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Diffstat (limited to 'src/libsodium/crypto_stream/aes256estream/hongjun/aes256-ctr.c')
-rw-r--r--src/libsodium/crypto_stream/aes256estream/hongjun/aes256-ctr.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/src/libsodium/crypto_stream/aes256estream/hongjun/aes256-ctr.c b/src/libsodium/crypto_stream/aes256estream/hongjun/aes256-ctr.c
new file mode 100644
index 0000000..c35e310
--- /dev/null
+++ b/src/libsodium/crypto_stream/aes256estream/hongjun/aes256-ctr.c
@@ -0,0 +1,239 @@
+/* aes-ctr.c */
+/* AES in CTR mode. */
+
+/* Hongjun Wu, January 2007*/
+
+
+/* ------------------------------------------------------------------------- */
+
+#include "api.h"
+#include "aes256.h"
+
+#include <string.h>
+
+/* ------------------------------------------------------------------------- */
+/* key setup for AES-256*/
+static void
+ECRYPT_keysetup(ECRYPT_ctx* ctx, const u8* key, u32 keysize, u32 ivsize)
+{
+ unsigned int w[Nk*(Nr+1)], temp;
+ int i, j;
+
+ (void) keysize;
+ (void) ivsize;
+ (void) sizeof(char[sizeof *ctx == crypto_stream_BEFORENMBYTES ? 1 : -1]);
+
+ for( i = 0; i < Nk; i++ ) {
+ w[i] = key[(i << 2)];
+ w[i] |= key[(i << 2)+1] << 8;
+ w[i] |= key[(i << 2)+2] << 16;
+ w[i] |= (unsigned int) key[(i << 2)+3] << 24;
+ }
+
+ i = Nk;
+
+ while( i < Nb*(Nr+1) ) {
+ temp = w[i-1];
+
+ temp = (unsigned int) Sbox[temp & 0xFF] << 24 ^
+ Sbox[(temp >> 8) & 0xFF] ^
+ (Sbox[(temp >> 16) & 0xFF] << 8 ) ^
+ (Sbox[(temp >> 24) & 0xFF] << 16) ^
+ Rcon[i/Nk];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ temp = Sbox[temp & 0xFF] ^
+ Sbox[(temp >> 8) & 0xFF] << 8 ^
+ (Sbox[(temp >> 16) & 0xFF] << 16) ^
+ ((unsigned int) Sbox[(temp >> 24) & 0xFF] << 24);
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+
+ temp = w[i-1];
+ w[i] = w[i-Nk] ^ temp;
+ i++;
+ }
+
+ for (i = 0; i <= Nr; i++) {
+ for (j = 0; j < Nb; j++) {
+ ctx->round_key[i][j] = SWP32(w[(i<<2)+j]);
+ }
+ }
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void
+ECRYPT_ivsetup(ECRYPT_ctx* ctx, const u8* iv)
+{
+ (void) sizeof(char[(sizeof ctx->counter) == crypto_stream_NONCEBYTES ? 1 : -1]);
+ memcpy(ctx->counter, iv, crypto_stream_NONCEBYTES);
+}
+
+/* ------------------------------------------------------------------------- */
+
+/*compute the intermediate values for the first two rounds*/
+static void
+partial_precompute_tworounds(ECRYPT_ctx* ctx)
+{
+ u32 x0,x1,x2,x3,y0,y1,y2,y3;
+
+ x0 = ctx->counter[0] ^ ctx->round_key[0][0];
+ x1 = ctx->counter[1] ^ ctx->round_key[0][1];
+ x2 = ctx->counter[2] ^ ctx->round_key[0][2];
+ x3 = ctx->counter[3] ^ ctx->round_key[0][3];
+ x0 &= SWP32(0xffffff00);
+ round(ctx,x0,x1,x2,x3,y0,y1,y2,y3,1);
+ ctx->first_round_output_x0 = y0 ^ T0[0];
+ y0 = 0;
+ round(ctx,y0,y1,y2,y3,x0,x1,x2,x3,2);
+ ctx->second_round_output[0] = x0 ^ T0[0];
+ ctx->second_round_output[1] = x1 ^ T3[0];
+ ctx->second_round_output[2] = x2 ^ T2[0];
+ ctx->second_round_output[3] = x3 ^ T1[0];
+}
+
+/* ------------------------------------------------------------------------- */
+
+#ifndef CPU_ALIGNED_ACCESS_REQUIRED
+# define UNALIGNED_U32_READ(P, I) (((const u32 *)(const void *) (P))[(I)])
+#else
+static inline uint32_t
+UNALIGNED_U32_READ(const u8 * const p, const size_t i)
+{
+ uint32_t t;
+ (void) sizeof(int[sizeof(*p) == sizeof(char) ? 1 : -1]);
+ memcpy(&t, p + i * (sizeof t / sizeof *p), sizeof t);
+ return t;
+}
+#endif
+
+/* ------------------------------------------------------------------------- */
+
+static void
+ECRYPT_process_bytes(int action, ECRYPT_ctx* ctx, const u8* input, u8* output,
+ u32 msglen)
+{
+ __attribute__((aligned(32))) u8 keystream[16];
+ u32 i;
+
+ (void) action;
+ memset(keystream, 0, sizeof keystream);
+ partial_precompute_tworounds(ctx);
+
+ for ( ; msglen >= 16; msglen -= 16, input += 16, output += 16) {
+ aes256_enc_block(ctx->counter, keystream, ctx);
+
+ ((u32*)output)[0] = UNALIGNED_U32_READ(input, 0) ^ ((u32*)keystream)[0] ^ ctx->round_key[Nr][0];
+ ((u32*)output)[1] = UNALIGNED_U32_READ(input, 1) ^ ((u32*)keystream)[1] ^ ctx->round_key[Nr][1];
+ ((u32*)output)[2] = UNALIGNED_U32_READ(input, 2) ^ ((u32*)keystream)[2] ^ ctx->round_key[Nr][2];
+ ((u32*)output)[3] = UNALIGNED_U32_READ(input, 3) ^ ((u32*)keystream)[3] ^ ctx->round_key[Nr][3];
+
+ ctx->counter[0] = SWP32(SWP32(ctx->counter[0]) + 1);
+
+ if ((ctx->counter[0] & SWP32(0xff))== 0) {
+ partial_precompute_tworounds(ctx);
+ }
+ }
+
+ if (msglen > 0) {
+ aes256_enc_block(ctx->counter, keystream, ctx);
+ ((u32*)keystream)[0] ^= ctx->round_key[Nr][0];
+ ((u32*)keystream)[1] ^= ctx->round_key[Nr][1];
+ ((u32*)keystream)[2] ^= ctx->round_key[Nr][2];
+ ((u32*)keystream)[3] ^= ctx->round_key[Nr][3];
+
+ for (i = 0; i < msglen; i ++) {
+ output[i] = input[i] ^ keystream[i];
+ }
+ }
+}
+
+/* ------------------------------------------------------------------------- */
+
+#include "ecrypt-sync.h"
+
+int
+crypto_stream_beforenm(unsigned char *c, const unsigned char *k)
+{
+ ECRYPT_ctx * const ctx = (ECRYPT_ctx *) c;
+
+ ECRYPT_keysetup(ctx, k, crypto_stream_KEYBYTES * 8,
+ crypto_stream_NONCEBYTES * 8);
+ return 0;
+}
+
+int
+crypto_stream_afternm(unsigned char *out, unsigned long long len,
+ const unsigned char *nonce, const unsigned char *c)
+{
+ ECRYPT_ctx * const ctx = (ECRYPT_ctx *) c;
+ unsigned long long i;
+
+ ECRYPT_ivsetup(ctx, nonce);
+ for (i = 0U; i < len; ++i) {
+ out[i] = 0U;
+ }
+ ECRYPT_encrypt_bytes(ctx, (u8 *) out, (u8 *) out, len);
+
+ return 0;
+}
+
+int
+crypto_stream_xor_afternm(unsigned char *out, const unsigned char *in,
+ unsigned long long len, const unsigned char *nonce,
+ const unsigned char *c)
+{
+ ECRYPT_ctx * const ctx = (ECRYPT_ctx *) c;
+
+ ECRYPT_ivsetup(ctx, nonce);
+ ECRYPT_encrypt_bytes(ctx, (const u8 *) in, (u8 *) out, len);
+
+ return 0;
+}
+
+int
+crypto_stream(unsigned char *out, unsigned long long outlen,
+ const unsigned char *n, const unsigned char *k)
+{
+ unsigned char d[crypto_stream_BEFORENMBYTES];
+
+ crypto_stream_beforenm(d, k);
+ crypto_stream_afternm(out, outlen, n, d);
+
+ return 0;
+}
+
+int crypto_stream_xor(unsigned char *out, const unsigned char *in,
+ unsigned long long inlen, const unsigned char *n,
+ const unsigned char *k)
+{
+ unsigned char d[crypto_stream_BEFORENMBYTES];
+
+ crypto_stream_beforenm(d, k);
+ crypto_stream_xor_afternm(out, in, inlen, n, d);
+
+ return 0;
+}
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