Mercurial > dropbear
view pkcs_5_2.c @ 147:c2b93763dac9 libtomcrypt
Fixes for it to compile and work nicely with Dropbear.
In particular, OS X's 'ar' doesn't seem to like arrays
which don't have initialising values.
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 19 Dec 2004 16:23:32 +0000 |
parents | 5d99163f7e32 |
children |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://libtomcrypt.org */ #include <mycrypt.h> /* PKCS #5, Algorithm #2 */ #ifdef PKCS_5 int pkcs_5_alg2(const unsigned char *password, unsigned long password_len, const unsigned char *salt, unsigned long salt_len, int iteration_count, int hash_idx, unsigned char *out, unsigned long *outlen) { int err, itts; unsigned long stored, left, x, y, blkno; unsigned char *buf[2]; hmac_state *hmac; _ARGCHK(password != NULL); _ARGCHK(salt != NULL); _ARGCHK(out != NULL); _ARGCHK(outlen != NULL); /* test hash IDX */ if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { return err; } buf[0] = XMALLOC(MAXBLOCKSIZE * 2); hmac = XMALLOC(sizeof(hmac_state)); if (hmac == NULL || buf[0] == NULL) { if (hmac != NULL) { XFREE(hmac); } if (buf[0] != NULL) { XFREE(buf[0]); } return CRYPT_MEM; } /* buf[1] points to the second block of MAXBLOCKSIZE bytes */ buf[1] = buf[0] + MAXBLOCKSIZE; left = *outlen; blkno = 1; stored = 0; while (left != 0) { /* process block number blkno */ zeromem(buf[0], MAXBLOCKSIZE*2); /* store current block number and increment for next pass */ STORE32H(blkno, buf[1]); ++blkno; /* get PRF(P, S||int(blkno)) */ if ((err = hmac_init(hmac, hash_idx, password, password_len)) != CRYPT_OK) { goto __ERR; } if ((err = hmac_process(hmac, salt, salt_len)) != CRYPT_OK) { goto __ERR; } if ((err = hmac_process(hmac, buf[1], 4)) != CRYPT_OK) { goto __ERR; } x = MAXBLOCKSIZE; if ((err = hmac_done(hmac, buf[0], &x)) != CRYPT_OK) { goto __ERR; } /* now compute repeated and XOR it in buf[1] */ XMEMCPY(buf[1], buf[0], x); for (itts = 1; itts < iteration_count; ++itts) { if ((err = hmac_memory(hash_idx, password, password_len, buf[0], x, buf[0], &x)) != CRYPT_OK) { goto __ERR; } for (y = 0; y < x; y++) { buf[1][y] ^= buf[0][y]; } } /* now emit upto x bytes of buf[1] to output */ for (y = 0; y < x && left != 0; ++y) { out[stored++] = buf[1][y]; --left; } } *outlen = stored; err = CRYPT_OK; __ERR: #ifdef CLEAN_STACK zeromem(buf[0], MAXBLOCKSIZE*2); zeromem(hmac, sizeof(hmac_state)); #endif XFREE(hmac); XFREE(buf[0]); return err; } #endif