UPSTREAM: crypto: poly1305 - expose init/update/final library interface
Expose the existing generic Poly1305 code via a init/update/final
library interface so that callers are not required to go through
the crypto API's shash abstraction to access it. At the same time,
make some preparations so that the library implementation can be
superseded by an accelerated arch-specific version in the future.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit a1d93064094cc5e24d64e35cf093e7191d0c9344)
Bug: 152722841
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ibd2539acddd9b8de1100d9fab832e58006736607
diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c
index 6241c79..58e334d 100644
--- a/crypto/poly1305_generic.c
+++ b/crypto/poly1305_generic.c
@@ -85,31 +85,11 @@
int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
{
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
- __le32 digest[4];
- u64 f = 0;
if (unlikely(!dctx->sset))
return -ENOKEY;
- if (unlikely(dctx->buflen)) {
- dctx->buf[dctx->buflen++] = 1;
- memset(dctx->buf + dctx->buflen, 0,
- POLY1305_BLOCK_SIZE - dctx->buflen);
- poly1305_core_blocks(&dctx->h, dctx->r, dctx->buf, 1, 0);
- }
-
- poly1305_core_emit(&dctx->h, digest);
-
- /* mac = (h + s) % (2^128) */
- f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0];
- put_unaligned_le32(f, dst + 0);
- f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1];
- put_unaligned_le32(f, dst + 4);
- f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2];
- put_unaligned_le32(f, dst + 8);
- f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3];
- put_unaligned_le32(f, dst + 12);
-
+ poly1305_final_generic(dctx, dst);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_poly1305_final);
diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h
index 36b5886..74c6e1c 100644
--- a/include/crypto/poly1305.h
+++ b/include/crypto/poly1305.h
@@ -35,7 +35,43 @@
/* accumulator */
struct poly1305_state h;
/* key */
- struct poly1305_key r[1];
+ struct poly1305_key r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE];
};
+void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key);
+void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
+
+static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
+{
+ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
+ poly1305_init_arch(desc, key);
+ else
+ poly1305_init_generic(desc, key);
+}
+
+void poly1305_update_arch(struct poly1305_desc_ctx *desc, const u8 *src,
+ unsigned int nbytes);
+void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
+ unsigned int nbytes);
+
+static inline void poly1305_update(struct poly1305_desc_ctx *desc,
+ const u8 *src, unsigned int nbytes)
+{
+ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
+ poly1305_update_arch(desc, src, nbytes);
+ else
+ poly1305_update_generic(desc, src, nbytes);
+}
+
+void poly1305_final_arch(struct poly1305_desc_ctx *desc, u8 *digest);
+void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *digest);
+
+static inline void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest)
+{
+ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
+ poly1305_final_arch(desc, digest);
+ else
+ poly1305_final_generic(desc, digest);
+}
+
#endif
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index 5e29f35..97bc1ee 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -28,5 +28,31 @@
by either the generic implementation or an arch-specific one, if one
is available and enabled.
+config CRYPTO_LIB_POLY1305_RSIZE
+ int
+ default 1
+
+config CRYPTO_ARCH_HAVE_LIB_POLY1305
+ tristate
+ help
+ Declares whether the architecture provides an arch-specific
+ accelerated implementation of the Poly1305 library interface,
+ either builtin or as a module.
+
config CRYPTO_LIB_POLY1305_GENERIC
tristate
+ help
+ This symbol can be depended upon by arch implementations of the
+ Poly1305 library interface that require the generic code as a
+ fallback, e.g., for SIMD implementations. If no arch specific
+ implementation is enabled, this implementation serves the users
+ of CRYPTO_LIB_POLY1305.
+
+config CRYPTO_LIB_POLY1305
+ tristate "Poly1305 library interface"
+ depends on CRYPTO_ARCH_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_HAVE_LIB_POLY1305
+ select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
+ help
+ Enable the Poly1305 library interface. This interface may be fulfilled
+ by either the generic implementation or an arch-specific one, if one
+ is available and enabled.
diff --git a/lib/crypto/poly1305.c b/lib/crypto/poly1305.c
index f019a57..32ec293 100644
--- a/lib/crypto/poly1305.c
+++ b/lib/crypto/poly1305.c
@@ -154,5 +154,79 @@
}
EXPORT_SYMBOL_GPL(poly1305_core_emit);
+void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
+{
+ poly1305_core_setkey(desc->r, key);
+ desc->s[0] = get_unaligned_le32(key + 16);
+ desc->s[1] = get_unaligned_le32(key + 20);
+ desc->s[2] = get_unaligned_le32(key + 24);
+ desc->s[3] = get_unaligned_le32(key + 28);
+ poly1305_core_init(&desc->h);
+ desc->buflen = 0;
+ desc->sset = true;
+ desc->rset = 1;
+}
+EXPORT_SYMBOL_GPL(poly1305_init_generic);
+
+void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
+ unsigned int nbytes)
+{
+ unsigned int bytes;
+
+ if (unlikely(desc->buflen)) {
+ bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
+ memcpy(desc->buf + desc->buflen, src, bytes);
+ src += bytes;
+ nbytes -= bytes;
+ desc->buflen += bytes;
+
+ if (desc->buflen == POLY1305_BLOCK_SIZE) {
+ poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 1);
+ desc->buflen = 0;
+ }
+ }
+
+ if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
+ poly1305_core_blocks(&desc->h, desc->r, src,
+ nbytes / POLY1305_BLOCK_SIZE, 1);
+ src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
+ nbytes %= POLY1305_BLOCK_SIZE;
+ }
+
+ if (unlikely(nbytes)) {
+ desc->buflen = nbytes;
+ memcpy(desc->buf, src, nbytes);
+ }
+}
+EXPORT_SYMBOL_GPL(poly1305_update_generic);
+
+void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)
+{
+ __le32 digest[4];
+ u64 f = 0;
+
+ if (unlikely(desc->buflen)) {
+ desc->buf[desc->buflen++] = 1;
+ memset(desc->buf + desc->buflen, 0,
+ POLY1305_BLOCK_SIZE - desc->buflen);
+ poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 0);
+ }
+
+ poly1305_core_emit(&desc->h, digest);
+
+ /* mac = (h + s) % (2^128) */
+ f = (f >> 32) + le32_to_cpu(digest[0]) + desc->s[0];
+ put_unaligned_le32(f, dst + 0);
+ f = (f >> 32) + le32_to_cpu(digest[1]) + desc->s[1];
+ put_unaligned_le32(f, dst + 4);
+ f = (f >> 32) + le32_to_cpu(digest[2]) + desc->s[2];
+ put_unaligned_le32(f, dst + 8);
+ f = (f >> 32) + le32_to_cpu(digest[3]) + desc->s[3];
+ put_unaligned_le32(f, dst + 12);
+
+ *desc = (struct poly1305_desc_ctx){};
+}
+EXPORT_SYMBOL_GPL(poly1305_final_generic);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");