Add current version of libSRTP from CVS.

libsrtp/crypto/kernel/crypto_kernel.c

+/*
+ * crypto_kernel.c
+ *
+ * header for the cryptographic kernel
+ *
+ * David A. McGrew
+ * Cisco Systems, Inc.
+ */
+/*
+ *      
+ * Copyright(c) 2001-2006 Cisco Systems, Inc.
+ * 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 Cisco Systems, Inc. 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 HOLDERS 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.
+ *
+ */
+
+
+#include "alloc.h"
+
+#include "crypto_kernel.h"
+
+/* the debug module for the crypto_kernel */
+
+debug_module_t mod_crypto_kernel = {
+  0,                  /* debugging is off by default */
+  "crypto kernel"     /* printable name for module   */
+};
+
+/*
+ * other debug modules that can be included in the kernel
+ */
+
+extern debug_module_t mod_auth;
+extern debug_module_t mod_cipher;
+extern debug_module_t mod_stat;
+extern debug_module_t mod_alloc;
+
+/* 
+ * cipher types that can be included in the kernel
+ */ 
+
+extern cipher_type_t null_cipher;
+extern cipher_type_t aes_icm;
+extern cipher_type_t aes_cbc;
+
+
+/*
+ * auth func types that can be included in the kernel
+ */
+
+extern auth_type_t null_auth;
+extern auth_type_t hmac;
+
+/* crypto_kernel is a global variable, the only one of its datatype */
+
+crypto_kernel_t
+crypto_kernel = {
+  crypto_kernel_state_insecure,    /* start off in insecure state */
+  NULL,                            /* no cipher types yet         */
+  NULL,                            /* no auth types yet           */
+  NULL                             /* no debug modules yet        */
+};
+
+#define MAX_RNG_TRIALS 25
+
+err_status_t
+crypto_kernel_init() {
+  err_status_t status;  
+
+  /* check the security state */
+  if (crypto_kernel.state == crypto_kernel_state_secure) {
+    
+    /*
+     * we're already in the secure state, but we've been asked to
+     * re-initialize, so we just re-run the self-tests and then return
+     */
+    return crypto_kernel_status(); 
+  }
+
+  /* initialize error reporting system */
+  status = err_reporting_init("crypto");
+  if (status)
+    return status;
+
+  /* load debug modules */
+  status = crypto_kernel_load_debug_module(&mod_crypto_kernel);
+  if (status)
+    return status;
+  status = crypto_kernel_load_debug_module(&mod_auth);
+  if (status)
+    return status;
+  status = crypto_kernel_load_debug_module(&mod_cipher);
+  if (status)
+    return status;
+  status = crypto_kernel_load_debug_module(&mod_stat);
+  if (status)
+    return status;
+  status = crypto_kernel_load_debug_module(&mod_alloc);
+  if (status)
+    return status;
+  
+  /* initialize random number generator */
+  status = rand_source_init();
+  if (status)
+    return status;
+
+  /* run FIPS-140 statistical tests on rand_source */  
+  status = stat_test_rand_source_with_repetition(rand_source_get_octet_string, MAX_RNG_TRIALS);
+  if (status)
+    return status;
+
+  /* initialize pseudorandom number generator */
+  status = ctr_prng_init(rand_source_get_octet_string);
+  if (status)
+    return status;
+
+  /* run FIPS-140 statistical tests on ctr_prng */  
+  status = stat_test_rand_source_with_repetition(ctr_prng_get_octet_string, MAX_RNG_TRIALS);
+  if (status)
+    return status;
+ 
+  /* load cipher types */
+  status = crypto_kernel_load_cipher_type(&null_cipher, NULL_CIPHER);
+  if (status) 
+    return status;
+  status = crypto_kernel_load_cipher_type(&aes_icm, AES_ICM);
+  if (status) 
+    return status;
+  status = crypto_kernel_load_cipher_type(&aes_cbc, AES_CBC);
+  if (status) 
+    return status;
+
+  /* load auth func types */
+  status = crypto_kernel_load_auth_type(&null_auth, NULL_AUTH);
+  if (status)
+    return status;
+  status = crypto_kernel_load_auth_type(&hmac, HMAC_SHA1);
+  if (status)
+    return status;
+
+  /* change state to secure */
+  crypto_kernel.state = crypto_kernel_state_secure;
+
+  return err_status_ok;
+}
+
+err_status_t
+crypto_kernel_status() {
+  err_status_t status;
+  kernel_cipher_type_t  *ctype = crypto_kernel.cipher_type_list;
+  kernel_auth_type_t    *atype = crypto_kernel.auth_type_list;
+  kernel_debug_module_t *dm    = crypto_kernel.debug_module_list;
+
+  /* run FIPS-140 statistical tests on rand_source */  
+  printf("testing rand_source...");
+  status = stat_test_rand_source_with_repetition(rand_source_get_octet_string, MAX_RNG_TRIALS);
+  if (status) {
+    printf("failed\n");
+    crypto_kernel.state = crypto_kernel_state_insecure;
+    return status;
+  }  
+  printf("passed\n");
+
+  /* for each cipher type, describe and test */
+  while(ctype != NULL) {
+    printf("cipher: %s\n", ctype->cipher_type->description);
+    printf("  instance count: %d\n", ctype->cipher_type->ref_count);
+    printf("  self-test: ");
+    status = cipher_type_self_test(ctype->cipher_type);
+    if (status) {
+      printf("failed with error code %d\n", status);
+      exit(status);
+    }
+    printf("passed\n");
+    ctype = ctype->next;
+  }
+  
+  /* for each auth type, describe and test */
+  while(atype != NULL) {
+    printf("auth func: %s\n", atype->auth_type->description);
+    printf("  instance count: %d\n", atype->auth_type->ref_count);
+    printf("  self-test: ");
+    status = auth_type_self_test(atype->auth_type);
+    if (status) {
+      printf("failed with error code %d\n", status);
+      exit(status);
+    }
+    printf("passed\n");
+    atype = atype->next;
+  }
+
+  /* describe each debug module */
+  printf("debug modules loaded:\n");
+  while (dm != NULL) {
+    printf("  %s ", dm->mod->name);  
+    if (dm->mod->on)
+      printf("(on)\n");
+    else
+      printf("(off)\n");
+    dm = dm->next;
+  }
+
+  return err_status_ok;
+}
+
+err_status_t
+crypto_kernel_list_debug_modules() {
+  kernel_debug_module_t *dm = crypto_kernel.debug_module_list;
+
+  /* describe each debug module */
+  printf("debug modules loaded:\n");
+  while (dm != NULL) {
+    printf("  %s ", dm->mod->name);  
+    if (dm->mod->on)
+      printf("(on)\n");
+    else
+      printf("(off)\n");
+    dm = dm->next;
+  }
+
+  return err_status_ok;
+}
+
+err_status_t
+crypto_kernel_shutdown() {
+  err_status_t status;
+
+  /*
+   * free dynamic memory used in crypto_kernel at present
+   */
+
+  /* walk down cipher type list, freeing memory */
+  while (crypto_kernel.cipher_type_list != NULL) {
+    kernel_cipher_type_t *ctype = crypto_kernel.cipher_type_list;
+    crypto_kernel.cipher_type_list = ctype->next;
+    debug_print(mod_crypto_kernel, 
+                "freeing memory for cipher %s", 
+                ctype->cipher_type->description);
+    crypto_free(ctype);
+  }
+
+  /* walk down authetication module list, freeing memory */
+  while (crypto_kernel.auth_type_list != NULL) {
+     kernel_auth_type_t *atype = crypto_kernel.auth_type_list;
+     crypto_kernel.auth_type_list = atype->next;
+     debug_print(mod_crypto_kernel, 
+                "freeing memory for authentication %s",
+                atype->auth_type->description);
+     crypto_free(atype);
+  }
+
+  /* walk down debug module list, freeing memory */
+  while (crypto_kernel.debug_module_list != NULL) {
+    kernel_debug_module_t *kdm = crypto_kernel.debug_module_list;
+    crypto_kernel.debug_module_list = kdm->next;
+    debug_print(mod_crypto_kernel, 
+                "freeing memory for debug module %s", 
+                kdm->mod->name);
+    crypto_free(kdm);
+  }
+
+  /* de-initialize random number generator */  status = rand_source_deinit();
+  if (status)
+    return status;
+
+  /* return to insecure state */
+  crypto_kernel.state = crypto_kernel_state_insecure;
+  
+  return err_status_ok;
+}
+
+inline err_status_t
+crypto_kernel_do_load_cipher_type(cipher_type_t *new_ct, cipher_type_id_t id,
+                                  int replace) {
+  kernel_cipher_type_t *ctype, *new_ctype;
+  err_status_t status;
+
+  /* defensive coding */
+  if (new_ct == NULL)
+    return err_status_bad_param;
+
+  if (new_ct->id != id)
+    return err_status_bad_param;
+
+  /* check cipher type by running self-test */
+  status = cipher_type_self_test(new_ct);
+  if (status) {
+    return status;
+  }
+
+  /* walk down list, checking if this type is in the list already  */
+  ctype = crypto_kernel.cipher_type_list;
+  while (ctype != NULL) {
+    if (id == ctype->id) {
+      if (!replace)
+        return err_status_bad_param;
+      status = cipher_type_test(new_ct, ctype->cipher_type->test_data);
+      if (status)
+        return status;
+      new_ctype = ctype;
+      break;
+    }
+    else if (new_ct == ctype->cipher_type)
+      return err_status_bad_param;    
+    ctype = ctype->next;
+  }
+
+  /* if not found, put new_ct at the head of the list */
+  if (ctype == NULL) {
+  /* allocate memory */
+    new_ctype = (kernel_cipher_type_t *) crypto_alloc(sizeof(kernel_cipher_type_t));
+    if (new_ctype == NULL)
+      return err_status_alloc_fail;
+    new_ctype->next = crypto_kernel.cipher_type_list;
+
+    /* set head of list to new cipher type */
+    crypto_kernel.cipher_type_list = new_ctype;    
+  }
+    
+  /* set fields */
+  new_ctype->cipher_type = new_ct;
+  new_ctype->id = id;
+
+  /* load debug module, if there is one present */
+  if (new_ct->debug != NULL)
+    crypto_kernel_load_debug_module(new_ct->debug);
+  /* we could check for errors here */
+
+  return err_status_ok;
+}
+
+err_status_t
+crypto_kernel_load_cipher_type(cipher_type_t *new_ct, cipher_type_id_t id) {
+  return crypto_kernel_do_load_cipher_type(new_ct, id, 0);
+}
+
+err_status_t
+crypto_kernel_replace_cipher_type(cipher_type_t *new_ct, cipher_type_id_t id) {
+  return crypto_kernel_do_load_cipher_type(new_ct, id, 1);
+}
+
+err_status_t
+crypto_kernel_do_load_auth_type(auth_type_t *new_at, auth_type_id_t id,
+                                int replace) {
+  kernel_auth_type_t *atype, *new_atype;
+  err_status_t status;
+
+  /* defensive coding */
+  if (new_at == NULL)
+    return err_status_bad_param;
+
+  if (new_at->id != id)
+    return err_status_bad_param;
+
+  /* check auth type by running self-test */
+  status = auth_type_self_test(new_at);
+  if (status) {
+    return status;
+  }
+
+  /* walk down list, checking if this type is in the list already  */
+  atype = crypto_kernel.auth_type_list;
+  while (atype != NULL) {
+    if (id == atype->id) {
+      if (!replace)
+        return err_status_bad_param;
+      status = auth_type_test(new_at, atype->auth_type->test_data);
+      if (status)
+        return status;
+      new_atype = atype;
+      break;
+    }
+    else if (new_at == atype->auth_type)
+      return err_status_bad_param;    
+    atype = atype->next;
+  }
+
+  /* if not found, put new_at at the head of the list */
+  if (atype == NULL) {
+    /* allocate memory */
+    new_atype = (kernel_auth_type_t *)crypto_alloc(sizeof(kernel_auth_type_t));
+    if (new_atype == NULL)
+      return err_status_alloc_fail;
+
+    new_atype->next = crypto_kernel.auth_type_list;
+    /* set head of list to new auth type */
+    crypto_kernel.auth_type_list = new_atype;
+  }
+    
+  /* set fields */
+  new_atype->auth_type = new_at;
+  new_atype->id = id;
+
+  /* load debug module, if there is one present */
+  if (new_at->debug != NULL)
+    crypto_kernel_load_debug_module(new_at->debug);
+  /* we could check for errors here */
+
+  return err_status_ok;
+
+}
+
+err_status_t
+crypto_kernel_load_auth_type(auth_type_t *new_at, auth_type_id_t id) {
+  return crypto_kernel_do_load_auth_type(new_at, id, 0);
+}
+
+err_status_t
+crypto_kernel_replace_auth_type(auth_type_t *new_at, auth_type_id_t id) {
+  return crypto_kernel_do_load_auth_type(new_at, id, 1);
+}
+
+
+cipher_type_t *
+crypto_kernel_get_cipher_type(cipher_type_id_t id) {
+  kernel_cipher_type_t *ctype;
+  
+  /* walk down list, looking for id  */
+  ctype = crypto_kernel.cipher_type_list;
+  while (ctype != NULL) {
+    if (id == ctype->id)
+      return ctype->cipher_type; 
+    ctype = ctype->next;
+  } 
+
+  /* haven't found the right one, indicate failure by returning NULL */
+  return NULL;
+}
+
+
+err_status_t
+crypto_kernel_alloc_cipher(cipher_type_id_t id, 
+                              cipher_pointer_t *cp, 
+                              int key_len) {
+  cipher_type_t *ct;
+
+  /* 
+   * if the crypto_kernel is not yet initialized, we refuse to allocate
+   * any ciphers - this is a bit extra-paranoid
+   */
+  if (crypto_kernel.state != crypto_kernel_state_secure)
+    return err_status_init_fail;
+
+  ct = crypto_kernel_get_cipher_type(id);
+  if (!ct)
+    return err_status_fail;
+  
+  return ((ct)->alloc(cp, key_len));
+}
+
+
+
+auth_type_t *
+crypto_kernel_get_auth_type(auth_type_id_t id) {
+  kernel_auth_type_t *atype;
+  
+  /* walk down list, looking for id  */
+  atype = crypto_kernel.auth_type_list;
+  while (atype != NULL) {
+    if (id == atype->id)
+      return atype->auth_type; 
+    atype = atype->next;
+  } 
+
+  /* haven't found the right one, indicate failure by returning NULL */
+  return NULL;
+}
+
+err_status_t
+crypto_kernel_alloc_auth(auth_type_id_t id, 
+                         auth_pointer_t *ap, 
+                         int key_len,
+                         int tag_len) {
+  auth_type_t *at;
+
+  /* 
+   * if the crypto_kernel is not yet initialized, we refuse to allocate
+   * any auth functions - this is a bit extra-paranoid
+   */
+  if (crypto_kernel.state != crypto_kernel_state_secure)
+    return err_status_init_fail;
+
+  at = crypto_kernel_get_auth_type(id);
+  if (!at)
+    return err_status_fail;
+  
+  return ((at)->alloc(ap, key_len, tag_len));
+}
+
+err_status_t
+crypto_kernel_load_debug_module(debug_module_t *new_dm) {
+  kernel_debug_module_t *kdm, *new;
+
+  /* defensive coding */
+  if (new_dm == NULL)
+    return err_status_bad_param;
+
+  /* walk down list, checking if this type is in the list already  */
+  kdm = crypto_kernel.debug_module_list;
+  while (kdm != NULL) {
+    if (strncmp(new_dm->name, kdm->mod->name, 64) == 0)
+      return err_status_bad_param;    
+    kdm = kdm->next;
+  }
+
+  /* put new_dm at the head of the list */
+  /* allocate memory */
+  new = (kernel_debug_module_t *)crypto_alloc(sizeof(kernel_debug_module_t));
+  if (new == NULL)
+    return err_status_alloc_fail;
+    
+  /* set fields */
+  new->mod = new_dm;
+  new->next = crypto_kernel.debug_module_list;
+
+  /* set head of list to new cipher type */
+  crypto_kernel.debug_module_list = new;    
+
+  return err_status_ok;
+}
+
+err_status_t
+crypto_kernel_set_debug_module(char *name, int on) {
+  kernel_debug_module_t *kdm;
+  
+  /* walk down list, checking if this type is in the list already  */
+  kdm = crypto_kernel.debug_module_list;
+  while (kdm != NULL) {
+    if (strncmp(name, kdm->mod->name, 64) == 0) {
+      kdm->mod->on = on;
+      return err_status_ok;
+    }
+    kdm = kdm->next;
+  }
+
+  return err_status_fail;
+}
+
+err_status_t
+crypto_get_random(unsigned char *buffer, unsigned int length) {
+  if (crypto_kernel.state == crypto_kernel_state_secure)
+    return ctr_prng_get_octet_string(buffer, length);
+  else
+    return err_status_fail;
+}