diff options
Diffstat (limited to 'src/lib/crypto/builtin/enc_provider')
| -rw-r--r-- | src/lib/crypto/builtin/enc_provider/aes.c | 151 |
1 files changed, 139 insertions, 12 deletions
diff --git a/src/lib/crypto/builtin/enc_provider/aes.c b/src/lib/crypto/builtin/enc_provider/aes.c index bcfe3b3..2a23f7b 100644 --- a/src/lib/crypto/builtin/enc_provider/aes.c +++ b/src/lib/crypto/builtin/enc_provider/aes.c @@ -72,9 +72,130 @@ xorblock(unsigned char *out, const unsigned char *in) } } +krb5_error_code +krb5int_aes_encrypt(krb5_key key, const krb5_data *ivec, + const krb5_data *input, krb5_data *output) +{ + aes_ctx ctx; + unsigned char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE]; + int nblocks = 0, blockno; + const unsigned char *idata = (const unsigned char *) input->data; + unsigned char *odata = (unsigned char *) output->data; + +/* CHECK_SIZES; */ + + if (aes_enc_key(key->keyblock.contents, key->keyblock.length, + &ctx) != aes_good) + abort(); + + if (ivec) + memcpy(tmp, ivec->data, BLOCK_SIZE); + else + memset(tmp, 0, BLOCK_SIZE); + + nblocks = (input->length + BLOCK_SIZE - 1) / BLOCK_SIZE; + + if (nblocks == 1) { + /* XXX Used for DK function. */ + enc(odata, idata, &ctx); + } else { + unsigned int nleft; + + for (blockno = 0; blockno < nblocks - 2; blockno++) { + xorblock(tmp, idata + blockno * BLOCK_SIZE); + enc(tmp2, tmp, &ctx); + memcpy(odata + blockno * BLOCK_SIZE, tmp2, BLOCK_SIZE); + + /* Set up for next block. */ + memcpy(tmp, tmp2, BLOCK_SIZE); + } + /* Do final CTS step for last two blocks (the second of which + may or may not be incomplete). */ + xorblock(tmp, idata + (nblocks - 2) * BLOCK_SIZE); + enc(tmp2, tmp, &ctx); + nleft = input->length - (nblocks - 1) * BLOCK_SIZE; + memcpy(odata + (nblocks - 1) * BLOCK_SIZE, tmp2, nleft); + memcpy(tmp, tmp2, BLOCK_SIZE); + + memset(tmp3, 0, sizeof(tmp3)); + memcpy(tmp3, idata + (nblocks - 1) * BLOCK_SIZE, nleft); + xorblock(tmp, tmp3); + enc(tmp2, tmp, &ctx); + memcpy(odata + (nblocks - 2) * BLOCK_SIZE, tmp2, BLOCK_SIZE); + if (ivec) + memcpy(ivec->data, tmp2, BLOCK_SIZE); + } + + return 0; +} + +krb5_error_code +krb5int_aes_decrypt(krb5_key key, const krb5_data *ivec, + const krb5_data *input, krb5_data *output) +{ + aes_ctx ctx; + unsigned char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE]; + int nblocks = 0, blockno; + const unsigned char *idata = (const unsigned char *) input->data; + unsigned char *odata = (unsigned char *) output->data; + + CHECK_SIZES; + + if (aes_dec_key(key->keyblock.contents, key->keyblock.length, + &ctx) != aes_good) + abort(); + + if (ivec) + memcpy(tmp, ivec->data, BLOCK_SIZE); + else + memset(tmp, 0, BLOCK_SIZE); + + nblocks = (input->length + BLOCK_SIZE - 1) / BLOCK_SIZE; + + if (nblocks == 1) { + if (input->length < BLOCK_SIZE) + abort(); + dec(odata, idata, &ctx); + } else { + + for (blockno = 0; blockno < nblocks - 2; blockno++) { + dec(tmp2, idata + blockno * BLOCK_SIZE, &ctx); + xorblock(tmp2, tmp); + memcpy(odata + blockno * BLOCK_SIZE, tmp2, BLOCK_SIZE); + memcpy(tmp, idata + blockno * BLOCK_SIZE, BLOCK_SIZE); + } + /* Do last two blocks, the second of which (next-to-last block + of plaintext) may be incomplete. */ + dec(tmp2, idata + (nblocks - 2) * BLOCK_SIZE, &ctx); + /* Set tmp3 to last ciphertext block, padded. */ + memset(tmp3, 0, sizeof(tmp3)); + memcpy(tmp3, idata + (nblocks - 1) * BLOCK_SIZE, + input->length - (nblocks - 1) * BLOCK_SIZE); + /* Set tmp2 to last (possibly partial) plaintext block, and + save it. */ + xorblock(tmp2, tmp3); + memcpy(odata + (nblocks - 1) * BLOCK_SIZE, tmp2, + input->length - (nblocks - 1) * BLOCK_SIZE); + /* Maybe keep the trailing part, and copy in the last + ciphertext block. */ + memcpy(tmp2, tmp3, input->length - (nblocks - 1) * BLOCK_SIZE); + /* Decrypt, to get next to last plaintext block xor previous + ciphertext. */ + dec(tmp3, tmp2, &ctx); + xorblock(tmp3, tmp); + memcpy(odata + (nblocks - 2) * BLOCK_SIZE, tmp3, BLOCK_SIZE); + if (ivec) + memcpy(ivec->data, idata + (nblocks - 2) * BLOCK_SIZE, BLOCK_SIZE); + } + + return 0; +} + static krb5_error_code -aes_encrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data, - size_t num_data) +krb5int_aes_encrypt_iov(krb5_key key, + const krb5_data *ivec, + krb5_crypto_iov *data, + size_t num_data) { aes_ctx ctx; unsigned char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE]; @@ -158,8 +279,10 @@ aes_encrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data, } static krb5_error_code -aes_decrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data, - size_t num_data) +krb5int_aes_decrypt_iov(krb5_key key, + const krb5_data *ivec, + krb5_crypto_iov *data, + size_t num_data) { aes_ctx ctx; unsigned char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE]; @@ -249,8 +372,8 @@ aes_decrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data, } static krb5_error_code -aes_init_state(const krb5_keyblock *key, krb5_keyusage usage, - krb5_data *state) +krb5int_aes_init_state (const krb5_keyblock *key, krb5_keyusage usage, + krb5_data *state) { state->length = 16; state->data = malloc(16); @@ -263,19 +386,23 @@ aes_init_state(const krb5_keyblock *key, krb5_keyusage usage, const struct krb5_enc_provider krb5int_enc_aes128 = { 16, 16, 16, - aes_encrypt, - aes_decrypt, + krb5int_aes_encrypt, + krb5int_aes_decrypt, krb5int_aes_make_key, - aes_init_state, + krb5int_aes_init_state, krb5int_default_free_state, + krb5int_aes_encrypt_iov, + krb5int_aes_decrypt_iov }; const struct krb5_enc_provider krb5int_enc_aes256 = { 16, 32, 32, - aes_encrypt, - aes_decrypt, + krb5int_aes_encrypt, + krb5int_aes_decrypt, krb5int_aes_make_key, - aes_init_state, + krb5int_aes_init_state, krb5int_default_free_state, + krb5int_aes_encrypt_iov, + krb5int_aes_decrypt_iov }; |