diff options
Diffstat (limited to 'third_party/bearssl/src/aes_big_ctrcbc.c')
| -rw-r--r-- | third_party/bearssl/src/aes_big_ctrcbc.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/third_party/bearssl/src/aes_big_ctrcbc.c b/third_party/bearssl/src/aes_big_ctrcbc.c new file mode 100644 index 0000000..d45ca76 --- /dev/null +++ b/third_party/bearssl/src/aes_big_ctrcbc.c @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2017 Thomas Pornin <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "inner.h" + +/* see bearssl_block.h */ +void +br_aes_big_ctrcbc_init(br_aes_big_ctrcbc_keys *ctx, + const void *key, size_t len) +{ + ctx->vtable = &br_aes_big_ctrcbc_vtable; + ctx->num_rounds = br_aes_keysched(ctx->skey, key, len); +} + +static void +xorbuf(void *dst, const void *src, size_t len) +{ + unsigned char *d; + const unsigned char *s; + + d = dst; + s = src; + while (len -- > 0) { + *d ++ ^= *s ++; + } +} + +/* see bearssl_block.h */ +void +br_aes_big_ctrcbc_ctr(const br_aes_big_ctrcbc_keys *ctx, + void *ctr, void *data, size_t len) +{ + unsigned char *buf, *bctr; + uint32_t cc0, cc1, cc2, cc3; + + buf = data; + bctr = ctr; + cc3 = br_dec32be(bctr + 0); + cc2 = br_dec32be(bctr + 4); + cc1 = br_dec32be(bctr + 8); + cc0 = br_dec32be(bctr + 12); + while (len > 0) { + unsigned char tmp[16]; + uint32_t carry; + + br_enc32be(tmp + 0, cc3); + br_enc32be(tmp + 4, cc2); + br_enc32be(tmp + 8, cc1); + br_enc32be(tmp + 12, cc0); + br_aes_big_encrypt(ctx->num_rounds, ctx->skey, tmp); + xorbuf(buf, tmp, 16); + buf += 16; + len -= 16; + cc0 ++; + carry = (~(cc0 | -cc0)) >> 31; + cc1 += carry; + carry &= (~(cc1 | -cc1)) >> 31; + cc2 += carry; + carry &= (~(cc2 | -cc2)) >> 31; + cc3 += carry; + } + br_enc32be(bctr + 0, cc3); + br_enc32be(bctr + 4, cc2); + br_enc32be(bctr + 8, cc1); + br_enc32be(bctr + 12, cc0); +} + +/* see bearssl_block.h */ +void +br_aes_big_ctrcbc_mac(const br_aes_big_ctrcbc_keys *ctx, + void *cbcmac, const void *data, size_t len) +{ + const unsigned char *buf; + + buf = data; + while (len > 0) { + xorbuf(cbcmac, buf, 16); + br_aes_big_encrypt(ctx->num_rounds, ctx->skey, cbcmac); + buf += 16; + len -= 16; + } +} + +/* see bearssl_block.h */ +void +br_aes_big_ctrcbc_encrypt(const br_aes_big_ctrcbc_keys *ctx, + void *ctr, void *cbcmac, void *data, size_t len) +{ + br_aes_big_ctrcbc_ctr(ctx, ctr, data, len); + br_aes_big_ctrcbc_mac(ctx, cbcmac, data, len); +} + +/* see bearssl_block.h */ +void +br_aes_big_ctrcbc_decrypt(const br_aes_big_ctrcbc_keys *ctx, + void *ctr, void *cbcmac, void *data, size_t len) +{ + br_aes_big_ctrcbc_mac(ctx, cbcmac, data, len); + br_aes_big_ctrcbc_ctr(ctx, ctr, data, len); +} + +/* see bearssl_block.h */ +const br_block_ctrcbc_class br_aes_big_ctrcbc_vtable = { + sizeof(br_aes_big_ctrcbc_keys), + 16, + 4, + (void (*)(const br_block_ctrcbc_class **, const void *, size_t)) + &br_aes_big_ctrcbc_init, + (void (*)(const br_block_ctrcbc_class *const *, + void *, void *, void *, size_t)) + &br_aes_big_ctrcbc_encrypt, + (void (*)(const br_block_ctrcbc_class *const *, + void *, void *, void *, size_t)) + &br_aes_big_ctrcbc_decrypt, + (void (*)(const br_block_ctrcbc_class *const *, + void *, void *, size_t)) + &br_aes_big_ctrcbc_ctr, + (void (*)(const br_block_ctrcbc_class *const *, + void *, const void *, size_t)) + &br_aes_big_ctrcbc_mac +}; |