int openssh_encrypted(char *filename);
struct ssh2_userkey *openssh_read(char *filename, char *passphrase);
+int openssh_write(char *filename, struct ssh2_userkey *key, char *passphrase);
int sshcom_encrypted(char *filename, char **comment);
struct ssh2_userkey *sshcom_read(char *filename, char *passphrase);
int export_ssh2(char *filename, int type,
struct ssh2_userkey *key, char *passphrase)
{
-#if 0
if (type == SSH_KEYTYPE_OPENSSH)
return openssh_write(filename, key, passphrase);
+#if 0
if (type == SSH_KEYTYPE_SSHCOM)
return sshcom_write(filename, key, passphrase);
#endif
extern int base64_decode_atom(char *atom, unsigned char *out);
extern int base64_lines(int datalen);
extern void base64_encode_atom(unsigned char *data, int n, char *out);
-extern void base64_encode(FILE * fp, unsigned char *data, int datalen);
+extern void base64_encode(FILE *fp, unsigned char *data, int datalen);
/*
* Read an ASN.1/BER identifier and length pair.
return p - (unsigned char *) source;
}
+/*
+ * Write an ASN.1/BER identifier and length pair. Returns the
+ * number of bytes consumed. Assumes dest contains enough space.
+ * Will avoid writing anything if dest is NULL, but still return
+ * amount of space required.
+ */
+int ber_write_id_len(void *dest, int id, int length, int flags)
+{
+ unsigned char *d = (unsigned char *)dest;
+ int len = 0;
+
+ if (id <= 30) {
+ /*
+ * Identifier is one byte.
+ */
+ len++;
+ if (d) *d++ = id | flags;
+ } else {
+ int n;
+ /*
+ * Identifier is multiple bytes: the first byte is 11111
+ * plus the flags, and subsequent bytes encode the value of
+ * the identifier, 7 bits at a time, with the top bit of
+ * each byte 1 except the last one which is 0.
+ */
+ len++;
+ if (d) *d++ = 0x1F | flags;
+ for (n = 1; (id >> (7*n)) > 0; n++)
+ continue; /* count the bytes */
+ while (n--) {
+ len++;
+ if (d) *d++ = (n ? 0x80 : 0) | ((id >> (7*n)) & 0x7F);
+ }
+ }
+
+ if (length < 128) {
+ /*
+ * Length is one byte.
+ */
+ len++;
+ if (d) *d++ = length;
+ } else {
+ int n;
+ /*
+ * Length is multiple bytes. The first is 0x80 plus the
+ * number of subsequent bytes, and the subsequent bytes
+ * encode the actual length.
+ */
+ for (n = 1; (length >> (8*n)) > 0; n++)
+ continue; /* count the bytes */
+ len++;
+ if (d) *d++ = 0x80 | n;
+ while (n--) {
+ len++;
+ if (d) *d++ = (length >> (8*n)) & 0xFF;
+ }
+ }
+
+ return len;
+}
+
static int put_string(void *target, void *data, int len)
{
unsigned char *d = (unsigned char *)target;
}
}
+/* Simple structure to point to an mp-int within a blob. */
+struct mpint_pos { void *start; int bytes; };
+
+int ssh2_read_mpint(void *data, int len, struct mpint_pos *ret)
+{
+ int bytes;
+ unsigned char *d = (unsigned char *) data;
+
+ if (len < 4)
+ goto error;
+ bytes = GET_32BIT(d);
+ if (len < 4+bytes)
+ goto error;
+
+ ret->start = d + 4;
+ ret->bytes = bytes;
+ return bytes+4;
+
+ error:
+ ret->start = NULL;
+ ret->bytes = -1;
+ return len; /* ensure further calls fail as well */
+}
+
/* ----------------------------------------------------------------------
- * Code to read OpenSSH private keys.
+ * Code to read and write OpenSSH private keys.
*/
enum { OSSH_DSA, OSSH_RSA };
return retval;
}
+int openssh_write(char *filename, struct ssh2_userkey *key, char *passphrase)
+{
+ unsigned char *pubblob, *privblob, *spareblob;
+ int publen, privlen, sparelen;
+ unsigned char *outblob;
+ int outlen;
+ struct mpint_pos numbers[9];
+ int nnumbers, pos, len, seqlen, i;
+ char *header, *footer;
+ char zero[1];
+ unsigned char iv[8];
+ int ret = 0;
+ FILE *fp;
+
+ /*
+ * Fetch the key blobs.
+ */
+ pubblob = key->alg->public_blob(key->data, &publen);
+ privblob = key->alg->private_blob(key->data, &privlen);
+ spareblob = outblob = NULL;
+
+ /*
+ * Find the sequence of integers to be encoded into the OpenSSH
+ * key blob, and also decide on the header line.
+ */
+ if (key->alg == &ssh_rsa) {
+ int pos;
+ struct mpint_pos n, e, d, p, q, iqmp, dmp1, dmq1;
+ Bignum bd, bp, bq, bdmp1, bdmq1;
+
+ pos = 4 + GET_32BIT(pubblob);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &e);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &n);
+ pos = 0;
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &d);
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &p);
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &q);
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &iqmp);
+
+ assert(e.start && iqmp.start); /* can't go wrong */
+
+ /* We also need d mod (p-1) and d mod (q-1). */
+ bd = bignum_from_bytes(d.start, d.bytes);
+ bp = bignum_from_bytes(p.start, p.bytes);
+ bq = bignum_from_bytes(q.start, q.bytes);
+ decbn(bp);
+ decbn(bq);
+ bdmp1 = bigmod(bd, bp);
+ bdmq1 = bigmod(bd, bq);
+ freebn(bd);
+ freebn(bp);
+ freebn(bq);
+
+ dmp1.bytes = (bignum_bitcount(bdmp1)+8)/8;
+ dmq1.bytes = (bignum_bitcount(bdmq1)+8)/8;
+ sparelen = dmp1.bytes + dmq1.bytes;
+ spareblob = smalloc(sparelen);
+ dmp1.start = spareblob;
+ dmq1.start = spareblob + dmp1.bytes;
+ for (i = 0; i < dmp1.bytes; i++)
+ spareblob[i] = bignum_byte(bdmp1, dmp1.bytes-1 - i);
+ for (i = 0; i < dmq1.bytes; i++)
+ spareblob[i+dmp1.bytes] = bignum_byte(bdmq1, dmq1.bytes-1 - i);
+ freebn(bdmp1);
+ freebn(bdmq1);
+
+ numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
+ numbers[1] = n;
+ numbers[2] = e;
+ numbers[3] = d;
+ numbers[4] = p;
+ numbers[5] = q;
+ numbers[6] = dmp1;
+ numbers[7] = dmq1;
+ numbers[8] = iqmp;
+
+ nnumbers = 9;
+ header = "-----BEGIN RSA PRIVATE KEY-----\n";
+ footer = "-----END RSA PRIVATE KEY-----\n";
+ } else if (key->alg == &ssh_dss) {
+ int pos;
+ struct mpint_pos p, q, g, y, x;
+
+ pos = 4 + GET_32BIT(pubblob);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &p);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &q);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &g);
+ pos += ssh2_read_mpint(pubblob+pos, publen-pos, &y);
+ pos = 0;
+ pos += ssh2_read_mpint(privblob+pos, privlen-pos, &x);
+
+ assert(y.start && x.start); /* can't go wrong */
+
+ numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
+ numbers[1] = p;
+ numbers[2] = q;
+ numbers[3] = g;
+ numbers[4] = y;
+ numbers[5] = x;
+
+ nnumbers = 6;
+ header = "-----BEGIN DSA PRIVATE KEY-----\n";
+ footer = "-----END DSA PRIVATE KEY-----\n";
+ } else {
+ assert(0); /* zoinks! */
+ }
+
+ /*
+ * Now count up the total size of the ASN.1 encoded integers,
+ * so as to determine the length of the containing SEQUENCE.
+ */
+ len = 0;
+ for (i = 0; i < nnumbers; i++) {
+ len += ber_write_id_len(NULL, 2, numbers[i].bytes, 0);
+ len += numbers[i].bytes;
+ }
+ seqlen = len;
+ /* Now add on the SEQUENCE header. */
+ len += ber_write_id_len(NULL, 16, seqlen, ASN1_CONSTRUCTED);
+ /* And round up to the cipher block size. */
+ if (passphrase)
+ len = (len+7) &~ 7;
+
+ /*
+ * Now we know how big outblob needs to be. Allocate it.
+ */
+ outlen = len;
+ outblob = smalloc(outlen);
+
+ /*
+ * And write the data into it.
+ */
+ pos = 0;
+ pos += ber_write_id_len(outblob+pos, 16, seqlen, ASN1_CONSTRUCTED);
+ for (i = 0; i < nnumbers; i++) {
+ pos += ber_write_id_len(outblob+pos, 2, numbers[i].bytes, 0);
+ memcpy(outblob+pos, numbers[i].start, numbers[i].bytes);
+ pos += numbers[i].bytes;
+ }
+ while (pos < outlen) {
+ outblob[pos++] = random_byte();
+ }
+
+ /*
+ * Encrypt the key.
+ */
+ if (passphrase) {
+ /*
+ * Invent an iv. Then derive encryption key from passphrase
+ * and iv/salt:
+ *
+ * - let block A equal MD5(passphrase || iv)
+ * - let block B equal MD5(A || passphrase || iv)
+ * - block C would be MD5(B || passphrase || iv) and so on
+ * - encryption key is the first N bytes of A || B
+ */
+ struct MD5Context md5c;
+ unsigned char keybuf[32];
+
+ for (i = 0; i < 8; i++) iv[i] = random_byte();
+
+ MD5Init(&md5c);
+ MD5Update(&md5c, passphrase, strlen(passphrase));
+ MD5Update(&md5c, iv, 8);
+ MD5Final(keybuf, &md5c);
+
+ MD5Init(&md5c);
+ MD5Update(&md5c, keybuf, 16);
+ MD5Update(&md5c, passphrase, strlen(passphrase));
+ MD5Update(&md5c, iv, 8);
+ MD5Final(keybuf+16, &md5c);
+
+ /*
+ * Now encrypt the key blob.
+ */
+ des3_encrypt_pubkey_ossh(keybuf, iv, outblob, outlen);
+
+ memset(&md5c, 0, sizeof(md5c));
+ memset(keybuf, 0, sizeof(keybuf));
+ }
+
+ /*
+ * And save it. We'll use Unix line endings just in case it's
+ * subsequently transferred in binary mode.
+ */
+ fp = fopen(filename, "wb"); /* ensure Unix line endings */
+ if (!fp)
+ goto error;
+ fputs(header, fp);
+ if (passphrase) {
+ fprintf(fp, "Proc-Type: 4,ENCRYPTED\nDEK-Info: DES-EDE3-CBC,");
+ for (i = 0; i < 8; i++)
+ fprintf(fp, "%02X", iv[i]);
+ fprintf(fp, "\n\n");
+ }
+ base64_encode(fp, outblob, outlen);
+ fputs(footer, fp);
+ fclose(fp);
+ ret = 1;
+
+ error:
+ if (outblob) {
+ memset(outblob, 0, outlen);
+ sfree(outblob);
+ }
+ if (spareblob) {
+ memset(spareblob, 0, sparelen);
+ sfree(spareblob);
+ }
+ if (privblob) {
+ memset(privblob, 0, privlen);
+ sfree(privblob);
+ }
+ if (pubblob) {
+ memset(pubblob, 0, publen);
+ sfree(pubblob);
+ }
+ return ret;
+}
+
/* ----------------------------------------------------------------------
* Code to read ssh.com private keys.
*/
return answer;
}
-struct mpint_pos { void *start; int bytes; };
-
int sshcom_read_mpint(void *data, int len, struct mpint_pos *ret)
{
int bits;
projects / u / mdw / putty / commitdiff