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Diffstat (limited to 'src/lib/libcrypto/dsa/dsa_sign.c')
-rw-r--r-- | src/lib/libcrypto/dsa/dsa_sign.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/src/lib/libcrypto/dsa/dsa_sign.c b/src/lib/libcrypto/dsa/dsa_sign.c new file mode 100644 index 0000000000..6ca1c318f2 --- /dev/null +++ b/src/lib/libcrypto/dsa/dsa_sign.c | |||
@@ -0,0 +1,215 @@ | |||
1 | /* crypto/dsa/dsa_sign.c */ | ||
2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | ||
3 | * All rights reserved. | ||
4 | * | ||
5 | * This package is an SSL implementation written | ||
6 | * by Eric Young (eay@cryptsoft.com). | ||
7 | * The implementation was written so as to conform with Netscapes SSL. | ||
8 | * | ||
9 | * This library is free for commercial and non-commercial use as long as | ||
10 | * the following conditions are aheared to. The following conditions | ||
11 | * apply to all code found in this distribution, be it the RC4, RSA, | ||
12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | ||
13 | * included with this distribution is covered by the same copyright terms | ||
14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | ||
15 | * | ||
16 | * Copyright remains Eric Young's, and as such any Copyright notices in | ||
17 | * the code are not to be removed. | ||
18 | * If this package is used in a product, Eric Young should be given attribution | ||
19 | * as the author of the parts of the library used. | ||
20 | * This can be in the form of a textual message at program startup or | ||
21 | * in documentation (online or textual) provided with the package. | ||
22 | * | ||
23 | * Redistribution and use in source and binary forms, with or without | ||
24 | * modification, are permitted provided that the following conditions | ||
25 | * are met: | ||
26 | * 1. Redistributions of source code must retain the copyright | ||
27 | * notice, this list of conditions and the following disclaimer. | ||
28 | * 2. Redistributions in binary form must reproduce the above copyright | ||
29 | * notice, this list of conditions and the following disclaimer in the | ||
30 | * documentation and/or other materials provided with the distribution. | ||
31 | * 3. All advertising materials mentioning features or use of this software | ||
32 | * must display the following acknowledgement: | ||
33 | * "This product includes cryptographic software written by | ||
34 | * Eric Young (eay@cryptsoft.com)" | ||
35 | * The word 'cryptographic' can be left out if the rouines from the library | ||
36 | * being used are not cryptographic related :-). | ||
37 | * 4. If you include any Windows specific code (or a derivative thereof) from | ||
38 | * the apps directory (application code) you must include an acknowledgement: | ||
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | ||
40 | * | ||
41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND | ||
42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | ||
45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
51 | * SUCH DAMAGE. | ||
52 | * | ||
53 | * The licence and distribution terms for any publically available version or | ||
54 | * derivative of this code cannot be changed. i.e. this code cannot simply be | ||
55 | * copied and put under another distribution licence | ||
56 | * [including the GNU Public Licence.] | ||
57 | */ | ||
58 | |||
59 | /* Origional version from Steven Schoch <schoch@sheba.arc.nasa.gov> */ | ||
60 | |||
61 | #include <stdio.h> | ||
62 | #include "cryptlib.h" | ||
63 | #include "bn.h" | ||
64 | #include "dsa.h" | ||
65 | #include "rand.h" | ||
66 | #include "asn1.h" | ||
67 | |||
68 | /* data has already been hashed (probably with SHA or SHA-1). */ | ||
69 | /* DSAerr(DSA_F_DSA_SIGN,DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); */ | ||
70 | |||
71 | int DSA_sign(type,dgst,dlen,sig,siglen,dsa) | ||
72 | int type; | ||
73 | unsigned char *dgst; | ||
74 | int dlen; | ||
75 | unsigned char *sig; /* out */ | ||
76 | unsigned int *siglen; /* out */ | ||
77 | DSA *dsa; | ||
78 | { | ||
79 | BIGNUM *kinv=NULL,*r=NULL; | ||
80 | BIGNUM *m=NULL; | ||
81 | BIGNUM *xr=NULL,*s=NULL; | ||
82 | BN_CTX *ctx=NULL; | ||
83 | unsigned char *p; | ||
84 | int i,len=0,ret=0,reason=ERR_R_BN_LIB; | ||
85 | ASN1_INTEGER rbs,sbs; | ||
86 | MS_STATIC unsigned char rbuf[50]; /* assuming r is 20 bytes +extra */ | ||
87 | MS_STATIC unsigned char sbuf[50]; /* assuming s is 20 bytes +extra */ | ||
88 | |||
89 | i=BN_num_bytes(dsa->q); /* should be 20 */ | ||
90 | if ((dlen > i) || (dlen > 50)) | ||
91 | { | ||
92 | reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE; | ||
93 | goto err; | ||
94 | } | ||
95 | |||
96 | ctx=BN_CTX_new(); | ||
97 | if (ctx == NULL) goto err; | ||
98 | |||
99 | if ((dsa->kinv == NULL) || (dsa->r == NULL)) | ||
100 | { | ||
101 | if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err; | ||
102 | } | ||
103 | else | ||
104 | { | ||
105 | kinv=dsa->kinv; | ||
106 | dsa->kinv=NULL; | ||
107 | r=dsa->r; | ||
108 | dsa->r=NULL; | ||
109 | } | ||
110 | |||
111 | m=BN_new(); | ||
112 | xr=BN_new(); | ||
113 | s=BN_new(); | ||
114 | if (m == NULL || xr == NULL || s == NULL) goto err; | ||
115 | |||
116 | if (BN_bin2bn(dgst,dlen,m) == NULL) goto err; | ||
117 | |||
118 | /* Compute s = inv(k) (m + xr) mod q */ | ||
119 | if (!BN_mul(xr, dsa->priv_key, r)) goto err; /* s = xr */ | ||
120 | if (!BN_add(s, xr, m)) goto err; /* s = m + xr */ | ||
121 | if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err; | ||
122 | |||
123 | /* | ||
124 | * Now create a ASN.1 sequence of the integers R and S. | ||
125 | */ | ||
126 | rbs.data=rbuf; | ||
127 | sbs.data=sbuf; | ||
128 | rbs.type = V_ASN1_INTEGER; | ||
129 | sbs.type = V_ASN1_INTEGER; | ||
130 | rbs.length=BN_bn2bin(r,rbs.data); | ||
131 | sbs.length=BN_bn2bin(s,sbs.data); | ||
132 | |||
133 | len =i2d_ASN1_INTEGER(&rbs,NULL); | ||
134 | len+=i2d_ASN1_INTEGER(&sbs,NULL); | ||
135 | |||
136 | p=sig; | ||
137 | ASN1_put_object(&p,1,len,V_ASN1_SEQUENCE,V_ASN1_UNIVERSAL); | ||
138 | i2d_ASN1_INTEGER(&rbs,&p); | ||
139 | i2d_ASN1_INTEGER(&sbs,&p); | ||
140 | *siglen=(p-sig); | ||
141 | ret=1; | ||
142 | err: | ||
143 | if (!ret) DSAerr(DSA_F_DSA_SIGN,reason); | ||
144 | |||
145 | #if 1 /* do the right thing :-) */ | ||
146 | if (kinv != NULL) BN_clear_free(kinv); | ||
147 | if (r != NULL) BN_clear_free(r); | ||
148 | #endif | ||
149 | if (ctx != NULL) BN_CTX_free(ctx); | ||
150 | if (m != NULL) BN_clear_free(m); | ||
151 | if (xr != NULL) BN_clear_free(xr); | ||
152 | if (s != NULL) BN_clear_free(s); | ||
153 | return(ret); | ||
154 | } | ||
155 | |||
156 | int DSA_sign_setup(dsa,ctx_in,kinvp,rp) | ||
157 | DSA *dsa; | ||
158 | BN_CTX *ctx_in; | ||
159 | BIGNUM **kinvp; | ||
160 | BIGNUM **rp; | ||
161 | { | ||
162 | BN_CTX *ctx; | ||
163 | BIGNUM *k=NULL,*kinv=NULL,*r=NULL; | ||
164 | int ret=0; | ||
165 | |||
166 | if (ctx_in == NULL) | ||
167 | { | ||
168 | if ((ctx=BN_CTX_new()) == NULL) goto err; | ||
169 | } | ||
170 | else | ||
171 | ctx=ctx_in; | ||
172 | |||
173 | r=BN_new(); | ||
174 | k=BN_new(); | ||
175 | if ((r == NULL) || (k == NULL)) | ||
176 | goto err; | ||
177 | kinv=NULL; | ||
178 | |||
179 | if (r == NULL) goto err; | ||
180 | |||
181 | /* Get random k */ | ||
182 | for (;;) | ||
183 | { | ||
184 | if (!BN_rand(k, BN_num_bits(dsa->q), 1, 0)) goto err; | ||
185 | if (BN_cmp(k,dsa->q) >= 0) | ||
186 | BN_sub(k,k,dsa->q); | ||
187 | if (!BN_is_zero(k)) break; | ||
188 | } | ||
189 | |||
190 | /* Compute r = (g^k mod p) mod q */ | ||
191 | if (!BN_mod_exp(r,dsa->g,k,dsa->p,ctx)) goto err; | ||
192 | if (!BN_mod(r,r,dsa->q,ctx)) goto err; | ||
193 | |||
194 | /* Compute part of 's = inv(k) (m + xr) mod q' */ | ||
195 | if ((kinv=BN_mod_inverse(k,dsa->q,ctx)) == NULL) goto err; | ||
196 | |||
197 | if (*kinvp != NULL) BN_clear_free(*kinvp); | ||
198 | *kinvp=kinv; | ||
199 | kinv=NULL; | ||
200 | if (*rp != NULL) BN_clear_free(*rp); | ||
201 | *rp=r; | ||
202 | ret=1; | ||
203 | err: | ||
204 | if (!ret) | ||
205 | { | ||
206 | DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB); | ||
207 | if (kinv != NULL) BN_clear_free(kinv); | ||
208 | if (r != NULL) BN_clear_free(r); | ||
209 | } | ||
210 | if (ctx_in == NULL) BN_CTX_free(ctx); | ||
211 | if (k != NULL) BN_clear_free(k); | ||
212 | if (kinv != NULL) BN_clear_free(kinv); | ||
213 | return(ret); | ||
214 | } | ||
215 | |||