userapps/opensource/sshd/libtomcrypt/yarrow.c

   1 #include "mycrypt.h"
   2
   3 #ifdef YARROW
   4
   5 const struct _prng_descriptor yarrow_desc =
   6 {
   7     "yarrow",
   8     &yarrow_start,
   9     &yarrow_add_entropy,
  10     &yarrow_ready,
  11     &yarrow_read
  12 };
  13
  14 int yarrow_start(prng_state *prng)
  15 {
  16    int err;
  17
  18    _ARGCHK(prng != NULL);
  19
  20    /* these are the default hash/cipher combo used */
  21 #ifdef RIJNDAEL
  22    prng->yarrow.cipher = register_cipher(&rijndael_desc);
  23 #elif defined(NOEKEON)
  24    prng->yarrow.cipher = register_cipher(&noekeon_desc);
  25 #elif defined(BLOWFISH)
  26    prng->yarrow.cipher = register_cipher(&blowfish_desc);
  27 #elif defined(TWOFISH)
  28    prng->yarrow.cipher = register_cipher(&twofish_desc);
  29 #elif defined(CAST5)
  30    prng->yarrow.cipher = register_cipher(&cast5_desc);
  31 #elif defined(SAFER)
  32    prng->yarrow.cipher = register_cipher(&saferp_desc);
  33 #elif defined(RC5)
  34    prng->yarrow.cipher = register_cipher(&rc5_desc);
  35 #elif defined(RC6)
  36    prng->yarrow.cipher = register_cipher(&rc6_desc);
  37 #elif defined(XTEA)
  38    prng->yarrow.cipher = register_cipher(&xtea_desc);
  39 #elif defined(RC2)
  40    prng->yarrow.cipher = register_cipher(&rc2_desc);
  41 #elif defined(DES)
  42    prng->yarrow.cipher = register_cipher(&des3_desc);
  43 #elif
  44    #error YARROW needs at least one CIPHER
  45 #endif
  46    if ((err = cipher_is_valid(prng->yarrow.cipher)) != CRYPT_OK) {
  47       return err;
  48    }
  49
  50 #ifdef SHA256
  51    prng->yarrow.hash   = register_hash(&sha256_desc);
  52 #elif defined(SHA512)
  53    prng->yarrow.hash   = register_hash(&sha512_desc);
  54 #elif defined(SHA384)
  55    prng->yarrow.hash   = register_hash(&sha384_desc);
  56 #elif defined(SHA1)
  57    prng->yarrow.hash   = register_hash(&sha1_desc);
  58 #elif defined(TIGER)
  59    prng->yarrow.hash   = register_hash(&tiger_desc);
  60 #elif defined(MD5)
  61    prng->yarrow.hash   = register_hash(&md5_desc);
  62 #elif defined(MD4)
  63    prng->yarrow.hash   = register_hash(&md4_desc);
  64 #elif defined(MD2)
  65    prng->yarrow.hash   = register_hash(&md2_desc);
  66 #else
  67    #error YARROW needs at least one HASH
  68 #endif
  69    if ((err = hash_is_valid(prng->yarrow.hash)) != CRYPT_OK) {
  70       return err;
  71    }
  72
  73    /* zero the memory used */
  74    zeromem(prng->yarrow.pool, sizeof(prng->yarrow.pool));
  75
  76    return CRYPT_OK;
  77 }
  78
  79 int yarrow_add_entropy(const unsigned char *buf, unsigned long len, prng_state *prng)
  80 {
  81    hash_state md;
  82    int err;
  83
  84    _ARGCHK(buf != NULL);
  85    _ARGCHK(prng != NULL);
  86
  87    if ((err = hash_is_valid(prng->yarrow.hash)) != CRYPT_OK) {
  88       return err;
  89    }
  90
  91    /* start the hash */
  92    hash_descriptor[prng->yarrow.hash].init(&md);
  93
  94    /* hash the current pool */
  95    hash_descriptor[prng->yarrow.hash].process(&md, prng->yarrow.pool, hash_descriptor[prng->yarrow.hash].hashsize);
  96
  97    /* add the new entropy */
  98    hash_descriptor[prng->yarrow.hash].process(&md, buf, len);
  99
 100    /* store result */
 101    hash_descriptor[prng->yarrow.hash].done(&md, prng->yarrow.pool);
 102
 103    return CRYPT_OK;
 104 }
 105
 106 int yarrow_ready(prng_state *prng)
 107 {
 108    int ks, err;
 109
 110    _ARGCHK(prng != NULL);
 111
 112    if ((err = hash_is_valid(prng->yarrow.hash)) != CRYPT_OK) {
 113       return err;
 114    }
 115
 116    if ((err = cipher_is_valid(prng->yarrow.cipher)) != CRYPT_OK) {
 117       return err;
 118    }
 119
 120    /* setup CTR mode using the "pool" as the key */
 121    ks = (int)hash_descriptor[prng->yarrow.hash].hashsize;
 122    if ((err = cipher_descriptor[prng->yarrow.cipher].keysize(&ks)) != CRYPT_OK) {
 123       return err;
 124    }
 125
 126    if ((err = ctr_start(prng->yarrow.cipher, prng->yarrow.pool, prng->yarrow.pool, ks, 0, &prng->yarrow.ctr)) != CRYPT_OK) {
 127       return err;
 128    }
 129    return CRYPT_OK;
 130 }
 131
 132 unsigned long yarrow_read(unsigned char *buf, unsigned long len, prng_state *prng)
 133 {
 134    _ARGCHK(buf != NULL);
 135    _ARGCHK(prng != NULL);
 136
 137    /* put buf in predictable state first */
 138    zeromem(buf, len);
 139
 140    /* now randomize it */
 141    if (ctr_encrypt(buf, buf, len, &prng->yarrow.ctr) != CRYPT_OK) {
 142       return 0;
 143    }
 144    return len;
 145 }
 146
 147 #endif
 148