Reintegrate tools from trunk

1 files changed, 230 insertions, 0 deletions

diff --git a/tools/plink/sshdh.c b/tools/plink/sshdh.c
new file mode 100644
index 000000000..41df756db
--- /dev/null
+++ b/tools/plink/sshdh.c
@@ -0,0 +1,230 @@
+/*

+ * Diffie-Hellman implementation for PuTTY.

+ */

+

+#include "ssh.h"

+

+/*

+ * The primes used in the group1 and group14 key exchange.

+ */

+static const unsigned char P1[] = {

+    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,

+    0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,

+    0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,

+    0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,

+    0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,

+    0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,

+    0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,

+    0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,

+    0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,

+    0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,

+    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF

+};

+static const unsigned char P14[] = {

+    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,

+    0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,

+    0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,

+    0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,

+    0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,

+    0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,

+    0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,

+    0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,

+    0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,

+    0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE4, 0x5B, 0x3D,

+    0xC2, 0x00, 0x7C, 0xB8, 0xA1, 0x63, 0xBF, 0x05, 0x98, 0xDA, 0x48, 0x36,

+    0x1C, 0x55, 0xD3, 0x9A, 0x69, 0x16, 0x3F, 0xA8, 0xFD, 0x24, 0xCF, 0x5F,

+    0x83, 0x65, 0x5D, 0x23, 0xDC, 0xA3, 0xAD, 0x96, 0x1C, 0x62, 0xF3, 0x56,

+    0x20, 0x85, 0x52, 0xBB, 0x9E, 0xD5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6D,

+    0x67, 0x0C, 0x35, 0x4E, 0x4A, 0xBC, 0x98, 0x04, 0xF1, 0x74, 0x6C, 0x08,

+    0xCA, 0x18, 0x21, 0x7C, 0x32, 0x90, 0x5E, 0x46, 0x2E, 0x36, 0xCE, 0x3B,

+    0xE3, 0x9E, 0x77, 0x2C, 0x18, 0x0E, 0x86, 0x03, 0x9B, 0x27, 0x83, 0xA2,

+    0xEC, 0x07, 0xA2, 0x8F, 0xB5, 0xC5, 0x5D, 0xF0, 0x6F, 0x4C, 0x52, 0xC9,

+    0xDE, 0x2B, 0xCB, 0xF6, 0x95, 0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7C,

+    0xEA, 0x95, 0x6A, 0xE5, 0x15, 0xD2, 0x26, 0x18, 0x98, 0xFA, 0x05, 0x10,

+    0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAC, 0xAA, 0x68, 0xFF, 0xFF, 0xFF, 0xFF,

+    0xFF, 0xFF, 0xFF, 0xFF

+};

+

+/*

+ * The generator g = 2 (used for both group1 and group14).

+ */

+static const unsigned char G[] = { 2 };

+

+static const struct ssh_kex ssh_diffiehellman_group1_sha1 = {

+    "diffie-hellman-group1-sha1", "group1",

+    KEXTYPE_DH, P1, G, lenof(P1), lenof(G), &ssh_sha1

+};

+

+static const struct ssh_kex *const group1_list[] = {

+    &ssh_diffiehellman_group1_sha1

+};

+

+const struct ssh_kexes ssh_diffiehellman_group1 = {

+    sizeof(group1_list) / sizeof(*group1_list),

+    group1_list

+};

+

+static const struct ssh_kex ssh_diffiehellman_group14_sha1 = {

+    "diffie-hellman-group14-sha1", "group14",

+    KEXTYPE_DH, P14, G, lenof(P14), lenof(G), &ssh_sha1

+};

+

+static const struct ssh_kex *const group14_list[] = {

+    &ssh_diffiehellman_group14_sha1

+};

+

+const struct ssh_kexes ssh_diffiehellman_group14 = {

+    sizeof(group14_list) / sizeof(*group14_list),

+    group14_list

+};

+

+static const struct ssh_kex ssh_diffiehellman_gex_sha256 = {

+    "diffie-hellman-group-exchange-sha256", NULL,

+    KEXTYPE_DH, NULL, NULL, 0, 0, &ssh_sha256

+};

+

+static const struct ssh_kex ssh_diffiehellman_gex_sha1 = {

+    "diffie-hellman-group-exchange-sha1", NULL,

+    KEXTYPE_DH, NULL, NULL, 0, 0, &ssh_sha1

+};

+

+static const struct ssh_kex *const gex_list[] = {

+    &ssh_diffiehellman_gex_sha256,

+    &ssh_diffiehellman_gex_sha1

+};

+

+const struct ssh_kexes ssh_diffiehellman_gex = {

+    sizeof(gex_list) / sizeof(*gex_list),

+    gex_list

+};

+

+/*

+ * Variables.

+ */

+struct dh_ctx {

+    Bignum x, e, p, q, qmask, g;

+};

+

+/*

+ * Common DH initialisation.

+ */

+static void dh_init(struct dh_ctx *ctx)

+{

+    ctx->q = bignum_rshift(ctx->p, 1);

+    ctx->qmask = bignum_bitmask(ctx->q);

+    ctx->x = ctx->e = NULL;

+}

+

+/*

+ * Initialise DH for a standard group.

+ */

+void *dh_setup_group(const struct ssh_kex *kex)

+{

+    struct dh_ctx *ctx = snew(struct dh_ctx);

+    ctx->p = bignum_from_bytes(kex->pdata, kex->plen);

+    ctx->g = bignum_from_bytes(kex->gdata, kex->glen);

+    dh_init(ctx);

+    return ctx;

+}

+

+/*

+ * Initialise DH for a server-supplied group.

+ */

+void *dh_setup_gex(Bignum pval, Bignum gval)

+{

+    struct dh_ctx *ctx = snew(struct dh_ctx);

+    ctx->p = copybn(pval);

+    ctx->g = copybn(gval);

+    dh_init(ctx);

+    return ctx;

+}

+

+/*

+ * Clean up and free a context.

+ */

+void dh_cleanup(void *handle)

+{

+    struct dh_ctx *ctx = (struct dh_ctx *)handle;

+    freebn(ctx->x);

+    freebn(ctx->e);

+    freebn(ctx->p);

+    freebn(ctx->g);

+    freebn(ctx->q);

+    freebn(ctx->qmask);

+    sfree(ctx);

+}

+

+/*

+ * DH stage 1: invent a number x between 1 and q, and compute e =

+ * g^x mod p. Return e.

+ * 

+ * If `nbits' is greater than zero, it is used as an upper limit

+ * for the number of bits in x. This is safe provided that (a) you

+ * use twice as many bits in x as the number of bits you expect to

+ * use in your session key, and (b) the DH group is a safe prime

+ * (which SSH demands that it must be).

+ * 

+ * P. C. van Oorschot, M. J. Wiener

+ * "On Diffie-Hellman Key Agreement with Short Exponents".

+ * Advances in Cryptology: Proceedings of Eurocrypt '96

+ * Springer-Verlag, May 1996.

+ */

+Bignum dh_create_e(void *handle, int nbits)

+{

+    struct dh_ctx *ctx = (struct dh_ctx *)handle;

+    int i;

+

+    int nbytes;

+    unsigned char *buf;

+

+    nbytes = ssh1_bignum_length(ctx->qmask);

+    buf = snewn(nbytes, unsigned char);

+

+    do {

+	/*

+	 * Create a potential x, by ANDing a string of random bytes

+	 * with qmask.

+	 */

+	if (ctx->x)

+	    freebn(ctx->x);

+	if (nbits == 0 || nbits > bignum_bitcount(ctx->qmask)) {

+	    ssh1_write_bignum(buf, ctx->qmask);

+	    for (i = 2; i < nbytes; i++)

+		buf[i] &= random_byte();

+	    ssh1_read_bignum(buf, nbytes, &ctx->x);   /* can't fail */

+	} else {

+	    int b, nb;

+	    ctx->x = bn_power_2(nbits);

+	    b = nb = 0;

+	    for (i = 0; i < nbits; i++) {

+		if (nb == 0) {

+		    nb = 8;

+		    b = random_byte();

+		}

+		bignum_set_bit(ctx->x, i, b & 1);

+		b >>= 1;

+		nb--;

+	    }

+	}

+    } while (bignum_cmp(ctx->x, One) <= 0 || bignum_cmp(ctx->x, ctx->q) >= 0);

+

+    sfree(buf);

+

+    /*

+     * Done. Now compute e = g^x mod p.

+     */

+    ctx->e = modpow(ctx->g, ctx->x, ctx->p);

+

+    return ctx->e;

+}

+

+/*

+ * DH stage 2: given a number f, compute K = f^x mod p.

+ */

+Bignum dh_find_K(void *handle, Bignum f)

+{

+    struct dh_ctx *ctx = (struct dh_ctx *)handle;

+    Bignum ret;

+    ret = modpow(f, ctx->x, ctx->p);

+    return ret;

+}