1 files changed, 396 insertions, 0 deletions

diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
new file mode 100644
index 000000000000..42e56aa7d277
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -0,0 +1,396 @@
+/* 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 "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;
+};
+
+/**
+ * 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;
+                        mpi_free(sinfo->sig.mpi[0]);
+                        kfree(sinfo->sig.digest);
+                        kfree(sinfo);
+                }
+                kfree(pkcs7);
+        }
+}
+EXPORT_SYMBOL_GPL(pkcs7_free_message);
+
+/**
+ * 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;
+        long ret;
+
+        ret = -ENOMEM;
+        msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
+        if (!msg)
+                goto error_no_sig;
+        ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
+        if (!ctx)
+                goto error_no_ctx;
+        ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
+        if (!ctx->sinfo)
+                goto error_no_sinfo;
+
+        ctx->msg = msg;
+        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)
+                goto error_decode;
+
+        while (ctx->certs) {
+                struct x509_certificate *cert = ctx->certs;
+                ctx->certs = cert->next;
+                x509_free_certificate(cert);
+        }
+        mpi_free(ctx->sinfo->sig.mpi[0]);
+        kfree(ctx->sinfo->sig.digest);
+        kfree(ctx->sinfo);
+        kfree(ctx);
+        return msg;
+
+error_decode:
+        mpi_free(ctx->sinfo->sig.mpi[0]);
+        kfree(ctx->sinfo->sig.digest);
+        kfree(ctx->sinfo);
+error_no_sinfo:
+        kfree(ctx);
+error_no_ctx:
+        pkcs7_free_message(msg);
+error_no_sig:
+        return ERR_PTR(ret);
+}
+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
+ * @want_wrapper: True if the ASN.1 object header should be included in the data
+ *
+ * Get access to the data content of the PKCS#7 message, including, optionally,
+ * the header of the ASN.1 object that contains it.  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,
+                           bool want_wrapper)
+{
+        size_t wrapper;
+
+        if (!pkcs7->data)
+                return -ENODATA;
+
+        wrapper = want_wrapper ? pkcs7->data_hdrlen : 0;
+        *_data = pkcs7->data - wrapper;
+        *_data_len = pkcs7->data_len + wrapper;
+        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.pkey_hash_algo = HASH_ALGO_MD4;
+                break;
+        case OID_md5:
+                ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD5;
+                break;
+        case OID_sha1:
+                ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA1;
+                break;
+        case OID_sha256:
+                ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA256;
+                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 = PKEY_ALGO_RSA;
+                break;
+        default:
+                printk("Unsupported pkey algo: %u\n", ctx->last_oid);
+                return -ENOPKG;
+        }
+        return 0;
+}
+
+/*
+ * 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);
+
+        pr_debug("Got cert for %s\n", x509->subject);
+        pr_debug("- fingerprint %s\n", x509->fingerprint);
+
+        x509->index = ++ctx->x509_index;
+        *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;
+}
+
+/*
+ * 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;
+        ctx->msg->data_type = ctx->last_oid;
+        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;
+
+        pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
+
+        switch (ctx->last_oid) {
+        case OID_messageDigest:
+                if (tag != ASN1_OTS)
+                        return -EBADMSG;
+                ctx->sinfo->msgdigest = value;
+                ctx->sinfo->msgdigest_len = vlen;
+                return 0;
+        default:
+                return 0;
+        }
+}
+
+/*
+ * Note the set of auth attributes for digestion purposes [RFC2315 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;
+
+        /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
+        ctx->sinfo->authattrs = value - (hdrlen - 1);
+        ctx->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->sinfo->raw_serial = value;
+        ctx->sinfo->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->sinfo->raw_issuer = value;
+        ctx->sinfo->raw_issuer_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;
+        MPI mpi;
+
+        BUG_ON(ctx->sinfo->sig.pkey_algo != PKEY_ALGO_RSA);
+
+        mpi = mpi_read_raw_data(value, vlen);
+        if (!mpi)
+                return -ENOMEM;
+
+        ctx->sinfo->sig.mpi[0] = mpi;
+        ctx->sinfo->sig.nr_mpi = 1;
+        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;
+
+        ctx->sinfo->index = ++ctx->sinfo_index;
+        *ctx->ppsinfo = ctx->sinfo;
+        ctx->ppsinfo = &ctx->sinfo->next;
+        ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
+        if (!ctx->sinfo)
+                return -ENOMEM;
+        return 0;
+}