xfrm_algo.c

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/*
 * xfrm algorithm interface
 *
 * Copyright (c) 2002 James Morris <[email protected]>
 *
 * 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 <linux/module.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include <net/xfrm.h>
#if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE)
#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 = {
            .icv_truncbits = 64,
        }
    },

    .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 = {
            .icv_truncbits = 96,
        }
    },

    .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 = {
            .icv_truncbits = 128,
        }
    },

    .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 = {
            .icv_truncbits = 64,
        }
    },

    .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 = {
            .icv_truncbits = 96,
        }
    },

    .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 = {
            .icv_truncbits = 128,
        }
    },

    .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 = {
            .icv_truncbits = 128,
        }
    },

    .desc = {
        .sadb_alg_id = SADB_X_EALG_NULL_AES_GMAC,
        .sadb_alg_ivlen = 8,
        .sadb_alg_minbits = 128,
        .sadb_alg_maxbits = 256
    }
},
};

static struct xfrm_algo_desc aalg_list[] = {
{
    .name = "digest_null",

    .uinfo = {
        .auth = {
            .icv_truncbits = 0,
            .icv_fullbits = 0,
        }
    },

    .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,
        }
    },

    .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,
        }
    },

    .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,
        }
    },

    .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,
        }
    },

    .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,
        }
    },

    .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,
        }
    },

    .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,
        }
    },

    .desc = {
        .sadb_alg_id = SADB_X_AALG_AES_XCBC_MAC,
        .sadb_alg_ivlen = 0,
        .sadb_alg_minbits = 128,
        .sadb_alg_maxbits = 128
    }
},
};

static struct xfrm_algo_desc ealg_list[] = {
{
    .name = "ecb(cipher_null)",
    .compat = "cipher_null",

    .uinfo = {
        .encr = {
            .blockbits = 8,
            .defkeybits = 0,
        }
    },

    .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 = {
            .blockbits = 64,
            .defkeybits = 64,
        }
    },

    .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 = {
            .blockbits = 64,
            .defkeybits = 192,
        }
    },

    .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 = {
            .blockbits = 64,
            .defkeybits = 128,
        }
    },

    .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 = {
            .blockbits = 64,
            .defkeybits = 128,
        }
    },

    .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 = {
            .blockbits = 128,
            .defkeybits = 128,
        }
    },

    .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 = {
            .blockbits = 128,
            .defkeybits = 128,
        }
    },

    .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 = {
            .blockbits = 128,
            .defkeybits = 128,
        }
    },

    .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 = {
            .blockbits = 128,
            .defkeybits = 128,
        }
    },

    .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 = {
            .blockbits = 128,
            .defkeybits = 160, /* 128-bit key + 32-bit nonce */
        }
    },

    .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,
        }
    },
    .desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE }
},
{
    .name = "lzs",
    .uinfo = {
        .comp = {
            .threshold = 90,
        }
    },
    .desc = { .sadb_alg_id = SADB_X_CALG_LZS }
},
{
    .name = "lzjh",
    .uinfo = {
        .comp = {
            .threshold = 50,
        }
    },
    .desc = { .sadb_alg_id = SADB_X_CALG_LZJH }
},
};

static inline int aead_entries(void)
{
    return ARRAY_SIZE(aead_list);
}

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_hash(aalg_list[i].name, 0,
                     CRYPTO_ALG_ASYNC);
        if (aalg_list[i].available != status)
            aalg_list[i].available = status;
    }

    for (i = 0; i < ealg_entries(); i++) {
        status = crypto_has_blkcipher(ealg_list[i].name, 0,
                          CRYPTO_ALG_ASYNC);
        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_auth_supported(void)
{
    int i, n;

    for (i = 0, n = 0; i < aalg_entries(); i++)
        if (aalg_list[i].available)
            n++;
    return n;
}
EXPORT_SYMBOL_GPL(xfrm_count_auth_supported);

int xfrm_count_enc_supported(void)
{
    int i, n;

    for (i = 0, n = 0; i < ealg_entries(); i++)
        if (ealg_list[i].available)
            n++;
    return n;
}
EXPORT_SYMBOL_GPL(xfrm_count_enc_supported);

#if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE)

void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len)
{
    if (tail != skb) {
        skb->data_len += len;
        skb->len += len;
    }
    return skb_put(tail, len);
}
EXPORT_SYMBOL_GPL(pskb_put);
#endif

MODULE_LICENSE("GPL");