tests/no_prng.c

   1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
   2 /* SPDX-License-Identifier: Unlicense */
   3
   4 #include "tomcrypt.h"
   5 #include "tomcrypt_test.h"
   6
   7 /**
   8   @file no_prng.c
   9   NO PRNG, Steffen Jaeckel
  10 */
  11
  12 #ifdef LTC_PKCS_1
  13
  14 typedef struct
  15 {
  16    struct ltc_prng_descriptor desc;
  17    char name[64];
  18    unsigned char entropy[1024];
  19    unsigned long len;
  20    unsigned long offset;
  21 } no_prng_desc_t;
  22
  23 /**
  24   Start the PRNG
  25   @param prng     [out] The PRNG state to initialize
  26   @return CRYPT_OK if successful
  27 */
  28 static int no_prng_start(prng_state *prng)
  29 {
  30    no_prng_desc_t *no_prng = (no_prng_desc_t*) prng;
  31    LTC_ARGCHK(no_prng != NULL);
  32    LTC_ARGCHK(no_prng->name == (char*)no_prng + offsetof(no_prng_desc_t, name));
  33    no_prng->len = 0;
  34    no_prng->offset = 0;
  35
  36    return CRYPT_OK;
  37 }
  38
  39 /**
  40   Add entropy to the PRNG state
  41   @param in       The data to add
  42   @param inlen    Length of the data to add
  43   @param prng     PRNG state to update
  44   @return CRYPT_OK if successful
  45 */
  46 static int no_prng_add_entropy(const unsigned char *in, unsigned long inlen, prng_state *prng)
  47 {
  48    no_prng_desc_t *no_prng = (no_prng_desc_t*) prng;
  49    LTC_ARGCHK(no_prng != NULL);
  50    LTC_ARGCHK(no_prng->name == (char*)no_prng + offsetof(no_prng_desc_t, name));
  51    LTC_ARGCHK(in != NULL);
  52    LTC_ARGCHK(inlen <= sizeof(no_prng->entropy));
  53
  54    no_prng->len = MIN(inlen, sizeof(no_prng->entropy));
  55    memcpy(no_prng->entropy, in, no_prng->len);
  56    no_prng->offset = 0;
  57
  58    return CRYPT_OK;
  59
  60 }
  61
  62 /**
  63   Make the PRNG ready to read from
  64   @param prng   The PRNG to make active
  65   @return CRYPT_OK if successful
  66 */
  67 static int no_prng_ready(prng_state *prng)
  68 {
  69     LTC_ARGCHK(prng != NULL);
  70
  71     return CRYPT_OK;
  72 }
  73
  74 /**
  75   Read from the PRNG
  76   @param out      Destination
  77   @param outlen   Length of output
  78   @param prng     The active PRNG to read from
  79   @return Number of octets read
  80 */
  81 static unsigned long no_prng_read(unsigned char *out, unsigned long outlen, prng_state *prng)
  82 {
  83    no_prng_desc_t *no_prng = (no_prng_desc_t*) prng;
  84    LTC_ARGCHK(no_prng != NULL);
  85    LTC_ARGCHK(no_prng->name == (char*)no_prng + offsetof(no_prng_desc_t, name));
  86    LTC_ARGCHK(out != NULL);
  87
  88    outlen = MIN(outlen, no_prng->len - no_prng->offset);
  89    memcpy(out, &no_prng->entropy[no_prng->offset], outlen);
  90    no_prng->offset += outlen;
  91
  92    return outlen;
  93 }
  94
  95 /**
  96   Terminate the PRNG
  97   @param prng   The PRNG to terminate
  98   @return CRYPT_OK if successful
  99 */
 100 static int no_prng_done(prng_state *prng)
 101 {
 102    LTC_UNUSED_PARAM(prng);
 103    return CRYPT_OK;
 104 }
 105
 106 /**
 107   Export the PRNG state
 108   @param out       [out] Destination
 109   @param outlen    [in/out] Max size and resulting size of the state
 110   @param prng      The PRNG to export
 111   @return CRYPT_OK if successful
 112 */
 113 static int no_prng_export(unsigned char *out, unsigned long *outlen, prng_state *prng)
 114 {
 115    LTC_UNUSED_PARAM(out);
 116    LTC_UNUSED_PARAM(outlen);
 117    LTC_UNUSED_PARAM(prng);
 118    return CRYPT_OK;
 119 }
 120
 121 /**
 122   Import a PRNG state
 123   @param in       The PRNG state
 124   @param inlen    Size of the state
 125   @param prng     The PRNG to import
 126   @return CRYPT_OK if successful
 127 */
 128 static int no_prng_import(const unsigned char *in, unsigned long inlen, prng_state *prng)
 129 {
 130    LTC_UNUSED_PARAM(in);
 131    LTC_UNUSED_PARAM(inlen);
 132    LTC_UNUSED_PARAM(prng);
 133    return CRYPT_OK;
 134 }
 135
 136 /**
 137   PRNG self-test
 138   @return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled
 139 */
 140 static int no_prng_test(void)
 141 {
 142    return CRYPT_OK;
 143 }
 144
 145 static const struct ltc_prng_descriptor no_prng_desc =
 146 {
 147     NULL, 0,
 148     &no_prng_start,
 149     &no_prng_add_entropy,
 150     &no_prng_ready,
 151     &no_prng_read,
 152     &no_prng_done,
 153     &no_prng_export,
 154     &no_prng_import,
 155     &no_prng_test
 156 };
 157
 158 struct ltc_prng_descriptor* no_prng_desc_get(void)
 159 {
 160    int ret;
 161    no_prng_desc_t* no_prng = XMALLOC(sizeof(*no_prng));
 162    if (no_prng == NULL) return NULL;
 163    XMEMCPY(&no_prng->desc, &no_prng_desc, sizeof(no_prng_desc));
 164    ret = snprintf(no_prng->name, sizeof(no_prng->name), "no_prng@%p", no_prng);
 165    if((ret >= (int)sizeof(no_prng->name)) || (ret == -1)) {
 166       XFREE(no_prng);
 167       return NULL;
 168    }
 169    no_prng->desc.name = no_prng->name;
 170    return &no_prng->desc;
 171 }
 172
 173 void no_prng_desc_free(struct ltc_prng_descriptor* prng)
 174 {
 175    no_prng_desc_t *no_prng = (no_prng_desc_t*) prng;
 176    LTC_ARGCHKVD(no_prng != NULL);
 177    LTC_ARGCHKVD(no_prng->name == (char*)no_prng + offsetof(no_prng_desc_t, name));
 178    XFREE(no_prng);
 179 }
 180
 181 #endif
 182