nsp(4) - NetBSD Manual Pages

NSP(4)                  NetBSD Kernel Interfaces Manual                 NSP(4)


NAME

     nsp -- NBMK/CyberGuard/NetOctave NSP2000 crypto accelerator


SYNOPSIS

     nsp* at pci? dev ? function ?


DESCRIPTION

     The nsp driver supports cards using the NSP2000 cryptographic processor,
     originally manufactured and sold by NetOctave, then CyberGuard, and
     presently (late 2008) by NBMK Encryption Technologies.

     The NSP2000 is a cryptographic ``packet processor'' or ``macro
     processor'' featuring extensive support for protocol handshake accelera-
     tion and protocol record operations (e.g. single-pass pad-encrypt-and-
     hash for SSL or ESP messages).  It also provides various cryptographic
     and mathematical primitives such as random number generation, encryp-
     tion/decryption (DES, 3DES, and RC4), hash computation (MD5, SHA1, and
     HMAC), and an extensive set of operations for arbitrary precision arith-
     metic.  It contains a tamper-resistant write-only memory region for stor-
     age of cryptographic keys.

     The nsp driver registers support for the following operations with
     opencrypto(9):

           CRYPTO_DES_CBC      DES in CBC mode.

           CRYPTO_3DES_CBC     Triple-DES in CBC mode.

           CRYPTO_MD5          The MD5 hash algorithm.

           CRYPTO_SHA1         The SHA-1 hash algorithm.

           CRYPTO_SHA1_HMAC    The HMAC message authentication code using
                               SHA-1 as the hash function.

           CRYPTO_MD5_HMAC     The HMAC message authentication code using MD5
                               as the hash function.

           CRK_MOD             Compute x modulo y.

           CRK_MOD_ADD         Modular addition.

           CRK_MOD_ADDINV      Modular additive inversion.

           CRK_MOD_SUB         Modular subtraction.

           CRK_MOD_MULT        Modular multiplication.

           CRK_MOD_MULTINV     Modular multiplicative inversion.

           CRK_MOD_EXP         Modular exponentiation.

           CRK_DSA_SIGN        DSA signature creation.

           CRK_DSA_VERIFY      DSA signature verification.

           CRK_DH_COMPUTE_KEY  Diffie-Hellman key computation.


PERFORMANCE

     The nsp driver can perform several hundred 1024-bit RSA operations per
     second, and can encrypt and hash about 200Mbit/sec of data with symmetric
     operations.  Each figure is approximately 1/3 the rated throughput for
     the device.

     Several restrictions limit the performance of this driver:
     1.   The CRK_MOD_EXP_CRT operation (modular exponentiation with operands
          in Chinese Remainder Theorem form) is unfortunately not supported
          because the opencrypto(9) interface specifies this operation in a
          way which may only be compatible with the ubsec(4) accelerator.
     2.   The handshake operations and record transforms are not supported as
          they are a poor fit for the current opencrypto(9) API.  Support for
          either would require a method of passing record-transform contexts
          between layers of the framework, likely in both directions across
          the user-kernel boundary.  Without record operations, the host CPU
          will almost always perform RC4 faster than the NSP2000, so RC4 sup-
          port is disabled in the nsp driver.
     3.   The on-board key memory is not supported.  It would be relatively
          easy to add support for this feature to opencrypto(9), but the
          interface for supporting this functionality in OpenSSL in OpenSSL is
          complex and poorly documented, which makes kernel support useless.
     4.   The OpenSSL ``engine'' for crypto(4) does not yet support the HMAC
          forms of the hash operations, which roughly halves performance for
          many workloads.

     On a more positive note, the NSP2000 and nsp driver offer excellent per-
     formance for small modular arithmetic operations, achieving 75,000 or
     more such operations per second.


SEE ALSO

     crypto(4), fast_ipsec(4), intro(4), rnd(4), opencrypto(9)


HISTORY

     The nsp device driver is descended from the NetOctave SDK for
     FreeBSD 4.11, where it was called ``noct''.  It is unrelated to the
     driver of that name which appeared in OpenBSD 3.2, which does not support
     the public-key (or other bignum) functions of the device.  The nsp driver
     was ported to NetBSD 5.0 by Coyote Point Systems, Inc and generously made
     available under a BSD-style license by NBMK Encryption Technologies, Inc,
     the corporate successor of NetOctave.

     The nsp device driver does not currently support the device node inter-
     face provided by the original NetOctave ``noct'' driver (which offers
     handshake acceleration, record operations, memory-mapped handling of
     packet payloads, and several other useful features) but most of the code
     to do so is still present, albeit in untested form.


BUGS

     Support for limitations of the NSP2000 PCI interface (broken burst-mode
     operation, lack of scatter-gather support) is present but tested only on
     a fairly small range of host systems.

     It appears that most if not all NSP2000 cards ever manufactured were
     designed to carry either one or two accelerator chips, which suggests
     that cards exist with both chips populated.  The nsp driver has never
     been tested with more than one instance present at a time.

NetBSD 7.0                     November 2, 2008                     NetBSD 7.0