diff options
Diffstat (limited to 'code/crypto/chacha/chacha.c')
-rw-r--r-- | code/crypto/chacha/chacha.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/code/crypto/chacha/chacha.c b/code/crypto/chacha/chacha.c new file mode 100644 index 0000000..fba03c9 --- /dev/null +++ b/code/crypto/chacha/chacha.c @@ -0,0 +1,77 @@ +/* $OpenBSD: chacha.c,v 1.7 2015/12/09 14:07:55 bcook Exp $ */ +/* + * Copyright (c) 2014 Joel Sing <jsing@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <stdint.h> + +#include <chacha.h> + +#include "chacha-merged.c" + +void +ChaCha_set_key(ChaCha_ctx *ctx, const unsigned char *key, uint32_t keybits) +{ + chacha_keysetup((chacha_ctx *)ctx, key, keybits); + ctx->unused = 0; +} + +void +ChaCha_set_iv(ChaCha_ctx *ctx, const unsigned char *iv, + const unsigned char *counter) +{ + chacha_ivsetup((chacha_ctx *)ctx, iv, counter); + ctx->unused = 0; +} + +void +ChaCha(ChaCha_ctx *ctx, unsigned char *out, const unsigned char *in, size_t len) +{ + unsigned char *k; + int i, l; + + /* Consume remaining keystream, if any exists. */ + if (ctx->unused > 0) { + k = ctx->ks + 64 - ctx->unused; + l = (len > ctx->unused) ? ctx->unused : len; + for (i = 0; i < l; i++) + *(out++) = *(in++) ^ *(k++); + ctx->unused -= l; + len -= l; + } + + chacha_encrypt_bytes((chacha_ctx *)ctx, in, out, (uint32_t)len); +} + +void +CRYPTO_chacha_20(unsigned char *out, const unsigned char *in, size_t len, + const unsigned char key[32], const unsigned char iv[8], uint64_t counter) +{ + struct chacha_ctx ctx; + + /* + * chacha_ivsetup expects the counter to be in u8. Rather than + * converting size_t to u8 and then back again, pass a counter of + * NULL and manually assign it afterwards. + */ + chacha_keysetup(&ctx, key, 256); + chacha_ivsetup(&ctx, iv, NULL); + if (counter != 0) { + ctx.input[12] = (uint32_t)counter; + ctx.input[13] = (uint32_t)(counter >> 32); + } + + chacha_encrypt_bytes(&ctx, in, out, (uint32_t)len); +} |