diff options
Diffstat (limited to 'libtomcrypt/src/encauth/ocb/ocb_init.c')
| -rw-r--r-- | libtomcrypt/src/encauth/ocb/ocb_init.c | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/libtomcrypt/src/encauth/ocb/ocb_init.c b/libtomcrypt/src/encauth/ocb/ocb_init.c index 604ae0e..e008a44 100644 --- a/libtomcrypt/src/encauth/ocb/ocb_init.c +++ b/libtomcrypt/src/encauth/ocb/ocb_init.c @@ -5,8 +5,6 @@ * * The library is free for all purposes without any express * guarantee it works. - * - * Tom St Denis, tomstdenis@gmail.com, http://libtom.org */ /** @@ -19,7 +17,7 @@ static const struct { int len; - unsigned char poly_div[MAXBLOCKSIZE], + unsigned char poly_div[MAXBLOCKSIZE], poly_mul[MAXBLOCKSIZE]; } polys[] = { { @@ -27,7 +25,7 @@ static const struct { { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0D }, { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1B } }, { - 16, + 16, { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x43 }, { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, @@ -44,7 +42,7 @@ static const struct { @param nonce The session nonce (length of the block size of the cipher) @return CRYPT_OK if successful */ -int ocb_init(ocb_state *ocb, int cipher, +int ocb_init(ocb_state *ocb, int cipher, const unsigned char *key, unsigned long keylen, const unsigned char *nonce) { int poly, x, y, m, err; @@ -60,20 +58,24 @@ int ocb_init(ocb_state *ocb, int cipher, /* determine which polys to use */ ocb->block_len = cipher_descriptor[cipher].block_length; - for (poly = 0; poly < (int)(sizeof(polys)/sizeof(polys[0])); poly++) { - if (polys[poly].len == ocb->block_len) { + x = (int)(sizeof(polys)/sizeof(polys[0])); + for (poly = 0; poly < x; poly++) { + if (polys[poly].len == ocb->block_len) { break; } } + if (poly == x) { + return CRYPT_INVALID_ARG; /* block_len not found in polys */ + } if (polys[poly].len != ocb->block_len) { return CRYPT_INVALID_ARG; - } + } /* schedule the key */ if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, &ocb->key)) != CRYPT_OK) { return err; } - + /* find L = E[0] */ zeromem(ocb->L, ocb->block_len); if ((err = cipher_descriptor[cipher].ecb_encrypt(ocb->L, ocb->L, &ocb->key)) != CRYPT_OK) { @@ -102,36 +104,36 @@ int ocb_init(ocb_state *ocb, int cipher, ocb->Ls[x][y] ^= polys[poly].poly_mul[y]; } } - } + } - /* find Lr = L / x */ - m = ocb->L[ocb->block_len-1] & 1; + /* find Lr = L / x */ + m = ocb->L[ocb->block_len-1] & 1; - /* shift right */ - for (x = ocb->block_len - 1; x > 0; x--) { - ocb->Lr[x] = ((ocb->L[x] >> 1) | (ocb->L[x-1] << 7)) & 255; - } - ocb->Lr[0] = ocb->L[0] >> 1; + /* shift right */ + for (x = ocb->block_len - 1; x > 0; x--) { + ocb->Lr[x] = ((ocb->L[x] >> 1) | (ocb->L[x-1] << 7)) & 255; + } + ocb->Lr[0] = ocb->L[0] >> 1; - if (m == 1) { - for (x = 0; x < ocb->block_len; x++) { - ocb->Lr[x] ^= polys[poly].poly_div[x]; - } - } + if (m == 1) { + for (x = 0; x < ocb->block_len; x++) { + ocb->Lr[x] ^= polys[poly].poly_div[x]; + } + } - /* set Li, checksum */ - zeromem(ocb->Li, ocb->block_len); - zeromem(ocb->checksum, ocb->block_len); + /* set Li, checksum */ + zeromem(ocb->Li, ocb->block_len); + zeromem(ocb->checksum, ocb->block_len); - /* set other params */ - ocb->block_index = 1; - ocb->cipher = cipher; + /* set other params */ + ocb->block_index = 1; + ocb->cipher = cipher; - return CRYPT_OK; + return CRYPT_OK; } #endif -/* $Source$ */ -/* $Revision$ */ -/* $Date$ */ +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */ |