diff options
author | Ralf S. Engelschall <rse@openssl.org> | 1998-12-21 10:52:47 +0000 |
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committer | Ralf S. Engelschall <rse@openssl.org> | 1998-12-21 10:52:47 +0000 |
commit | d02b48c63a58ea4367a0e905979f140b7d090f86 (patch) | |
tree | 504f62ed3d84799f785b9cd9fab255a21b0e1b0e /crypto/dsa/dsa_sign.c |
Import of old SSLeay release: SSLeay 0.8.1b
Diffstat (limited to 'crypto/dsa/dsa_sign.c')
-rw-r--r-- | crypto/dsa/dsa_sign.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/crypto/dsa/dsa_sign.c b/crypto/dsa/dsa_sign.c new file mode 100644 index 0000000000..ebb758feb5 --- /dev/null +++ b/crypto/dsa/dsa_sign.c @@ -0,0 +1,215 @@ +/* crypto/dsa/dsa_sign.c */ +/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com) + * All rights reserved. + * + * This package is an SSL implementation written + * by Eric Young (eay@cryptsoft.com). + * The implementation was written so as to conform with Netscapes SSL. + * + * This library is free for commercial and non-commercial use as long as + * the following conditions are aheared to. The following conditions + * apply to all code found in this distribution, be it the RC4, RSA, + * lhash, DES, etc., code; not just the SSL code. The SSL documentation + * included with this distribution is covered by the same copyright terms + * except that the holder is Tim Hudson (tjh@cryptsoft.com). + * + * Copyright remains Eric Young's, and as such any Copyright notices in + * the code are not to be removed. + * If this package is used in a product, Eric Young should be given attribution + * as the author of the parts of the library used. + * This can be in the form of a textual message at program startup or + * in documentation (online or textual) provided with the package. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * "This product includes cryptographic software written by + * Eric Young (eay@cryptsoft.com)" + * The word 'cryptographic' can be left out if the rouines from the library + * being used are not cryptographic related :-). + * 4. If you include any Windows specific code (or a derivative thereof) from + * the apps directory (application code) you must include an acknowledgement: + * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" + * + * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * The licence and distribution terms for any publically available version or + * derivative of this code cannot be changed. i.e. this code cannot simply be + * copied and put under another distribution licence + * [including the GNU Public Licence.] + */ + +/* Origional version from Steven Schoch <schoch@sheba.arc.nasa.gov> */ + +#include <stdio.h> +#include "cryptlib.h" +#include "bn.h" +#include "dsa.h" +#include "rand.h" +#include "asn1.h" + +/* data has already been hashed (probably with SHA or SHA-1). */ +/* DSAerr(DSA_F_DSA_SIGN,DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); */ + +int DSA_sign(type,dgst,dlen,sig,siglen,dsa) +int type; +unsigned char *dgst; +int dlen; +unsigned char *sig; /* out */ +unsigned int *siglen; /* out */ +DSA *dsa; + { + BIGNUM *kinv=NULL,*r=NULL; + BIGNUM *m=NULL; + BIGNUM *xr=NULL,*s=NULL; + BN_CTX *ctx=NULL; + unsigned char *p; + int i,len=0,ret=0,reason=ERR_R_BN_LIB; + ASN1_INTEGER rbs,sbs; + MS_STATIC unsigned char rbuf[50]; /* assuming r is 20 bytes +extra */ + MS_STATIC unsigned char sbuf[50]; /* assuming s is 20 bytes +extra */ + + i=BN_num_bytes(dsa->q); /* should be 20 */ + if ((dlen > i) || (dlen > 50)) + { + reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE; + goto err; + } + + ctx=BN_CTX_new(); + if (ctx == NULL) goto err; + + if ((dsa->kinv == NULL) || (dsa->r == NULL)) + { + if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err; + } + else + { + kinv=dsa->kinv; + dsa->kinv=NULL; + r=dsa->r; + dsa->r=NULL; + } + + m=BN_new(); + xr=BN_new(); + s=BN_new(); + if (m == NULL || xr == NULL || s == NULL) goto err; + + if (BN_bin2bn(dgst,dlen,m) == NULL) goto err; + + /* Compute s = inv(k) (m + xr) mod q */ + if (!BN_mul(xr, dsa->priv_key, r)) goto err; /* s = xr */ + if (!BN_add(s, xr, m)) goto err; /* s = m + xr */ + if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err; + + /* + * Now create a ASN.1 sequence of the integers R and S. + */ + rbs.data=rbuf; + sbs.data=sbuf; + rbs.type = V_ASN1_INTEGER; + sbs.type = V_ASN1_INTEGER; + rbs.length=BN_bn2bin(r,rbs.data); + sbs.length=BN_bn2bin(s,sbs.data); + + len =i2d_ASN1_INTEGER(&rbs,NULL); + len+=i2d_ASN1_INTEGER(&sbs,NULL); + + p=sig; + ASN1_put_object(&p,1,len,V_ASN1_SEQUENCE,V_ASN1_UNIVERSAL); + i2d_ASN1_INTEGER(&rbs,&p); + i2d_ASN1_INTEGER(&sbs,&p); + *siglen=(p-sig); + ret=1; +err: + if (!ret) DSAerr(DSA_F_DSA_SIGN,reason); + +#if 1 /* do the right thing :-) */ + if (kinv != NULL) BN_clear_free(kinv); + if (r != NULL) BN_clear_free(r); +#endif + if (ctx != NULL) BN_CTX_free(ctx); + if (m != NULL) BN_clear_free(m); + if (xr != NULL) BN_clear_free(xr); + if (s != NULL) BN_clear_free(s); + return(ret); + } + +int DSA_sign_setup(dsa,ctx_in,kinvp,rp) +DSA *dsa; +BN_CTX *ctx_in; +BIGNUM **kinvp; +BIGNUM **rp; + { + BN_CTX *ctx; + BIGNUM *k=NULL,*kinv=NULL,*r=NULL; + int ret=0; + + if (ctx_in == NULL) + { + if ((ctx=BN_CTX_new()) == NULL) goto err; + } + else + ctx=ctx_in; + + r=BN_new(); + k=BN_new(); + if ((r == NULL) || (k == NULL)) + goto err; + kinv=NULL; + + if (r == NULL) goto err; + + /* Get random k */ + for (;;) + { + if (!BN_rand(k, BN_num_bits(dsa->q), 1, 0)) goto err; + if (BN_cmp(k,dsa->q) >= 0) + BN_sub(k,k,dsa->q); + if (!BN_is_zero(k)) break; + } + + /* Compute r = (g^k mod p) mod q */ + if (!BN_mod_exp(r,dsa->g,k,dsa->p,ctx)) goto err; + if (!BN_mod(r,r,dsa->q,ctx)) goto err; + + /* Compute part of 's = inv(k) (m + xr) mod q' */ + if ((kinv=BN_mod_inverse(k,dsa->q,ctx)) == NULL) goto err; + + if (*kinvp != NULL) BN_clear_free(*kinvp); + *kinvp=kinv; + kinv=NULL; + if (*rp != NULL) BN_clear_free(*rp); + *rp=r; + ret=1; +err: + if (!ret) + { + DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB); + if (kinv != NULL) BN_clear_free(kinv); + if (r != NULL) BN_clear_free(r); + } + if (ctx_in == NULL) BN_CTX_free(ctx); + if (k != NULL) BN_clear_free(k); + if (kinv != NULL) BN_clear_free(kinv); + return(ret); + } + |