text: /*
   * xfrm algorithm interface
   *
   * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   */
  
  #include <crypto/hash.h>
  #include <crypto/skcipher.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/pfkeyv2.h>
  #include <linux/crypto.h>
  #include <linux/scatterlist.h>
  #include <net/xfrm.h>
  #if IS_ENABLED(CONFIG_INET_ESP) || IS_ENABLED(CONFIG_INET6_ESP)
  #include <net/esp.h>
  #endif
  
  /*
   * Algorithms supported by IPsec.  These entries contain properties which
   * are used in key negotiation and xfrm processing, and are used to verify
   * that instantiated crypto transforms have correct parameters for IPsec
   * purposes.
   */
  static struct xfrm_algo_desc aead_list[] = {
  {
  	.name = "rfc4106(gcm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 64,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AES_GCM_ICV8,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc4106(gcm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 96,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AES_GCM_ICV12,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc4106(gcm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AES_GCM_ICV16,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc4309(ccm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 64,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AES_CCM_ICV8,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc4309(ccm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 96,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AES_CCM_ICV12,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc4309(ccm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AES_CCM_ICV16,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc4543(gcm(aes))",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_NULL_AES_GMAC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc7539esp(chacha20,poly1305)",
  
  	.uinfo = {
  		.aead = {
  			.geniv = "seqiv",
  			.icv_truncbits = 128,
  		}
  	},
  
  	.pfkey_supported = 0,
  },
  };
  
  static struct xfrm_algo_desc aalg_list[] = {
  {
  	.name = "digest_null",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 0,
  			.icv_fullbits = 0,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_AALG_NULL,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 0,
  		.sadb_alg_maxbits = 0
  	}
  },
  {
  	.name = "hmac(md5)",
  	.compat = "md5",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 96,
  			.icv_fullbits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_AALG_MD5HMAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 128
  	}
  },
  {
  	.name = "hmac(sha1)",
  	.compat = "sha1",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 96,
  			.icv_fullbits = 160,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_AALG_SHA1HMAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 160,
  		.sadb_alg_maxbits = 160
  	}
  },
  {
  	.name = "hmac(sha256)",
  	.compat = "sha256",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 96,
  			.icv_fullbits = 256,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_AALG_SHA2_256HMAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 256,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "hmac(sha384)",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 192,
  			.icv_fullbits = 384,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_AALG_SHA2_384HMAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 384,
  		.sadb_alg_maxbits = 384
  	}
  },
  {
  	.name = "hmac(sha512)",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 256,
  			.icv_fullbits = 512,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_AALG_SHA2_512HMAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 512,
  		.sadb_alg_maxbits = 512
  	}
  },
  {
  	.name = "hmac(rmd160)",
  	.compat = "rmd160",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 96,
  			.icv_fullbits = 160,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_AALG_RIPEMD160HMAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 160,
  		.sadb_alg_maxbits = 160
  	}
  },
  {
  	.name = "xcbc(aes)",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 96,
  			.icv_fullbits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_AALG_AES_XCBC_MAC,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 128
  	}
  },
  {
  	/* rfc4494 */
  	.name = "cmac(aes)",
  
  	.uinfo = {
  		.auth = {
  			.icv_truncbits = 96,
  			.icv_fullbits = 128,
  		}
  	},
  
  	.pfkey_supported = 0,
  },
  };
  
  static struct xfrm_algo_desc ealg_list[] = {
  {
  	.name = "ecb(cipher_null)",
  	.compat = "cipher_null",
  
  	.uinfo = {
  		.encr = {
  			.blockbits = 8,
  			.defkeybits = 0,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id =	SADB_EALG_NULL,
  		.sadb_alg_ivlen = 0,
  		.sadb_alg_minbits = 0,
  		.sadb_alg_maxbits = 0
  	}
  },
  {
  	.name = "cbc(des)",
  	.compat = "des",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 64,
  			.defkeybits = 64,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_EALG_DESCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 64,
  		.sadb_alg_maxbits = 64
  	}
  },
  {
  	.name = "cbc(des3_ede)",
  	.compat = "des3_ede",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 64,
  			.defkeybits = 192,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_EALG_3DESCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 192,
  		.sadb_alg_maxbits = 192
  	}
  },
  {
  	.name = "cbc(cast5)",
  	.compat = "cast5",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 64,
  			.defkeybits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_CASTCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 40,
  		.sadb_alg_maxbits = 128
  	}
  },
  {
  	.name = "cbc(blowfish)",
  	.compat = "blowfish",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 64,
  			.defkeybits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_BLOWFISHCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 40,
  		.sadb_alg_maxbits = 448
  	}
  },
  {
  	.name = "cbc(aes)",
  	.compat = "aes",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 128,
  			.defkeybits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AESCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "cbc(serpent)",
  	.compat = "serpent",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 128,
  			.defkeybits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_SERPENTCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256,
  	}
  },
  {
  	.name = "cbc(camellia)",
  	.compat = "camellia",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 128,
  			.defkeybits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_CAMELLIACBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "cbc(twofish)",
  	.compat = "twofish",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "echainiv",
  			.blockbits = 128,
  			.defkeybits = 128,
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_TWOFISHCBC,
  		.sadb_alg_ivlen = 8,
  		.sadb_alg_minbits = 128,
  		.sadb_alg_maxbits = 256
  	}
  },
  {
  	.name = "rfc3686(ctr(aes))",
  
  	.uinfo = {
  		.encr = {
  			.geniv = "seqiv",
  			.blockbits = 128,
  			.defkeybits = 160, /* 128-bit key + 32-bit nonce */
  		}
  	},
  
  	.pfkey_supported = 1,
  
  	.desc = {
  		.sadb_alg_id = SADB_X_EALG_AESCTR,
  		.sadb_alg_ivlen	= 8,
  		.sadb_alg_minbits = 160,
  		.sadb_alg_maxbits = 288
  	}
  },
  };
  
  static struct xfrm_algo_desc calg_list[] = {
  {
  	.name = "deflate",
  	.uinfo = {
  		.comp = {
  			.threshold = 90,
  		}
  	},
  	.pfkey_supported = 1,
  	.desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE }
  },
  {
  	.name = "lzs",
  	.uinfo = {
  		.comp = {
  			.threshold = 90,
  		}
  	},
  	.pfkey_supported = 1,
  	.desc = { .sadb_alg_id = SADB_X_CALG_LZS }
  },
  {
  	.name = "lzjh",
  	.uinfo = {
  		.comp = {
  			.threshold = 50,
  		}
  	},
  	.pfkey_supported = 1,
  	.desc = { .sadb_alg_id = SADB_X_CALG_LZJH }
  },
  };
  
  static inline int aalg_entries(void)
  {
  	return ARRAY_SIZE(aalg_list);
  }
  
  static inline int ealg_entries(void)
  {
  	return ARRAY_SIZE(ealg_list);
  }
  
  static inline int calg_entries(void)
  {
  	return ARRAY_SIZE(calg_list);
  }
  
  struct xfrm_algo_list {
  	struct xfrm_algo_desc *algs;
  	int entries;
  	u32 type;
  	u32 mask;
  };
  
  static const struct xfrm_algo_list xfrm_aead_list = {
  	.algs = aead_list,
  	.entries = ARRAY_SIZE(aead_list),
  	.type = CRYPTO_ALG_TYPE_AEAD,
  	.mask = CRYPTO_ALG_TYPE_MASK,
  };
  
  static const struct xfrm_algo_list xfrm_aalg_list = {
  	.algs = aalg_list,
  	.entries = ARRAY_SIZE(aalg_list),
  	.type = CRYPTO_ALG_TYPE_HASH,
  	.mask = CRYPTO_ALG_TYPE_HASH_MASK,
  };
  
  static const struct xfrm_algo_list xfrm_ealg_list = {
  	.algs = ealg_list,
  	.entries = ARRAY_SIZE(ealg_list),
  	.type = CRYPTO_ALG_TYPE_BLKCIPHER,
  	.mask = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
  };
  
  static const struct xfrm_algo_list xfrm_calg_list = {
  	.algs = calg_list,
  	.entries = ARRAY_SIZE(calg_list),
  	.type = CRYPTO_ALG_TYPE_COMPRESS,
  	.mask = CRYPTO_ALG_TYPE_MASK,
  };
  
  static struct xfrm_algo_desc *xfrm_find_algo(
  	const struct xfrm_algo_list *algo_list,
  	int match(const struct xfrm_algo_desc *entry, const void *data),
  	const void *data, int probe)
  {
  	struct xfrm_algo_desc *list = algo_list->algs;
  	int i, status;
  
  	for (i = 0; i < algo_list->entries; i++) {
  		if (!match(list + i, data))
  			continue;
  
  		if (list[i].available)
  			return &list[i];
  
  		if (!probe)
  			break;
  
  		status = crypto_has_alg(list[i].name, algo_list->type,
  					algo_list->mask);
  		if (!status)
  			break;
  
  		list[i].available = status;
  		return &list[i];
  	}
  	return NULL;
  }
  
  static int xfrm_alg_id_match(const struct xfrm_algo_desc *entry,
  			     const void *data)
  {
  	return entry->desc.sadb_alg_id == (unsigned long)data;
  }
  
  struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id)
  {
  	return xfrm_find_algo(&xfrm_aalg_list, xfrm_alg_id_match,
  			      (void *)(unsigned long)alg_id, 1);
  }
  EXPORT_SYMBOL_GPL(xfrm_aalg_get_byid);
  
  struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id)
  {
  	return xfrm_find_algo(&xfrm_ealg_list, xfrm_alg_id_match,
  			      (void *)(unsigned long)alg_id, 1);
  }
  EXPORT_SYMBOL_GPL(xfrm_ealg_get_byid);
  
  struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id)
  {
  	return xfrm_find_algo(&xfrm_calg_list, xfrm_alg_id_match,
  			      (void *)(unsigned long)alg_id, 1);
  }
  EXPORT_SYMBOL_GPL(xfrm_calg_get_byid);
  
  static int xfrm_alg_name_match(const struct xfrm_algo_desc *entry,
  			       const void *data)
  {
  	const char *name = data;
  
  	return name && (!strcmp(name, entry->name) ||
  			(entry->compat && !strcmp(name, entry->compat)));
  }
  
  struct xfrm_algo_desc *xfrm_aalg_get_byname(const char *name, int probe)
  {
  	return xfrm_find_algo(&xfrm_aalg_list, xfrm_alg_name_match, name,
  			      probe);
  }
  EXPORT_SYMBOL_GPL(xfrm_aalg_get_byname);
  
  struct xfrm_algo_desc *xfrm_ealg_get_byname(const char *name, int probe)
  {
  	return xfrm_find_algo(&xfrm_ealg_list, xfrm_alg_name_match, name,
  			      probe);
  }
  EXPORT_SYMBOL_GPL(xfrm_ealg_get_byname);
  
  struct xfrm_algo_desc *xfrm_calg_get_byname(const char *name, int probe)
  {
  	return xfrm_find_algo(&xfrm_calg_list, xfrm_alg_name_match, name,
  			      probe);
  }
  EXPORT_SYMBOL_GPL(xfrm_calg_get_byname);
  
  struct xfrm_aead_name {
  	const char *name;
  	int icvbits;
  };
  
  static int xfrm_aead_name_match(const struct xfrm_algo_desc *entry,
  				const void *data)
  {
  	const struct xfrm_aead_name *aead = data;
  	const char *name = aead->name;
  
  	return aead->icvbits == entry->uinfo.aead.icv_truncbits && name &&
  	       !strcmp(name, entry->name);
  }
  
  struct xfrm_algo_desc *xfrm_aead_get_byname(const char *name, int icv_len, int probe)
  {
  	struct xfrm_aead_name data = {
  		.name = name,
  		.icvbits = icv_len,
  	};
  
  	return xfrm_find_algo(&xfrm_aead_list, xfrm_aead_name_match, &data,
  			      probe);
  }
  EXPORT_SYMBOL_GPL(xfrm_aead_get_byname);
  
  struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx)
  {
  	if (idx >= aalg_entries())
  		return NULL;
  
  	return &aalg_list[idx];
  }
  EXPORT_SYMBOL_GPL(xfrm_aalg_get_byidx);
  
  struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx)
  {
  	if (idx >= ealg_entries())
  		return NULL;
  
  	return &ealg_list[idx];
  }
  EXPORT_SYMBOL_GPL(xfrm_ealg_get_byidx);
  
  /*
   * Probe for the availability of crypto algorithms, and set the available
   * flag for any algorithms found on the system.  This is typically called by
   * pfkey during userspace SA add, update or register.
   */
  void xfrm_probe_algs(void)
  {
  	int i, status;
  
  	BUG_ON(in_softirq());
  
  	for (i = 0; i < aalg_entries(); i++) {
  		status = crypto_has_ahash(aalg_list[i].name, 0, 0);
  		if (aalg_list[i].available != status)
  			aalg_list[i].available = status;
  	}
  
  	for (i = 0; i < ealg_entries(); i++) {
  		status = crypto_has_skcipher(ealg_list[i].name, 0, 0);
  		if (ealg_list[i].available != status)
  			ealg_list[i].available = status;
  	}
  
  	for (i = 0; i < calg_entries(); i++) {
  		status = crypto_has_comp(calg_list[i].name, 0,
  					 CRYPTO_ALG_ASYNC);
  		if (calg_list[i].available != status)
  			calg_list[i].available = status;
  	}
  }
  EXPORT_SYMBOL_GPL(xfrm_probe_algs);
  
  int xfrm_count_pfkey_auth_supported(void)
  {
  	int i, n;
  
  	for (i = 0, n = 0; i < aalg_entries(); i++)
  		if (aalg_list[i].available && aalg_list[i].pfkey_supported)
  			n++;
  	return n;
  }
  EXPORT_SYMBOL_GPL(xfrm_count_pfkey_auth_supported);
  
  int xfrm_count_pfkey_enc_supported(void)
  {
  	int i, n;
  
  	for (i = 0, n = 0; i < ealg_entries(); i++)
  		if (ealg_list[i].available && ealg_list[i].pfkey_supported)
  			n++;
  	return n;
  }
  EXPORT_SYMBOL_GPL(xfrm_count_pfkey_enc_supported);
  
  MODULE_LICENSE("GPL");
  