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authorLinus Torvalds <torvalds@linux-foundation.org>2024-09-16 06:28:28 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2024-09-16 06:28:28 +0200
commit85ffc6e4ed3712f8b3fedb3fbe42afae644a699c (patch)
tree294e5220ea434ce796e0e02a4da89edf034e072d /lib/crypto/mpi/mpi-mod.c
parentMerge tag 'net-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next (diff)
parentcrypto: n2 - Set err to EINVAL if snprintf fails for hmac (diff)
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Merge tag 'v6.12-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu" "API: - Make self-test asynchronous Algorithms: - Remove MPI functions added for SM3 - Add allocation error checks to remaining MPI functions (introduced for SM3) - Set default Jitter RNG OSR to 3 Drivers: - Add hwrng driver for Rockchip RK3568 SoC - Allow disabling SR-IOV VFs through sysfs in qat - Fix device reset bugs in hisilicon - Fix authenc key parsing by using generic helper in octeontx* Others: - Fix xor benchmarking on parisc" * tag 'v6.12-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (96 commits) crypto: n2 - Set err to EINVAL if snprintf fails for hmac crypto: camm/qi - Use ERR_CAST() to return error-valued pointer crypto: mips/crc32 - Clean up useless assignment operations crypto: qcom-rng - rename *_of_data to *_match_data crypto: qcom-rng - fix support for ACPI-based systems dt-bindings: crypto: qcom,prng: document support for SA8255p crypto: aegis128 - Fix indentation issue in crypto_aegis128_process_crypt() crypto: octeontx* - Select CRYPTO_AUTHENC crypto: testmgr - Hide ENOENT errors crypto: qat - Remove trailing space after \n newline crypto: hisilicon/sec - Remove trailing space after \n newline crypto: algboss - Pass instance creation error up crypto: api - Fix generic algorithm self-test races crypto: hisilicon/qm - inject error before stopping queue crypto: hisilicon/hpre - mask cluster timeout error crypto: hisilicon/qm - reset device before enabling it crypto: hisilicon/trng - modifying the order of header files crypto: hisilicon - add a lock for the qp send operation crypto: hisilicon - fix missed error branch crypto: ccp - do not request interrupt on cmd completion when irqs disabled ...
Diffstat (limited to '')
-rw-r--r--lib/crypto/mpi/mpi-mod.c148
1 files changed, 2 insertions, 146 deletions
diff --git a/lib/crypto/mpi/mpi-mod.c b/lib/crypto/mpi/mpi-mod.c
index 54fcc01564d9..d5fdaec3d0b6 100644
--- a/lib/crypto/mpi/mpi-mod.c
+++ b/lib/crypto/mpi/mpi-mod.c
@@ -5,153 +5,9 @@
* This file is part of Libgcrypt.
*/
-
#include "mpi-internal.h"
-#include "longlong.h"
-
-/* Context used with Barrett reduction. */
-struct barrett_ctx_s {
- MPI m; /* The modulus - may not be modified. */
- int m_copied; /* If true, M needs to be released. */
- int k;
- MPI y;
- MPI r1; /* Helper MPI. */
- MPI r2; /* Helper MPI. */
- MPI r3; /* Helper MPI allocated on demand. */
-};
-
-
-
-void mpi_mod(MPI rem, MPI dividend, MPI divisor)
-{
- mpi_fdiv_r(rem, dividend, divisor);
-}
-
-/* This function returns a new context for Barrett based operations on
- * the modulus M. This context needs to be released using
- * _gcry_mpi_barrett_free. If COPY is true M will be transferred to
- * the context and the user may change M. If COPY is false, M may not
- * be changed until gcry_mpi_barrett_free has been called.
- */
-mpi_barrett_t mpi_barrett_init(MPI m, int copy)
-{
- mpi_barrett_t ctx;
- MPI tmp;
-
- mpi_normalize(m);
- ctx = kcalloc(1, sizeof(*ctx), GFP_KERNEL);
- if (!ctx)
- return NULL;
-
- if (copy) {
- ctx->m = mpi_copy(m);
- ctx->m_copied = 1;
- } else
- ctx->m = m;
-
- ctx->k = mpi_get_nlimbs(m);
- tmp = mpi_alloc(ctx->k + 1);
-
- /* Barrett precalculation: y = floor(b^(2k) / m). */
- mpi_set_ui(tmp, 1);
- mpi_lshift_limbs(tmp, 2 * ctx->k);
- mpi_fdiv_q(tmp, tmp, m);
-
- ctx->y = tmp;
- ctx->r1 = mpi_alloc(2 * ctx->k + 1);
- ctx->r2 = mpi_alloc(2 * ctx->k + 1);
-
- return ctx;
-}
-
-void mpi_barrett_free(mpi_barrett_t ctx)
-{
- if (ctx) {
- mpi_free(ctx->y);
- mpi_free(ctx->r1);
- mpi_free(ctx->r2);
- if (ctx->r3)
- mpi_free(ctx->r3);
- if (ctx->m_copied)
- mpi_free(ctx->m);
- kfree(ctx);
- }
-}
-
-
-/* R = X mod M
- *
- * Using Barrett reduction. Before using this function
- * _gcry_mpi_barrett_init must have been called to do the
- * precalculations. CTX is the context created by this precalculation
- * and also conveys M. If the Barret reduction could no be done a
- * straightforward reduction method is used.
- *
- * We assume that these conditions are met:
- * Input: x =(x_2k-1 ...x_0)_b
- * m =(m_k-1 ....m_0)_b with m_k-1 != 0
- * Output: r = x mod m
- */
-void mpi_mod_barrett(MPI r, MPI x, mpi_barrett_t ctx)
-{
- MPI m = ctx->m;
- int k = ctx->k;
- MPI y = ctx->y;
- MPI r1 = ctx->r1;
- MPI r2 = ctx->r2;
- int sign;
-
- mpi_normalize(x);
- if (mpi_get_nlimbs(x) > 2*k) {
- mpi_mod(r, x, m);
- return;
- }
-
- sign = x->sign;
- x->sign = 0;
-
- /* 1. q1 = floor( x / b^k-1)
- * q2 = q1 * y
- * q3 = floor( q2 / b^k+1 )
- * Actually, we don't need qx, we can work direct on r2
- */
- mpi_set(r2, x);
- mpi_rshift_limbs(r2, k-1);
- mpi_mul(r2, r2, y);
- mpi_rshift_limbs(r2, k+1);
-
- /* 2. r1 = x mod b^k+1
- * r2 = q3 * m mod b^k+1
- * r = r1 - r2
- * 3. if r < 0 then r = r + b^k+1
- */
- mpi_set(r1, x);
- if (r1->nlimbs > k+1) /* Quick modulo operation. */
- r1->nlimbs = k+1;
- mpi_mul(r2, r2, m);
- if (r2->nlimbs > k+1) /* Quick modulo operation. */
- r2->nlimbs = k+1;
- mpi_sub(r, r1, r2);
-
- if (mpi_has_sign(r)) {
- if (!ctx->r3) {
- ctx->r3 = mpi_alloc(k + 2);
- mpi_set_ui(ctx->r3, 1);
- mpi_lshift_limbs(ctx->r3, k + 1);
- }
- mpi_add(r, r, ctx->r3);
- }
-
- /* 4. while r >= m do r = r - m */
- while (mpi_cmp(r, m) >= 0)
- mpi_sub(r, r, m);
-
- x->sign = sign;
-}
-
-void mpi_mul_barrett(MPI w, MPI u, MPI v, mpi_barrett_t ctx)
+int mpi_mod(MPI rem, MPI dividend, MPI divisor)
{
- mpi_mul(w, u, v);
- mpi_mod_barrett(w, w, ctx);
+ return mpi_fdiv_r(rem, dividend, divisor);
}