1 files changed, 678 insertions, 0 deletions

diff --git a/compat/verification/pkcs7_parser.c b/compat/verification/pkcs7_parser.c
new file mode 100644
index 0000000..d140d8b
--- /dev/null
+++ b/compat/verification/pkcs7_parser.c
@@ -0,0 +1,678 @@
+/* PKCS#7 parser
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "PKCS7: "fmt
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#include <crypto/public_key.h>
+#include "pkcs7_parser.h"
+#include "pkcs7-asn1.h"
+
+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)
+		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";
+		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;
+		if (ctx->msg->data_type != OID_msIndirectData) {
+			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;
+}