This patch adds support for the AES-CCM encryption algorithm for CPUs that
have support for the AES part of the ARM v8 Crypto Extensions.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Acked-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/crypto/Kconfig | 7 +
arch/arm64/crypto/Makefile | 3 +
arch/arm64/crypto/aes-ce-ccm-core.S | 222 +++++++++++++++++++++++++++
arch/arm64/crypto/aes-ce-ccm-glue.c | 297 ++++++++++++++++++++++++++++++++++++
4 files changed, 529 insertions(+)
create mode 100644 arch/arm64/crypto/aes-ce-ccm-core.S
create mode 100644 arch/arm64/crypto/aes-ce-ccm-glue.c
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index 9ba32c0da871..8fffd5af65ef 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -29,4 +29,11 @@ config CRYPTO_AES_ARM64_CE
select CRYPTO_ALGAPI
select CRYPTO_AES
+config CRYPTO_AES_ARM64_CE_CCM
+ tristate "AES in CCM mode using ARMv8 Crypto Extensions"
+ depends on ARM64 && KERNEL_MODE_NEON
+ select CRYPTO_ALGAPI
+ select CRYPTO_AES
+ select CRYPTO_AEAD
+
endif
diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
index 908abd9242b1..311287d68078 100644
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -19,3 +19,6 @@ ghash-ce-y := ghash-ce-glue.o ghash-ce-core.o
obj-$(CONFIG_CRYPTO_AES_ARM64_CE) += aes-ce-cipher.o
CFLAGS_aes-ce-cipher.o += -march=armv8-a+crypto
+
+obj-$(CONFIG_CRYPTO_AES_ARM64_CE_CCM) += aes-ce-ccm.o
+aes-ce-ccm-y := aes-ce-ccm-glue.o aes-ce-ccm-core.o
diff --git a/arch/arm64/crypto/aes-ce-ccm-core.S b/arch/arm64/crypto/aes-ce-ccm-core.S
new file mode 100644
index 000000000000..432e4841cd81
--- /dev/null
+++ b/arch/arm64/crypto/aes-ce-ccm-core.S
@@ -0,0 +1,222 @@
+/*
+ * aesce-ccm-core.S - AES-CCM transform for ARMv8 with Crypto Extensions
+ *
+ * Copyright (C) 2013 - 2014 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+ .text
+ .arch armv8-a+crypto
+
+ /*
+ * void ce_aes_ccm_auth_data(u8 mac[], u8 const in[], u32 abytes,
+ * u32 *macp, u8 const rk[], u32 rounds);
+ */
+ENTRY(ce_aes_ccm_auth_data)
+ ldr w8, [x3] /* leftover from prev round? */
+ ld1 {v0.2d}, [x0] /* load mac */
+ cbz w8, 1f
+ sub w8, w8, #16
+ eor v1.16b, v1.16b, v1.16b
+0: ldrb w7, [x1], #1 /* get 1 byte of input */
+ subs w2, w2, #1
+ add w8, w8, #1
+ ins v1.b[0], w7
+ ext v1.16b, v1.16b, v1.16b, #1 /* rotate in the input bytes */
+ beq 8f /* out of input? */
+ cbnz w8, 0b
+ eor v0.16b, v0.16b, v1.16b
+1: ld1 {v3.2d}, [x4] /* load first round key */
+ prfm pldl1strm, [x1]
+ cmp w5, #12 /* which key size? */
+ add x6, x4, #16
+ sub w7, w5, #2 /* modified # of rounds */
+ bmi 2f
+ bne 5f
+ mov v5.16b, v3.16b
+ b 4f
+2: mov v4.16b, v3.16b
+ ld1 {v5.2d}, [x6], #16 /* load 2nd round key */
+3: aese v0.16b, v4.16b
+ aesmc v0.16b, v0.16b
+4: ld1 {v3.2d}, [x6], #16 /* load next round key */
+ aese v0.16b, v5.16b
+ aesmc v0.16b, v0.16b
+5: ld1 {v4.2d}, [x6], #16 /* load next round key */
+ subs w7, w7, #3
+ aese v0.16b, v3.16b
+ aesmc v0.16b, v0.16b
+ ld1 {v5.2d}, [x6], #16 /* load next round key */
+ bpl 3b
+ aese v0.16b, v4.16b
+ subs w2, w2, #16 /* last data? */
+ eor v0.16b, v0.16b, v5.16b /* final round */
+ bmi 6f
+ ld1 {v1.16b}, [x1], #16 /* load next input block */
+ eor v0.16b, v0.16b, v1.16b /* xor with mac */
+ bne 1b
+6: st1 {v0.2d}, [x0] /* store mac */
+ beq 10f
+ adds w2, w2, #16
+ beq 10f
+ mov w8, w2
+7: ldrb w7, [x1], #1
+ umov w6, v0.b[0]
+ eor w6, w6, w7
+ strb w6, [x0], #1
+ subs w2, w2, #1
+ beq 10f
+ ext v0.16b, v0.16b, v0.16b, #1 /* rotate out the mac bytes */
+ b 7b
+8: mov w7, w8
+ add w8, w8, #16
+9: ext v1.16b, v1.16b, v1.16b, #1
+ adds w7, w7, #1
+ bne 9b
+ eor v0.16b, v0.16b, v1.16b
+ st1 {v0.2d}, [x0]
+10: str w8, [x3]
+ ret
+ENDPROC(ce_aes_ccm_auth_data)
+
+ /*
+ * void ce_aes_ccm_final(u8 mac[], u8 const ctr[], u8 const rk[],
+ * u32 rounds);
+ */
+ENTRY(ce_aes_ccm_final)
+ ld1 {v3.2d}, [x2], #16 /* load first round key */
+ ld1 {v0.2d}, [x0] /* load mac */
+ cmp w3, #12 /* which key size? */
+ sub w3, w3, #2 /* modified # of rounds */
+ ld1 {v1.2d}, [x1] /* load 1st ctriv */
+ bmi 0f
+ bne 3f
+ mov v5.16b, v3.16b
+ b 2f
+0: mov v4.16b, v3.16b
+1: ld1 {v5.2d}, [x2], #16 /* load next round key */
+ aese v0.16b, v4.16b
+ aese v1.16b, v4.16b
+ aesmc v0.16b, v0.16b
+ aesmc v1.16b, v1.16b
+2: ld1 {v3.2d}, [x2], #16 /* load next round key */
+ aese v0.16b, v5.16b
+ aese v1.16b, v5.16b
+ aesmc v0.16b, v0.16b
+ aesmc v1.16b, v1.16b
+3: ld1 {v4.2d}, [x2], #16 /* load next round key */
+ subs w3, w3, #3
+ aese v0.16b, v3.16b
+ aese v1.16b, v3.16b
+ aesmc v0.16b, v0.16b
+ aesmc v1.16b, v1.16b
+ bpl 1b
+ aese v0.16b, v4.16b
+ aese v1.16b, v4.16b
+ /* final round key cancels out */
+ eor v0.16b, v0.16b, v1.16b /* en-/decrypt the mac */
+ st1 {v0.2d}, [x0] /* store result */
+ ret
+ENDPROC(ce_aes_ccm_final)
+
+ .macro aes_ccm_do_crypt,enc
+ ldr x8, [x6, #8] /* load lower ctr */
+ ld1 {v0.2d}, [x5] /* load mac */
+ rev x8, x8 /* keep swabbed ctr in reg */
+0: /* outer loop */
+ ld1 {v1.1d}, [x6] /* load upper ctr */
+ prfm pldl1strm, [x1]
+ add x8, x8, #1
+ rev x9, x8
+ cmp w4, #12 /* which key size? */
+ sub w7, w4, #2 /* get modified # of rounds */
+ ins v1.d[1], x9 /* no carry in lower ctr */
+ ld1 {v3.2d}, [x3] /* load first round key */
+ add x10, x3, #16
+ bmi 1f
+ bne 4f
+ mov v5.16b, v3.16b
+ b 3f
+1: mov v4.16b, v3.16b
+ ld1 {v5.2d}, [x10], #16 /* load 2nd round key */
+2: /* inner loop: 3 rounds, 2x interleaved */
+ aese v0.16b, v4.16b
+ aese v1.16b, v4.16b
+ aesmc v0.16b, v0.16b
+ aesmc v1.16b, v1.16b
+3: ld1 {v3.2d}, [x10], #16 /* load next round key */
+ aese v0.16b, v5.16b
+ aese v1.16b, v5.16b
+ aesmc v0.16b, v0.16b
+ aesmc v1.16b, v1.16b
+4: ld1 {v4.2d}, [x10], #16 /* load next round key */
+ subs w7, w7, #3
+ aese v0.16b, v3.16b
+ aese v1.16b, v3.16b
+ aesmc v0.16b, v0.16b
+ aesmc v1.16b, v1.16b
+ ld1 {v5.2d}, [x10], #16 /* load next round key */
+ bpl 2b
+ aese v0.16b, v4.16b
+ aese v1.16b, v4.16b
+ subs w2, w2, #16
+ bmi 6f /* partial block? */
+ ld1 {v2.16b}, [x1], #16 /* load next input block */
+ .if \enc == 1
+ eor v2.16b, v2.16b, v5.16b /* final round enc+mac */
+ eor v1.16b, v1.16b, v2.16b /* xor with crypted ctr */
+ .else
+ eor v2.16b, v2.16b, v1.16b /* xor with crypted ctr */
+ eor v1.16b, v2.16b, v5.16b /* final round enc */
+ .endif
+ eor v0.16b, v0.16b, v2.16b /* xor mac with pt ^ rk[last] */
+ st1 {v1.16b}, [x0], #16 /* write output block */
+ bne 0b
+ rev x8, x8
+ st1 {v0.2d}, [x5] /* store mac */
+ str x8, [x6, #8] /* store lsb end of ctr (BE) */
+5: ret
+
+6: eor v0.16b, v0.16b, v5.16b /* final round mac */
+ eor v1.16b, v1.16b, v5.16b /* final round enc */
+ st1 {v0.2d}, [x5] /* store mac */
+ add w2, w2, #16 /* process partial tail block */
+7: ldrb w9, [x1], #1 /* get 1 byte of input */
+ umov w6, v1.b[0] /* get top crypted ctr byte */
+ umov w7, v0.b[0] /* get top mac byte */
+ .if \enc == 1
+ eor w7, w7, w9
+ eor w9, w9, w6
+ .else
+ eor w9, w9, w6
+ eor w7, w7, w9
+ .endif
+ strb w9, [x0], #1 /* store out byte */
+ strb w7, [x5], #1 /* store mac byte */
+ subs w2, w2, #1
+ beq 5b
+ ext v0.16b, v0.16b, v0.16b, #1 /* shift out mac byte */
+ ext v1.16b, v1.16b, v1.16b, #1 /* shift out ctr byte */
+ b 7b
+ .endm
+
+ /*
+ * void ce_aes_ccm_encrypt(u8 out[], u8 const in[], u32 cbytes,
+ * u8 const rk[], u32 rounds, u8 mac[],
+ * u8 ctr[]);
+ * void ce_aes_ccm_decrypt(u8 out[], u8 const in[], u32 cbytes,
+ * u8 const rk[], u32 rounds, u8 mac[],
+ * u8 ctr[]);
+ */
+ENTRY(ce_aes_ccm_encrypt)
+ aes_ccm_do_crypt 1
+ENDPROC(ce_aes_ccm_encrypt)
+
+ENTRY(ce_aes_ccm_decrypt)
+ aes_ccm_do_crypt 0
+ENDPROC(ce_aes_ccm_decrypt)
diff --git a/arch/arm64/crypto/aes-ce-ccm-glue.c b/arch/arm64/crypto/aes-ce-ccm-glue.c
new file mode 100644
index 000000000000..9e6cdde9b43d
--- /dev/null
+++ b/arch/arm64/crypto/aes-ce-ccm-glue.c
@@ -0,0 +1,297 @@
+/*
+ * aes-ccm-glue.c - AES-CCM transform for ARMv8 with Crypto Extensions
+ *
+ * Copyright (C) 2013 - 2014 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <asm/neon.h>
+#include <asm/unaligned.h>
+#include <crypto/aes.h>
+#include <crypto/algapi.h>
+#include <crypto/scatterwalk.h>
+#include <linux/crypto.h>
+#include <linux/module.h>
+
+static int num_rounds(struct crypto_aes_ctx *ctx)
+{
+ /*
+ * # of rounds specified by AES:
+ * 128 bit key 10 rounds
+ * 192 bit key 12 rounds
+ * 256 bit key 14 rounds
+ * => n byte key => 6 + (n/4) rounds
+ */
+ return 6 + ctx->key_length / 4;
+}
+
+asmlinkage void ce_aes_ccm_auth_data(u8 mac[], u8 const in[], u32 abytes,
+ u32 *macp, u32 const rk[], u32 rounds);
+
+asmlinkage void ce_aes_ccm_encrypt(u8 out[], u8 const in[], u32 cbytes,
+ u32 const rk[], u32 rounds, u8 mac[],
+ u8 ctr[]);
+
+asmlinkage void ce_aes_ccm_decrypt(u8 out[], u8 const in[], u32 cbytes,
+ u32 const rk[], u32 rounds, u8 mac[],
+ u8 ctr[]);
+
+asmlinkage void ce_aes_ccm_final(u8 mac[], u8 const ctr[], u32 const rk[],
+ u32 rounds);
+
+static int ccm_setkey(struct crypto_aead *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct crypto_aes_ctx *ctx = crypto_aead_ctx(tfm);
+ int ret;
+
+ ret = crypto_aes_expand_key(ctx, in_key, key_len);
+ if (!ret)
+ return 0;
+
+ tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+ return -EINVAL;
+}
+
+static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
+{
+ if ((authsize & 1) || authsize < 4)
+ return -EINVAL;
+ return 0;
+}
+
+static int ccm_init_mac(struct aead_request *req, u8 maciv[], u32 msglen)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ __be32 *n = (__be32 *)&maciv[AES_BLOCK_SIZE - 8];
+ u32 l = req->iv[0] + 1;
+
+ /* verify that CCM dimension 'L' is set correctly in the IV */
+ if (l < 2 || l > 8)
+ return -EINVAL;
+
+ /* verify that msglen can in fact be represented in L bytes */
+ if (l < 4 && msglen >> (8 * l))
+ return -EOVERFLOW;
+
+ /*
+ * Even if the CCM spec allows L values of up to 8, the Linux cryptoapi
+ * uses a u32 type to represent msglen so the top 4 bytes are always 0.
+ */
+ n[0] = 0;
+ n[1] = cpu_to_be32(msglen);
+
+ memcpy(maciv, req->iv, AES_BLOCK_SIZE - l);
+
+ /*
+ * Meaning of byte 0 according to CCM spec (RFC 3610/NIST 800-38C)
+ * - bits 0..2 : max # of bytes required to represent msglen, minus 1
+ * (already set by caller)
+ * - bits 3..5 : size of auth tag (1 => 4 bytes, 2 => 6 bytes, etc)
+ * - bit 6 : indicates presence of authenticate-only data
+ */
+ maciv[0] |= (crypto_aead_authsize(aead) - 2) << 2;
+ if (req->assoclen)
+ maciv[0] |= 0x40;
+
+ memset(&req->iv[AES_BLOCK_SIZE - l], 0, l);
+ return 0;
+}
+
+static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
+ struct __packed { __be16 l; __be32 h; u16 len; } ltag;
+ struct scatter_walk walk;
+ u32 len = req->assoclen;
+ u32 macp = 0;
+
+ /* prepend the AAD with a length tag */
+ if (len < 0xff00) {
+ ltag.l = cpu_to_be16(len);
+ ltag.len = 2;
+ } else {
+ ltag.l = cpu_to_be16(0xfffe);
+ put_unaligned_be32(len, <ag.h);
+ ltag.len = 6;
+ }
+
+ ce_aes_ccm_auth_data(mac, (u8 *)<ag, ltag.len, &macp, ctx->key_enc,
+ num_rounds(ctx));
+ scatterwalk_start(&walk, req->assoc);
+
+ do {
+ u32 n = scatterwalk_clamp(&walk, len);
+ u8 *p;
+
+ if (!n) {
+ scatterwalk_start(&walk, sg_next(walk.sg));
+ n = scatterwalk_clamp(&walk, len);
+ }
+ p = scatterwalk_map(&walk);
+ ce_aes_ccm_auth_data(mac, p, n, &macp, ctx->key_enc,
+ num_rounds(ctx));
+ len -= n;
+
+ scatterwalk_unmap(p);
+ scatterwalk_advance(&walk, n);
+ scatterwalk_done(&walk, 0, len);
+ } while (len);
+}
+
+static int ccm_encrypt(struct aead_request *req)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
+ struct blkcipher_desc desc = { .info = req->iv };
+ struct blkcipher_walk walk;
+ u8 __aligned(8) mac[AES_BLOCK_SIZE];
+ u8 buf[AES_BLOCK_SIZE];
+ u32 len = req->cryptlen;
+ int err;
+
+ err = ccm_init_mac(req, mac, len);
+ if (err)
+ return err;
+
+ kernel_neon_begin_partial(6);
+
+ if (req->assoclen)
+ ccm_calculate_auth_mac(req, mac);
+
+ /* preserve the original iv for the final round */
+ memcpy(buf, req->iv, AES_BLOCK_SIZE);
+
+ blkcipher_walk_init(&walk, req->dst, req->src, len);
+ err = blkcipher_aead_walk_virt_block(&desc, &walk, aead,
+ AES_BLOCK_SIZE);
+
+ while (walk.nbytes) {
+ u32 tail = walk.nbytes % AES_BLOCK_SIZE;
+
+ if (walk.nbytes == len)
+ tail = 0;
+
+ ce_aes_ccm_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
+ walk.nbytes - tail, ctx->key_enc,
+ num_rounds(ctx), mac, walk.iv);
+
+ len -= walk.nbytes - tail;
+ err = blkcipher_walk_done(&desc, &walk, tail);
+ }
+ if (!err)
+ ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx));
+
+ kernel_neon_end();
+
+ if (err)
+ return err;
+
+ /* copy authtag to end of dst */
+ scatterwalk_map_and_copy(mac, req->dst, req->cryptlen,
+ crypto_aead_authsize(aead), 1);
+
+ return 0;
+}
+
+static int ccm_decrypt(struct aead_request *req)
+{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
+ unsigned int authsize = crypto_aead_authsize(aead);
+ struct blkcipher_desc desc = { .info = req->iv };
+ struct blkcipher_walk walk;
+ u8 __aligned(8) mac[AES_BLOCK_SIZE];
+ u8 buf[AES_BLOCK_SIZE];
+ u32 len = req->cryptlen - authsize;
+ int err;
+
+ err = ccm_init_mac(req, mac, len);
+ if (err)
+ return err;
+
+ kernel_neon_begin_partial(6);
+
+ if (req->assoclen)
+ ccm_calculate_auth_mac(req, mac);
+
+ /* preserve the original iv for the final round */
+ memcpy(buf, req->iv, AES_BLOCK_SIZE);
+
+ blkcipher_walk_init(&walk, req->dst, req->src, len);
+ err = blkcipher_aead_walk_virt_block(&desc, &walk, aead,
+ AES_BLOCK_SIZE);
+
+ while (walk.nbytes) {
+ u32 tail = walk.nbytes % AES_BLOCK_SIZE;
+
+ if (walk.nbytes == len)
+ tail = 0;
+
+ ce_aes_ccm_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
+ walk.nbytes - tail, ctx->key_enc,
+ num_rounds(ctx), mac, walk.iv);
+
+ len -= walk.nbytes - tail;
+ err = blkcipher_walk_done(&desc, &walk, tail);
+ }
+ if (!err)
+ ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx));
+
+ kernel_neon_end();
+
+ if (err)
+ return err;
+
+ /* compare calculated auth tag with the stored one */
+ scatterwalk_map_and_copy(buf, req->src, req->cryptlen - authsize,
+ authsize, 0);
+
+ if (memcmp(mac, buf, authsize))
+ return -EBADMSG;
+ return 0;
+}
+
+static struct crypto_alg ccm_aes_alg = {
+ .cra_name = "ccm(aes)",
+ .cra_driver_name = "ccm-aes-ce",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_AEAD,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct crypto_aes_ctx),
+ .cra_alignmask = 7,
+ .cra_type = &crypto_aead_type,
+ .cra_module = THIS_MODULE,
+ .cra_aead = {
+ .ivsize = AES_BLOCK_SIZE,
+ .maxauthsize = AES_BLOCK_SIZE,
+ .setkey = ccm_setkey,
+ .setauthsize = ccm_setauthsize,
+ .encrypt = ccm_encrypt,
+ .decrypt = ccm_decrypt,
+ }
+};
+
+static int __init aes_mod_init(void)
+{
+ if (!(elf_hwcap & HWCAP_AES))
+ return -ENODEV;
+ return crypto_register_alg(&ccm_aes_alg);
+}
+
+static void __exit aes_mod_exit(void)
+{
+ crypto_unregister_alg(&ccm_aes_alg);
+}
+
+module_init(aes_mod_init);
+module_exit(aes_mod_exit);
+
+MODULE_DESCRIPTION("Synchronous AES in CCM mode using ARMv8 Crypto Extensions");
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("ccm(aes)");
--
1.8.3.2
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