Diff: crypto/crypto_misc.c

Revision:

0:5a29fd060ac8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/crypto_misc.c	Mon May 13 18:15:18 2013 +0000
@@ -0,0 +1,375 @@
+/*
+ * Copyright (c) 2007, Cameron Rich
+ * 
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, 
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice, 
+ *   this list of conditions and the following disclaimer in the documentation 
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of the axTLS project nor the names of its contributors 
+ *   may be used to endorse or promote products derived from this software 
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * Some misc. routines to help things out
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include "os_port.h"
+#include <lwip/def.h>
+#include "sockets.h"
+#include "crypto_misc.h"
+#include "config.h"
+
+#include <time.h>
+#ifdef CONFIG_WIN32_USE_CRYPTO_LIB
+#include "wincrypt.h"
+#endif
+
+#ifndef WIN32
+static int rng_fd = -1;
+#elif defined(CONFIG_WIN32_USE_CRYPTO_LIB)
+static HCRYPTPROV gCryptProv;
+#endif
+
+#if (!defined(CONFIG_USE_DEV_URANDOM) && !defined(CONFIG_WIN32_USE_CRYPTO_LIB))
+/* change to processor registers as appropriate */
+#define ENTROPY_POOL_SIZE 32
+#define ENTROPY_COUNTER1 ((((uint64_t)tv.tv_sec)<<32) | tv.tv_usec)
+#define ENTROPY_COUNTER2 rand()
+static uint8_t entropy_pool[ENTROPY_POOL_SIZE];
+#endif
+
+const char * const unsupported_str = "Error: Feature not supported\n";
+
+#ifndef CONFIG_SSL_SKELETON_MODE
+/** 
+ * Retrieve a file and put it into memory
+ * @return The size of the file, or -1 on failure.
+ */
+int get_file(const char *filename, uint8_t **buf)
+{
+    int total_bytes = 0;
+    int bytes_read = 0; 
+    int filesize;
+    FILE *stream = fopen(filename, "rb");
+
+    if (stream == NULL)
+    {
+#ifdef CONFIG_SSL_FULL_MODE         
+        printf("file '%s' does not exist\n", filename); TTY_FLUSH();
+#endif
+        return -1;
+    }
+
+    /* Win CE doesn't support stat() */
+    fseek(stream, 0, SEEK_END);
+    filesize = ftell(stream);
+    *buf = (uint8_t *)malloc(filesize);
+    fseek(stream, 0, SEEK_SET);
+
+    do
+    {
+        bytes_read = fread(*buf+total_bytes, 1, filesize-total_bytes, stream);
+        total_bytes += bytes_read;
+    } while (total_bytes < filesize && bytes_read > 0);
+    
+    fclose(stream);
+    return filesize;
+}
+#endif
+
+/**
+ * Initialise the Random Number Generator engine.
+ * - On Win32 use the platform SDK's crypto engine.
+ * - On Linux use /dev/urandom
+ * - If none of these work then use a custom RNG.
+ */
+EXP_FUNC void STDCALL RNG_initialize()
+{
+#if !defined(WIN32) && defined(CONFIG_USE_DEV_URANDOM)
+    rng_fd = ax_open("/dev/urandom", O_RDONLY);
+#elif defined(WIN32) && defined(CONFIG_WIN32_USE_CRYPTO_LIB)
+    if (!CryptAcquireContext(&gCryptProv, 
+                      NULL, NULL, PROV_RSA_FULL, 0))
+    {
+        if (GetLastError() == NTE_BAD_KEYSET &&
+                !CryptAcquireContext(&gCryptProv, 
+                       NULL, 
+                       NULL, 
+                       PROV_RSA_FULL, 
+                       CRYPT_NEWKEYSET))
+        {
+            printf("CryptoLib: %x\n", unsupported_str, GetLastError());
+            exit(1);
+        }
+    }
+#else
+    /* start of with a stack to copy across */
+    int i;
+    memcpy(entropy_pool, &i, ENTROPY_POOL_SIZE);
+    srand((unsigned int)&i); 
+#endif
+}
+
+/**
+ * If no /dev/urandom, then initialise the RNG with something interesting.
+ */
+EXP_FUNC void STDCALL RNG_custom_init(const uint8_t *seed_buf, int size)
+{
+#if defined(WIN32) || defined(CONFIG_WIN32_USE_CRYPTO_LIB)
+    int i;
+
+    for (i = 0; i < ENTROPY_POOL_SIZE && i < size; i++)
+        entropy_pool[i] ^= seed_buf[i];
+#endif
+}
+
+/**
+ * Terminate the RNG engine.
+ */
+EXP_FUNC void STDCALL RNG_terminate(void)
+{
+#ifndef WIN32
+    //close(rng_fd);
+#elif defined(CONFIG_WIN32_USE_CRYPTO_LIB)
+    CryptReleaseContext(gCryptProv, 0);
+#endif
+}
+
+/**
+ * Set a series of bytes with a random number. Individual bytes can be 0
+ */
+EXP_FUNC void STDCALL get_random(int num_rand_bytes, uint8_t *rand_data)
+{   
+#if !defined(WIN32) && defined(CONFIG_USE_DEV_URANDOM)
+    /* use the Linux default */
+    read(rng_fd, rand_data, num_rand_bytes);    /* read from /dev/urandom */
+#elif defined(WIN32) && defined(CONFIG_WIN32_USE_CRYPTO_LIB)
+    /* use Microsoft Crypto Libraries */
+    CryptGenRandom(gCryptProv, num_rand_bytes, rand_data);
+#else   /* nothing else to use, so use a custom RNG */
+    /* The method we use when we've got nothing better. Use RC4, time 
+       and a couple of random seeds to generate a random sequence */
+    RC4_CTX rng_ctx;
+    struct timeval tv;
+    MD5_CTX rng_digest_ctx;
+    uint8_t digest[MD5_SIZE];
+    uint64_t *ep;
+    int i;
+
+    /* A proper implementation would use counters etc for entropy */
+    // XXX XXX XX X need to seed this properly
+    gettimeofday(&tv, NULL);    
+    ep = (uint64_t *)entropy_pool;
+    
+    ep[0] ^= ENTROPY_COUNTER1;
+    ep[1] ^= ENTROPY_COUNTER2; 
+    
+
+    /* use a digested version of the entropy pool as a key */
+    MD5_Init(&rng_digest_ctx);
+    MD5_Update(&rng_digest_ctx, entropy_pool, ENTROPY_POOL_SIZE);
+    MD5_Final(digest, &rng_digest_ctx);
+
+    /* come up with the random sequence */
+    RC4_setup(&rng_ctx, digest, MD5_SIZE); /* use as a key */
+    memcpy(rand_data, entropy_pool, num_rand_bytes < ENTROPY_POOL_SIZE ?
+                num_rand_bytes : ENTROPY_POOL_SIZE);
+    RC4_crypt(&rng_ctx, rand_data, rand_data, num_rand_bytes);
+
+    /* move things along */
+    for (i = ENTROPY_POOL_SIZE-1; i >= MD5_SIZE ; i--)
+        entropy_pool[i] = entropy_pool[i-MD5_SIZE];
+
+    /* insert the digest at the start of the entropy pool */
+    memcpy(entropy_pool, digest, MD5_SIZE);
+#endif
+}
+
+/**
+ * Set a series of bytes with a random number. Individual bytes are not zero.
+ */
+void get_random_NZ(int num_rand_bytes, uint8_t *rand_data)
+{
+    int i;
+    get_random(num_rand_bytes, rand_data);
+
+    for (i = 0; i < num_rand_bytes; i++)
+    {
+        while (rand_data[i] == 0)  /* can't be 0 */
+            rand_data[i] = (uint8_t)(rand());
+    }
+}
+
+/**
+ * Some useful diagnostic routines
+ */
+#if defined(CONFIG_SSL_FULL_MODE) || defined(CONFIG_DEBUG)
+int hex_finish;
+int hex_index;
+
+static void print_hex_init(int finish)
+{
+    hex_finish = finish;
+    hex_index = 0;
+}
+
+static void print_hex(uint8_t hex)
+{
+    static int column;
+
+    if (hex_index == 0)
+    {
+        column = 0;
+    }
+
+    printf("%02x ", hex);
+    if (++column == 8)
+    {
+        printf(": ");
+    }
+    else if (column >= 16)
+    {
+        printf("\r\n");
+        column = 0;
+    }
+
+    if (++hex_index >= hex_finish && column > 0)
+    {
+        printf("\r\n");
+    }
+}
+
+/**
+ * Spit out a blob of data for diagnostics. The data is is a nice column format
+ * for easy reading.
+ *
+ * @param format   [in]    The string (with possible embedded format characters)
+ * @param size     [in]    The number of numbers to print
+ * @param data     [in]    The start of data to use
+ * @param ...      [in]    Any additional arguments
+ */
+EXP_FUNC void STDCALL print_blob(const char *format, 
+        const uint8_t *data, int size, ...)
+{
+    int i;
+    char tmp[80];
+    va_list(ap);
+
+    va_start(ap, size);
+    sprintf(tmp, "%s\n", format);
+    vprintf(tmp, ap);
+    print_hex_init(size);
+    for (i = 0; i < size; i++)
+    {
+        print_hex(data[i]);
+    }
+
+    va_end(ap);
+    TTY_FLUSH();
+}
+#elif defined(WIN32)
+/* VC6.0 doesn't handle variadic macros */
+EXP_FUNC void STDCALL print_blob(const char *format, const unsigned char *data,
+        int size, ...) {}
+#endif
+
+#if defined(CONFIG_SSL_HAS_PEM) || defined(CONFIG_HTTP_HAS_AUTHORIZATION)
+/* base64 to binary lookup table */
+static const uint8_t map[128] =
+{
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,
+    52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,
+    255, 254, 255, 255, 255,   0,   1,   2,   3,   4,   5,   6,
+    7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,
+    19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255, 255,
+    255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,
+    37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
+    49,  50,  51, 255, 255, 255, 255, 255
+};
+
+EXP_FUNC int STDCALL base64_decode(const char *in, int len,
+                    uint8_t *out, int *outlen)
+{
+    int g, t, x, y, z;
+    uint8_t c;
+    int ret = -1;
+
+    g = 3;
+    for (x = y = z = t = 0; x < len; x++)
+    {
+        if ((c = map[in[x]&0x7F]) == 0xff)
+            continue;
+
+        if (c == 254)   /* this is the end... */
+        {
+            c = 0;
+
+            if (--g < 0)
+                goto error;
+        }
+        else if (g != 3) /* only allow = at end */
+            goto error;
+
+        t = (t<<6) | c;
+
+        if (++y == 4)
+        {
+            out[z++] = (uint8_t)((t>>16)&255);
+
+            if (g > 1)
+                out[z++] = (uint8_t)((t>>8)&255);
+
+            if (g > 2)
+                out[z++] = (uint8_t)(t&255);
+
+            y = t = 0;
+        }
+
+        /* check that we don't go past the output buffer */
+        if (z > *outlen) 
+            goto error;
+    }
+
+    if (y != 0)
+        goto error;
+
+    *outlen = z;
+    ret = 0;
+
+error:
+#ifdef CONFIG_SSL_FULL_MODE
+    if (ret < 0)
+        printf("Error: Invalid base64\n"); TTY_FLUSH();
+#endif
+    TTY_FLUSH();
+    return ret;
+
+}
+#endif
+