diff options
Diffstat (limited to 'src/libsodium/crypto_stream/salsa208/ref/xor_salsa208.c')
-rw-r--r-- | src/libsodium/crypto_stream/salsa208/ref/xor_salsa208.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/libsodium/crypto_stream/salsa208/ref/xor_salsa208.c b/src/libsodium/crypto_stream/salsa208/ref/xor_salsa208.c new file mode 100644 index 0000000..9f6dac5 --- /dev/null +++ b/src/libsodium/crypto_stream/salsa208/ref/xor_salsa208.c @@ -0,0 +1,54 @@ +/* +version 20080913 +D. J. Bernstein +Public domain. +*/ + +#include "api.h" +#include "crypto_core_salsa208.h" + +typedef unsigned int uint32; + +static const unsigned char sigma[16] = { + 'e', 'x', 'p', 'a', 'n', 'd', ' ', '3', '2', '-', 'b', 'y', 't', 'e', ' ', 'k' +}; + +int crypto_stream_xor( + unsigned char *c, + const unsigned char *m,unsigned long long mlen, + const unsigned char *n, + const unsigned char *k +) +{ + unsigned char in[16]; + unsigned char block[64]; + unsigned long long i; + unsigned int u; + + if (!mlen) return 0; + + for (i = 0;i < 8;++i) in[i] = n[i]; + for (i = 8;i < 16;++i) in[i] = 0; + + while (mlen >= 64) { + crypto_core_salsa208(block,in,k,sigma); + for (i = 0;i < 64;++i) c[i] = m[i] ^ block[i]; + + u = 1; + for (i = 8;i < 16;++i) { + u += (unsigned int) in[i]; + in[i] = u; + u >>= 8; + } + + mlen -= 64; + c += 64; + m += 64; + } + + if (mlen) { + crypto_core_salsa208(block,in,k,sigma); + for (i = 0;i < mlen;++i) c[i] = m[i] ^ block[i]; + } + return 0; +} |