/*
* 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 <stdio.h>
#include <stdlib.h>
+#include <assert.h>
+#include "putty.h"
#include "ssh.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]))
+#include "misc.h"
#define rsa_signature "SSH PRIVATE KEY FILE FORMAT 1.1\n"
(x)=='+' ? 62 : \
(x)=='/' ? 63 : 0 )
-static int loadrsakey_main(FILE *fp, struct RSAKey *key, struct RSAAux *aux,
- char **commentptr, char *passphrase) {
+static int loadrsakey_main(FILE * fp, struct RSAKey *key, int pub_only,
+ char **commentptr, char *passphrase,
+ const char **error)
+{
unsigned char buf[16384];
unsigned char keybuf[16];
int len;
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))
- goto end; /* file too big or not read */
+ 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.)
*/
- if (len-i < 1 || buf[i] != 0)
- goto end;
+ if (len - i < 1 || buf[i] != 0)
+ goto end;
i++;
/* One byte giving encryption type, and one reserved uint32. */
- if (len-i < 1)
- goto end;
+ if (len - i < 1)
+ goto end;
ciphertype = buf[i];
if (ciphertype != 0 && ciphertype != SSH_CIPHER_3DES)
- goto end;
+ goto end;
i++;
- if (len-i < 4)
- goto end; /* reserved field not present */
- if (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0 || buf[i+3] != 0)
- goto end; /* reserved field nonzero, panic! */
+ if (len - i < 4)
+ goto end; /* reserved field not present */
+ if (buf[i] != 0 || buf[i + 1] != 0 || buf[i + 2] != 0
+ || 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)
- goto end; /* overran */
+ /* Now the serious stuff. An ordinary SSH-1 public key. */
+ j = makekey(buf + i, len, key, NULL, 1);
+ if (j < 0)
+ goto end; /* overran */
+ i += j;
/* Next, the comment field. */
- j = GET_32BIT(buf+i);
+ j = toint(GET_32BIT(buf + i));
i += 4;
- if (len-i < j) goto end;
- comment = malloc(j+1);
+ if (j < 0 || len - i < j)
+ goto end;
+ comment = snewn(j + 1, char);
if (comment) {
- memcpy(comment, buf+i, j);
- comment[j] = '\0';
+ memcpy(comment, buf + i, j);
+ comment[j] = '\0';
}
i += j;
if (commentptr)
- *commentptr = comment;
+ *commentptr = dupstr(comment);
if (key)
- key->comment = comment;
+ 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;
}
/*
* Decrypt remainder of buffer.
*/
if (ciphertype) {
- MD5Init(&md5c);
- MD5Update(&md5c, passphrase, strlen(passphrase));
- MD5Final(keybuf, &md5c);
- des3_decrypt_pubkey(keybuf, buf+i, (len-i+7)&~7);
- memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
+ MD5Init(&md5c);
+ MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
+ MD5Final(keybuf, &md5c);
+ des3_decrypt_pubkey(keybuf, buf + i, (len - i + 7) & ~7);
+ smemclr(keybuf, sizeof(keybuf)); /* burn the evidence */
}
/*
* We are now in the secret part of the key. The first four
* bytes should be of the form a, b, a, b.
*/
- if (len-i < 4) goto end;
- if (buf[i] != buf[i+2] || buf[i+1] != buf[i+3]) { ret = -1; goto end; }
+ 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;
+ }
i += 4;
/*
* decryption exponent, and then the three auxiliary values
* (iqmp, q, p).
*/
- i += makeprivate(buf+i, key);
- if (len-i < 0) goto end;
- if (aux) {
- i += ssh1_read_bignum(buf+i, &aux->iqmp);
- if (len-i < 0) goto end;
- i += ssh1_read_bignum(buf+i, &aux->q);
- if (len-i < 0) goto end;
- i += ssh1_read_bignum(buf+i, &aux->p);
- if (len-i < 0) goto end;
- }
-
- ret = 1;
- end:
- memset(buf, 0, sizeof(buf)); /* burn the evidence */
+ 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:
+ smemclr(buf, sizeof(buf)); /* burn the evidence */
return ret;
}
-int loadrsakey(char *filename, struct RSAKey *key, struct RSAAux *aux,
- char *passphrase) {
+int loadrsakey(const Filename *filename, struct RSAKey *key, 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, aux, NULL, passphrase);
+ if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
+ /*
+ * 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 */
+ return 0; /* doesn't even exist */
/*
* 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, NULL, NULL, comment, NULL);
+ if (fgets(buf, sizeof(buf), fp) && !strcmp(buf, rsa_signature)) {
+ const char *dummy;
+ /*
+ * This routine will take care of calling fclose() for us.
+ */
+ return loadrsakey_main(fp, NULL, FALSE, comment, NULL, &dummy);
}
- return 0; /* wasn't the right kind of file */
+ fclose(fp);
+ return 0; /* wasn't the right kind of file */
+}
+
+/*
+ * Return a malloc'ed chunk of memory containing the public blob of
+ * an RSA key, as given in the agent protocol (modulus bits,
+ * exponent, modulus).
+ */
+int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
+ char **commentptr, const char **errorstr)
+{
+ FILE *fp;
+ char buf[64];
+ struct RSAKey key;
+ int ret;
+ const char *error = NULL;
+
+ /* Default return if we fail. */
+ *blob = NULL;
+ *bloblen = 0;
+ ret = 0;
+
+ 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)) {
+ memset(&key, 0, sizeof(key));
+ 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 {
+ error = "not an SSH-1 RSA file";
+ }
+
+ 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, struct RSAAux *aux,
- char *passphrase) {
+int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase)
+{
unsigned char buf[16384];
unsigned char keybuf[16];
struct MD5Context md5c;
- char *p, *estart;
+ unsigned char *p, *estart;
FILE *fp;
/*
* uint32.
*/
*p++ = (passphrase ? SSH_CIPHER_3DES : 0);
- PUT_32BIT(p, 0); p += 4;
+ PUT_32BIT(p, 0);
+ 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.
*/
- PUT_32BIT(p, ssh1_bignum_bitcount(key->modulus)); p += 4;
+ PUT_32BIT(p, bignum_bitcount(key->modulus));
+ p += 4;
p += ssh1_write_bignum(p, key->modulus);
p += ssh1_write_bignum(p, key->exponent);
* A string containing the comment field.
*/
if (key->comment) {
- PUT_32BIT(p, strlen(key->comment)); p += 4;
- memcpy(p, key->comment, strlen(key->comment));
- p += strlen(key->comment);
+ PUT_32BIT(p, strlen(key->comment));
+ p += 4;
+ memcpy(p, key->comment, strlen(key->comment));
+ p += strlen(key->comment);
} else {
- PUT_32BIT(p, 0); p += 4;
+ PUT_32BIT(p, 0);
+ p += 4;
}
/*
*/
*p++ = random_byte();
*p++ = random_byte();
- p[0] = p[-2]; p[1] = p[-1]; p += 2;
+ p[0] = p[-2];
+ p[1] = p[-1];
+ p += 2;
/*
* Four more bignums: the decryption exponent, then iqmp, then
* q, then p.
*/
p += ssh1_write_bignum(p, key->private_exponent);
- p += ssh1_write_bignum(p, aux->iqmp);
- p += ssh1_write_bignum(p, aux->q);
- p += ssh1_write_bignum(p, aux->p);
+ p += ssh1_write_bignum(p, key->iqmp);
+ p += ssh1_write_bignum(p, key->q);
+ p += ssh1_write_bignum(p, key->p);
/*
* Now write zeros until the encrypted portion is a multiple of
* 8 bytes.
*/
- while ((p-estart) % 8)
- *p++ = '\0';
+ while ((p - estart) % 8)
+ *p++ = '\0';
/*
* Now encrypt the encrypted portion.
*/
if (passphrase) {
- MD5Init(&md5c);
- MD5Update(&md5c, passphrase, strlen(passphrase));
- MD5Final(keybuf, &md5c);
- des3_encrypt_pubkey(keybuf, estart, p-estart);
- memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
+ MD5Init(&md5c);
+ MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
+ MD5Final(keybuf, &md5c);
+ des3_encrypt_pubkey(keybuf, estart, p - estart);
+ 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);
- return ret;
+ int ret = (fwrite(buf, 1, p - buf, fp) == (size_t) (p - buf));
+ if (fclose(fp))
+ ret = 0;
+ return ret;
+ } else
+ return 0;
+}
+
+/* ----------------------------------------------------------------------
+ * SSH-2 private key load/store functions.
+ */
+
+/*
+ * 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.
+ *
+ * The first line says "PuTTY-User-Key-File-2: " plus the name of the
+ * algorithm ("ssh-dss", "ssh-rsa" etc).
+ *
+ * The next line says "Encryption: " plus an encryption type.
+ * Currently the only supported encryption types are "aes256-cbc"
+ * and "none".
+ *
+ * The next line says "Comment: " plus the comment string.
+ *
+ * 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 SSH-2 public key
+ * blob (with no initial length): so for RSA, for example, it will
+ * read
+ *
+ * string "ssh-rsa"
+ * mpint exponent
+ * mpint modulus
+ *
+ * Next, there is a line saying "Private-Lines: " plus a number N,
+ * and then N lines containing the (potentially encrypted) private
+ * part of the key. For the key type "ssh-rsa", this will be
+ * composed of
+ *
+ * mpint private_exponent
+ * mpint p (the larger of the two primes)
+ * mpint q (the smaller prime)
+ * mpint iqmp (the inverse of q modulo p)
+ * data padding (to reach a multiple of the cipher block size)
+ *
+ * And for "ssh-dss", it will be composed of
+ *
+ * mpint x (the private key parameter)
+ * [ string hash 20-byte hash of mpints p || q || g only in old format ]
+ *
+ * Finally, there is a line saying "Private-MAC: " plus a hex
+ * representation of a HMAC-SHA-1 of:
+ *
+ * string name of algorithm ("ssh-dss", "ssh-rsa")
+ * string encryption type
+ * string comment
+ * string public-blob
+ * string private-plaintext (the plaintext version of the
+ * private part, including the final
+ * padding)
+ *
+ * The key to the MAC is itself a SHA-1 hash of:
+ *
+ * data "putty-private-key-file-mac-key"
+ * data passphrase
+ *
+ * (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
+ * is the hash of:
+ *
+ * uint32 sequence-number
+ * data passphrase
+ *
+ * where the sequence-number increases from zero. As many of these
+ * hashes are used as necessary.
+ *
+ * For backwards compatibility with snapshots between 0.51 and
+ * 0.52, we also support the older key file format, which begins
+ * 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, 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 (1) {
+ c = fgetc(fp);
+ if (c == '\n' || c == '\r' || c == EOF)
+ return 0; /* failure */
+ if (c == ':') {
+ c = fgetc(fp);
+ if (c != ' ')
+ return 0;
+ *header = '\0';
+ return 1; /* success! */
+ }
+ if (len == 0)
+ return 0; /* failure */
+ *header++ = c;
+ len--;
+ }
+ return 0; /* failure */
+}
+
+static char *read_body(FILE * fp)
+{
+ char *text;
+ int len;
+ int size;
+ int c;
+
+ size = 128;
+ text = snewn(size, char);
+ len = 0;
+ text[len] = '\0';
+
+ while (1) {
+ c = fgetc(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 (len + 1 >= size) {
+ size += 128;
+ 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 unsigned char *read_blob(FILE * fp, int nlines, int *bloblen)
+{
+ unsigned char *blob;
+ char *line;
+ int linelen, len;
+ int i, j, k;
+
+ /* We expect at most 64 base64 characters, ie 48 real bytes, per line. */
+ blob = snewn(48 * nlines, unsigned char);
+ len = 0;
+ for (i = 0; i < nlines; i++) {
+ line = read_body(fp);
+ if (!line) {
+ sfree(blob);
+ return NULL;
+ }
+ linelen = strlen(line);
+ if (linelen % 4 != 0 || linelen > 64) {
+ sfree(blob);
+ sfree(line);
+ return NULL;
+ }
+ for (j = 0; j < linelen; j += 4) {
+ k = base64_decode_atom(line + j, blob + len);
+ if (!k) {
+ sfree(line);
+ sfree(blob);
+ return NULL;
+ }
+ len += k;
+ }
+ sfree(line);
+ }
+ *bloblen = len;
+ return blob;
+}
+
+/*
+ * Magic error return value for when the passphrase is wrong.
+ */
+struct ssh2_userkey ssh2_wrong_passphrase = {
+ NULL, NULL, NULL
+};
+
+const struct ssh_signkey *find_pubkey_alg(const char *name)
+{
+ if (!strcmp(name, "ssh-rsa"))
+ return &ssh_rsa;
+ else if (!strcmp(name, "ssh-dss"))
+ return &ssh_dss;
+ else
+ return NULL;
+}
+
+struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
+ char *passphrase, const char **errorstr)
+{
+ FILE *fp;
+ char header[40], *b, *encryption, *comment, *mac;
+ const struct ssh_signkey *alg;
+ struct ssh2_userkey *ret;
+ int cipher, cipherblk;
+ unsigned char *public_blob, *private_blob;
+ 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 */
+ encryption = comment = mac = NULL;
+ public_blob = private_blob = NULL;
+
+ 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))
+ goto error;
+ if (0 == strcmp(header, "PuTTY-User-Key-File-2")) {
+ old_fmt = 0;
+ } else if (0 == strcmp(header, "PuTTY-User-Key-File-1")) {
+ /* this is an old key file; warn and then continue */
+ old_keyfile_warning();
+ old_fmt = 1;
+ } 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. */
+ alg = find_pubkey_alg(b);
+ if (!alg) {
+ sfree(b);
+ goto error;
+ }
+ sfree(b);
+
+ /* Read the Encryption header line. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
+ goto error;
+ if ((encryption = read_body(fp)) == NULL)
+ goto error;
+ if (!strcmp(encryption, "aes256-cbc")) {
+ cipher = 1;
+ cipherblk = 16;
+ } else if (!strcmp(encryption, "none")) {
+ cipher = 0;
+ cipherblk = 1;
+ } else {
+ goto error;
+ }
+
+ /* Read the Comment header line. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
+ goto error;
+ if ((comment = read_body(fp)) == NULL)
+ goto error;
+
+ /* Read the Public-Lines header line and the public blob. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Public-Lines"))
+ goto error;
+ if ((b = read_body(fp)) == NULL)
+ goto error;
+ i = atoi(b);
+ sfree(b);
+ if ((public_blob = read_blob(fp, i, &public_blob_len)) == NULL)
+ goto error;
+
+ /* Read the Private-Lines header line and the Private blob. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Private-Lines"))
+ goto error;
+ if ((b = read_body(fp)) == NULL)
+ goto error;
+ i = atoi(b);
+ sfree(b);
+ if ((private_blob = read_blob(fp, i, &private_blob_len)) == NULL)
+ goto error;
+
+ /* Read the Private-MAC or Private-Hash header line. */
+ if (!read_header(fp, header))
+ goto error;
+ if (0 == strcmp(header, "Private-MAC")) {
+ if ((mac = read_body(fp)) == NULL)
+ goto error;
+ is_mac = 1;
+ } else if (0 == strcmp(header, "Private-Hash") && old_fmt) {
+ if ((mac = read_body(fp)) == NULL)
+ goto error;
+ is_mac = 0;
} else
- return 0;
+ goto error;
+
+ fclose(fp);
+ fp = NULL;
+
+ /*
+ * Decrypt the private blob.
+ */
+ if (cipher) {
+ unsigned char key[40];
+ SHA_State s;
+
+ if (!passphrase)
+ goto error;
+ if (private_blob_len % cipherblk)
+ goto error;
+
+ SHA_Init(&s);
+ SHA_Bytes(&s, "\0\0\0\0", 4);
+ SHA_Bytes(&s, passphrase, passlen);
+ SHA_Final(&s, key + 0);
+ SHA_Init(&s);
+ SHA_Bytes(&s, "\0\0\0\1", 4);
+ SHA_Bytes(&s, passphrase, passlen);
+ SHA_Final(&s, key + 20);
+ aes256_decrypt_pubkey(key, private_blob, private_blob_len);
+ }
+
+ /*
+ * Verify the MAC.
+ */
+ {
+ char realmac[41];
+ unsigned char binary[20];
+ unsigned char *macdata;
+ int maclen;
+ int free_macdata;
+
+ if (old_fmt) {
+ /* MAC (or hash) only covers the private blob. */
+ macdata = private_blob;
+ maclen = private_blob_len;
+ free_macdata = 0;
+ } else {
+ unsigned char *p;
+ int namelen = strlen(alg->name);
+ int enclen = strlen(encryption);
+ int commlen = strlen(comment);
+ maclen = (4 + namelen +
+ 4 + enclen +
+ 4 + commlen +
+ 4 + public_blob_len +
+ 4 + private_blob_len);
+ 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);
+ DO_STR(encryption, enclen);
+ DO_STR(comment, commlen);
+ DO_STR(public_blob, public_blob_len);
+ DO_STR(private_blob, private_blob_len);
+
+ free_macdata = 1;
+ }
+
+ if (is_mac) {
+ SHA_State s;
+ unsigned char mackey[20];
+ char header[] = "putty-private-key-file-mac-key";
+
+ SHA_Init(&s);
+ SHA_Bytes(&s, header, sizeof(header)-1);
+ if (cipher && passphrase)
+ SHA_Bytes(&s, passphrase, passlen);
+ SHA_Final(&s, mackey);
+
+ hmac_sha1_simple(mackey, 20, macdata, maclen, binary);
+
+ smemclr(mackey, sizeof(mackey));
+ smemclr(&s, sizeof(s));
+ } else {
+ SHA_Simple(macdata, maclen, binary);
+ }
+
+ if (free_macdata) {
+ smemclr(macdata, maclen);
+ sfree(macdata);
+ }
+
+ for (i = 0; i < 20; i++)
+ sprintf(realmac + 2 * i, "%02x", binary[i]);
+
+ if (strcmp(mac, realmac)) {
+ /* An incorrect MAC is an unconditional Error if the key is
+ * unencrypted. Otherwise, it means Wrong Passphrase. */
+ if (cipher) {
+ error = "wrong passphrase";
+ ret = SSH2_WRONG_PASSPHRASE;
+ } else {
+ error = "MAC failed";
+ ret = NULL;
+ }
+ goto error;
+ }
+ }
+ sfree(mac);
+
+ /*
+ * Create and return the key.
+ */
+ ret = snew(struct ssh2_userkey);
+ ret->alg = alg;
+ ret->comment = comment;
+ ret->data = alg->createkey(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);
+ sfree(private_blob);
+ sfree(encryption);
+ if (errorstr)
+ *errorstr = NULL;
+ return ret;
+
+ /*
+ * Error processing.
+ */
+ error:
+ if (fp)
+ fclose(fp);
+ if (comment)
+ sfree(comment);
+ if (encryption)
+ sfree(encryption);
+ if (mac)
+ sfree(mac);
+ if (public_blob)
+ sfree(public_blob);
+ if (private_blob)
+ sfree(private_blob);
+ if (errorstr)
+ *errorstr = error;
+ return ret;
+}
+
+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;
+ const char *error = NULL;
+ char *comment;
+
+ public_blob = NULL;
+
+ 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)
+ || (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
+ 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. */
+ alg = find_pubkey_alg(b);
+ if (!alg) {
+ sfree(b);
+ goto error;
+ }
+ sfree(b);
+
+ /* Read the Encryption header line. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Encryption"))
+ goto error;
+ if ((b = read_body(fp)) == NULL)
+ goto error;
+ sfree(b); /* we don't care */
+
+ /* Read the Comment header line. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Comment"))
+ goto error;
+ if ((comment = read_body(fp)) == NULL)
+ goto error;
+
+ 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"))
+ goto error;
+ if ((b = read_body(fp)) == NULL)
+ goto error;
+ i = atoi(b);
+ sfree(b);
+ if ((public_blob = read_blob(fp, i, &public_blob_len)) == NULL)
+ goto error;
+
+ fclose(fp);
+ if (pub_blob_len)
+ *pub_blob_len = public_blob_len;
+ if (algorithm)
+ *algorithm = alg->name;
+ return public_blob;
+
+ /*
+ * Error processing.
+ */
+ error:
+ if (fp)
+ fclose(fp);
+ if (public_blob)
+ sfree(public_blob);
+ if (errorstr)
+ *errorstr = error;
+ return NULL;
+}
+
+int ssh2_userkey_encrypted(const Filename *filename, char **commentptr)
+{
+ FILE *fp;
+ char header[40], *b, *comment;
+ int ret;
+
+ if (commentptr)
+ *commentptr = NULL;
+
+ fp = f_open(filename, "rb", FALSE);
+ if (!fp)
+ return 0;
+ if (!read_header(fp, header)
+ || (0 != strcmp(header, "PuTTY-User-Key-File-2") &&
+ 0 != strcmp(header, "PuTTY-User-Key-File-1"))) {
+ fclose(fp);
+ return 0;
+ }
+ if ((b = read_body(fp)) == NULL) {
+ fclose(fp);
+ return 0;
+ }
+ sfree(b); /* we don't care about key type here */
+ /* Read the Encryption header line. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Encryption")) {
+ fclose(fp);
+ return 0;
+ }
+ if ((b = read_body(fp)) == NULL) {
+ fclose(fp);
+ return 0;
+ }
+
+ /* Read the Comment header line. */
+ if (!read_header(fp, header) || 0 != strcmp(header, "Comment")) {
+ fclose(fp);
+ sfree(b);
+ return 1;
+ }
+ if ((comment = read_body(fp)) == NULL) {
+ fclose(fp);
+ sfree(b);
+ return 1;
+ }
+
+ if (commentptr)
+ *commentptr = comment;
+ else
+ sfree(comment);
+
+ fclose(fp);
+ if (!strcmp(b, "aes256-cbc"))
+ ret = 1;
+ else
+ ret = 0;
+ sfree(b);
+ return ret;
+}
+
+int base64_lines(int datalen)
+{
+ /* When encoding, we use 64 chars/line, which equals 48 real chars. */
+ return (datalen + 47) / 48;
+}
+
+void base64_encode(FILE * fp, unsigned char *data, int datalen, int cpl)
+{
+ int linelen = 0;
+ char out[4];
+ int n, i;
+
+ while (datalen > 0) {
+ n = (datalen < 3 ? datalen : 3);
+ base64_encode_atom(data, n, out);
+ data += n;
+ datalen -= n;
+ 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(const Filename *filename, struct ssh2_userkey *key,
+ char *passphrase)
+{
+ FILE *fp;
+ unsigned char *pub_blob, *priv_blob, *priv_blob_encrypted;
+ int pub_blob_len, priv_blob_len, priv_encrypted_len;
+ int passlen;
+ int cipherblk;
+ int i;
+ char *cipherstr;
+ unsigned char priv_mac[20];
+
+ /*
+ * Fetch the key component blobs.
+ */
+ pub_blob = key->alg->public_blob(key->data, &pub_blob_len);
+ priv_blob = key->alg->private_blob(key->data, &priv_blob_len);
+ if (!pub_blob || !priv_blob) {
+ sfree(pub_blob);
+ sfree(priv_blob);
+ return 0;
+ }
+
+ /*
+ * Determine encryption details, and encrypt the private blob.
+ */
+ if (passphrase) {
+ cipherstr = "aes256-cbc";
+ cipherblk = 16;
+ } else {
+ cipherstr = "none";
+ cipherblk = 1;
+ }
+ priv_encrypted_len = priv_blob_len + cipherblk - 1;
+ priv_encrypted_len -= priv_encrypted_len % cipherblk;
+ 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
+ * too easy a known-plaintext attack on the last block. */
+ SHA_Simple(priv_blob, priv_blob_len, priv_mac);
+ assert(priv_encrypted_len - priv_blob_len < 20);
+ memcpy(priv_blob_encrypted + priv_blob_len, priv_mac,
+ priv_encrypted_len - priv_blob_len);
+
+ /* Now create the MAC. */
+ {
+ unsigned char *macdata;
+ int maclen;
+ unsigned char *p;
+ int namelen = strlen(key->alg->name);
+ int enclen = strlen(cipherstr);
+ int commlen = strlen(key->comment);
+ SHA_State s;
+ unsigned char mackey[20];
+ char header[] = "putty-private-key-file-mac-key";
+
+ maclen = (4 + namelen +
+ 4 + enclen +
+ 4 + commlen +
+ 4 + pub_blob_len +
+ 4 + priv_encrypted_len);
+ 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);
+ DO_STR(cipherstr, enclen);
+ DO_STR(key->comment, commlen);
+ DO_STR(pub_blob, pub_blob_len);
+ DO_STR(priv_blob_encrypted, priv_encrypted_len);
+
+ SHA_Init(&s);
+ SHA_Bytes(&s, header, sizeof(header)-1);
+ if (passphrase)
+ SHA_Bytes(&s, passphrase, strlen(passphrase));
+ SHA_Final(&s, mackey);
+ hmac_sha1_simple(mackey, 20, macdata, maclen, priv_mac);
+ smemclr(macdata, maclen);
+ sfree(macdata);
+ smemclr(mackey, sizeof(mackey));
+ smemclr(&s, sizeof(s));
+ }
+
+ if (passphrase) {
+ unsigned char key[40];
+ SHA_State s;
+
+ passlen = strlen(passphrase);
+
+ SHA_Init(&s);
+ SHA_Bytes(&s, "\0\0\0\0", 4);
+ SHA_Bytes(&s, passphrase, passlen);
+ SHA_Final(&s, key + 0);
+ SHA_Init(&s);
+ SHA_Bytes(&s, "\0\0\0\1", 4);
+ SHA_Bytes(&s, passphrase, passlen);
+ SHA_Final(&s, key + 20);
+ aes256_encrypt_pubkey(key, priv_blob_encrypted,
+ priv_encrypted_len);
+
+ smemclr(key, sizeof(key));
+ smemclr(&s, sizeof(s));
+ }
+
+ fp = f_open(filename, "w", TRUE);
+ if (!fp)
+ 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, 64);
+ fprintf(fp, "Private-Lines: %d\n", base64_lines(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]);
+ fprintf(fp, "\n");
+ fclose(fp);
+
+ sfree(pub_blob);
+ smemclr(priv_blob, priv_blob_len);
+ sfree(priv_blob);
+ sfree(priv_blob_encrypted);
+ return 1;
+}
+
+/* ----------------------------------------------------------------------
+ * A function to determine the type of a private key file. Returns
+ * 0 on failure, 1 or 2 on success.
+ */
+int key_type(const Filename *filename)
+{
+ FILE *fp;
+ char buf[32];
+ const char putty2_sig[] = "PuTTY-User-Key-File-";
+ const char sshcom_sig[] = "---- BEGIN SSH2 ENCRYPTED PRIVAT";
+ const char openssh_sig[] = "-----BEGIN ";
+ int i;
+
+ fp = f_open(filename, "r", FALSE);
+ if (!fp)
+ return SSH_KEYTYPE_UNOPENABLE;
+ i = fread(buf, 1, sizeof(buf), fp);
+ fclose(fp);
+ if (i < 0)
+ return SSH_KEYTYPE_UNOPENABLE;
+ if (i < 32)
+ return SSH_KEYTYPE_UNKNOWN;
+ if (!memcmp(buf, rsa_signature, sizeof(rsa_signature)-1))
+ return SSH_KEYTYPE_SSH1;
+ if (!memcmp(buf, putty2_sig, sizeof(putty2_sig)-1))
+ return SSH_KEYTYPE_SSH2;
+ if (!memcmp(buf, openssh_sig, sizeof(openssh_sig)-1))
+ return SSH_KEYTYPE_OPENSSH;
+ if (!memcmp(buf, sshcom_sig, sizeof(sshcom_sig)-1))
+ return SSH_KEYTYPE_SSHCOM;
+ return SSH_KEYTYPE_UNKNOWN; /* unrecognised or EOF */
+}
+
+/*
+ * Convert the type word to a string, for `wrong type' error
+ * messages.
+ */
+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 private key"; 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: return "OpenSSH SSH-2 private key"; break;
+ case SSH_KEYTYPE_SSHCOM: return "ssh.com SSH-2 private key"; break;
+ default: return "INTERNAL ERROR"; break;
+ }
}
projects / u / mdw / putty / blobdiff