/*
* Generic SSH public-key handling operations. In particular,
* reading of SSH public-key files, and also the generic `sign'
- * operation for ssh2 (which checks the type of the key and
+ * operation for SSH-2 (which checks the type of the key and
* dispatches to the appropriate key-type specific function).
*/
#include <stdlib.h>
#include <assert.h>
+#include "putty.h"
#include "ssh.h"
#include "misc.h"
-#define PUT_32BIT(cp, value) do { \
- (cp)[3] = (value); \
- (cp)[2] = (value) >> 8; \
- (cp)[1] = (value) >> 16; \
- (cp)[0] = (value) >> 24; } while (0)
-
-#define GET_32BIT(cp) \
- (((unsigned long)(unsigned char)(cp)[0] << 24) | \
- ((unsigned long)(unsigned char)(cp)[1] << 16) | \
- ((unsigned long)(unsigned char)(cp)[2] << 8) | \
- ((unsigned long)(unsigned char)(cp)[3]))
-
#define rsa_signature "SSH PRIVATE KEY FILE FORMAT 1.1\n"
#define BASE64_TOINT(x) ( (x)-'A'<26 ? (x)-'A'+0 :\
(x)=='+' ? 62 : \
(x)=='/' ? 63 : 0 )
+static int key_type_fp(FILE *fp);
+
static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only,
- char **commentptr, char *passphrase)
+ char **commentptr, const char *passphrase,
+ const char **error)
{
unsigned char buf[16384];
unsigned char keybuf[16];
struct MD5Context md5c;
char *comment;
+ *error = NULL;
+
/* Slurp the whole file (minus the header) into a buffer. */
len = fread(buf, 1, sizeof(buf), fp);
fclose(fp);
- if (len < 0 || len == sizeof(buf))
+ if (len < 0 || len == sizeof(buf)) {
+ *error = "error reading file";
goto end; /* file too big or not read */
+ }
i = 0;
+ *error = "file format error";
/*
* A zero byte. (The signature includes a terminating NUL.)
|| buf[i + 3] != 0) goto end; /* reserved field nonzero, panic! */
i += 4;
- /* Now the serious stuff. An ordinary SSH 1 public key. */
- i += makekey(buf + i, key, NULL, 1);
- if (len - i < 0)
+ /* Now the serious stuff. An ordinary SSH-1 public key. */
+ j = makekey(buf + i, len - i, key, NULL, 1);
+ if (j < 0)
goto end; /* overran */
-
- if (pub_only) {
- ret = 1;
- goto end;
- }
+ i += j;
/* Next, the comment field. */
- j = GET_32BIT(buf + i);
+ j = toint(GET_32BIT(buf + i));
i += 4;
- if (len - i < j)
+ if (j < 0 || len - i < j)
goto end;
- comment = smalloc(j + 1);
+ comment = snewn(j + 1, char);
if (comment) {
memcpy(comment, buf + i, j);
comment[j] = '\0';
}
i += j;
if (commentptr)
- *commentptr = comment;
+ *commentptr = dupstr(comment);
if (key)
key->comment = comment;
+ else
+ sfree(comment);
+
+ if (pub_only) {
+ ret = 1;
+ goto end;
+ }
+
if (!key) {
- return ciphertype != 0;
+ ret = ciphertype != 0;
+ *error = NULL;
+ goto end;
}
/*
*/
if (ciphertype) {
MD5Init(&md5c);
- MD5Update(&md5c, passphrase, strlen(passphrase));
+ MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
MD5Final(keybuf, &md5c);
des3_decrypt_pubkey(keybuf, buf + i, (len - i + 7) & ~7);
- memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
+ smemclr(keybuf, sizeof(keybuf)); /* burn the evidence */
}
/*
if (len - i < 4)
goto end;
if (buf[i] != buf[i + 2] || buf[i + 1] != buf[i + 3]) {
+ *error = "wrong passphrase";
ret = -1;
goto end;
}
* decryption exponent, and then the three auxiliary values
* (iqmp, q, p).
*/
- i += makeprivate(buf + i, key);
- if (len - i < 0)
- goto end;
- i += ssh1_read_bignum(buf + i, &key->iqmp);
- if (len - i < 0)
- goto end;
- i += ssh1_read_bignum(buf + i, &key->q);
- if (len - i < 0)
- goto end;
- i += ssh1_read_bignum(buf + i, &key->p);
- if (len - i < 0)
- goto end;
+ j = makeprivate(buf + i, len - i, key);
+ if (j < 0) goto end;
+ i += j;
+ j = ssh1_read_bignum(buf + i, len - i, &key->iqmp);
+ if (j < 0) goto end;
+ i += j;
+ j = ssh1_read_bignum(buf + i, len - i, &key->q);
+ if (j < 0) goto end;
+ i += j;
+ j = ssh1_read_bignum(buf + i, len - i, &key->p);
+ if (j < 0) goto end;
+ i += j;
if (!rsa_verify(key)) {
+ *error = "rsa_verify failed";
freersakey(key);
ret = 0;
} else
ret = 1;
end:
- memset(buf, 0, sizeof(buf)); /* burn the evidence */
+ smemclr(buf, sizeof(buf)); /* burn the evidence */
return ret;
}
-int loadrsakey(char *filename, struct RSAKey *key, char *passphrase)
+int loadrsakey(const Filename *filename, struct RSAKey *key,
+ const char *passphrase, const char **errorstr)
{
FILE *fp;
- unsigned char buf[64];
+ char buf[64];
+ int ret = 0;
+ const char *error = NULL;
- fp = fopen(filename, "rb");
- if (!fp)
- return 0; /* doesn't even exist */
+ fp = f_open(filename, "rb", FALSE);
+ if (!fp) {
+ error = "can't open file";
+ goto end;
+ }
/*
* Read the first line of the file and see if it's a v1 private
* key file.
*/
if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
- return loadrsakey_main(fp, key, FALSE, NULL, passphrase);
+ /*
+ * This routine will take care of calling fclose() for us.
+ */
+ ret = loadrsakey_main(fp, key, FALSE, NULL, passphrase, &error);
+ fp = NULL;
+ goto end;
}
/*
* Otherwise, we have nothing. Return empty-handed.
*/
- fclose(fp);
- return 0;
+ error = "not an SSH-1 RSA file";
+
+ end:
+ if (fp)
+ fclose(fp);
+ if ((ret != 1) && errorstr)
+ *errorstr = error;
+ return ret;
}
/*
* See whether an RSA key is encrypted. Return its comment field as
* well.
*/
-int rsakey_encrypted(char *filename, char **comment)
+int rsakey_encrypted(const Filename *filename, char **comment)
{
FILE *fp;
- unsigned char buf[64];
+ char buf[64];
- fp = fopen(filename, "rb");
+ fp = f_open(filename, "rb", FALSE);
if (!fp)
return 0; /* doesn't even exist */
* key file.
*/
if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
- return loadrsakey_main(fp, NULL, FALSE, comment, NULL);
+ const char *dummy;
+ /*
+ * This routine will take care of calling fclose() for us.
+ */
+ return loadrsakey_main(fp, NULL, FALSE, comment, NULL, &dummy);
}
fclose(fp);
return 0; /* wasn't the right kind of file */
* an RSA key, as given in the agent protocol (modulus bits,
* exponent, modulus).
*/
-int rsakey_pubblob(char *filename, void **blob, int *bloblen)
+int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
+ char **commentptr, const char **errorstr)
{
FILE *fp;
- unsigned char buf[64];
+ char buf[64];
struct RSAKey key;
int ret;
+ const char *error = NULL;
/* Default return if we fail. */
*blob = NULL;
*bloblen = 0;
ret = 0;
- fp = fopen(filename, "rb");
- if (!fp)
- return 0; /* doesn't even exist */
+ fp = f_open(filename, "rb", FALSE);
+ if (!fp) {
+ error = "can't open file";
+ goto end;
+ }
/*
* Read the first line of the file and see if it's a v1 private
*/
if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
memset(&key, 0, sizeof(key));
- if (loadrsakey_main(fp, &key, TRUE, NULL, NULL)) {
+ if (loadrsakey_main(fp, &key, TRUE, commentptr, NULL, &error)) {
*blob = rsa_public_blob(&key, bloblen);
freersakey(&key);
ret = 1;
}
+ fp = NULL; /* loadrsakey_main unconditionally closes fp */
+ } else {
+ /*
+ * Try interpreting the file as an SSH-1 public key.
+ */
+ char *line, *p, *bitsp, *expp, *modp, *commentp;
+
+ rewind(fp);
+ line = chomp(fgetline(fp));
+ p = line;
+
+ bitsp = p;
+ p += strspn(p, "0123456789");
+ if (*p != ' ')
+ goto not_public_either;
+ *p++ = '\0';
+
+ expp = p;
+ p += strspn(p, "0123456789");
+ if (*p != ' ')
+ goto not_public_either;
+ *p++ = '\0';
+
+ modp = p;
+ p += strspn(p, "0123456789");
+ if (*p) {
+ if (*p != ' ')
+ goto not_public_either;
+ *p++ = '\0';
+ commentp = p;
+ } else {
+ commentp = NULL;
+ }
+
+ memset(&key, 0, sizeof(key));
+ key.exponent = bignum_from_decimal(expp);
+ key.modulus = bignum_from_decimal(modp);
+ if (atoi(bitsp) != bignum_bitcount(key.modulus)) {
+ freebn(key.exponent);
+ freebn(key.modulus);
+ sfree(line);
+ error = "key bit count does not match in SSH-1 public key file";
+ goto end;
+ }
+ if (commentptr)
+ *commentptr = commentp ? dupstr(commentp) : NULL;
+ *blob = rsa_public_blob(&key, bloblen);
+ freersakey(&key);
+ sfree(line);
+ fclose(fp);
+ return 1;
+
+ not_public_either:
+ sfree(line);
+ error = "not an SSH-1 RSA file";
}
- fclose(fp);
+
+ end:
+ if (fp)
+ fclose(fp);
+ if ((ret != 1) && errorstr)
+ *errorstr = error;
return ret;
}
/*
* Save an RSA key file. Return nonzero on success.
*/
-int saversakey(char *filename, struct RSAKey *key, char *passphrase)
+int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase)
{
unsigned char buf[16384];
unsigned char keybuf[16];
p += 4;
/*
- * An ordinary SSH 1 public key consists of: a uint32
+ * An ordinary SSH-1 public key consists of: a uint32
* containing the bit count, then two bignums containing the
* modulus and exponent respectively.
*/
*/
if (passphrase) {
MD5Init(&md5c);
- MD5Update(&md5c, passphrase, strlen(passphrase));
+ MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
MD5Final(keybuf, &md5c);
des3_encrypt_pubkey(keybuf, estart, p - estart);
- memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
+ smemclr(keybuf, sizeof(keybuf)); /* burn the evidence */
}
/*
* Done. Write the result to the file.
*/
- fp = fopen(filename, "wb");
+ fp = f_open(filename, "wb", TRUE);
if (fp) {
int ret = (fwrite(buf, 1, p - buf, fp) == (size_t) (p - buf));
- ret = ret && (fclose(fp) == 0);
+ if (fclose(fp))
+ ret = 0;
return ret;
} else
return 0;
}
/* ----------------------------------------------------------------------
- * SSH2 private key load/store functions.
+ * SSH-2 private key load/store functions.
*/
/*
- * PuTTY's own format for SSH2 keys is as follows:
+ * PuTTY's own format for SSH-2 keys is as follows:
*
* The file is text. Lines are terminated by CRLF, although CR-only
* and LF-only are tolerated on input.
*
* Next there is a line saying "Public-Lines: " plus a number N.
* The following N lines contain a base64 encoding of the public
- * part of the key. This is encoded as the standard SSH2 public key
+ * part of the key. This is encoded as the standard SSH-2 public key
* blob (with no initial length): so for RSA, for example, it will
* read
*
* data "putty-private-key-file-mac-key"
* data passphrase
*
- * Encrypted keys should have a MAC, whereas unencrypted ones must
- * have a hash.
+ * (An empty passphrase is used for unencrypted keys.)
*
* If the key is encrypted, the encryption key is derived from the
* passphrase by means of a succession of SHA-1 hashes. Each hash
* with "PuTTY-User-Key-File-1" (version number differs). In this
* format the Private-MAC: field only covers the private-plaintext
* field and nothing else (and without the 4-byte string length on
- * the front too). Moreover, for RSA keys the Private-MAC: field
- * can be replaced with a Private-Hash: field which is a plain
- * SHA-1 hash instead of an HMAC. This is not allowable in DSA
- * keys. (Yes, the old format was a mess. Guess why it changed :-)
+ * the front too). Moreover, the Private-MAC: field can be replaced
+ * with a Private-Hash: field which is a plain SHA-1 hash instead of
+ * an HMAC (this was generated for unencrypted keys).
*/
static int read_header(FILE * fp, char *header)
int len = 39;
int c;
- while (len > 0) {
+ while (1) {
c = fgetc(fp);
if (c == '\n' || c == '\r' || c == EOF)
return 0; /* failure */
int c;
size = 128;
- text = smalloc(size);
+ text = snewn(size, char);
len = 0;
text[len] = '\0';
while (1) {
c = fgetc(fp);
- if (c == '\r' || c == '\n') {
- c = fgetc(fp);
- if (c != '\r' && c != '\n' && c != EOF)
- ungetc(c, fp);
+ if (c == '\r' || c == '\n' || c == EOF) {
+ if (c != EOF) {
+ c = fgetc(fp);
+ if (c != '\r' && c != '\n')
+ ungetc(c, fp);
+ }
return text;
}
- if (c == EOF) {
- sfree(text);
- return NULL;
- }
- if (len + 1 > size) {
+ if (len + 1 >= size) {
size += 128;
- text = srealloc(text, size);
+ text = sresize(text, size, char);
}
text[len++] = c;
text[len] = '\0';
}
}
-int base64_decode_atom(char *atom, unsigned char *out)
-{
- int vals[4];
- int i, v, len;
- unsigned word;
- char c;
-
- for (i = 0; i < 4; i++) {
- c = atom[i];
- if (c >= 'A' && c <= 'Z')
- v = c - 'A';
- else if (c >= 'a' && c <= 'z')
- v = c - 'a' + 26;
- else if (c >= '0' && c <= '9')
- v = c - '0' + 52;
- else if (c == '+')
- v = 62;
- else if (c == '/')
- v = 63;
- else if (c == '=')
- v = -1;
- else
- return 0; /* invalid atom */
- vals[i] = v;
- }
-
- if (vals[0] == -1 || vals[1] == -1)
- return 0;
- if (vals[2] == -1 && vals[3] != -1)
- return 0;
-
- if (vals[3] != -1)
- len = 3;
- else if (vals[2] != -1)
- len = 2;
- else
- len = 1;
-
- word = ((vals[0] << 18) |
- (vals[1] << 12) | ((vals[2] & 0x3F) << 6) | (vals[3] & 0x3F));
- out[0] = (word >> 16) & 0xFF;
- if (len > 1)
- out[1] = (word >> 8) & 0xFF;
- if (len > 2)
- out[2] = word & 0xFF;
- return len;
-}
-
-static char *read_blob(FILE * fp, int nlines, int *bloblen)
+static unsigned char *read_blob(FILE * fp, int nlines, int *bloblen)
{
unsigned char *blob;
char *line;
int i, j, k;
/* We expect at most 64 base64 characters, ie 48 real bytes, per line. */
- blob = smalloc(48 * nlines);
+ blob = snewn(48 * nlines, unsigned char);
len = 0;
for (i = 0; i < nlines; i++) {
line = read_body(fp);
NULL, NULL, NULL
};
-struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase)
+const struct ssh_signkey *find_pubkey_alg_len(int namelen, const char *name)
+{
+ if (match_ssh_id(namelen, name, "ssh-rsa"))
+ return &ssh_rsa;
+ else if (match_ssh_id(namelen, name, "ssh-dss"))
+ return &ssh_dss;
+ else if (match_ssh_id(namelen, name, "ecdsa-sha2-nistp256"))
+ return &ssh_ecdsa_nistp256;
+ else if (match_ssh_id(namelen, name, "ecdsa-sha2-nistp384"))
+ return &ssh_ecdsa_nistp384;
+ else if (match_ssh_id(namelen, name, "ecdsa-sha2-nistp521"))
+ return &ssh_ecdsa_nistp521;
+ else if (match_ssh_id(namelen, name, "ssh-ed25519"))
+ return &ssh_ecdsa_ed25519;
+ else
+ return NULL;
+}
+
+const struct ssh_signkey *find_pubkey_alg(const char *name)
+{
+ return find_pubkey_alg_len(strlen(name), name);
+}
+
+struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
+ const char *passphrase,
+ const char **errorstr)
{
FILE *fp;
char header[40], *b, *encryption, *comment, *mac;
int public_blob_len, private_blob_len;
int i, is_mac, old_fmt;
int passlen = passphrase ? strlen(passphrase) : 0;
+ const char *error = NULL;
ret = NULL; /* return NULL for most errors */
- comment = mac = NULL;
+ encryption = comment = mac = NULL;
public_blob = private_blob = NULL;
- fp = fopen(filename, "rb");
- if (!fp)
+ fp = f_open(filename, "rb", FALSE);
+ if (!fp) {
+ error = "can't open file";
goto error;
+ }
/* Read the first header line which contains the key type. */
if (!read_header(fp, header))
/* this is an old key file; warn and then continue */
old_keyfile_warning();
old_fmt = 1;
- } else
+ } else if (0 == strncmp(header, "PuTTY-User-Key-File-", 20)) {
+ /* this is a key file FROM THE FUTURE; refuse it, but with a
+ * more specific error message than the generic one below */
+ error = "PuTTY key format too new";
+ goto error;
+ } else {
+ error = "not a PuTTY SSH-2 private key";
goto error;
+ }
+ error = "file format error";
if ((b = read_body(fp)) == NULL)
goto error;
/* Select key algorithm structure. */
- if (!strcmp(b, "ssh-rsa"))
- alg = &ssh_rsa;
- else if (!strcmp(b, "ssh-dss"))
- alg = &ssh_dss;
- else {
+ alg = find_pubkey_alg(b);
+ if (!alg) {
sfree(b);
goto error;
}
cipher = 0;
cipherblk = 1;
} else {
- sfree(encryption);
goto error;
}
if ((mac = read_body(fp)) == NULL)
goto error;
is_mac = 1;
- } else if (0 == strcmp(header, "Private-Hash") &&
- alg == &ssh_rsa && old_fmt) {
+ } else if (0 == strcmp(header, "Private-Hash") && old_fmt) {
if ((mac = read_body(fp)) == NULL)
goto error;
is_mac = 0;
4 + commlen +
4 + public_blob_len +
4 + private_blob_len);
- macdata = smalloc(maclen);
+ macdata = snewn(maclen, unsigned char);
p = macdata;
#define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len)
DO_STR(alg->name, namelen);
SHA_Init(&s);
SHA_Bytes(&s, header, sizeof(header)-1);
- if (passphrase)
+ if (cipher && passphrase)
SHA_Bytes(&s, passphrase, passlen);
SHA_Final(&s, mackey);
hmac_sha1_simple(mackey, 20, macdata, maclen, binary);
- memset(mackey, 0, sizeof(mackey));
- memset(&s, 0, sizeof(s));
+ smemclr(mackey, sizeof(mackey));
+ smemclr(&s, sizeof(s));
} else {
SHA_Simple(macdata, maclen, binary);
}
if (free_macdata) {
- memset(macdata, 0, maclen);
+ smemclr(macdata, maclen);
sfree(macdata);
}
if (strcmp(mac, realmac)) {
/* An incorrect MAC is an unconditional Error if the key is
* unencrypted. Otherwise, it means Wrong Passphrase. */
- ret = cipher ? SSH2_WRONG_PASSPHRASE : NULL;
+ if (cipher) {
+ error = "wrong passphrase";
+ ret = SSH2_WRONG_PASSPHRASE;
+ } else {
+ error = "MAC failed";
+ ret = NULL;
+ }
goto error;
}
}
sfree(mac);
+ mac = NULL;
/*
* Create and return the key.
*/
- ret = smalloc(sizeof(struct ssh2_userkey));
+ ret = snew(struct ssh2_userkey);
ret->alg = alg;
ret->comment = comment;
- ret->data = alg->createkey(public_blob, public_blob_len,
+ ret->data = alg->createkey(alg, public_blob, public_blob_len,
private_blob, private_blob_len);
if (!ret->data) {
- sfree(ret->comment);
sfree(ret);
ret = NULL;
+ error = "createkey failed";
+ goto error;
}
sfree(public_blob);
+ smemclr(private_blob, private_blob_len);
sfree(private_blob);
sfree(encryption);
+ if (errorstr)
+ *errorstr = NULL;
return ret;
/*
sfree(mac);
if (public_blob)
sfree(public_blob);
- if (private_blob)
- sfree(private_blob);
+ if (private_blob) {
+ smemclr(private_blob, private_blob_len);
+ sfree(private_blob);
+ }
+ if (errorstr)
+ *errorstr = error;
return ret;
}
-char *ssh2_userkey_loadpub(char *filename, char **algorithm,
- int *pub_blob_len)
+unsigned char *rfc4716_loadpub(FILE *fp, char **algorithm,
+ int *pub_blob_len, char **commentptr,
+ const char **errorstr)
+{
+ const char *error;
+ char *line, *colon, *value;
+ char *comment = NULL;
+ unsigned char *pubblob = NULL;
+ int pubbloblen, pubblobsize;
+ char base64in[4];
+ unsigned char base64out[3];
+ int base64bytes;
+ int alglen;
+
+ line = chomp(fgetline(fp));
+ if (!line || 0 != strcmp(line, "---- BEGIN SSH2 PUBLIC KEY ----")) {
+ error = "invalid begin line in SSH-2 public key file";
+ goto error;
+ }
+ sfree(line); line = NULL;
+
+ while (1) {
+ line = chomp(fgetline(fp));
+ if (!line) {
+ error = "truncated SSH-2 public key file";
+ goto error;
+ }
+ colon = strstr(line, ": ");
+ if (!colon)
+ break;
+ *colon = '\0';
+ value = colon + 2;
+
+ if (!strcmp(line, "Comment")) {
+ char *p, *q;
+
+ /* Remove containing double quotes, if present */
+ p = value;
+ if (*p == '"' && p[strlen(p)-1] == '"') {
+ p[strlen(p)-1] = '\0';
+ p++;
+ }
+
+ /* Remove \-escaping, not in RFC4716 but seen in the wild
+ * in practice. */
+ for (q = line; *p; p++) {
+ if (*p == '\\' && p[1])
+ p++;
+ *q++ = *p;
+ }
+
+ *q = '\0';
+ sfree(comment); /* *just* in case of multiple Comment headers */
+ comment = dupstr(line);
+ } else if (!strcmp(line, "Subject") ||
+ !strncmp(line, "x-", 2)) {
+ /* Headers we recognise and ignore. Do nothing. */
+ } else {
+ error = "unrecognised header in SSH-2 public key file";
+ goto error;
+ }
+
+ sfree(line); line = NULL;
+ }
+
+ /*
+ * Now line contains the initial line of base64 data. Loop round
+ * while it still does contain base64.
+ */
+ pubblobsize = 4096;
+ pubblob = snewn(pubblobsize, unsigned char);
+ pubbloblen = 0;
+ base64bytes = 0;
+ while (line && line[0] != '-') {
+ char *p;
+ for (p = line; *p; p++) {
+ base64in[base64bytes++] = *p;
+ if (base64bytes == 4) {
+ int n = base64_decode_atom(base64in, base64out);
+ if (pubbloblen + n > pubblobsize) {
+ pubblobsize = (pubbloblen + n) * 5 / 4 + 1024;
+ pubblob = sresize(pubblob, pubblobsize, unsigned char);
+ }
+ memcpy(pubblob + pubbloblen, base64out, n);
+ pubbloblen += n;
+ base64bytes = 0;
+ }
+ }
+ sfree(line); line = NULL;
+ line = chomp(fgetline(fp));
+ }
+
+ /*
+ * Finally, check the END line makes sense.
+ */
+ if (!line || 0 != strcmp(line, "---- END SSH2 PUBLIC KEY ----")) {
+ error = "invalid end line in SSH-2 public key file";
+ goto error;
+ }
+ sfree(line); line = NULL;
+
+ /*
+ * OK, we now have a public blob and optionally a comment. We must
+ * return the key algorithm string too, so look for that at the
+ * start of the public blob.
+ */
+ if (pubbloblen < 4) {
+ error = "not enough data in SSH-2 public key file";
+ goto error;
+ }
+ alglen = toint(GET_32BIT(pubblob));
+ if (alglen < 0 || alglen > pubbloblen-4) {
+ error = "invalid algorithm prefix in SSH-2 public key file";
+ goto error;
+ }
+ if (algorithm)
+ *algorithm = dupprintf("%.*s", alglen, pubblob+4);
+ if (pub_blob_len)
+ *pub_blob_len = pubbloblen;
+ if (commentptr)
+ *commentptr = comment;
+ else
+ sfree(comment);
+ return pubblob;
+
+ error:
+ sfree(line);
+ sfree(comment);
+ sfree(pubblob);
+ if (errorstr)
+ *errorstr = error;
+ return NULL;
+}
+
+unsigned char *openssh_loadpub(FILE *fp, char **algorithm,
+ int *pub_blob_len, char **commentptr,
+ const char **errorstr)
+{
+ const char *error;
+ char *line, *base64;
+ char *comment = NULL;
+ unsigned char *pubblob = NULL;
+ int pubbloblen, pubblobsize;
+ int alglen;
+
+ line = chomp(fgetline(fp));
+
+ base64 = strchr(line, ' ');
+ if (!base64) {
+ error = "no key blob in OpenSSH public key file";
+ goto error;
+ }
+ *base64++ = '\0';
+
+ comment = strchr(base64, ' ');
+ if (comment) {
+ *comment++ = '\0';
+ comment = dupstr(comment);
+ }
+
+ pubblobsize = strlen(base64) / 4 * 3;
+ pubblob = snewn(pubblobsize, unsigned char);
+ pubbloblen = 0;
+
+ while (!memchr(base64, '\0', 4)) {
+ assert(pubbloblen + 3 <= pubblobsize);
+ pubbloblen += base64_decode_atom(base64, pubblob + pubbloblen);
+ base64 += 4;
+ }
+ if (*base64) {
+ error = "invalid length for base64 data in OpenSSH public key file";
+ goto error;
+ }
+
+ /*
+ * Sanity check: the first word on the line should be the key
+ * algorithm, and should match the encoded string at the start of
+ * the public blob.
+ */
+ alglen = strlen(line);
+ if (pubbloblen < alglen + 4 ||
+ GET_32BIT(pubblob) != alglen ||
+ 0 != memcmp(pubblob + 4, line, alglen)) {
+ error = "key algorithms do not match in OpenSSH public key file";
+ goto error;
+ }
+
+ /*
+ * Done.
+ */
+ if (algorithm)
+ *algorithm = dupstr(line);
+ if (pub_blob_len)
+ *pub_blob_len = pubbloblen;
+ if (commentptr)
+ *commentptr = comment;
+ else
+ sfree(comment);
+ sfree(line);
+ return pubblob;
+
+ error:
+ sfree(line);
+ sfree(comment);
+ sfree(pubblob);
+ if (errorstr)
+ *errorstr = error;
+ return NULL;
+}
+
+unsigned char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
+ int *pub_blob_len, char **commentptr,
+ const char **errorstr)
{
FILE *fp;
char header[40], *b;
const struct ssh_signkey *alg;
unsigned char *public_blob;
int public_blob_len;
- int i;
+ int type, i;
+ const char *error = NULL;
+ char *comment = NULL;
public_blob = NULL;
- fp = fopen(filename, "rb");
- if (!fp)
+ fp = f_open(filename, "rb", FALSE);
+ if (!fp) {
+ error = "can't open file";
goto error;
+ }
+
+ /* Initially, check if this is a public-only key file. Sometimes
+ * we'll be asked to read a public blob from one of those. */
+ type = key_type_fp(fp);
+ if (type == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716) {
+ unsigned char *ret = rfc4716_loadpub(fp, algorithm, pub_blob_len,
+ commentptr, errorstr);
+ fclose(fp);
+ return ret;
+ } else if (type == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
+ unsigned char *ret = openssh_loadpub(fp, algorithm, pub_blob_len,
+ commentptr, errorstr);
+ fclose(fp);
+ return ret;
+ } else if (type != SSH_KEYTYPE_SSH2) {
+ error = "not a PuTTY SSH-2 private key";
+ goto error;
+ }
/* Read the first header line which contains the key type. */
if (!read_header(fp, header)
|| (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
- 0 != strcmp(header, "PuTTY-User-Key-File-1")))
+ 0 != strcmp(header, "PuTTY-User-Key-File-1"))) {
+ if (0 == strncmp(header, "PuTTY-User-Key-File-", 20))
+ error = "PuTTY key format too new";
+ else
+ error = "not a PuTTY SSH-2 private key";
goto error;
+ }
+ error = "file format error";
if ((b = read_body(fp)) == NULL)
goto error;
- /* Select key algorithm structure. Currently only ssh-rsa. */
- if (!strcmp(b, "ssh-rsa"))
- alg = &ssh_rsa;
- else if (!strcmp(b, "ssh-dss"))
- alg = &ssh_dss;
- else {
- sfree(b);
+ /* Select key algorithm structure. */
+ alg = find_pubkey_alg(b);
+ sfree(b);
+ if (!alg) {
goto error;
}
- sfree(b);
/* Read the Encryption header line. */
if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
/* Read the Comment header line. */
if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
goto error;
- if ((b = read_body(fp)) == NULL)
+ if ((comment = read_body(fp)) == NULL)
goto error;
- sfree(b); /* we don't care */
+
+ if (commentptr)
+ *commentptr = comment;
+ else
+ sfree(comment);
/* Read the Public-Lines header line and the public blob. */
if (!read_header(fp, header) || 0 != strcmp(header, "Public-Lines"))
if (pub_blob_len)
*pub_blob_len = public_blob_len;
if (algorithm)
- *algorithm = alg->name;
+ *algorithm = dupstr(alg->name);
return public_blob;
/*
fclose(fp);
if (public_blob)
sfree(public_blob);
+ if (errorstr)
+ *errorstr = error;
+ if (comment && commentptr) {
+ sfree(comment);
+ *commentptr = NULL;
+ }
return NULL;
}
-int ssh2_userkey_encrypted(char *filename, char **commentptr)
+int ssh2_userkey_encrypted(const Filename *filename, char **commentptr)
{
FILE *fp;
char header[40], *b, *comment;
if (commentptr)
*commentptr = NULL;
- fp = fopen(filename, "rb");
+ fp = f_open(filename, "rb", FALSE);
if (!fp)
return 0;
if (!read_header(fp, header)
if (commentptr)
*commentptr = comment;
+ else
+ sfree(comment);
fclose(fp);
if (!strcmp(b, "aes256-cbc"))
return (datalen + 47) / 48;
}
-void base64_encode_atom(unsigned char *data, int n, char *out)
-{
- static const char base64_chars[] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-
- unsigned word;
-
- word = data[0] << 16;
- if (n > 1)
- word |= data[1] << 8;
- if (n > 2)
- word |= data[2];
- out[0] = base64_chars[(word >> 18) & 0x3F];
- out[1] = base64_chars[(word >> 12) & 0x3F];
- if (n > 1)
- out[2] = base64_chars[(word >> 6) & 0x3F];
- else
- out[2] = '=';
- if (n > 2)
- out[3] = base64_chars[word & 0x3F];
- else
- out[3] = '=';
-}
-
-void base64_encode(FILE * fp, unsigned char *data, int datalen)
+void base64_encode(FILE *fp, const unsigned char *data, int datalen, int cpl)
{
int linelen = 0;
char out[4];
- int n;
+ int n, i;
while (datalen > 0) {
- if (linelen >= 64) {
- linelen = 0;
- fputc('\n', fp);
- }
n = (datalen < 3 ? datalen : 3);
base64_encode_atom(data, n, out);
data += n;
datalen -= n;
- fwrite(out, 1, 4, fp);
- linelen += 4;
+ for (i = 0; i < 4; i++) {
+ if (linelen >= cpl) {
+ linelen = 0;
+ fputc('\n', fp);
+ }
+ fputc(out[i], fp);
+ linelen++;
+ }
}
fputc('\n', fp);
}
-int ssh2_save_userkey(char *filename, struct ssh2_userkey *key,
+int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key,
char *passphrase)
{
FILE *fp;
int passlen;
int cipherblk;
int i;
- char *cipherstr;
+ const char *cipherstr;
unsigned char priv_mac[20];
/*
}
priv_encrypted_len = priv_blob_len + cipherblk - 1;
priv_encrypted_len -= priv_encrypted_len % cipherblk;
- priv_blob_encrypted = smalloc(priv_encrypted_len);
+ priv_blob_encrypted = snewn(priv_encrypted_len, unsigned char);
memset(priv_blob_encrypted, 0, priv_encrypted_len);
memcpy(priv_blob_encrypted, priv_blob, priv_blob_len);
/* Create padding based on the SHA hash of the unpadded blob. This prevents
4 + commlen +
4 + pub_blob_len +
4 + priv_encrypted_len);
- macdata = smalloc(maclen);
+ macdata = snewn(maclen, unsigned char);
p = macdata;
#define DO_STR(s,len) PUT_32BIT(p,(len));memcpy(p+4,(s),(len));p+=4+(len)
DO_STR(key->alg->name, namelen);
SHA_Bytes(&s, passphrase, strlen(passphrase));
SHA_Final(&s, mackey);
hmac_sha1_simple(mackey, 20, macdata, maclen, priv_mac);
- memset(macdata, 0, maclen);
+ smemclr(macdata, maclen);
sfree(macdata);
- memset(mackey, 0, sizeof(mackey));
- memset(&s, 0, sizeof(s));
+ smemclr(mackey, sizeof(mackey));
+ smemclr(&s, sizeof(s));
}
if (passphrase) {
- char key[40];
+ unsigned char key[40];
SHA_State s;
passlen = strlen(passphrase);
aes256_encrypt_pubkey(key, priv_blob_encrypted,
priv_encrypted_len);
- memset(key, 0, sizeof(key));
- memset(&s, 0, sizeof(s));
+ smemclr(key, sizeof(key));
+ smemclr(&s, sizeof(s));
}
- fp = fopen(filename, "w");
- if (!fp)
- return 0;
+ fp = f_open(filename, "w", TRUE);
+ if (!fp) {
+ sfree(pub_blob);
+ smemclr(priv_blob, priv_blob_len);
+ sfree(priv_blob);
+ smemclr(priv_blob_encrypted, priv_blob_len);
+ sfree(priv_blob_encrypted);
+ return 0;
+ }
fprintf(fp, "PuTTY-User-Key-File-2: %s\n", key->alg->name);
fprintf(fp, "Encryption: %s\n", cipherstr);
fprintf(fp, "Comment: %s\n", key->comment);
fprintf(fp, "Public-Lines: %d\n", base64_lines(pub_blob_len));
- base64_encode(fp, pub_blob, pub_blob_len);
+ base64_encode(fp, pub_blob, pub_blob_len, 64);
fprintf(fp, "Private-Lines: %d\n", base64_lines(priv_encrypted_len));
- base64_encode(fp, priv_blob_encrypted, priv_encrypted_len);
+ base64_encode(fp, priv_blob_encrypted, priv_encrypted_len, 64);
fprintf(fp, "Private-MAC: ");
for (i = 0; i < 20; i++)
fprintf(fp, "%02x", priv_mac[i]);
fclose(fp);
sfree(pub_blob);
- memset(priv_blob, 0, priv_blob_len);
+ smemclr(priv_blob, priv_blob_len);
sfree(priv_blob);
+ smemclr(priv_blob_encrypted, priv_blob_len);
sfree(priv_blob_encrypted);
return 1;
}
/* ----------------------------------------------------------------------
- * A function to determine which version of SSH to try on a private
- * key file. Returns 0 on failure, 1 or 2 on success.
+ * Output public keys.
*/
-int keyfile_version(char *filename)
+char *ssh1_pubkey_str(struct RSAKey *key)
{
- FILE *fp;
+ char *buffer;
+ char *dec1, *dec2;
+
+ dec1 = bignum_decimal(key->exponent);
+ dec2 = bignum_decimal(key->modulus);
+ buffer = dupprintf("%d %s %s%s%s", bignum_bitcount(key->modulus),
+ dec1, dec2,
+ key->comment ? " " : "",
+ key->comment ? key->comment : "");
+ sfree(dec1);
+ sfree(dec2);
+ return buffer;
+}
+
+void ssh1_write_pubkey(FILE *fp, struct RSAKey *key)
+{
+ char *buffer = ssh1_pubkey_str(key);
+ fprintf(fp, "%s\n", buffer);
+ sfree(buffer);
+}
+
+static char *ssh2_pubkey_openssh_str_internal(const char *comment,
+ const void *v_pub_blob,
+ int pub_len)
+{
+ const unsigned char *ssh2blob = (const unsigned char *)v_pub_blob;
+ const char *alg;
+ int alglen;
+ char *buffer, *p;
+ int i;
+
+ if (pub_len < 4) {
+ alg = NULL;
+ } else {
+ alglen = GET_32BIT(ssh2blob);
+ if (alglen > 0 && alglen < pub_len - 4) {
+ alg = (const char *)ssh2blob + 4;
+ } else {
+ alg = NULL;
+ }
+ }
+
+ if (!alg) {
+ alg = "INVALID-ALGORITHM";
+ alglen = strlen(alg);
+ }
+
+ buffer = snewn(alglen +
+ 4 * ((pub_len+2) / 3) +
+ (comment ? strlen(comment) : 0) + 3, char);
+ p = buffer + sprintf(buffer, "%.*s ", alglen, alg);
+ i = 0;
+ while (i < pub_len) {
+ int n = (pub_len - i < 3 ? pub_len - i : 3);
+ base64_encode_atom(ssh2blob + i, n, p);
+ i += n;
+ p += 4;
+ }
+ if (*comment) {
+ *p++ = ' ';
+ strcpy(p, comment);
+ } else
+ *p++ = '\0';
+
+ return buffer;
+}
+
+char *ssh2_pubkey_openssh_str(struct ssh2_userkey *key)
+{
+ int bloblen;
+ unsigned char *blob;
+ char *ret;
+
+ blob = key->alg->public_blob(key->data, &bloblen);
+ ret = ssh2_pubkey_openssh_str_internal(key->comment, blob, bloblen);
+ sfree(blob);
+
+ return ret;
+}
+
+void ssh2_write_pubkey(FILE *fp, const char *comment,
+ const void *v_pub_blob, int pub_len,
+ int keytype)
+{
+ unsigned char *pub_blob = (unsigned char *)v_pub_blob;
+
+ if (keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716) {
+ const char *p;
+ int i, column;
+
+ fprintf(fp, "---- BEGIN SSH2 PUBLIC KEY ----\n");
+
+ if (comment) {
+ fprintf(fp, "Comment: \"");
+ for (p = comment; *p; p++) {
+ if (*p == '\\' || *p == '\"')
+ fputc('\\', fp);
+ fputc(*p, fp);
+ }
+ fprintf(fp, "\"\n");
+ }
+
+ i = 0;
+ column = 0;
+ while (i < pub_len) {
+ char buf[5];
+ int n = (pub_len - i < 3 ? pub_len - i : 3);
+ base64_encode_atom(pub_blob + i, n, buf);
+ i += n;
+ buf[4] = '\0';
+ fputs(buf, fp);
+ if (++column >= 16) {
+ fputc('\n', fp);
+ column = 0;
+ }
+ }
+ if (column > 0)
+ fputc('\n', fp);
+
+ fprintf(fp, "---- END SSH2 PUBLIC KEY ----\n");
+ } else if (keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) {
+ char *buffer = ssh2_pubkey_openssh_str_internal(comment,
+ v_pub_blob, pub_len);
+ fprintf(fp, "%s\n", buffer);
+ sfree(buffer);
+ } else {
+ assert(0 && "Bad key type in ssh2_write_pubkey");
+ }
+}
+
+/* ----------------------------------------------------------------------
+ * Utility functions to compute SSH-2 fingerprints in a uniform way.
+ */
+char *ssh2_fingerprint_blob(const void *blob, int bloblen)
+{
+ unsigned char digest[16];
+ char fingerprint_str[16*3];
+ const char *algstr;
+ int alglen;
+ const struct ssh_signkey *alg;
int i;
- fp = fopen(filename, "r");
+ /*
+ * The fingerprint hash itself is always just the MD5 of the blob.
+ */
+ MD5Simple(blob, bloblen, digest);
+ for (i = 0; i < 16; i++)
+ sprintf(fingerprint_str + i*3, "%02x%s", digest[i], i==15 ? "" : ":");
+
+ /*
+ * Identify the key algorithm, if possible.
+ */
+ alglen = toint(GET_32BIT((const unsigned char *)blob));
+ if (alglen > 0 && alglen < bloblen-4) {
+ algstr = (const char *)blob + 4;
+
+ /*
+ * If we can actually identify the algorithm as one we know
+ * about, get hold of the key's bit count too.
+ */
+ alg = find_pubkey_alg_len(alglen, algstr);
+ if (alg) {
+ int bits = alg->pubkey_bits(alg, blob, bloblen);
+ return dupprintf("%.*s %d %s", alglen, algstr,
+ bits, fingerprint_str);
+ } else {
+ return dupprintf("%.*s %s", alglen, algstr, fingerprint_str);
+ }
+ } else {
+ /*
+ * No algorithm available (which means a seriously confused
+ * key blob, but there we go). Return only the hash.
+ */
+ return dupstr(fingerprint_str);
+ }
+}
+
+char *ssh2_fingerprint(const struct ssh_signkey *alg, void *data)
+{
+ int len;
+ unsigned char *blob = alg->public_blob(data, &len);
+ char *ret = ssh2_fingerprint_blob(blob, len);
+ sfree(blob);
+ return ret;
+}
+
+/* ----------------------------------------------------------------------
+ * Determine the type of a private key file.
+ */
+static int key_type_fp(FILE *fp)
+{
+ char buf[1024];
+ const char public_std_sig[] = "---- BEGIN SSH2 PUBLIC KEY";
+ const char putty2_sig[] = "PuTTY-User-Key-File-";
+ const char sshcom_sig[] = "---- BEGIN SSH2 ENCRYPTED PRIVAT";
+ const char openssh_new_sig[] = "-----BEGIN OPENSSH PRIVATE KEY";
+ const char openssh_sig[] = "-----BEGIN ";
+ int i;
+ char *p;
+
+ i = fread(buf, 1, sizeof(buf)-1, fp);
+ rewind(fp);
+
+ if (i < 0)
+ return SSH_KEYTYPE_UNOPENABLE;
+ if (i < 32)
+ return SSH_KEYTYPE_UNKNOWN;
+ assert(i > 0 && i < sizeof(buf));
+ buf[i] = '\0';
+ if (!memcmp(buf, rsa_signature, sizeof(rsa_signature)-1))
+ return SSH_KEYTYPE_SSH1;
+ if (!memcmp(buf, public_std_sig, sizeof(public_std_sig)-1))
+ return SSH_KEYTYPE_SSH2_PUBLIC_RFC4716;
+ if (!memcmp(buf, putty2_sig, sizeof(putty2_sig)-1))
+ return SSH_KEYTYPE_SSH2;
+ if (!memcmp(buf, openssh_new_sig, sizeof(openssh_new_sig)-1))
+ return SSH_KEYTYPE_OPENSSH_NEW;
+ if (!memcmp(buf, openssh_sig, sizeof(openssh_sig)-1))
+ return SSH_KEYTYPE_OPENSSH_PEM;
+ if (!memcmp(buf, sshcom_sig, sizeof(sshcom_sig)-1))
+ return SSH_KEYTYPE_SSHCOM;
+ if ((p = buf + strspn(buf, "0123456789"), *p == ' ') &&
+ (p = p+1 + strspn(p+1, "0123456789"), *p == ' ') &&
+ (p = p+1 + strspn(p+1, "0123456789"), *p == ' ' || *p == '\n' || !*p))
+ return SSH_KEYTYPE_SSH1_PUBLIC;
+ if ((p = buf + strcspn(buf, " "), find_pubkey_alg_len(p-buf, buf)) &&
+ (p = p+1 + strspn(p+1, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghij"
+ "klmnopqrstuvwxyz+/="),
+ *p == ' ' || *p == '\n' || !*p))
+ return SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH;
+ return SSH_KEYTYPE_UNKNOWN; /* unrecognised or EOF */
+}
+
+int key_type(const Filename *filename)
+{
+ FILE *fp;
+ int ret;
+
+ fp = f_open(filename, "r", FALSE);
if (!fp)
- return 0;
- i = fgetc(fp);
+ return SSH_KEYTYPE_UNOPENABLE;
+ ret = key_type_fp(fp);
fclose(fp);
- if (i == 'S')
- return 1; /* "SSH PRIVATE KEY FORMAT" etc */
- if (i == 'P') /* "PuTTY-User-Key-File" etc */
- return 2;
- return 0; /* unrecognised or EOF */
+ return ret;
+}
+
+/*
+ * Convert the type word to a string, for `wrong type' error
+ * messages.
+ */
+const char *key_type_to_str(int type)
+{
+ switch (type) {
+ case SSH_KEYTYPE_UNOPENABLE: return "unable to open file"; break;
+ case SSH_KEYTYPE_UNKNOWN: return "not a recognised key file format"; break;
+ case SSH_KEYTYPE_SSH1_PUBLIC: return "SSH-1 public key"; break;
+ case SSH_KEYTYPE_SSH2_PUBLIC_RFC4716: return "SSH-2 public key (RFC 4716 format)"; break;
+ case SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH: return "SSH-2 public key (OpenSSH format)"; break;
+ case SSH_KEYTYPE_SSH1: return "SSH-1 private key"; break;
+ case SSH_KEYTYPE_SSH2: return "PuTTY SSH-2 private key"; break;
+ case SSH_KEYTYPE_OPENSSH_PEM: return "OpenSSH SSH-2 private key (old PEM format)"; break;
+ case SSH_KEYTYPE_OPENSSH_NEW: return "OpenSSH SSH-2 private key (new format)"; break;
+ case SSH_KEYTYPE_SSHCOM: return "ssh.com SSH-2 private key"; break;
+ /*
+ * This function is called with a key type derived from
+ * looking at an actual key file, so the output-only type
+ * OPENSSH_AUTO should never get here, and is much an INTERNAL
+ * ERROR as a code we don't even understand.
+ */
+ case SSH_KEYTYPE_OPENSSH_AUTO: return "INTERNAL ERROR (OPENSSH_AUTO)"; break;
+ default: return "INTERNAL ERROR"; break;
+ }
}