crypto: inside-secure - Added support for the CHACHA20 skcipher

Added support for the CHACHA20 skcipher algorithm.
Tested on an eip197c-iesb configuration in the Xilinx VCU118 devboard,
passes all testmgr vectors plus the extra fuzzing tests.

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:
- made switch entry SAFEXCEL_AES explit and added empty default, as
  requested by Antoine Tenart. Also needed to make SM4 patches apply.

changes since v3:
- nothing
Signed-off-by: Pascal van Leeuwen <pvanleeuwen@verimatrix.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/inside-secure/safexcel.c

@@ -1173,6 +1173,7 @@ static struct safexcel_alg_template *safexcel_algs[] = {
 	&safexcel_alg_cbcmac,
 	&safexcel_alg_xcbcmac,
 	&safexcel_alg_cmac,
+	&safexcel_alg_chacha20,
 };
 
 static int safexcel_register_algorithms(struct safexcel_crypto_priv *priv)

drivers/crypto/inside-secure/safexcel.h

@@ -358,6 +358,7 @@ struct safexcel_context_record {
 #define CONTEXT_CONTROL_CRYPTO_ALG_AES128	(0x5 << 17)
 #define CONTEXT_CONTROL_CRYPTO_ALG_AES192	(0x6 << 17)
 #define CONTEXT_CONTROL_CRYPTO_ALG_AES256	(0x7 << 17)
+#define CONTEXT_CONTROL_CRYPTO_ALG_CHACHA20	(0x8 << 17)
 #define CONTEXT_CONTROL_DIGEST_PRECOMPUTED	(0x1 << 21)
 #define CONTEXT_CONTROL_DIGEST_XCM		(0x2 << 21)
 #define CONTEXT_CONTROL_DIGEST_HMAC		(0x3 << 21)
@@ -378,6 +379,7 @@ struct safexcel_context_record {
 /* control1 */
 #define CONTEXT_CONTROL_CRYPTO_MODE_ECB		(0 << 0)
 #define CONTEXT_CONTROL_CRYPTO_MODE_CBC		(1 << 0)
+#define CONTEXT_CONTROL_CHACHA20_MODE_256_32	(2 << 0)
 #define CONTEXT_CONTROL_CRYPTO_MODE_OFB		(4 << 0)
 #define CONTEXT_CONTROL_CRYPTO_MODE_CFB		(5 << 0)
 #define CONTEXT_CONTROL_CRYPTO_MODE_CTR_LOAD	(6 << 0)
@@ -858,5 +860,6 @@ extern struct safexcel_alg_template safexcel_alg_crc32;
 extern struct safexcel_alg_template safexcel_alg_cbcmac;
 extern struct safexcel_alg_template safexcel_alg_xcbcmac;
 extern struct safexcel_alg_template safexcel_alg_cmac;
+extern struct safexcel_alg_template safexcel_alg_chacha20;
 
 #endif

drivers/crypto/inside-secure/safexcel_cipher.c

@@ -5,13 +5,14 @@
  * Antoine Tenart <antoine.tenart@free-electrons.com>
  */
 
+#include <asm/unaligned.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmapool.h>
-
 #include <crypto/aead.h>
 #include <crypto/aes.h>
 #include <crypto/authenc.h>
+#include <crypto/chacha.h>
 #include <crypto/ctr.h>
 #include <crypto/internal/des.h>
 #include <crypto/gcm.h>
@@ -33,6 +34,7 @@ enum safexcel_cipher_alg {
 	SAFEXCEL_DES,
 	SAFEXCEL_3DES,
 	SAFEXCEL_AES,
+	SAFEXCEL_CHACHA20,
 };
 
 struct safexcel_cipher_ctx {
@@ -80,6 +82,15 @@ static void safexcel_cipher_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 		/* 32 bit counter, start at 1 (big endian!) */
 		cdesc->control_data.token[3] = cpu_to_be32(1);
 
+		return;
+	} 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;
+
 		return;
 	} else if (ctx->xcm == EIP197_XCM_MODE_GCM) {
 		cdesc->control_data.options |= EIP197_OPTION_4_TOKEN_IV_CMD;
@@ -116,6 +127,8 @@ static void safexcel_cipher_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 			block_sz = AES_BLOCK_SIZE;
 			cdesc->control_data.options |= EIP197_OPTION_4_TOKEN_IV_CMD;
 			break;
+		default:
+			break;
 		}
 		memcpy(cdesc->control_data.token, iv, block_sz);
 	}
@@ -480,6 +493,9 @@ static int safexcel_context_control(struct safexcel_cipher_ctx *ctx,
 				ctx->key_len >> ctx->xts);
 			return -EINVAL;
 		}
+	} else if (ctx->alg == SAFEXCEL_CHACHA20) {
+		cdesc->control_data.control0 |=
+			CONTEXT_CONTROL_CRYPTO_ALG_CHACHA20;
 	}
 
 	return 0;
@@ -2303,3 +2319,68 @@ struct safexcel_alg_template safexcel_alg_ccm = {
 		},
 	},
 };
+
+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);
+	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] !=
+			    get_unaligned_le32(key + i * sizeof(u32))) {
+				ctx->base.needs_inv = true;
+				break;
+			}
+		}
+	}
+
+	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;
+
+	return 0;
+}
+
+static int safexcel_skcipher_chacha20_cra_init(struct crypto_tfm *tfm)
+{
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	safexcel_skcipher_cra_init(tfm);
+	ctx->alg  = SAFEXCEL_CHACHA20;
+	ctx->mode = CONTEXT_CONTROL_CHACHA20_MODE_256_32;
+	return 0;
+}
+
+struct safexcel_alg_template safexcel_alg_chacha20 = {
+	.type = SAFEXCEL_ALG_TYPE_SKCIPHER,
+	.algo_mask = SAFEXCEL_ALG_CHACHA20,
+	.alg.skcipher = {
+		.setkey = safexcel_skcipher_chacha20_setkey,
+		.encrypt = safexcel_encrypt,
+		.decrypt = safexcel_decrypt,
+		.min_keysize = CHACHA_KEY_SIZE,
+		.max_keysize = CHACHA_KEY_SIZE,
+		.ivsize = CHACHA_IV_SIZE,
+		.base = {
+			.cra_name = "chacha20",
+			.cra_driver_name = "safexcel-chacha20",
+			.cra_priority = SAFEXCEL_CRA_PRIORITY,
+			.cra_flags = CRYPTO_ALG_ASYNC |
+				     CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_blocksize = 1,
+			.cra_ctxsize = sizeof(struct safexcel_cipher_ctx),
+			.cra_alignmask = 0,
+			.cra_init = safexcel_skcipher_chacha20_cra_init,
+			.cra_exit = safexcel_skcipher_cra_exit,
+			.cra_module = THIS_MODULE,
+		},
+	},
+};