+ 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;
+}
+
+char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
+ int *pub_blob_len, 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;
+
+ public_blob = NULL;
+
+ fp = f_open(*filename, "rb");
+ 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. Currently only ssh-rsa. */
+ 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 ((b = read_body(fp)) == NULL)
+ goto error;
+ sfree(b); /* we don't care */
+
+ /* 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 (char *)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");
+ 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");
+ 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");
+ 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 "SSH1 private key"; break;
+ case SSH_KEYTYPE_SSH2: return "PuTTY SSH2 private key"; break;
+ case SSH_KEYTYPE_OPENSSH: return "OpenSSH SSH2 private key"; break;
+ case SSH_KEYTYPE_SSHCOM: return "ssh.com SSH2 private key"; break;
+ default: return "INTERNAL ERROR"; break;
+ }