Mercurial > dropbear
diff src/pk/dsa/dsa_export.c @ 192:9cc34777b479 libtomcrypt
propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9)
to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 08 May 2005 06:36:47 +0000 |
parents | 1c15b283127b |
children | 39d5d58461d6 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/pk/dsa/dsa_export.c Sun May 08 06:36:47 2005 +0000 @@ -0,0 +1,75 @@ +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, [email protected], http://libtomcrypt.org + */ +#include "tomcrypt.h" + +/** + @file dsa_export.c + DSA implementation, export key, Tom St Denis +*/ + +#ifdef MDSA + +/** + Export a DSA key to a binary packet + @param out [out] Where to store the packet + @param outlen [in/out] The max size and resulting size of the packet + @param type The type of key to export (PK_PRIVATE or PK_PUBLIC) + @param key The key to export + @return CRYPT_OK if successful +*/ +int dsa_export(unsigned char *out, unsigned long *outlen, int type, dsa_key *key) +{ + unsigned long y, z; + int err; + + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + LTC_ARGCHK(key != NULL); + + /* can we store the static header? */ + if (*outlen < (PACKET_SIZE + 1 + 2)) { + return CRYPT_BUFFER_OVERFLOW; + } + + if (type == PK_PRIVATE && key->type != PK_PRIVATE) { + return CRYPT_PK_TYPE_MISMATCH; + } + + if (type != PK_PUBLIC && type != PK_PRIVATE) { + return CRYPT_INVALID_ARG; + } + + /* store header */ + packet_store_header(out, PACKET_SECT_DSA, PACKET_SUB_KEY); + y = PACKET_SIZE; + + /* store g, p, q, qord */ + out[y++] = type; + out[y++] = (key->qord>>8)&255; + out[y++] = key->qord & 255; + + OUTPUT_BIGNUM(&key->g,out,y,z); + OUTPUT_BIGNUM(&key->p,out,y,z); + OUTPUT_BIGNUM(&key->q,out,y,z); + + /* public exponent */ + OUTPUT_BIGNUM(&key->y,out,y,z); + + if (type == PK_PRIVATE) { + OUTPUT_BIGNUM(&key->x,out,y,z); + } + + *outlen = y; + return CRYPT_OK; +} + +#endif +