Home | History | Annotate | Download | only in pkcs5 
      1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
      2  *
      3  * LibTomCrypt is a library that provides various cryptographic
      4  * algorithms in a highly modular and flexible manner.
      5  *
      6  * The library is free for all purposes without any express
      7  * guarantee it works.
      8  *
      9  * Tom St Denis, tomstdenis (at) gmail.com, http://libtomcrypt.com
     10  */
     11 #include <tomcrypt.h>
     12 
     13 /**
     14    @file pkcs_5_1.c
     15    PKCS #5, Algorithm #1, Tom St Denis
     16 */
     17 #ifdef PKCS_5
     18 /**
     19    Execute PKCS #5 v1
     20    @param password         The password (or key)
     21    @param password_len     The length of the password (octet)
     22    @param salt             The salt (or nonce) which is 8 octets long
     23    @param iteration_count  The PKCS #5 v1 iteration count
     24    @param hash_idx         The index of the hash desired
     25    @param out              [out] The destination for this algorithm
     26    @param outlen           [in/out] The max size and resulting size of the algorithm output
     27    @return CRYPT_OK if successful
     28 */
     29 int pkcs_5_alg1(const unsigned char *password, unsigned long password_len,
     30                 const unsigned char *salt,
     31                 int iteration_count,  int hash_idx,
     32                 unsigned char *out,   unsigned long *outlen)
     33 {
     34    int err;
     35    unsigned long x;
     36    hash_state    *md;
     37    unsigned char *buf;
     38 
     39    LTC_ARGCHK(password != NULL);
     40    LTC_ARGCHK(salt     != NULL);
     41    LTC_ARGCHK(out      != NULL);
     42    LTC_ARGCHK(outlen   != NULL);
     43 
     44    /* test hash IDX */
     45    if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
     46       return err;
     47    }
     48 
     49    /* allocate memory */
     50    md  = XMALLOC(sizeof(hash_state));
     51    buf = XMALLOC(MAXBLOCKSIZE);
     52    if (md == NULL || buf == NULL) {
     53       if (md != NULL) {
     54          XFREE(md);
     55       }
     56       if (buf != NULL) {
     57          XFREE(buf);
     58       }
     59       return CRYPT_MEM;
     60    }
     61 
     62    /* hash initial password + salt */
     63    if ((err = hash_descriptor[hash_idx].init(md)) != CRYPT_OK) {
     64        goto LBL_ERR;
     65    }
     66    if ((err = hash_descriptor[hash_idx].process(md, password, password_len)) != CRYPT_OK) {
     67        goto LBL_ERR;
     68    }
     69    if ((err = hash_descriptor[hash_idx].process(md, salt, 8)) != CRYPT_OK) {
     70        goto LBL_ERR;
     71    }
     72    if ((err = hash_descriptor[hash_idx].done(md, buf)) != CRYPT_OK) {
     73        goto LBL_ERR;
     74    }
     75 
     76    while (--iteration_count) {
     77       /* code goes here. */
     78       x = MAXBLOCKSIZE;
     79       if ((err = hash_memory(hash_idx, buf, hash_descriptor[hash_idx].hashsize, buf, &x)) != CRYPT_OK) {
     80          goto LBL_ERR;
     81       }
     82    }
     83 
     84    /* copy upto outlen bytes */
     85    for (x = 0; x < hash_descriptor[hash_idx].hashsize && x < *outlen; x++) {
     86        out[x] = buf[x];
     87    }
     88    *outlen = x;
     89    err = CRYPT_OK;
     90 LBL_ERR:
     91 #ifdef LTC_CLEAN_STACK
     92    zeromem(buf, MAXBLOCKSIZE);
     93    zeromem(md, sizeof(hash_state));
     94 #endif
     95 
     96    XFREE(buf);
     97    XFREE(md);
     98 
     99    return err;
    100 }
    101 
    102 #endif
    103 
    104 /* $Source: /cvs/libtom/libtomcrypt/src/misc/pkcs5/pkcs_5_1.c,v $ */
    105 /* $Revision: 1.5 $ */
    106 /* $Date: 2006/03/31 14:15:35 $ */
    107