Mercurial > dropbear
view libtomcrypt/src/pk/pkcs1/pkcs_1_mgf1.c @ 397:2908122e9eed channel-fix
disapproval of revision '1250b8af44b62d8f4fe0f8d9fc7e7a1cc34e7e1c'
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sat, 03 Feb 2007 08:10:09 +0000 |
parents | 1b9e69c058d2 |
children | 0cbe8f6dbf9e |
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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 "tomcrypt.h" /** @file pkcs_1_mgf1.c The Mask Generation Function (MGF1) for PKCS #1, Tom St Denis */ #ifdef PKCS_1 /** Perform PKCS #1 MGF1 (internal) @param seed The seed for MGF1 @param seedlen The length of the seed @param hash_idx The index of the hash desired @param mask [out] The destination @param masklen The length of the mask desired @return CRYPT_OK if successful */ int pkcs_1_mgf1(const unsigned char *seed, unsigned long seedlen, int hash_idx, unsigned char *mask, unsigned long masklen) { unsigned long hLen, x; ulong32 counter; int err; hash_state *md; unsigned char *buf; LTC_ARGCHK(seed != NULL); LTC_ARGCHK(mask != NULL); /* ensure valid hash */ if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { return err; } /* get hash output size */ hLen = hash_descriptor[hash_idx].hashsize; /* allocate memory */ md = XMALLOC(sizeof(hash_state)); buf = XMALLOC(hLen); if (md == NULL || buf == NULL) { if (md != NULL) { XFREE(md); } if (buf != NULL) { XFREE(buf); } return CRYPT_MEM; } /* start counter */ counter = 0; while (masklen > 0) { /* handle counter */ STORE32H(counter, buf); ++counter; /* get hash of seed || counter */ if ((err = hash_descriptor[hash_idx].init(md)) != CRYPT_OK) { goto LBL_ERR; } if ((err = hash_descriptor[hash_idx].process(md, seed, seedlen)) != CRYPT_OK) { goto LBL_ERR; } if ((err = hash_descriptor[hash_idx].process(md, buf, 4)) != CRYPT_OK) { goto LBL_ERR; } if ((err = hash_descriptor[hash_idx].done(md, buf)) != CRYPT_OK) { goto LBL_ERR; } /* store it */ for (x = 0; x < hLen && masklen > 0; x++, masklen--) { *mask++ = buf[x]; } } err = CRYPT_OK; LBL_ERR: #ifdef LTC_CLEAN_STACK zeromem(buf, hLen); zeromem(md, sizeof(hash_state)); #endif XFREE(buf); XFREE(md); return err; } #endif /* PKCS_1 */ /* $Source: /cvs/libtom/libtomcrypt/src/pk/pkcs1/pkcs_1_mgf1.c,v $ */ /* $Revision: 1.4 $ */ /* $Date: 2005/05/05 14:35:59 $ */