crypto: inside-secure - Add support for the Chacha20-Poly1305 AEAD

This patch adds support for the Chacha20-Poly1305 cipher suite.
It adds both the basic rfc7539(chacha20,poly1305) as well as the
rfc7539esp(chacha20,poly1305) variant for IPsec ESP acceleration.

changes since v1:
- rebased on top of DES library changes done on cryptodev/master
- fixed crypto/Kconfig so that generic fallback is compiled as well

changes since v2:
- nothing

changes since v3:
- Fixed a problem where the tcrypt performance test would run fully on the
  fallback cipher instead of the HW due to using an AAD length of 8 for
  rfc7539esp. While this is not actually legal ESP (which includes SPI and
  sequence number in the AAD as well), it is both inconvenient and not
  necessary to run these vectors on the fallback cipher.
- Due to above, also realised that for plain (non-ESP) rfc7539, you
  probably want to be able to run vectors with less than 8 bytes of AAD
  on the HW, and this is actually possible as long as cryptlen is large
  enough, so made that possible as well.

Signed-off-by: Pascal van Leeuwen <pvanleeuwen@verimatrix.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 253 insertions, 24 deletions

diff --git a/drivers/crypto/inside-secure/safexcel_cipher.c b/drivers/crypto/inside-secure/safexcel_cipher.c
index 15d98a913da0..f1e6cae9e1c8 100644
--- a/drivers/crypto/inside-secure/safexcel_cipher.c
+++ b/drivers/crypto/inside-secure/safexcel_cipher.c
@@ -17,6 +17,7 @@
 #include <crypto/internal/des.h>
 #include <crypto/gcm.h>
 #include <crypto/ghash.h>
+#include <crypto/poly1305.h>
 #include <crypto/sha.h>
 #include <crypto/xts.h>
 #include <crypto/skcipher.h>
@@ -43,8 +44,8 @@ struct safexcel_cipher_ctx {
 
 	u32 mode;
 	enum safexcel_cipher_alg alg;
-	bool aead;
-	int  xcm; /* 0=authenc, 1=GCM, 2 reserved for CCM */
+	char aead; /* !=0=AEAD, 2=IPSec ESP AEAD */
+	char xcm;  /* 0=authenc, 1=GCM, 2 reserved for CCM */
 
 	__le32 key[16];
 	u32 nonce;
@@ -57,6 +58,7 @@ struct safexcel_cipher_ctx {
 	u32 opad[SHA512_DIGEST_SIZE / sizeof(u32)];
 
 	struct crypto_cipher *hkaes;
+	struct crypto_aead *fback;
 };
 
 struct safexcel_cipher_req {
@@ -86,10 +88,24 @@ static void safexcel_cipher_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 	} else if (ctx->alg == SAFEXCEL_CHACHA20) {
 		cdesc->control_data.options |= EIP197_OPTION_4_TOKEN_IV_CMD;
 
-		/* 96 bit nonce part */
-		memcpy(&cdesc->control_data.token[0], &iv[4], 12);
-		/* 32 bit counter */
-		cdesc->control_data.token[3] = *(u32 *)iv;
+		if (ctx->aead == EIP197_AEAD_TYPE_IPSEC_ESP) {
+			/* 32 bit nonce part */
+			cdesc->control_data.token[0] = ctx->nonce;
+			/* 64 bit IV part */
+			memcpy(&cdesc->control_data.token[1], iv, 8);
+			/* 32 bit counter, starting at 0 */
+			cdesc->control_data.token[3] = 0;
+		} else if (ctx->aead) {
+			/* 96 bit nonce part */
+			memcpy(&cdesc->control_data.token[0], iv, 12);
+			/* 32 bit counter, starting at 0 */
+			cdesc->control_data.token[3] = 0;
+		} else {
+			/* 96 bit nonce part */
+			memcpy(&cdesc->control_data.token[0], &iv[4], 12);
+			/* 32 bit counter */
+			cdesc->control_data.token[3] = *(u32 *)iv;
+		}
 
 		return;
 	} else if (ctx->xcm == EIP197_XCM_MODE_GCM) {
@@ -195,12 +211,20 @@ static void safexcel_aead_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 		token[13].instructions = EIP197_TOKEN_INS_TYPE_OUTPUT;
 	}
 
+	if (ctx->aead == EIP197_AEAD_TYPE_IPSEC_ESP) {
+		/* For ESP mode, skip over the IV */
+		token[7].opcode = EIP197_TOKEN_OPCODE_DIRECTION;
+		token[7].packet_length = EIP197_AEAD_IPSEC_IV_SIZE;
+
+		assoclen -= EIP197_AEAD_IPSEC_IV_SIZE;
+	}
+
 	token[6].opcode = EIP197_TOKEN_OPCODE_DIRECTION;
 	token[6].packet_length = assoclen;
+	token[6].instructions = EIP197_TOKEN_INS_LAST |
+				EIP197_TOKEN_INS_TYPE_HASH;
 
-	if (likely(cryptlen)) {
-		token[6].instructions = EIP197_TOKEN_INS_TYPE_HASH;
-
+	if (likely(cryptlen || ctx->alg == SAFEXCEL_CHACHA20)) {
 		token[10].opcode = EIP197_TOKEN_OPCODE_DIRECTION;
 		token[10].packet_length = cryptlen;
 		token[10].stat = EIP197_TOKEN_STAT_LAST_HASH;
@@ -210,8 +234,6 @@ static void safexcel_aead_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 					 EIP197_TOKEN_INS_TYPE_OUTPUT;
 	} else if (ctx->xcm != EIP197_XCM_MODE_CCM) {
 		token[6].stat = EIP197_TOKEN_STAT_LAST_HASH;
-		token[6].instructions = EIP197_TOKEN_INS_LAST |
-					EIP197_TOKEN_INS_TYPE_HASH;
 	}
 
 	if (!ctx->xcm)
@@ -226,10 +248,7 @@ static void safexcel_aead_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 	token[9].instructions = EIP197_TOKEN_INS_TYPE_OUTPUT |
 				EIP197_TOKEN_INS_TYPE_CRYPTO;
 
-	if (ctx->xcm == EIP197_XCM_MODE_GCM) {
-		token[6].instructions = EIP197_TOKEN_INS_LAST |
-					EIP197_TOKEN_INS_TYPE_HASH;
-	} else {
+	if (ctx->xcm != EIP197_XCM_MODE_GCM) {
 		u8 *cbcmaciv = (u8 *)&token[1];
 		u32 *aadlen = (u32 *)&token[5];
 
@@ -388,7 +407,7 @@ static int safexcel_aead_setkey(struct crypto_aead *ctfm, const u8 *key,
 			goto badkey;
 		break;
 	default:
-		dev_err(priv->dev, "aead: unsupported hash algorithm\n");
+		dev_err(priv->dev, "aead: unsupported hash algorithmn");
 		goto badkey;
 	}
 
@@ -436,6 +455,17 @@ static int safexcel_context_control(struct safexcel_cipher_ctx *ctx,
 				CONTEXT_CONTROL_DIGEST_XCM |
 				ctx->hash_alg |
 				CONTEXT_CONTROL_SIZE(ctrl_size);
+		} else if (ctx->alg == SAFEXCEL_CHACHA20) {
+			/* Chacha20-Poly1305 */
+			cdesc->control_data.control0 =
+				CONTEXT_CONTROL_KEY_EN |
+				CONTEXT_CONTROL_CRYPTO_ALG_CHACHA20 |
+				(sreq->direction == SAFEXCEL_ENCRYPT ?
+					CONTEXT_CONTROL_TYPE_ENCRYPT_HASH_OUT :
+					CONTEXT_CONTROL_TYPE_HASH_DECRYPT_IN) |
+				ctx->hash_alg |
+				CONTEXT_CONTROL_SIZE(ctrl_size);
+			return 0;
 		} else {
 			ctrl_size += ctx->state_sz / sizeof(u32) * 2;
 			cdesc->control_data.control0 =
@@ -2320,18 +2350,12 @@ struct safexcel_alg_template safexcel_alg_ccm = {
 	},
 };
 
-static int safexcel_skcipher_chacha20_setkey(struct crypto_skcipher *ctfm,
-					     const u8 *key, unsigned int len)
+static void safexcel_chacha20_setkey(struct safexcel_cipher_ctx *ctx,
+				     const u8 *key)
 {
-	struct safexcel_cipher_ctx *ctx = crypto_skcipher_ctx(ctfm);
 	struct safexcel_crypto_priv *priv = ctx->priv;
 	int i;
 
-	if (len != CHACHA_KEY_SIZE) {
-		crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
-		return -EINVAL;
-	}
-
 	if (priv->flags & EIP197_TRC_CACHE && ctx->base.ctxr_dma) {
 		for (i = 0; i < CHACHA_KEY_SIZE / sizeof(u32); i++) {
 			if (ctx->key[i] !=
@@ -2345,6 +2369,18 @@ static int safexcel_skcipher_chacha20_setkey(struct crypto_skcipher *ctfm,
 	for (i = 0; i < CHACHA_KEY_SIZE / sizeof(u32); i++)
 		ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
 	ctx->key_len = CHACHA_KEY_SIZE;
+}
+
+static int safexcel_skcipher_chacha20_setkey(struct crypto_skcipher *ctfm,
+					     const u8 *key, unsigned int len)
+{
+	struct safexcel_cipher_ctx *ctx = crypto_skcipher_ctx(ctfm);
+
+	if (len != CHACHA_KEY_SIZE) {
+		crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	safexcel_chacha20_setkey(ctx, key);
 
 	return 0;
 }
@@ -2384,3 +2420,196 @@ struct safexcel_alg_template safexcel_alg_chacha20 = {
 		},
 	},
 };
+
+static int safexcel_aead_chachapoly_setkey(struct crypto_aead *ctfm,
+				    const u8 *key, unsigned int len)
+{
+	struct safexcel_cipher_ctx *ctx = crypto_aead_ctx(ctfm);
+
+	if (ctx->aead  == EIP197_AEAD_TYPE_IPSEC_ESP &&
+	    len > EIP197_AEAD_IPSEC_NONCE_SIZE) {
+		/* ESP variant has nonce appended to key */
+		len -= EIP197_AEAD_IPSEC_NONCE_SIZE;
+		ctx->nonce = *(u32 *)(key + len);
+	}
+	if (len != CHACHA_KEY_SIZE) {
+		crypto_aead_set_flags(ctfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	safexcel_chacha20_setkey(ctx, key);
+
+	return 0;
+}
+
+static int safexcel_aead_chachapoly_setauthsize(struct crypto_aead *tfm,
+					 unsigned int authsize)
+{
+	if (authsize != POLY1305_DIGEST_SIZE)
+		return -EINVAL;
+	return 0;
+}
+
+static int safexcel_aead_chachapoly_crypt(struct aead_request *req,
+					  enum safexcel_cipher_direction dir)
+{
+	struct safexcel_cipher_req *creq = aead_request_ctx(req);
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_aead_tfm(aead);
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct aead_request *subreq = aead_request_ctx(req);
+	u32 key[CHACHA_KEY_SIZE / sizeof(u32) + 1];
+	int i, ret = 0;
+
+	/*
+	 * Instead of wasting time detecting umpteen silly corner cases,
+	 * just dump all "small" requests to the fallback implementation.
+	 * HW would not be faster on such small requests anyway.
+	 */
+	if (likely((ctx->aead != EIP197_AEAD_TYPE_IPSEC_ESP ||
+		    req->assoclen >= EIP197_AEAD_IPSEC_IV_SIZE) &&
+		   req->cryptlen > POLY1305_DIGEST_SIZE)) {
+		return safexcel_queue_req(&req->base, creq, dir);
+	}
+
+	/* HW cannot do full (AAD+payload) zero length, use fallback */
+	for (i = 0; i < CHACHA_KEY_SIZE / sizeof(u32); i++)
+		key[i] = cpu_to_le32(ctx->key[i]);
+	if (ctx->aead == EIP197_AEAD_TYPE_IPSEC_ESP) {
+		/* ESP variant has nonce appended to the key */
+		key[CHACHA_KEY_SIZE / sizeof(u32)] = ctx->nonce;
+		ret = crypto_aead_setkey(ctx->fback, (u8 *)key,
+					 CHACHA_KEY_SIZE +
+					 EIP197_AEAD_IPSEC_NONCE_SIZE);
+	} else {
+		ret = crypto_aead_setkey(ctx->fback, (u8 *)key,
+					 CHACHA_KEY_SIZE);
+	}
+	if (ret) {
+		crypto_aead_clear_flags(aead, CRYPTO_TFM_REQ_MASK);
+		crypto_aead_set_flags(aead, crypto_aead_get_flags(ctx->fback) &
+					    CRYPTO_TFM_REQ_MASK);
+		return ret;
+	}
+
+	aead_request_set_tfm(subreq, ctx->fback);
+	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
+				  req->base.data);
+	aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
+			       req->iv);
+	aead_request_set_ad(subreq, req->assoclen);
+
+	return (dir ==  SAFEXCEL_ENCRYPT) ?
+		crypto_aead_encrypt(subreq) :
+		crypto_aead_decrypt(subreq);
+}
+
+static int safexcel_aead_chachapoly_encrypt(struct aead_request *req)
+{
+	return safexcel_aead_chachapoly_crypt(req, SAFEXCEL_ENCRYPT);
+}
+
+static int safexcel_aead_chachapoly_decrypt(struct aead_request *req)
+{
+	return safexcel_aead_chachapoly_crypt(req, SAFEXCEL_DECRYPT);
+}
+
+static int safexcel_aead_chachapoly_cra_init(struct crypto_tfm *tfm)
+{
+	struct crypto_aead *aead = __crypto_aead_cast(tfm);
+	struct aead_alg *alg = crypto_aead_alg(aead);
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	safexcel_aead_cra_init(tfm);
+	ctx->alg  = SAFEXCEL_CHACHA20;
+	ctx->mode = CONTEXT_CONTROL_CHACHA20_MODE_256_32 |
+		    CONTEXT_CONTROL_CHACHA20_MODE_CALC_OTK;
+	ctx->hash_alg = CONTEXT_CONTROL_CRYPTO_ALG_POLY1305;
+	ctx->state_sz = 0; /* Precomputed by HW */
+
+	/* Allocate fallback implementation */
+	ctx->fback = crypto_alloc_aead(alg->base.cra_name, 0,
+				       CRYPTO_ALG_ASYNC |
+				       CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(ctx->fback))
+		return PTR_ERR(ctx->fback);
+
+	crypto_aead_set_reqsize(aead, max(sizeof(struct safexcel_cipher_req),
+					  sizeof(struct aead_request) +
+					  crypto_aead_reqsize(ctx->fback)));
+
+	return 0;
+}
+
+static void safexcel_aead_chachapoly_cra_exit(struct crypto_tfm *tfm)
+{
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_aead(ctx->fback);
+	safexcel_aead_cra_exit(tfm);
+}
+
+struct safexcel_alg_template safexcel_alg_chachapoly = {
+	.type = SAFEXCEL_ALG_TYPE_AEAD,
+	.algo_mask = SAFEXCEL_ALG_CHACHA20 | SAFEXCEL_ALG_POLY1305,
+	.alg.aead = {
+		.setkey = safexcel_aead_chachapoly_setkey,
+		.setauthsize = safexcel_aead_chachapoly_setauthsize,
+		.encrypt = safexcel_aead_chachapoly_encrypt,
+		.decrypt = safexcel_aead_chachapoly_decrypt,
+		.ivsize = CHACHAPOLY_IV_SIZE,
+		.maxauthsize = POLY1305_DIGEST_SIZE,
+		.base = {
+			.cra_name = "rfc7539(chacha20,poly1305)",
+			.cra_driver_name = "safexcel-chacha20-poly1305",
+			/* +1 to put it above HW chacha + SW poly */
+			.cra_priority = SAFEXCEL_CRA_PRIORITY + 1,
+			.cra_flags = CRYPTO_ALG_ASYNC |
+				     CRYPTO_ALG_KERN_DRIVER_ONLY |
+				     CRYPTO_ALG_NEED_FALLBACK,
+			.cra_blocksize = 1,
+			.cra_ctxsize = sizeof(struct safexcel_cipher_ctx),
+			.cra_alignmask = 0,
+			.cra_init = safexcel_aead_chachapoly_cra_init,
+			.cra_exit = safexcel_aead_chachapoly_cra_exit,
+			.cra_module = THIS_MODULE,
+		},
+	},
+};
+
+static int safexcel_aead_chachapolyesp_cra_init(struct crypto_tfm *tfm)
+{
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+	int ret;
+
+	ret = safexcel_aead_chachapoly_cra_init(tfm);
+	ctx->aead  = EIP197_AEAD_TYPE_IPSEC_ESP;
+	return ret;
+}
+
+struct safexcel_alg_template safexcel_alg_chachapoly_esp = {
+	.type = SAFEXCEL_ALG_TYPE_AEAD,
+	.algo_mask = SAFEXCEL_ALG_CHACHA20 | SAFEXCEL_ALG_POLY1305,
+	.alg.aead = {
+		.setkey = safexcel_aead_chachapoly_setkey,
+		.setauthsize = safexcel_aead_chachapoly_setauthsize,
+		.encrypt = safexcel_aead_chachapoly_encrypt,
+		.decrypt = safexcel_aead_chachapoly_decrypt,
+		.ivsize = CHACHAPOLY_IV_SIZE - EIP197_AEAD_IPSEC_NONCE_SIZE,
+		.maxauthsize = POLY1305_DIGEST_SIZE,
+		.base = {
+			.cra_name = "rfc7539esp(chacha20,poly1305)",
+			.cra_driver_name = "safexcel-chacha20-poly1305-esp",
+			/* +1 to put it above HW chacha + SW poly */
+			.cra_priority = SAFEXCEL_CRA_PRIORITY + 1,
+			.cra_flags = CRYPTO_ALG_ASYNC |
+				     CRYPTO_ALG_KERN_DRIVER_ONLY |
+				     CRYPTO_ALG_NEED_FALLBACK,
+			.cra_blocksize = 1,
+			.cra_ctxsize = sizeof(struct safexcel_cipher_ctx),
+			.cra_alignmask = 0,
+			.cra_init = safexcel_aead_chachapolyesp_cra_init,
+			.cra_exit = safexcel_aead_chachapoly_cra_exit,
+			.cra_module = THIS_MODULE,
+		},
+	},
+};