diff options
Diffstat (limited to 'tools/plink/sshpubk.c')
| -rw-r--r-- | tools/plink/sshpubk.c | 1217 |
1 files changed, 0 insertions, 1217 deletions
diff --git a/tools/plink/sshpubk.c b/tools/plink/sshpubk.c deleted file mode 100644 index 7b5a69071..000000000 --- a/tools/plink/sshpubk.c +++ /dev/null @@ -1,1217 +0,0 @@ -/*
- * Generic SSH public-key handling operations. In particular,
- * reading of SSH public-key files, and also the generic `sign'
- * 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"
-#include "misc.h"
-
-#define rsa_signature "SSH PRIVATE KEY FILE FORMAT 1.1\n"
-
-#define BASE64_TOINT(x) ( (x)-'A'<26 ? (x)-'A'+0 :\
- (x)-'a'<26 ? (x)-'a'+26 :\
- (x)-'0'<10 ? (x)-'0'+52 :\
- (x)=='+' ? 62 : \
- (x)=='/' ? 63 : 0 )
-
-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;
- int i, j, ciphertype;
- int ret = 0;
- 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)) {
- *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;
- i++;
-
- /* One byte giving encryption type, and one reserved uint32. */
- if (len - i < 1)
- goto end;
- ciphertype = buf[i];
- if (ciphertype != 0 && ciphertype != SSH_CIPHER_3DES)
- 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! */
- i += 4;
-
- /* Now the serious stuff. An ordinary SSH-1 public key. */
- i += makekey(buf + i, len, key, NULL, 1);
- if (i < 0)
- goto end; /* overran */
-
- /* Next, the comment field. */
- j = GET_32BIT(buf + i);
- i += 4;
- if (len - i < j)
- goto end;
- comment = snewn(j + 1, char);
- if (comment) {
- memcpy(comment, buf + i, j);
- comment[j] = '\0';
- }
- i += j;
- if (commentptr)
- *commentptr = dupstr(comment);
- if (key)
- key->comment = comment;
- else
- sfree(comment);
-
- if (pub_only) {
- ret = 1;
- goto end;
- }
-
- if (!key) {
- ret = ciphertype != 0;
- *error = NULL;
- goto end;
- }
-
- /*
- * Decrypt remainder of buffer.
- */
- if (ciphertype) {
- MD5Init(&md5c);
- 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 */
- }
-
- /*
- * 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]) {
- *error = "wrong passphrase";
- ret = -1;
- goto end;
- }
- i += 4;
-
- /*
- * After that, we have one further bignum which is our
- * decryption exponent, and then the three auxiliary values
- * (iqmp, q, p).
- */
- 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 */
- return ret;
-}
-
-int loadrsakey(const Filename *filename, struct RSAKey *key, char *passphrase,
- const char **errorstr)
-{
- FILE *fp;
- char buf[64];
- int ret = 0;
- const char *error = NULL;
-
- 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)) {
- /*
- * 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.
- */
- 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(const Filename *filename, char **comment)
-{
- FILE *fp;
- char buf[64];
-
- fp = f_open(*filename, "rb", FALSE);
- if (!fp)
- 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)) {
- 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 */
-}
-
-/*
- * 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;
- }
- } 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(const Filename *filename, struct RSAKey *key, char *passphrase)
-{
- unsigned char buf[16384];
- unsigned char keybuf[16];
- struct MD5Context md5c;
- unsigned char *p, *estart;
- FILE *fp;
-
- /*
- * Write the initial signature.
- */
- p = buf;
- memcpy(p, rsa_signature, sizeof(rsa_signature));
- p += sizeof(rsa_signature);
-
- /*
- * One byte giving encryption type, and one reserved (zero)
- * uint32.
- */
- *p++ = (passphrase ? SSH_CIPHER_3DES : 0);
- PUT_32BIT(p, 0);
- p += 4;
-
- /*
- * 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, 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);
- } else {
- PUT_32BIT(p, 0);
- p += 4;
- }
-
- /*
- * The encrypted portion starts here.
- */
- estart = p;
-
- /*
- * Two bytes, then the same two bytes repeated.
- */
- *p++ = random_byte();
- *p++ = random_byte();
- 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, 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';
-
- /*
- * Now encrypt the encrypted portion.
- */
- if (passphrase) {
- MD5Init(&md5c);
- 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 */
- }
-
- /*
- * Done. Write the result to the file.
- */
- fp = f_open(*filename, "wb", TRUE);
- if (fp) {
- 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 (len > 0) {
- 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 {
- 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 {
- sfree(encryption);
- 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
- 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);
-
- memset(mackey, 0, sizeof(mackey));
- memset(&s, 0, sizeof(s));
- } else {
- SHA_Simple(macdata, maclen, binary);
- }
-
- if (free_macdata) {
- memset(macdata, 0, 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"))) {
- 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;
-
- 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);
- memset(macdata, 0, maclen);
- sfree(macdata);
- memset(mackey, 0, sizeof(mackey));
- memset(&s, 0, 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);
-
- memset(key, 0, sizeof(key));
- memset(&s, 0, 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);
- memset(priv_blob, 0, 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;
- }
-}
|