backports: add signature verification code

Uh, this was awful. Because the crypto/ things are completely
impossible to backport, I've actually implemented this by using
mbedtls and embedding the relevant functions it has...

The mbedtls code is taken from mbedtls version 2.6.0 and only
minimally modified (mostly to remove <string.h> and similar).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 135 insertions, 0 deletions

diff --git a/backport/compat/verification/mbedtls/sha1.h b/backport/compat/verification/mbedtls/sha1.h
new file mode 100644
index 00000000..b8752edd
--- /dev/null
+++ b/backport/compat/verification/mbedtls/sha1.h
@@ -0,0 +1,135 @@
+/**
+ * \file sha1.h
+ *
+ * \brief SHA-1 cryptographic hash function
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: GPL-2.0
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+#ifndef MBEDTLS_SHA1_H
+#define MBEDTLS_SHA1_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if !defined(MBEDTLS_SHA1_ALT)
+// Regular implementation
+//
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief          SHA-1 context structure
+ */
+typedef struct
+{
+    uint32_t total[2];          /*!< number of bytes processed  */
+    uint32_t state[5];          /*!< intermediate digest state  */
+    unsigned char buffer[64];   /*!< data block being processed */
+}
+mbedtls_sha1_context;
+
+/**
+ * \brief          Initialize SHA-1 context
+ *
+ * \param ctx      SHA-1 context to be initialized
+ */
+void mbedtls_sha1_init( mbedtls_sha1_context *ctx );
+
+/**
+ * \brief          Clear SHA-1 context
+ *
+ * \param ctx      SHA-1 context to be cleared
+ */
+void mbedtls_sha1_free( mbedtls_sha1_context *ctx );
+
+/**
+ * \brief          Clone (the state of) a SHA-1 context
+ *
+ * \param dst      The destination context
+ * \param src      The context to be cloned
+ */
+void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
+                         const mbedtls_sha1_context *src );
+
+/**
+ * \brief          SHA-1 context setup
+ *
+ * \param ctx      context to be initialized
+ */
+void mbedtls_sha1_starts( mbedtls_sha1_context *ctx );
+
+/**
+ * \brief          SHA-1 process buffer
+ *
+ * \param ctx      SHA-1 context
+ * \param input    buffer holding the  data
+ * \param ilen     length of the input data
+ */
+void mbedtls_sha1_update( mbedtls_sha1_context *ctx, const unsigned char *input, size_t ilen );
+
+/**
+ * \brief          SHA-1 final digest
+ *
+ * \param ctx      SHA-1 context
+ * \param output   SHA-1 checksum result
+ */
+void mbedtls_sha1_finish( mbedtls_sha1_context *ctx, unsigned char output[20] );
+
+/* Internal use */
+void mbedtls_sha1_process( mbedtls_sha1_context *ctx, const unsigned char data[64] );
+
+#ifdef __cplusplus
+}
+#endif
+
+#else  /* MBEDTLS_SHA1_ALT */
+#include "sha1_alt.h"
+#endif /* MBEDTLS_SHA1_ALT */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief          Output = SHA-1( input buffer )
+ *
+ * \param input    buffer holding the  data
+ * \param ilen     length of the input data
+ * \param output   SHA-1 checksum result
+ */
+void mbedtls_sha1( const unsigned char *input, size_t ilen, unsigned char output[20] );
+
+/**
+ * \brief          Checkup routine
+ *
+ * \return         0 if successful, or 1 if the test failed
+ */
+int mbedtls_sha1_self_test( int verbose );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* mbedtls_sha1.h */