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Diffstat (limited to 'src/crypto/cipher/salsa20/xmm/salsa20_xmm.c')
-rw-r--r--src/crypto/cipher/salsa20/xmm/salsa20_xmm.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/src/crypto/cipher/salsa20/xmm/salsa20_xmm.c b/src/crypto/cipher/salsa20/xmm/salsa20_xmm.c
index 52c4b6d..a85ed72 100644
--- a/src/crypto/cipher/salsa20/xmm/salsa20_xmm.c
+++ b/src/crypto/cipher/salsa20/xmm/salsa20_xmm.c
@@ -23,15 +23,21 @@
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-/*
- The assembly implementations were written by D. J. Bernstein and are
- Public Domain. For more information see http://cr.yp.to/snuffle.html
+/**
+ \file
+
+ The XMM Salsa20 implementation for SSE2-capable x86 systems
+
+ The assembly implementations were written by D. J. Bernstein and are
+ Public Domain. For more information see http://cr.yp.to/snuffle.html
*/
+
#include "../../../../crypto.h"
#include "../../../../cpuid.h"
+/** The length of the key used by Salsa20 */
#define KEYBYTES 32
@@ -44,18 +50,22 @@
#endif
+/** The actual Salsa20 assembly implementation */
int crypto_stream_salsa20_xor(unsigned char *c, const unsigned char *m, unsigned long long mlen, const unsigned char *n, const unsigned char *k);
+/** The cipher state */
struct fastd_cipher_state {
- uint8_t key[KEYBYTES];
+ uint8_t key[KEYBYTES]; /**< The encryption key */
};
+/** Checks if the runtime platform supports SSE2 */
static bool salsa20_available(void) {
return fastd_cpuid() & CPUID_SSE2;
}
+/** Initializes the cipher state */
static fastd_cipher_state_t* salsa20_init(const uint8_t *key) {
fastd_cipher_state_t *state = malloc(sizeof(fastd_cipher_state_t));
memcpy(state->key, key, KEYBYTES);
@@ -63,11 +73,13 @@ static fastd_cipher_state_t* salsa20_init(const uint8_t *key) {
return state;
}
+/** XORs data with the Salsa20 cipher stream */
static bool salsa20_crypt(const fastd_cipher_state_t *state, fastd_block128_t *out, const fastd_block128_t *in, size_t len, const uint8_t *iv) {
crypto_stream_salsa20_xor(out->b, in->b, len, iv, state->key);
return true;
}
+/** Frees the cipher state */
static void salsa20_free(fastd_cipher_state_t *state) {
if (state) {
secure_memzero(state, sizeof(*state));
@@ -75,6 +87,8 @@ static void salsa20_free(fastd_cipher_state_t *state) {
}
}
+
+/** The xmm salsa20 implementation */
const fastd_cipher_t fastd_cipher_salsa20_xmm = {
.available = salsa20_available,