2 * Copyright (c) 2013, SUSE Inc.
4 * This program is licensed under the BSD license, read LICENSE.BSD
5 * for further information
8 /* simple and slow rsa/dsa verification code. */
15 #include "solv_pgpvrfy.h"
17 typedef unsigned int mp_t;
18 typedef unsigned long long mp2_t;
20 #define MP_T_BITS (MP_T_BYTES * 8)
23 mpzero(int len, mp_t *target)
25 memset(target, 0, MP_T_BYTES * len);
31 return solv_calloc(len, MP_T_BYTES);
34 /* target[len] = x, target = target % mod */
36 mpdomod(int len, mp_t *target, mp2_t x, mp_t *mod)
39 /* assumes that x does not overflow, i.e. target is not much bigger than mod! */
40 for (i = len - 1; i >= 0; i--)
42 x = (x << MP_T_BITS) | target[i];
49 while (x >= 2 * (mp2_t)mod[i])
52 mp2_t z = x / ((mp2_t)mod[i] + 1);
54 for (j = 0; j < i; j++)
73 for (j = i - 1; j >= 0; j--)
74 if (target[j] < mod[j])
76 else if (target[j] > mod[j])
79 /* target >= mod, subtract mod */
81 for (j = 0; j <= i; j++)
83 mp2_t n2 = mod[j] + n;
84 n = n2 > target[j] ? 1 : 0;
85 target[j] -= (mp_t)n2;
90 /* target += src * m */
92 mpmult_add_int(int len, mp_t *target, mp_t *src, mp2_t m, mp_t *mod)
96 for (i = 0; i < len; i++)
98 x += src[i] * m + target[i];
102 mpdomod(len, target, x, mod);
105 /* target = target * 2^MP_T_BITS */
107 mpshift(int len, mp_t *target, mp_t *mod)
114 memmove(target + 1, target, (len - 1) * MP_T_BYTES);
116 mpdomod(len, target, x, mod);
119 /* target += m1 * m2 */
121 mpmult_add(int len, mp_t *target, mp_t *m1, int m2len, mp_t *m2, mp_t *mod)
125 for (j = m2len - 1; j >= 0; j--)
131 memcpy(t, m1, len * MP_T_BYTES);
132 for (i = 0; i < j; i++)
135 mpmult_add_int(len, target, t, m2[i], mod);
136 mpshift(len, t, mod);
139 mpmult_add_int(len, target, t, m2[i], mod);
143 /* target = target * m */
145 mpmult_inplace(int len, mp_t *target, mp_t *m, mp_t *tmp, mp_t *mod)
148 mpmult_add(len, tmp, target, len, m, mod);
149 memcpy(target, tmp, len * MP_T_BYTES);
152 /* target = target ^ (16 + e) */
154 mppow_int(int len, mp_t *target, mp_t *t, mp_t *mod, int e)
156 mpmult_inplace(len, target, target, t, mod);
157 mpmult_inplace(len, target, target, t, mod);
158 mpmult_inplace(len, target, target, t, mod);
159 mpmult_inplace(len, target, target, t, mod);
161 mpmult_inplace(len, target, t + len * e, t, mod);
166 mppow(int len, mp_t *target, mp_t *b, int elen, mp_t *e, mp_t *mod)
172 for (i = elen - 1; i >= 0; i--)
178 memcpy(t + len, b, len * MP_T_BYTES);
179 for (j = 2; j < 16; j++)
180 mpmult_add(len, t + len * j, b, len, t + len * j - len, mod);
184 mppow_int(len, target, t, mod, (e[i] >> 28) & 0x0f);
185 mppow_int(len, target, t, mod, (e[i] >> 24) & 0x0f);
186 mppow_int(len, target, t, mod, (e[i] >> 20) & 0x0f);
187 mppow_int(len, target, t, mod, (e[i] >> 16) & 0x0f);
188 mppow_int(len, target, t, mod, (e[i] >> 12) & 0x0f);
189 mppow_int(len, target, t, mod, (e[i] >> 8) & 0x0f);
190 mppow_int(len, target, t, mod, (e[i] >> 4) & 0x0f);
191 mppow_int(len, target, t, mod, e[i] & 0x0f);
192 #elif MP_T_BYTES == 1
193 mppow_int(len, target, t, mod, (e[i] >> 4) & 0x0f);
194 mppow_int(len, target, t, mod, e[i] & 0x0f);
201 mpisless(int len, mp_t *a, mp_t *b)
204 for (i = len - 1; i >= 0; i--)
207 else if (a[i] > b[i])
213 mpiszero(int len, mp_t *a)
216 for (i = 0; i < len; i++)
223 mpdec(int len, mp_t *a)
226 for (i = 0; i < len; i++)
234 static void mpdump(int l, mp_t *a, char *s)
238 fprintf(stderr, "%s", s);
239 for (i = l - 1; i >= 0; i--)
240 fprintf(stderr, "%08x", a[i]);
241 fprintf(stderr, "\n");
246 mpdsa(int pl, mp_t *p, int ql, mp_t *q, mp_t *g, mp_t *y, mp_t *r, mp_t *s, int hl, mp_t *h)
253 mpdump(pl, p, "p = ");
254 mpdump(ql, q, "q = ");
255 mpdump(pl, g, "g = ");
256 mpdump(pl, y, "y = ");
257 mpdump(ql, r, "r = ");
258 mpdump(ql, s, "s = ");
259 mpdump(hl, h, "h = ");
261 if (pl < ql || !mpisless(pl, g, p) || !mpisless(pl, y, p))
262 return 0; /* hmm, bad pubkey? */
263 if (!mpisless(ql, r, q) || mpiszero(ql, r))
265 if (!mpisless(ql, s, q) || mpiszero(ql, s))
267 tmp = mpnew(pl); /* note pl! */
268 memcpy(tmp, q, ql * MP_T_BYTES); /* tmp = q */
269 mpdec(ql, tmp); /* tmp-- */
270 mpdec(ql, tmp); /* tmp-- */
272 mppow(ql, w, s, ql, tmp, q); /* w = s ^ tmp (s ^ -1) */
273 u1 = mpnew(pl); /* u1 = 0 */
274 /* order is important here: h can be >= q */
275 mpmult_add(ql, u1, w, hl, h, q); /* u1 += w * h */
276 u2 = mpnew(pl); /* u2 = 0 */
277 mpmult_add(ql, u2, w, ql, r, q); /* u2 += w * r */
281 mppow(pl, gu1, g, pl, u1, p); /* gu1 = g ^ u1 */
282 mppow(pl, yu2, y, pl, u2, p); /* yu2 = y ^ u2 */
283 mpzero(pl, u1); /* u1 = 0 */
284 mpmult_add(pl, u1, gu1, pl, yu2, p); /* u1 += gu1 * yu2 */
288 u2[0] = 1; /* u2 = 1 */
289 mpzero(ql, tmp); /* tmp = 0 */
290 mpmult_add(ql, tmp, u2, pl, u1, q); /* tmp += u2 * u1 */
294 mpdump(ql, tmp, "res = ");
296 if (memcmp(tmp, r, ql * MP_T_BYTES) != 0)
306 mprsa(int nl, mp_t *n, int el, mp_t *e, mp_t *m, mp_t *c)
310 mpdump(nl, n, "n = ");
311 mpdump(el, e, "e = ");
312 mpdump(nl, m, "m = ");
313 mpdump(nl, c, "c = ");
315 if (!mpisless(nl, m, n))
317 if (!mpisless(nl, c, n))
320 mppow(nl, tmp, m, el, e, n); /* tmp = m ^ e */
322 mpdump(nl, tmp, "res = ");
324 if (memcmp(tmp, c, nl * MP_T_BYTES) != 0)
333 /* create mp with size tbits from data with size dbits */
335 mpbuild(unsigned char *d, int dbits, int tbits, int *mplp)
337 int l = (tbits + MP_T_BITS - 1) / MP_T_BITS;
340 mp_t *out = mpnew(l ? l : 1);
343 dl = (dbits + 7) / 8;
346 dl = (tbits + 7) / 8;
347 for (i = 0; dl > 0; dl--, i++)
350 out[i / MP_T_BYTES] |= x << (8 * (i % MP_T_BYTES));
355 static unsigned char *
356 findmpi(unsigned char **mpip, int *mpilp, int maxbits, int *outlen)
359 unsigned char *mpi = *mpip;
360 unsigned char *out = 0;
366 bits = mpi[0] << 8 | mpi[1];
367 l = 2 + (bits + 7) / 8;
368 if (bits > maxbits || mpil < l)
381 solv_pgpvrfy(unsigned char *pub, int publ, unsigned char *sig, int sigl)
384 unsigned char *oid = 0;
389 if (!pub || !sig || publ < 1 || sigl < 2)
391 if (pub[0] != sig[0])
392 return 0; /* key algo mismatch */
396 hashl = 16; /* MD5 */
397 oid = (unsigned char *)"\022\060\040\060\014\006\010\052\206\110\206\367\015\002\005\005\000\004\020";
400 hashl = 20; /* SHA-1 */
401 oid = (unsigned char *)"\017\060\041\060\011\006\005\053\016\003\002\032\005\000\004\024";
404 hashl = 32; /* SHA-256 */
405 oid = (unsigned char *)"\023\060\061\060\015\006\011\140\206\110\001\145\003\004\002\001\005\000\004\040";
408 hashl = 64; /* SHA-512 */
409 oid = (unsigned char *)"\023\060\121\060\015\006\011\140\206\110\001\145\003\004\002\003\005\000\004\100";
412 return 0; /* unsupported hash algo */
414 if (sigl < 2 + hashl)
420 unsigned char *n, *e, *m, *c;
421 int nlen, elen, mlen, clen;
422 mp_t *nx, *ex, *mx, *cx;
427 n = findmpi(&mpi, &mpil, 8192, &nlen);
428 e = findmpi(&mpi, &mpil, 1024, &elen);
429 mpi = sig + 2 + hashl;
430 mpil = sigl - (2 + hashl);
431 m = findmpi(&mpi, &mpil, nlen, &mlen);
432 if (!n || !e || !m || !nlen || !elen)
434 /* build padding block */
435 clen = (nlen - 1) / 8;
436 if (hashl + *oid + 2 > clen)
438 c = solv_malloc(clen);
439 memset(c, 0xff, clen);
441 memcpy(c + clen - hashl, sig + 2, hashl);
442 memcpy(c + clen - hashl - *oid, oid + 1, *oid);
443 c[clen - hashl - *oid - 1] = 0;
444 clen = clen * 8 - 7; /* always <= nlen */
445 nx = mpbuild(n, nlen, nlen, &nxl);
446 ex = mpbuild(e, elen, elen, &exl);
447 mx = mpbuild(m, mlen, nlen, 0);
448 cx = mpbuild(c, clen, nlen, 0);
450 res = mprsa(nxl, nx, exl, ex, mx, cx);
459 unsigned char *p, *q, *g, *y, *r, *s;
460 int plen, qlen, glen, ylen, rlen, slen, hlen;
461 mp_t *px, *qx, *gx, *yx, *rx, *sx, *hx;
466 p = findmpi(&mpi, &mpil, 8192, &plen);
467 q = findmpi(&mpi, &mpil, 1024, &qlen);
468 g = findmpi(&mpi, &mpil, plen, &glen);
469 y = findmpi(&mpi, &mpil, plen, &ylen);
470 mpi = sig + 2 + hashl;
471 mpil = sigl - (2 + hashl);
472 r = findmpi(&mpi, &mpil, qlen, &rlen);
473 s = findmpi(&mpi, &mpil, qlen, &slen);
474 if (!p || !q || !g || !y || !r || !s || !plen || !qlen)
476 hlen = (qlen + 7) & ~7;
477 if (hlen > hashl * 8)
479 px = mpbuild(p, plen, plen, &pxl);
480 qx = mpbuild(q, qlen, qlen, &qxl);
481 gx = mpbuild(g, glen, plen, 0);
482 yx = mpbuild(y, ylen, plen, 0);
483 rx = mpbuild(r, rlen, qlen, 0);
484 sx = mpbuild(s, slen, qlen, 0);
485 hx = mpbuild(sig + 2, hlen, hlen, &hxl);
486 res = mpdsa(pxl, px, qxl, qx, gx, yx, rx, sx, hxl, hx);
497 return 0; /* unsupported pubkey algo */