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Diffstat (limited to 'lib/crypto/chacha20poly1305.c')
-rw-r--r--lib/crypto/chacha20poly1305.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c
index c12ddbe9eb92..821e5cc9b14e 100644
--- a/lib/crypto/chacha20poly1305.c
+++ b/lib/crypto/chacha20poly1305.c
@@ -11,6 +11,7 @@
#include <crypto/chacha20poly1305.h>
#include <crypto/chacha.h>
#include <crypto/poly1305.h>
+#include <crypto/scatterwalk.h>
#include <asm/unaligned.h>
#include <linux/kernel.h>
@@ -205,6 +206,155 @@ bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
}
EXPORT_SYMBOL(xchacha20poly1305_decrypt);
+static
+bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,
+ const size_t src_len,
+ const u8 *ad, const size_t ad_len,
+ const u64 nonce,
+ const u8 key[CHACHA20POLY1305_KEY_SIZE],
+ int encrypt)
+{
+ const u8 *pad0 = page_address(ZERO_PAGE(0));
+ struct poly1305_desc_ctx poly1305_state;
+ u32 chacha_state[CHACHA_STATE_WORDS];
+ struct sg_mapping_iter miter;
+ size_t partial = 0;
+ unsigned int flags;
+ bool ret = true;
+ int sl;
+ union {
+ struct {
+ u32 k[CHACHA_KEY_WORDS];
+ __le64 iv[2];
+ };
+ u8 block0[POLY1305_KEY_SIZE];
+ u8 chacha_stream[CHACHA_BLOCK_SIZE];
+ struct {
+ u8 mac[2][POLY1305_DIGEST_SIZE];
+ };
+ __le64 lens[2];
+ } b __aligned(16);
+
+ chacha_load_key(b.k, key);
+
+ b.iv[0] = 0;
+ b.iv[1] = cpu_to_le64(nonce);
+
+ chacha_init(chacha_state, b.k, (u8 *)b.iv);
+ chacha_crypt(chacha_state, b.block0, pad0, sizeof(b.block0), 20);
+ poly1305_init(&poly1305_state, b.block0);
+
+ if (unlikely(ad_len)) {
+ poly1305_update(&poly1305_state, ad, ad_len);
+ if (ad_len & 0xf)
+ poly1305_update(&poly1305_state, pad0, 0x10 - (ad_len & 0xf));
+ }
+
+ flags = SG_MITER_TO_SG;
+ if (!preemptible())
+ flags |= SG_MITER_ATOMIC;
+
+ sg_miter_start(&miter, src, sg_nents(src), flags);
+
+ for (sl = src_len; sl > 0 && sg_miter_next(&miter); sl -= miter.length) {
+ u8 *addr = miter.addr;
+ size_t length = min_t(size_t, sl, miter.length);
+
+ if (!encrypt)
+ poly1305_update(&poly1305_state, addr, length);
+
+ if (unlikely(partial)) {
+ size_t l = min(length, CHACHA_BLOCK_SIZE - partial);
+
+ crypto_xor(addr, b.chacha_stream + partial, l);
+ partial = (partial + l) & (CHACHA_BLOCK_SIZE - 1);
+
+ addr += l;
+ length -= l;
+ }
+
+ if (likely(length >= CHACHA_BLOCK_SIZE || length == sl)) {
+ size_t l = length;
+
+ if (unlikely(length < sl))
+ l &= ~(CHACHA_BLOCK_SIZE - 1);
+ chacha_crypt(chacha_state, addr, addr, l, 20);
+ addr += l;
+ length -= l;
+ }
+
+ if (unlikely(length > 0)) {
+ chacha_crypt(chacha_state, b.chacha_stream, pad0,
+ CHACHA_BLOCK_SIZE, 20);
+ crypto_xor(addr, b.chacha_stream, length);
+ partial = length;
+ }
+
+ if (encrypt)
+ poly1305_update(&poly1305_state, miter.addr,
+ min_t(size_t, sl, miter.length));
+ }
+
+ if (src_len & 0xf)
+ poly1305_update(&poly1305_state, pad0, 0x10 - (src_len & 0xf));
+
+ b.lens[0] = cpu_to_le64(ad_len);
+ b.lens[1] = cpu_to_le64(src_len);
+ poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens));
+
+ if (likely(sl <= -POLY1305_DIGEST_SIZE)) {
+ if (encrypt) {
+ poly1305_final(&poly1305_state,
+ miter.addr + miter.length + sl);
+ ret = true;
+ } else {
+ poly1305_final(&poly1305_state, b.mac[0]);
+ ret = !crypto_memneq(b.mac[0],
+ miter.addr + miter.length + sl,
+ POLY1305_DIGEST_SIZE);
+ }
+ }
+
+ sg_miter_stop(&miter);
+
+ if (unlikely(sl > -POLY1305_DIGEST_SIZE)) {
+ poly1305_final(&poly1305_state, b.mac[1]);
+ scatterwalk_map_and_copy(b.mac[encrypt], src, src_len,
+ sizeof(b.mac[1]), encrypt);
+ ret = encrypt ||
+ !crypto_memneq(b.mac[0], b.mac[1], POLY1305_DIGEST_SIZE);
+ }
+
+ memzero_explicit(chacha_state, sizeof(chacha_state));
+ memzero_explicit(&b, sizeof(b));
+
+ return ret;
+}
+
+bool chacha20poly1305_encrypt_sg_inplace(struct scatterlist *src, size_t src_len,
+ const u8 *ad, const size_t ad_len,
+ const u64 nonce,
+ const u8 key[CHACHA20POLY1305_KEY_SIZE])
+{
+ return chacha20poly1305_crypt_sg_inplace(src, src_len, ad, ad_len,
+ nonce, key, 1);
+}
+EXPORT_SYMBOL(chacha20poly1305_encrypt_sg_inplace);
+
+bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len,
+ const u8 *ad, const size_t ad_len,
+ const u64 nonce,
+ const u8 key[CHACHA20POLY1305_KEY_SIZE])
+{
+ if (unlikely(src_len < POLY1305_DIGEST_SIZE))
+ return false;
+
+ return chacha20poly1305_crypt_sg_inplace(src,
+ src_len - POLY1305_DIGEST_SIZE,
+ ad, ad_len, nonce, key, 0);
+}
+EXPORT_SYMBOL(chacha20poly1305_decrypt_sg_inplace);
+
static int __init mod_init(void)
{
if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) &&