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path: root/src/lib/libcrypto/dsa/dsa_sign.c
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Diffstat (limited to 'src/lib/libcrypto/dsa/dsa_sign.c')
-rw-r--r--src/lib/libcrypto/dsa/dsa_sign.c123
1 files changed, 2 insertions, 121 deletions
diff --git a/src/lib/libcrypto/dsa/dsa_sign.c b/src/lib/libcrypto/dsa/dsa_sign.c
index 774c161964..89205026f0 100644
--- a/src/lib/libcrypto/dsa/dsa_sign.c
+++ b/src/lib/libcrypto/dsa/dsa_sign.c
@@ -67,73 +67,9 @@
67 67
68DSA_SIG * DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa) 68DSA_SIG * DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
69 { 69 {
70 BIGNUM *kinv=NULL,*r=NULL,*s=NULL; 70 return dsa->meth->dsa_do_sign(dgst, dlen, dsa);
71 BIGNUM m;
72 BIGNUM xr;
73 BN_CTX *ctx=NULL;
74 int i,reason=ERR_R_BN_LIB;
75 DSA_SIG *ret=NULL;
76
77 BN_init(&m);
78 BN_init(&xr);
79 s=BN_new();
80 if (s == NULL) goto err;
81
82 i=BN_num_bytes(dsa->q); /* should be 20 */
83 if ((dlen > i) || (dlen > 50))
84 {
85 reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
86 goto err;
87 }
88
89 ctx=BN_CTX_new();
90 if (ctx == NULL) goto err;
91
92 if ((dsa->kinv == NULL) || (dsa->r == NULL))
93 {
94 if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
95 }
96 else
97 {
98 kinv=dsa->kinv;
99 dsa->kinv=NULL;
100 r=dsa->r;
101 dsa->r=NULL;
102 }
103
104 if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
105
106 /* Compute s = inv(k) (m + xr) mod q */
107 if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
108 if (!BN_add(s, &xr, &m)) goto err; /* s = m + xr */
109 if (BN_cmp(s,dsa->q) > 0)
110 BN_sub(s,s,dsa->q);
111 if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
112
113 ret=DSA_SIG_new();
114 if (ret == NULL) goto err;
115 ret->r = r;
116 ret->s = s;
117
118err:
119 if (!ret)
120 {
121 DSAerr(DSA_F_DSA_DO_SIGN,reason);
122 BN_free(r);
123 BN_free(s);
124 }
125 if (ctx != NULL) BN_CTX_free(ctx);
126 BN_clear_free(&m);
127 BN_clear_free(&xr);
128 if (kinv != NULL) /* dsa->kinv is NULL now if we used it */
129 BN_clear_free(kinv);
130 return(ret);
131 } 71 }
132 72
133/* data has already been hashed (probably with SHA or SHA-1). */
134
135/* unsigned char *sig: out */
136/* unsigned int *siglen: out */
137int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig, 73int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
138 unsigned int *siglen, DSA *dsa) 74 unsigned int *siglen, DSA *dsa)
139 { 75 {
@@ -151,61 +87,6 @@ int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
151 87
152int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp) 88int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
153 { 89 {
154 BN_CTX *ctx; 90 return dsa->meth->dsa_sign_setup(dsa, ctx_in, kinvp, rp);
155 BIGNUM k,*kinv=NULL,*r=NULL;
156 int ret=0;
157
158 if (ctx_in == NULL)
159 {
160 if ((ctx=BN_CTX_new()) == NULL) goto err;
161 }
162 else
163 ctx=ctx_in;
164
165 BN_init(&k);
166 if ((r=BN_new()) == NULL) goto err;
167 kinv=NULL;
168
169 /* Get random k */
170 for (;;)
171 {
172 if (!BN_rand(&k, BN_num_bits(dsa->q), 1, 0)) goto err;
173 if (BN_cmp(&k,dsa->q) >= 0)
174 BN_sub(&k,&k,dsa->q);
175 if (!BN_is_zero(&k)) break;
176 }
177
178 if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
179 {
180 if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
181 if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
182 dsa->p,ctx)) goto err;
183 }
184
185 /* Compute r = (g^k mod p) mod q */
186 if (!BN_mod_exp_mont(r,dsa->g,&k,dsa->p,ctx,
187 (BN_MONT_CTX *)dsa->method_mont_p)) goto err;
188 if (!BN_mod(r,r,dsa->q,ctx)) goto err;
189
190 /* Compute part of 's = inv(k) (m + xr) mod q' */
191 if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
192
193 if (*kinvp != NULL) BN_clear_free(*kinvp);
194 *kinvp=kinv;
195 kinv=NULL;
196 if (*rp != NULL) BN_clear_free(*rp);
197 *rp=r;
198 ret=1;
199err:
200 if (!ret)
201 {
202 DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
203 if (kinv != NULL) BN_clear_free(kinv);
204 if (r != NULL) BN_clear_free(r);
205 }
206 if (ctx_in == NULL) BN_CTX_free(ctx);
207 if (kinv != NULL) BN_clear_free(kinv);
208 BN_clear_free(&k);
209 return(ret);
210 } 91 }
211 92