From 2fe678653b7dd9f61dbbcd5e7d862360882bd7e8 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Thu, 29 May 2014 05:00:11 +0200 Subject: Document *everything* --- src/crypto/cipher/salsa20/xmm/salsa20_xmm.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'src/crypto/cipher/salsa20/xmm') 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, -- cgit v1.2.3