/* 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;
}
EVP_PKEY *EVP_parse_public_key(CBS *cbs) {
/* Parse the SubjectPublicKeyInfo. */
CBS spki, algorithm, oid, key;
uint8_t padding;
if (!CBS_get_asn1(cbs, &spki, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
!CBS_get_asn1(&spki, &key, CBS_ASN1_BITSTRING) ||
CBS_len(&spki) != 0 ||
/* Every key type defined encodes the key as a byte string with the same
* conversion to BIT STRING. */
!CBS_get_u8(&key, &padding) ||
padding != 0) {
OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
return NULL;
}
/* Set up an |EVP_PKEY| of the appropriate type. */
EVP_PKEY *ret = EVP_PKEY_new();
if (ret == NULL ||
!EVP_PKEY_set_type(ret, OBJ_cbs2nid(&oid))) {
goto err;
}
/* Call into the type-specific SPKI decoding function. */
if (ret->ameth->pub_decode == NULL) {
OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
goto err;
}
if (!ret->ameth->pub_decode(ret, &algorithm, &key)) {
goto err;
}
return ret;
err:
EVP_PKEY_free(ret);
return NULL;
}
EVP_PKEY *EVP_parse_private_key(CBS *cbs) {
/* Parse the PrivateKeyInfo. */
CBS pkcs8, algorithm, oid, key;
uint64_t version;
if (!CBS_get_asn1(cbs, &pkcs8, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1_uint64(&pkcs8, &version) ||
version != 0 ||
!CBS_get_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
!CBS_get_asn1(&pkcs8, &key, CBS_ASN1_OCTETSTRING)) {
OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
return NULL;
}
/* A PrivateKeyInfo ends with a SET of Attributes which we ignore. */
/* Set up an |EVP_PKEY| of the appropriate type. */
EVP_PKEY *ret = EVP_PKEY_new();
if (ret == NULL ||
!EVP_PKEY_set_type(ret, OBJ_cbs2nid(&oid))) {
goto err;
}
/* Call into the type-specific PrivateKeyInfo decoding function. */
if (ret->ameth->priv_decode == NULL) {
OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
goto err;
}
if (!ret->ameth->priv_decode(ret, &algorithm, &key)) {
goto err;
}
return ret;
err:
EVP_PKEY_free(ret);
return NULL;
}
/* PKCS12_handle_content_info parses a single PKCS#7 ContentInfo element in a
* PKCS#12 structure. */
static int PKCS12_handle_content_info(CBS *content_info, unsigned depth,
struct pkcs12_context *ctx) {
CBS content_type, wrapped_contents, contents, content_infos;
int nid, ret = 0;
if (!CBS_get_asn1(content_info, &content_type, CBS_ASN1_OBJECT) ||
!CBS_get_asn1(content_info, &wrapped_contents,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0)) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_parse, PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
nid = OBJ_cbs2nid(&content_type);
if (nid == NID_pkcs7_encrypted) {
/* See https://tools.ietf.org/html/rfc2315#section-13.
*
* PKCS#7 encrypted data inside a PKCS#12 structure is generally an
* encrypted certificate bag and it's generally encrypted with 40-bit
* RC2-CBC. */
CBS version_bytes, eci, contents_type, ai, encrypted_contents;
X509_ALGOR *algor = NULL;
const uint8_t *inp;
uint8_t *out;
size_t out_len;
if (!CBS_get_asn1(&wrapped_contents, &contents, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&contents, &version_bytes, CBS_ASN1_INTEGER) ||
/* EncryptedContentInfo, see
* https://tools.ietf.org/html/rfc2315#section-10.1 */
!CBS_get_asn1(&contents, &eci, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&eci, &contents_type, CBS_ASN1_OBJECT) ||
/* AlgorithmIdentifier, see
* https://tools.ietf.org/html/rfc5280#section-4.1.1.2 */
!CBS_get_asn1_element(&eci, &ai, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&eci, &encrypted_contents,
CBS_ASN1_CONTEXT_SPECIFIC | 0)) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
if (OBJ_cbs2nid(&contents_type) != NID_pkcs7_data) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
inp = CBS_data(&ai);
algor = d2i_X509_ALGOR(NULL, &inp, CBS_len(&ai));
if (algor == NULL) {
goto err;
}
if (inp != CBS_data(&ai) + CBS_len(&ai)) {
X509_ALGOR_free(algor);
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
if (!pbe_crypt(algor, ctx->password, ctx->password_len,
CBS_data(&encrypted_contents), CBS_len(&encrypted_contents),
&out, &out_len, 0 /* decrypt */)) {
X509_ALGOR_free(algor);
goto err;
}
X509_ALGOR_free(algor);
CBS_init(&content_infos, out, out_len);
ret = PKCS12_handle_content_infos(&content_infos, depth + 1, ctx);
OPENSSL_free(out);
} else if (nid == NID_pkcs7_data) {
CBS octet_string_contents;
if (!CBS_get_asn1(&wrapped_contents, &octet_string_contents,
CBS_ASN1_OCTETSTRING)) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
ret = PKCS12_handle_content_infos(&octet_string_contents, depth + 1, ctx);
} else if (nid == NID_pkcs8ShroudedKeyBag) {
/* See ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1.pdf, section
* 4.2.2. */
const uint8_t *inp = CBS_data(&wrapped_contents);
PKCS8_PRIV_KEY_INFO *pki = NULL;
X509_SIG *encrypted = NULL;
if (*ctx->out_key) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_MULTIPLE_PRIVATE_KEYS_IN_PKCS12);
goto err;
}
/* encrypted isn't actually an X.509 signature, but it has the same
* structure as one and so |X509_SIG| is reused to store it. */
encrypted = d2i_X509_SIG(NULL, &inp, CBS_len(&wrapped_contents));
if (encrypted == NULL) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
if (inp != CBS_data(&wrapped_contents) + CBS_len(&wrapped_contents)) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
X509_SIG_free(encrypted);
goto err;
}
pki = PKCS8_decrypt_pbe(encrypted, ctx->password, ctx->password_len);
X509_SIG_free(encrypted);
if (pki == NULL) {
goto err;
}
*ctx->out_key = EVP_PKCS82PKEY(pki);
PKCS8_PRIV_KEY_INFO_free(pki);
if (ctx->out_key == NULL) {
goto err;
}
ret = 1;
} else if (nid == NID_certBag) {
CBS cert_bag, cert_type, wrapped_cert, cert;
if (!CBS_get_asn1(&wrapped_contents, &cert_bag, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1(&cert_bag, &cert_type, CBS_ASN1_OBJECT) ||
!CBS_get_asn1(&cert_bag, &wrapped_cert,
CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
!CBS_get_asn1(&wrapped_cert, &cert, CBS_ASN1_OCTETSTRING)) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
if (OBJ_cbs2nid(&cert_type) == NID_x509Certificate) {
const uint8_t *inp = CBS_data(&cert);
X509 *x509 = d2i_X509(NULL, &inp, CBS_len(&cert));
if (!x509) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
goto err;
}
if (inp != CBS_data(&cert) + CBS_len(&cert)) {
OPENSSL_PUT_ERROR(PKCS8, PKCS12_handle_content_info,
PKCS8_R_BAD_PKCS12_DATA);
X509_free(x509);
goto err;
}
if (0 == sk_X509_push(ctx->out_certs, x509)) {
X509_free(x509);
goto err;
}
}
ret = 1;
} else {
/* Unknown element type - ignore it. */
ret = 1;
}
err:
return ret;
}
