diff options
Diffstat (limited to 'security/nss/lib/freebl/chacha20.c')
-rw-r--r-- | security/nss/lib/freebl/chacha20.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/chacha20.c b/security/nss/lib/freebl/chacha20.c new file mode 100644 index 000000000..f55d1e670 --- /dev/null +++ b/security/nss/lib/freebl/chacha20.c @@ -0,0 +1,119 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* Adopted from the public domain code in NaCl by djb. */ + +#include <string.h> +#include <stdio.h> + +#include "prtypes.h" +#include "secport.h" +#include "chacha20.h" + +#if defined(_MSC_VER) +#pragma intrinsic(_lrotl) +#define ROTL32(x, n) _lrotl(x, n) +#else +#define ROTL32(x, n) ((x << n) | (x >> ((8 * sizeof x) - n))) +#endif + +#define ROTATE(v, c) ROTL32((v), (c)) + +#define U32TO8_LITTLE(p, v) \ + { \ + (p)[0] = ((v)) & 0xff; \ + (p)[1] = ((v) >> 8) & 0xff; \ + (p)[2] = ((v) >> 16) & 0xff; \ + (p)[3] = ((v) >> 24) & 0xff; \ + } +#define U8TO32_LITTLE(p) \ + (((PRUint32)((p)[0])) | ((PRUint32)((p)[1]) << 8) | \ + ((PRUint32)((p)[2]) << 16) | ((PRUint32)((p)[3]) << 24)) + +#define QUARTERROUND(x, a, b, c, d) \ + x[a] = x[a] + x[b]; \ + x[d] = ROTATE(x[d] ^ x[a], 16); \ + x[c] = x[c] + x[d]; \ + x[b] = ROTATE(x[b] ^ x[c], 12); \ + x[a] = x[a] + x[b]; \ + x[d] = ROTATE(x[d] ^ x[a], 8); \ + x[c] = x[c] + x[d]; \ + x[b] = ROTATE(x[b] ^ x[c], 7); + +static void +ChaChaCore(unsigned char output[64], const PRUint32 input[16], int num_rounds) +{ + PRUint32 x[16]; + int i; + + PORT_Memcpy(x, input, sizeof(PRUint32) * 16); + for (i = num_rounds; i > 0; i -= 2) { + QUARTERROUND(x, 0, 4, 8, 12) + QUARTERROUND(x, 1, 5, 9, 13) + QUARTERROUND(x, 2, 6, 10, 14) + QUARTERROUND(x, 3, 7, 11, 15) + QUARTERROUND(x, 0, 5, 10, 15) + QUARTERROUND(x, 1, 6, 11, 12) + QUARTERROUND(x, 2, 7, 8, 13) + QUARTERROUND(x, 3, 4, 9, 14) + } + + for (i = 0; i < 16; ++i) { + x[i] = x[i] + input[i]; + } + for (i = 0; i < 16; ++i) { + U32TO8_LITTLE(output + 4 * i, x[i]); + } +} + +static const unsigned char sigma[16] = "expand 32-byte k"; + +void +ChaCha20XOR(unsigned char *out, const unsigned char *in, unsigned int inLen, + const unsigned char key[32], const unsigned char nonce[12], + uint32_t counter) +{ + unsigned char block[64]; + PRUint32 input[16]; + unsigned int i; + + input[4] = U8TO32_LITTLE(key + 0); + input[5] = U8TO32_LITTLE(key + 4); + input[6] = U8TO32_LITTLE(key + 8); + input[7] = U8TO32_LITTLE(key + 12); + + input[8] = U8TO32_LITTLE(key + 16); + input[9] = U8TO32_LITTLE(key + 20); + input[10] = U8TO32_LITTLE(key + 24); + input[11] = U8TO32_LITTLE(key + 28); + + input[0] = U8TO32_LITTLE(sigma + 0); + input[1] = U8TO32_LITTLE(sigma + 4); + input[2] = U8TO32_LITTLE(sigma + 8); + input[3] = U8TO32_LITTLE(sigma + 12); + + input[12] = counter; + input[13] = U8TO32_LITTLE(nonce + 0); + input[14] = U8TO32_LITTLE(nonce + 4); + input[15] = U8TO32_LITTLE(nonce + 8); + + while (inLen >= 64) { + ChaChaCore(block, input, 20); + for (i = 0; i < 64; i++) { + out[i] = in[i] ^ block[i]; + } + + input[12]++; + inLen -= 64; + in += 64; + out += 64; + } + + if (inLen > 0) { + ChaChaCore(block, input, 20); + for (i = 0; i < inLen; i++) { + out[i] = in[i] ^ block[i]; + } + } +} |