aboutsummaryrefslogtreecommitdiff
path: root/src/crypto/chacha20.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/crypto/chacha20.cpp')
-rw-r--r--src/crypto/chacha20.cpp132
1 files changed, 131 insertions, 1 deletions
diff --git a/src/crypto/chacha20.cpp b/src/crypto/chacha20.cpp
index ac4470f04f..42a17f02ff 100644
--- a/src/crypto/chacha20.cpp
+++ b/src/crypto/chacha20.cpp
@@ -71,7 +71,7 @@ void ChaCha20::Seek(uint64_t pos)
input[13] = pos >> 32;
}
-void ChaCha20::Output(unsigned char* c, size_t bytes)
+void ChaCha20::Keystream(unsigned char* c, size_t bytes)
{
uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
@@ -178,3 +178,133 @@ void ChaCha20::Output(unsigned char* c, size_t bytes)
c += 64;
}
}
+
+void ChaCha20::Crypt(const unsigned char* m, unsigned char* c, size_t bytes)
+{
+ uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
+ uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
+ unsigned char *ctarget = nullptr;
+ unsigned char tmp[64];
+ unsigned int i;
+
+ if (!bytes) return;
+
+ j0 = input[0];
+ j1 = input[1];
+ j2 = input[2];
+ j3 = input[3];
+ j4 = input[4];
+ j5 = input[5];
+ j6 = input[6];
+ j7 = input[7];
+ j8 = input[8];
+ j9 = input[9];
+ j10 = input[10];
+ j11 = input[11];
+ j12 = input[12];
+ j13 = input[13];
+ j14 = input[14];
+ j15 = input[15];
+
+ for (;;) {
+ if (bytes < 64) {
+ // if m has fewer than 64 bytes available, copy m to tmp and
+ // read from tmp instead
+ for (i = 0;i < bytes;++i) tmp[i] = m[i];
+ m = tmp;
+ ctarget = c;
+ c = tmp;
+ }
+ x0 = j0;
+ x1 = j1;
+ x2 = j2;
+ x3 = j3;
+ x4 = j4;
+ x5 = j5;
+ x6 = j6;
+ x7 = j7;
+ x8 = j8;
+ x9 = j9;
+ x10 = j10;
+ x11 = j11;
+ x12 = j12;
+ x13 = j13;
+ x14 = j14;
+ x15 = j15;
+ for (i = 20;i > 0;i -= 2) {
+ QUARTERROUND( x0, x4, x8,x12)
+ QUARTERROUND( x1, x5, x9,x13)
+ QUARTERROUND( x2, x6,x10,x14)
+ QUARTERROUND( x3, x7,x11,x15)
+ QUARTERROUND( x0, x5,x10,x15)
+ QUARTERROUND( x1, x6,x11,x12)
+ QUARTERROUND( x2, x7, x8,x13)
+ QUARTERROUND( x3, x4, x9,x14)
+ }
+ x0 += j0;
+ x1 += j1;
+ x2 += j2;
+ x3 += j3;
+ x4 += j4;
+ x5 += j5;
+ x6 += j6;
+ x7 += j7;
+ x8 += j8;
+ x9 += j9;
+ x10 += j10;
+ x11 += j11;
+ x12 += j12;
+ x13 += j13;
+ x14 += j14;
+ x15 += j15;
+
+ x0 ^= ReadLE32(m + 0);
+ x1 ^= ReadLE32(m + 4);
+ x2 ^= ReadLE32(m + 8);
+ x3 ^= ReadLE32(m + 12);
+ x4 ^= ReadLE32(m + 16);
+ x5 ^= ReadLE32(m + 20);
+ x6 ^= ReadLE32(m + 24);
+ x7 ^= ReadLE32(m + 28);
+ x8 ^= ReadLE32(m + 32);
+ x9 ^= ReadLE32(m + 36);
+ x10 ^= ReadLE32(m + 40);
+ x11 ^= ReadLE32(m + 44);
+ x12 ^= ReadLE32(m + 48);
+ x13 ^= ReadLE32(m + 52);
+ x14 ^= ReadLE32(m + 56);
+ x15 ^= ReadLE32(m + 60);
+
+ ++j12;
+ if (!j12) ++j13;
+
+ WriteLE32(c + 0, x0);
+ WriteLE32(c + 4, x1);
+ WriteLE32(c + 8, x2);
+ WriteLE32(c + 12, x3);
+ WriteLE32(c + 16, x4);
+ WriteLE32(c + 20, x5);
+ WriteLE32(c + 24, x6);
+ WriteLE32(c + 28, x7);
+ WriteLE32(c + 32, x8);
+ WriteLE32(c + 36, x9);
+ WriteLE32(c + 40, x10);
+ WriteLE32(c + 44, x11);
+ WriteLE32(c + 48, x12);
+ WriteLE32(c + 52, x13);
+ WriteLE32(c + 56, x14);
+ WriteLE32(c + 60, x15);
+
+ if (bytes <= 64) {
+ if (bytes < 64) {
+ for (i = 0;i < bytes;++i) ctarget[i] = c[i];
+ }
+ input[12] = j12;
+ input[13] = j13;
+ return;
+ }
+ bytes -= 64;
+ c += 64;
+ m += 64;
+ }
+}