 0; i < sk_CRYPTO_BUFFER_num(raw); i++) {
CRYPTO_BUFFER *buf = sk_CRYPTO_BUFFER_value(raw, i);
X509 *x509 = X509_parse_from_buffer(buf);
if (x509 == NULL ||
!sk_X509_push(out_certs, x509)) {
X509_free(x509);
goto err;
}
}
ret = 1;
err:
sk_CRYPTO_BUFFER_pop_free(raw, CRYPTO_BUFFER_free);
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, has_crls;
const size_t initial_crls_len = sk_X509_CRL_num(out_crls);
// See https://tools.ietf.org/html/rfc2315#section-9.1
if (!pkcs7_parse_header(&der_bytes, &signed_data, cbs) ||
// Even if only CRLs are included, there may be an empty certificates
// block. OpenSSL does this, for example.
!CBS_get_optional_asn1(
&signed_data, NULL, NULL,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
!CBS_get_optional_asn1(
&signed_data, &crls, &has_crls,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 1)) {
goto err;
}
if (!has_crls) {
CBS_init(&crls, NULL, 0);
}
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;
}
if (CBS_len(&crl_data) > LONG_MAX) {
goto err;
}
inp = CBS_data(&crl_data);
crl = d2i_X509_CRL(NULL, &inp, (long)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:
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;
}
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;
}
}
// |certificates| is a implicitly-tagged SET OF.
return CBB_flush_asn1_set_of(&certificates) && CBB_flush(out);
}
int PKCS7_bundle_certificates(CBB *out, const STACK_OF(X509) *certs) {
return pkcs7_add_signed_data(out, /*digest_algos_cb=*/NULL,
pkcs7_bundle_certificates_cb,
/*signer_infos_cb=*/NULL, 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;
}
}
// |crl_data| is a implicitly-tagged SET OF.
return CBB_flush_asn1_set_of(&crl_data) && CBB_flush(out);
}
int PKCS7_bundle_CRLs(CBB *out, const STACK_OF(X509_CRL) *crls) {
return pkcs7_add_signed_data(out, /*digest_algos_cb=*/NULL,
pkcs7_bundle_crls_cb,
/*signer_infos_cb=*/NULL, crls);
}
static PKCS7 *pkcs7_new(CBS *cbs) {
PKCS7 *ret = OPENSSL_malloc(sizeof(PKCS7));
if (ret == NULL) {
return NULL;
}
OPENSSL_memset(ret, 0, sizeof(PKCS7));
ret->type = OBJ_nid2obj(NID_pkcs7_signed);
ret->d.sign = OPENSSL_malloc(sizeof(PKCS7_SIGNED));
if (ret->d.sign == NULL) {
goto err;
}
ret->d.sign->cert = sk_X509_new_null();
ret->d.sign->crl = sk_X509_CRL_new_null();
CBS copy = *cbs, copy2 = *cbs;
if (ret->d.sign->cert == NULL || ret->d.sign->crl == NULL ||
!PKCS7_get_certificates(ret->d.sign->cert, ©) ||
!PKCS7_get_CRLs(ret->d.sign->crl, cbs)) {
goto err;
}
if (sk_X509_num(ret->d.sign->cert) == 0) {
sk_X509_free(ret->d.sign->cert);
ret->d.sign->cert = NULL;
}
if (sk_X509_CRL_num(ret->d.sign->crl) == 0) {
sk_X509_CRL_free(ret->d.sign->crl);
ret->d.sign->crl = NULL;
}
ret->ber_len = CBS_len(©2) - CBS_len(cbs);
ret->ber_bytes = OPENSSL_memdup(CBS_data(©2), ret->ber_len);
if (ret->ber_bytes == NULL) {
goto err;
}
return ret;
err:
PKCS7_free(ret);
return NULL;
}
PKCS7 *d2i_PKCS7(PKCS7 **out, const uint8_t **inp,
size_t len) {
CBS cbs;
CBS_init(&cbs, *inp, len);
PKCS7 *ret = pkcs7_new(&cbs);
if (ret == NULL) {
return NULL;
}
*inp = CBS_data(&cbs);
if (out != NULL) {
PKCS7_free(*out);
*out = ret;
}
return ret;
}
PKCS7 *d2i_PKCS7_bio(BIO *bio, PKCS7 **out) {
// Use a generous bound, to allow for PKCS#7 files containing large root sets.
static const size_t kMaxSize = 4 * 1024 * 1024;
uint8_t *data;
size_t len;
if (!BIO_read_asn1(bio, &data, &len, kMaxSize)) {
return NULL;
}
CBS cbs;
CBS_init(&cbs, data, len);
PKCS7 *ret = pkcs7_new(&cbs);
OPENSSL_free(data);
if (out != NULL && ret != NULL) {
PKCS7_free(*out);
*out = ret;
}
return ret;
}
int i2d_PKCS7(const PKCS7 *p7, uint8_t **out) {
if (p7->ber_len > INT_MAX) {
OPENSSL_PUT_ERROR(PKCS8, ERR_R_OVERFLOW);
return -1;
}
if (out == NULL) {
return (int)p7->ber_len;
}
if (*out == NULL) {
*out = OPENSSL_malloc(p7->ber_len);
if (*out == NULL) {
OPENSSL_PUT_ERROR(PKCS8, ERR_R_MALLOC_FAILURE);
return -1;
}
OPENSSL_memcpy(*out, p7->ber_bytes, p7->ber_len);
} else {
OPENSSL_memcpy(*out, p7->ber_bytes, p7->ber_len);
*out += p7->ber_len;
}
return (int)p7->ber_len;
}
int i2d_PKCS7_bio(BIO *bio, const PKCS7 *p7) {
return BIO_write_all(bio, p7->ber_bytes, p7->ber_len);
}
void PKCS7_free(PKCS7 *p7) {
if (p7 == NULL) {
return;
}
OPENSSL_free(p7->ber_bytes);
ASN1_OBJECT_free(p7->type);
// We only supported signed data.
if (p7->d.sign != NULL) {
sk_X509_pop_free(p7->d.sign->cert, X509_free);
sk_X509_CRL_pop_free(p7->d.sign->crl, X509_CRL_free);
OPENSSL_free(p7->d.sign);
}
OPENSSL_free(p7);
}
// We only support signed data, so these getters are no-ops.
int PKCS7_type_is_data(const PKCS7 *p7) { return 0; }
int PKCS7_type_is_digest(const PKCS7 *p7) { return 0; }
int PKCS7_type_is_encrypted(const PKCS7 *p7) { return 0; }
int PKCS7_type_is_enveloped(const PKCS7 *p7) { return 0; }
int PKCS7_type_is_signed(const PKCS7 *p7) { return 1; }
int PKCS7_type_is_signedAndEnveloped(const PKCS7 *p7) { return 0; }
// write_sha256_ai writes an AlgorithmIdentifier for SHA-256 to
// |digest_algos_set|.
static int write_sha256_ai(CBB *digest_algos_set, const void *arg) {
CBB seq;
return CBB_add_asn1(digest_algos_set, &seq, CBS_ASN1_SEQUENCE) &&
OBJ_nid2cbb(&seq, NID_sha256) && //
// https://datatracker.ietf.org/doc/html/rfc5754#section-2
// "Implementations MUST generate SHA2 AlgorithmIdentifiers with absent
// parameters."
CBB_flush(digest_algos_set);
}
// sign_sha256 writes at most |max_out_sig| bytes of the signature of |data| by
// |pkey| to |out_sig| and sets |*out_sig_len| to the number of bytes written.
// It returns one on success or zero on error.
static int sign_sha256(uint8_t *out_sig, size_t *out_sig_len,
size_t max_out_sig, EVP_PKEY *pkey, BIO *data) {
static const size_t kBufSize = 4096;
uint8_t *buffer = OPENSSL_malloc(kBufSize);
if (!buffer) {
return 0;
}
EVP_MD_CTX ctx;
EVP_MD_CTX_init(&ctx);
int ret = 0;
if (!EVP_DigestSignInit(&ctx, NULL, EVP_sha256(), NULL, pkey)) {
goto out;
}
for (;;) {
const int n = BIO_read(data, buffer, kBufSize);
if (n == 0) {
break;
} else if (n < 0 || !EVP_DigestSignUpdate(&ctx, buffer, n)) {
goto out;
}
}
*out_sig_len = max_out_sig;
if (!EVP_DigestSignFinal(&ctx, out_sig, out_sig_len)) {
goto out;
}
ret = 1;
out:
EVP_MD_CTX_cleanup(&ctx);
OPENSSL_free(buffer);
return ret;
}
struct signer_info_data {
const X509 *sign_cert;
uint8_t *signature;
size_t signature_len;
};
// write_signer_info writes the SignerInfo structure from
// https://datatracker.ietf.org/doc/html/rfc2315#section-9.2 to |out|. It
// returns one on success or zero on error.
static int write_signer_info(CBB *out, const void *arg) {
const struct signer_info_data *const si_data = arg;
int ret = 0;
uint8_t *subject_bytes = NULL;
uint8_t *serial_bytes = NULL;
const int subject_len =
i2d_X509_NAME(X509_get_subject_name(si_data->sign_cert), &subject_bytes);
const int serial_len = i2d_ASN1_INTEGER(
(ASN1_INTEGER *)X509_get0_serialNumber(si_data->sign_cert),
&serial_bytes);
CBB seq, issuer_and_serial, signing_algo, null, signature;
if (subject_len < 0 ||
serial_len < 0 ||
!CBB_add_asn1(out, &seq, CBS_ASN1_SEQUENCE) ||
// version
!CBB_add_asn1_uint64(&seq, 1) ||
!CBB_add_asn1(&seq, &issuer_and_serial, CBS_ASN1_SEQUENCE) ||
!CBB_add_bytes(&issuer_and_serial, subject_bytes, subject_len) ||
!CBB_add_bytes(&issuer_and_serial, serial_bytes, serial_len) ||
!write_sha256_ai(&seq, NULL) ||
!CBB_add_asn1(&seq, &signing_algo, CBS_ASN1_SEQUENCE) ||
!OBJ_nid2cbb(&signing_algo, NID_rsaEncryption) ||
!CBB_add_asn1(&signing_algo, &null, CBS_ASN1_NULL) ||
!CBB_add_asn1(&seq, &signature, CBS_ASN1_OCTETSTRING) ||
!CBB_add_bytes(&signature, si_data->signature, si_data->signature_len) ||
!CBB_flush(out)) {
goto out;
}
ret = 1;
out:
OPENSSL_free(subject_bytes);
OPENSSL_free(serial_bytes);
return ret;
}
PKCS7 *PKCS7_sign(X509 *sign_cert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
BIO *data, int flags) {
CBB cbb;
if (!CBB_init(&cbb, 2048)) {
return NULL;
}
uint8_t *der = NULL;
size_t len;
PKCS7 *ret = NULL;
if (sign_cert == NULL && pkey == NULL && flags == PKCS7_DETACHED) {
// Caller just wants to bundle certificates.
if (!PKCS7_bundle_certificates(&cbb, certs)) {
goto out;
}
} else if (sign_cert != NULL && pkey != NULL && certs == NULL &&
data != NULL &&
flags == (PKCS7_NOATTR | PKCS7_BINARY | PKCS7_NOCERTS |
PKCS7_DETACHED) &&
EVP_PKEY_id(pkey) == NID_rsaEncryption) {
// sign-file.c from the Linux kernel.
const size_t signature_max_len = EVP_PKEY_size(pkey);
struct signer_info_data si_data = {
.sign_cert = sign_cert,
.signature = OPENSSL_malloc(signature_max_len),
};
if (!si_data.signature ||
!sign_sha256(si_data.signature, &si_data.signature_len,
signature_max_len, pkey, data) ||
!pkcs7_add_signed_data(&cbb, write_sha256_ai, /*cert_crl_cb=*/NULL,
write_signer_info, &si_data)) {
OPENSSL_free(si_data.signature);
goto out;
}
OPENSSL_free(si_data.signature);
} else {
OPENSSL_PUT_ERROR(PKCS7, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
goto out;
}
if (!CBB_finish(&cbb, &der, &len)) {
goto out;
}
CBS cbs;
CBS_init(&cbs, der, len);
ret = pkcs7_new(&cbs);
out:
CBB_cleanup(&cbb);
OPENSSL_free(der);
return ret;
}