From a3fd82105b9d149033984bf018f473140f5b94bc Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 10 Feb 2014 11:26:29 +0100 Subject: [PATCH] arm64/crypto: AES in CCM mode using ARMv8 Crypto Extensions 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 Acked-by: Herbert Xu --- 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 + * + * 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 + + .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 + * + * 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 +#include +#include +#include +#include +#include +#include + +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 "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("ccm(aes)");