lib: crypto: add pkcs7 message parser
Imported from linux kernel v5.3:
pkcs7.asn1 without changes
pkcs7.h with changes marked as __UBOOT__
pkcs7_parser.h without changes
pkcs7_parser.c with changes marked as __UBOOT__
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/lib/crypto/pkcs7_parser.c b/lib/crypto/pkcs7_parser.c
new file mode 100644
index 0000000..bf9e7e8
--- /dev/null
+++ b/lib/crypto/pkcs7_parser.c
@@ -0,0 +1,693 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* PKCS#7 parser
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) "PKCS7: "fmt
+#ifdef __UBOOT__
+#include <linux/bitops.h>
+#include <linux/compat.h>
+#endif
+#include <linux/kernel.h>
+#ifndef __UBOOT__
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#endif
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#include <crypto/public_key.h>
+#include "pkcs7_parser.h"
+#include "pkcs7.asn1.h"
+
+MODULE_DESCRIPTION("PKCS#7 parser");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+
+struct pkcs7_parse_context {
+ struct pkcs7_message *msg; /* Message being constructed */
+ struct pkcs7_signed_info *sinfo; /* SignedInfo being constructed */
+ struct pkcs7_signed_info **ppsinfo;
+ struct x509_certificate *certs; /* Certificate cache */
+ struct x509_certificate **ppcerts;
+ unsigned long data; /* Start of data */
+ enum OID last_oid; /* Last OID encountered */
+ unsigned x509_index;
+ unsigned sinfo_index;
+ const void *raw_serial;
+ unsigned raw_serial_size;
+ unsigned raw_issuer_size;
+ const void *raw_issuer;
+ const void *raw_skid;
+ unsigned raw_skid_size;
+ bool expect_skid;
+};
+
+/*
+ * Free a signed information block.
+ */
+static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
+{
+ if (sinfo) {
+ public_key_signature_free(sinfo->sig);
+ kfree(sinfo);
+ }
+}
+
+/**
+ * pkcs7_free_message - Free a PKCS#7 message
+ * @pkcs7: The PKCS#7 message to free
+ */
+void pkcs7_free_message(struct pkcs7_message *pkcs7)
+{
+ struct x509_certificate *cert;
+ struct pkcs7_signed_info *sinfo;
+
+ if (pkcs7) {
+ while (pkcs7->certs) {
+ cert = pkcs7->certs;
+ pkcs7->certs = cert->next;
+ x509_free_certificate(cert);
+ }
+ while (pkcs7->crl) {
+ cert = pkcs7->crl;
+ pkcs7->crl = cert->next;
+ x509_free_certificate(cert);
+ }
+ while (pkcs7->signed_infos) {
+ sinfo = pkcs7->signed_infos;
+ pkcs7->signed_infos = sinfo->next;
+ pkcs7_free_signed_info(sinfo);
+ }
+ kfree(pkcs7);
+ }
+}
+EXPORT_SYMBOL_GPL(pkcs7_free_message);
+
+/*
+ * Check authenticatedAttributes are provided or not provided consistently.
+ */
+static int pkcs7_check_authattrs(struct pkcs7_message *msg)
+{
+ struct pkcs7_signed_info *sinfo;
+ bool want = false;
+
+ sinfo = msg->signed_infos;
+ if (!sinfo)
+ goto inconsistent;
+
+ if (sinfo->authattrs) {
+ want = true;
+ msg->have_authattrs = true;
+ }
+
+ for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
+ if (!!sinfo->authattrs != want)
+ goto inconsistent;
+ return 0;
+
+inconsistent:
+ pr_warn("Inconsistently supplied authAttrs\n");
+ return -EINVAL;
+}
+
+/**
+ * pkcs7_parse_message - Parse a PKCS#7 message
+ * @data: The raw binary ASN.1 encoded message to be parsed
+ * @datalen: The size of the encoded message
+ */
+struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
+{
+ struct pkcs7_parse_context *ctx;
+ struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
+ int ret;
+
+ ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
+ if (!ctx)
+ goto out_no_ctx;
+ ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
+ if (!ctx->msg)
+ goto out_no_msg;
+ ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
+ if (!ctx->sinfo)
+ goto out_no_sinfo;
+ ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
+ GFP_KERNEL);
+ if (!ctx->sinfo->sig)
+ goto out_no_sig;
+
+ ctx->data = (unsigned long)data;
+ ctx->ppcerts = &ctx->certs;
+ ctx->ppsinfo = &ctx->msg->signed_infos;
+
+ /* Attempt to decode the signature */
+ ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
+ if (ret < 0) {
+ msg = ERR_PTR(ret);
+ goto out;
+ }
+
+ ret = pkcs7_check_authattrs(ctx->msg);
+ if (ret < 0) {
+ msg = ERR_PTR(ret);
+ goto out;
+ }
+
+ msg = ctx->msg;
+ ctx->msg = NULL;
+
+out:
+ while (ctx->certs) {
+ struct x509_certificate *cert = ctx->certs;
+ ctx->certs = cert->next;
+ x509_free_certificate(cert);
+ }
+out_no_sig:
+ pkcs7_free_signed_info(ctx->sinfo);
+out_no_sinfo:
+ pkcs7_free_message(ctx->msg);
+out_no_msg:
+ kfree(ctx);
+out_no_ctx:
+ return msg;
+}
+EXPORT_SYMBOL_GPL(pkcs7_parse_message);
+
+/**
+ * pkcs7_get_content_data - Get access to the PKCS#7 content
+ * @pkcs7: The preparsed PKCS#7 message to access
+ * @_data: Place to return a pointer to the data
+ * @_data_len: Place to return the data length
+ * @_headerlen: Size of ASN.1 header not included in _data
+ *
+ * Get access to the data content of the PKCS#7 message. The size of the
+ * header of the ASN.1 object that contains it is also provided and can be used
+ * to adjust *_data and *_data_len to get the entire object.
+ *
+ * Returns -ENODATA if the data object was missing from the message.
+ */
+int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
+ const void **_data, size_t *_data_len,
+ size_t *_headerlen)
+{
+ if (!pkcs7->data)
+ return -ENODATA;
+
+ *_data = pkcs7->data;
+ *_data_len = pkcs7->data_len;
+ if (_headerlen)
+ *_headerlen = pkcs7->data_hdrlen;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
+
+/*
+ * Note an OID when we find one for later processing when we know how
+ * to interpret it.
+ */
+int pkcs7_note_OID(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ ctx->last_oid = look_up_OID(value, vlen);
+ if (ctx->last_oid == OID__NR) {
+ char buffer[50];
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ printk("PKCS7: Unknown OID: [%lu] %s\n",
+ (unsigned long)value - ctx->data, buffer);
+ }
+ return 0;
+}
+
+/*
+ * Note the digest algorithm for the signature.
+ */
+int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ switch (ctx->last_oid) {
+ case OID_md4:
+ ctx->sinfo->sig->hash_algo = "md4";
+ break;
+ case OID_md5:
+ ctx->sinfo->sig->hash_algo = "md5";
+ break;
+ case OID_sha1:
+ ctx->sinfo->sig->hash_algo = "sha1";
+ break;
+ case OID_sha256:
+ ctx->sinfo->sig->hash_algo = "sha256";
+ break;
+ case OID_sha384:
+ ctx->sinfo->sig->hash_algo = "sha384";
+ break;
+ case OID_sha512:
+ ctx->sinfo->sig->hash_algo = "sha512";
+ break;
+ case OID_sha224:
+ ctx->sinfo->sig->hash_algo = "sha224";
+ break;
+ default:
+ printk("Unsupported digest algo: %u\n", ctx->last_oid);
+ return -ENOPKG;
+ }
+ return 0;
+}
+
+/*
+ * Note the public key algorithm for the signature.
+ */
+int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ switch (ctx->last_oid) {
+ case OID_rsaEncryption:
+ ctx->sinfo->sig->pkey_algo = "rsa";
+ ctx->sinfo->sig->encoding = "pkcs1";
+ break;
+ default:
+ printk("Unsupported pkey algo: %u\n", ctx->last_oid);
+ return -ENOPKG;
+ }
+ return 0;
+}
+
+/*
+ * We only support signed data [RFC2315 sec 9].
+ */
+int pkcs7_check_content_type(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ if (ctx->last_oid != OID_signed_data) {
+ pr_warn("Only support pkcs7_signedData type\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Note the SignedData version
+ */
+int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ unsigned version;
+
+ if (vlen != 1)
+ goto unsupported;
+
+ ctx->msg->version = version = *(const u8 *)value;
+ switch (version) {
+ case 1:
+ /* PKCS#7 SignedData [RFC2315 sec 9.1]
+ * CMS ver 1 SignedData [RFC5652 sec 5.1]
+ */
+ break;
+ case 3:
+ /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
+ break;
+ default:
+ goto unsupported;
+ }
+
+ return 0;
+
+unsupported:
+ pr_warn("Unsupported SignedData version\n");
+ return -EINVAL;
+}
+
+/*
+ * Note the SignerInfo version
+ */
+int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ unsigned version;
+
+ if (vlen != 1)
+ goto unsupported;
+
+ version = *(const u8 *)value;
+ switch (version) {
+ case 1:
+ /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
+ * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
+ */
+ if (ctx->msg->version != 1)
+ goto version_mismatch;
+ ctx->expect_skid = false;
+ break;
+ case 3:
+ /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
+ if (ctx->msg->version == 1)
+ goto version_mismatch;
+ ctx->expect_skid = true;
+ break;
+ default:
+ goto unsupported;
+ }
+
+ return 0;
+
+unsupported:
+ pr_warn("Unsupported SignerInfo version\n");
+ return -EINVAL;
+version_mismatch:
+ pr_warn("SignedData-SignerInfo version mismatch\n");
+ return -EBADMSG;
+}
+
+/*
+ * Extract a certificate and store it in the context.
+ */
+int pkcs7_extract_cert(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ struct x509_certificate *x509;
+
+ if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
+ pr_debug("Cert began with tag %02x at %lu\n",
+ tag, (unsigned long)ctx - ctx->data);
+ return -EBADMSG;
+ }
+
+ /* We have to correct for the header so that the X.509 parser can start
+ * from the beginning. Note that since X.509 stipulates DER, there
+ * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
+ * stipulates BER).
+ */
+ value -= hdrlen;
+ vlen += hdrlen;
+
+ if (((u8*)value)[1] == 0x80)
+ vlen += 2; /* Indefinite length - there should be an EOC */
+
+ x509 = x509_cert_parse(value, vlen);
+ if (IS_ERR(x509))
+ return PTR_ERR(x509);
+
+ x509->index = ++ctx->x509_index;
+ pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
+ pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
+
+ *ctx->ppcerts = x509;
+ ctx->ppcerts = &x509->next;
+ return 0;
+}
+
+/*
+ * Save the certificate list
+ */
+int pkcs7_note_certificate_list(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ pr_devel("Got cert list (%02x)\n", tag);
+
+ *ctx->ppcerts = ctx->msg->certs;
+ ctx->msg->certs = ctx->certs;
+ ctx->certs = NULL;
+ ctx->ppcerts = &ctx->certs;
+ return 0;
+}
+
+/*
+ * Note the content type.
+ */
+int pkcs7_note_content(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ if (ctx->last_oid != OID_data &&
+ ctx->last_oid != OID_msIndirectData) {
+ pr_warn("Unsupported data type %d\n", ctx->last_oid);
+ return -EINVAL;
+ }
+
+ ctx->msg->data_type = ctx->last_oid;
+ return 0;
+}
+
+/*
+ * Extract the data from the message and store that and its content type OID in
+ * the context.
+ */
+int pkcs7_note_data(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ pr_debug("Got data\n");
+
+ ctx->msg->data = value;
+ ctx->msg->data_len = vlen;
+ ctx->msg->data_hdrlen = hdrlen;
+ return 0;
+}
+
+/*
+ * Parse authenticated attributes.
+ */
+int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ struct pkcs7_signed_info *sinfo = ctx->sinfo;
+ enum OID content_type;
+
+ pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
+
+ switch (ctx->last_oid) {
+ case OID_contentType:
+ if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
+ goto repeated;
+ content_type = look_up_OID(value, vlen);
+ if (content_type != ctx->msg->data_type) {
+ pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
+ ctx->msg->data_type, sinfo->index,
+ content_type);
+ return -EBADMSG;
+ }
+ return 0;
+
+ case OID_signingTime:
+ if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
+ goto repeated;
+ /* Should we check that the signing time is consistent
+ * with the signer's X.509 cert?
+ */
+ return x509_decode_time(&sinfo->signing_time,
+ hdrlen, tag, value, vlen);
+
+ case OID_messageDigest:
+ if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
+ goto repeated;
+ if (tag != ASN1_OTS)
+ return -EBADMSG;
+ sinfo->msgdigest = value;
+ sinfo->msgdigest_len = vlen;
+ return 0;
+
+ case OID_smimeCapabilites:
+ if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
+ goto repeated;
+#ifdef __UBOOT__ /* OID_data is needed for authenticated UEFI variables */
+ if (ctx->msg->data_type != OID_msIndirectData &&
+ ctx->msg->data_type != OID_data) {
+#else
+ if (ctx->msg->data_type != OID_msIndirectData) {
+#endif
+ pr_warn("S/MIME Caps only allowed with Authenticode\n");
+ return -EKEYREJECTED;
+ }
+ return 0;
+
+ /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
+ * char URLs and cont[1] 8-bit char URLs.
+ *
+ * Microsoft StatementType seems to contain a list of OIDs that
+ * are also used as extendedKeyUsage types in X.509 certs.
+ */
+ case OID_msSpOpusInfo:
+ if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
+ goto repeated;
+ goto authenticode_check;
+ case OID_msStatementType:
+ if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
+ goto repeated;
+ authenticode_check:
+ if (ctx->msg->data_type != OID_msIndirectData) {
+ pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
+ return -EKEYREJECTED;
+ }
+ /* I'm not sure how to validate these */
+ return 0;
+ default:
+ return 0;
+ }
+
+repeated:
+ /* We permit max one item per AuthenticatedAttribute and no repeats */
+ pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
+ return -EKEYREJECTED;
+}
+
+/*
+ * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
+ */
+int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ struct pkcs7_signed_info *sinfo = ctx->sinfo;
+
+ if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
+ !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
+ pr_warn("Missing required AuthAttr\n");
+ return -EBADMSG;
+ }
+
+ if (ctx->msg->data_type != OID_msIndirectData &&
+ test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
+ pr_warn("Unexpected Authenticode AuthAttr\n");
+ return -EBADMSG;
+ }
+
+ /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
+ sinfo->authattrs = value - (hdrlen - 1);
+ sinfo->authattrs_len = vlen + (hdrlen - 1);
+ return 0;
+}
+
+/*
+ * Note the issuing certificate serial number
+ */
+int pkcs7_sig_note_serial(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ ctx->raw_serial = value;
+ ctx->raw_serial_size = vlen;
+ return 0;
+}
+
+/*
+ * Note the issuer's name
+ */
+int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ ctx->raw_issuer = value;
+ ctx->raw_issuer_size = vlen;
+ return 0;
+}
+
+/*
+ * Note the issuing cert's subjectKeyIdentifier
+ */
+int pkcs7_sig_note_skid(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
+
+ ctx->raw_skid = value;
+ ctx->raw_skid_size = vlen;
+ return 0;
+}
+
+/*
+ * Note the signature data
+ */
+int pkcs7_sig_note_signature(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
+ if (!ctx->sinfo->sig->s)
+ return -ENOMEM;
+
+ ctx->sinfo->sig->s_size = vlen;
+ return 0;
+}
+
+/*
+ * Note a signature information block
+ */
+int pkcs7_note_signed_info(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+ struct pkcs7_signed_info *sinfo = ctx->sinfo;
+ struct asymmetric_key_id *kid;
+
+ if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
+ pr_warn("Authenticode requires AuthAttrs\n");
+ return -EBADMSG;
+ }
+
+ /* Generate cert issuer + serial number key ID */
+ if (!ctx->expect_skid) {
+ kid = asymmetric_key_generate_id(ctx->raw_serial,
+ ctx->raw_serial_size,
+ ctx->raw_issuer,
+ ctx->raw_issuer_size);
+ } else {
+ kid = asymmetric_key_generate_id(ctx->raw_skid,
+ ctx->raw_skid_size,
+ "", 0);
+ }
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+
+ pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
+
+ sinfo->sig->auth_ids[0] = kid;
+ sinfo->index = ++ctx->sinfo_index;
+ *ctx->ppsinfo = sinfo;
+ ctx->ppsinfo = &sinfo->next;
+ ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
+ if (!ctx->sinfo)
+ return -ENOMEM;
+ ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
+ GFP_KERNEL);
+ if (!ctx->sinfo->sig)
+ return -ENOMEM;
+ return 0;
+}