+++ /dev/null
-/*\r
- * Diffie-Hellman implementation for PuTTY.\r
- */\r
-\r
-#include "ssh.h"\r
-\r
-/*\r
- * The primes used in the group1 and group14 key exchange.\r
- */\r
-static const unsigned char P1[] = {\r
- 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,\r
- 0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,\r
- 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,\r
- 0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,\r
- 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,\r
- 0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,\r
- 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,\r
- 0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,\r
- 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,\r
- 0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,\r
- 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF\r
-};\r
-static const unsigned char P14[] = {\r
- 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,\r
- 0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,\r
- 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,\r
- 0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,\r
- 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,\r
- 0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,\r
- 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,\r
- 0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,\r
- 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,\r
- 0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D,\r
- 0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, 0x98, 0xDA, 0x48, 0x36,\r
- 0x1C, 0x55, 0xD3, 0x9A, 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F,\r
- 0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, 0x1C, 0x62, 0xF3, 0x56,\r
- 0x20, 0x85, 0x52, 0xBB, 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D,\r
- 0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, 0xF1, 0x74, 0x6C, 0x08,\r
- 0xCA, 0x18, 0x21, 0x7C, 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B,\r
- 0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03, 0x9B, 0x27, 0x83, 0xA2,\r
- 0xEC, 0x07, 0xA2, 0x8F, 0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9,\r
- 0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7C,\r
- 0xEA, 0x95, 0x6A, 0xE5, 0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10,\r
- 0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAC, 0xAA, 0x68, 0xFF, 0xFF, 0xFF, 0xFF,\r
- 0xFF, 0xFF, 0xFF, 0xFF\r
-};\r
-\r
-/*\r
- * The generator g = 2 (used for both group1 and group14).\r
- */\r
-static const unsigned char G[] = { 2 };\r
-\r
-static const struct ssh_kex ssh_diffiehellman_group1_sha1 = {\r
- "diffie-hellman-group1-sha1", "group1",\r
- KEXTYPE_DH, P1, G, lenof(P1), lenof(G), &ssh_sha1\r
-};\r
-\r
-static const struct ssh_kex *const group1_list[] = {\r
- &ssh_diffiehellman_group1_sha1\r
-};\r
-\r
-const struct ssh_kexes ssh_diffiehellman_group1 = {\r
- sizeof(group1_list) / sizeof(*group1_list),\r
- group1_list\r
-};\r
-\r
-static const struct ssh_kex ssh_diffiehellman_group14_sha1 = {\r
- "diffie-hellman-group14-sha1", "group14",\r
- KEXTYPE_DH, P14, G, lenof(P14), lenof(G), &ssh_sha1\r
-};\r
-\r
-static const struct ssh_kex *const group14_list[] = {\r
- &ssh_diffiehellman_group14_sha1\r
-};\r
-\r
-const struct ssh_kexes ssh_diffiehellman_group14 = {\r
- sizeof(group14_list) / sizeof(*group14_list),\r
- group14_list\r
-};\r
-\r
-static const struct ssh_kex ssh_diffiehellman_gex_sha256 = {\r
- "diffie-hellman-group-exchange-sha256", NULL,\r
- KEXTYPE_DH, NULL, NULL, 0, 0, &ssh_sha256\r
-};\r
-\r
-static const struct ssh_kex ssh_diffiehellman_gex_sha1 = {\r
- "diffie-hellman-group-exchange-sha1", NULL,\r
- KEXTYPE_DH, NULL, NULL, 0, 0, &ssh_sha1\r
-};\r
-\r
-static const struct ssh_kex *const gex_list[] = {\r
- &ssh_diffiehellman_gex_sha256,\r
- &ssh_diffiehellman_gex_sha1\r
-};\r
-\r
-const struct ssh_kexes ssh_diffiehellman_gex = {\r
- sizeof(gex_list) / sizeof(*gex_list),\r
- gex_list\r
-};\r
-\r
-/*\r
- * Variables.\r
- */\r
-struct dh_ctx {\r
- Bignum x, e, p, q, qmask, g;\r
-};\r
-\r
-/*\r
- * Common DH initialisation.\r
- */\r
-static void dh_init(struct dh_ctx *ctx)\r
-{\r
- ctx->q = bignum_rshift(ctx->p, 1);\r
- ctx->qmask = bignum_bitmask(ctx->q);\r
- ctx->x = ctx->e = NULL;\r
-}\r
-\r
-/*\r
- * Initialise DH for a standard group.\r
- */\r
-void *dh_setup_group(const struct ssh_kex *kex)\r
-{\r
- struct dh_ctx *ctx = snew(struct dh_ctx);\r
- ctx->p = bignum_from_bytes(kex->pdata, kex->plen);\r
- ctx->g = bignum_from_bytes(kex->gdata, kex->glen);\r
- dh_init(ctx);\r
- return ctx;\r
-}\r
-\r
-/*\r
- * Initialise DH for a server-supplied group.\r
- */\r
-void *dh_setup_gex(Bignum pval, Bignum gval)\r
-{\r
- struct dh_ctx *ctx = snew(struct dh_ctx);\r
- ctx->p = copybn(pval);\r
- ctx->g = copybn(gval);\r
- dh_init(ctx);\r
- return ctx;\r
-}\r
-\r
-/*\r
- * Clean up and free a context.\r
- */\r
-void dh_cleanup(void *handle)\r
-{\r
- struct dh_ctx *ctx = (struct dh_ctx *)handle;\r
- freebn(ctx->x);\r
- freebn(ctx->e);\r
- freebn(ctx->p);\r
- freebn(ctx->g);\r
- freebn(ctx->q);\r
- freebn(ctx->qmask);\r
- sfree(ctx);\r
-}\r
-\r
-/*\r
- * DH stage 1: invent a number x between 1 and q, and compute e =\r
- * g^x mod p. Return e.\r
- * \r
- * If `nbits' is greater than zero, it is used as an upper limit\r
- * for the number of bits in x. This is safe provided that (a) you\r
- * use twice as many bits in x as the number of bits you expect to\r
- * use in your session key, and (b) the DH group is a safe prime\r
- * (which SSH demands that it must be).\r
- * \r
- * P. C. van Oorschot, M. J. Wiener\r
- * "On Diffie-Hellman Key Agreement with Short Exponents".\r
- * Advances in Cryptology: Proceedings of Eurocrypt '96\r
- * Springer-Verlag, May 1996.\r
- */\r
-Bignum dh_create_e(void *handle, int nbits)\r
-{\r
- struct dh_ctx *ctx = (struct dh_ctx *)handle;\r
- int i;\r
-\r
- int nbytes;\r
- unsigned char *buf;\r
-\r
- nbytes = ssh1_bignum_length(ctx->qmask);\r
- buf = snewn(nbytes, unsigned char);\r
-\r
- do {\r
- /*\r
- * Create a potential x, by ANDing a string of random bytes\r
- * with qmask.\r
- */\r
- if (ctx->x)\r
- freebn(ctx->x);\r
- if (nbits == 0 || nbits > bignum_bitcount(ctx->qmask)) {\r
- ssh1_write_bignum(buf, ctx->qmask);\r
- for (i = 2; i < nbytes; i++)\r
- buf[i] &= random_byte();\r
- ssh1_read_bignum(buf, nbytes, &ctx->x); /* can't fail */\r
- } else {\r
- int b, nb;\r
- ctx->x = bn_power_2(nbits);\r
- b = nb = 0;\r
- for (i = 0; i < nbits; i++) {\r
- if (nb == 0) {\r
- nb = 8;\r
- b = random_byte();\r
- }\r
- bignum_set_bit(ctx->x, i, b & 1);\r
- b >>= 1;\r
- nb--;\r
- }\r
- }\r
- } while (bignum_cmp(ctx->x, One) <= 0 || bignum_cmp(ctx->x, ctx->q) >= 0);\r
-\r
- sfree(buf);\r
-\r
- /*\r
- * Done. Now compute e = g^x mod p.\r
- */\r
- ctx->e = modpow(ctx->g, ctx->x, ctx->p);\r
-\r
- return ctx->e;\r
-}\r
-\r
-/*\r
- * DH stage 2: given a number f, compute K = f^x mod p.\r
- */\r
-Bignum dh_find_K(void *handle, Bignum f)\r
-{\r
- struct dh_ctx *ctx = (struct dh_ctx *)handle;\r
- Bignum ret;\r
- ret = modpow(f, ctx->x, ctx->p);\r
- return ret;\r
-}\r
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