/*
- * Read SSH public keys from files.
- *
- * First implementation: only supports unencrypted SSH 1.1 format
- * RSA keys. Encryption, and SSH 2 DSS keys, to be supported later.
+ * 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
+ * dispatches to the appropriate key-type specific function).
*/
#include <stdio.h>
-
-#include <stdio.h> /* FIXME */
-#include <stdarg.h> /* FIXME */
-#include <windows.h> /* FIXME */
-#include "putty.h" /* FIXME */
+#include <stdlib.h>
#include "ssh.h"
#define rsa_signature "SSH PRIVATE KEY FILE FORMAT 1.1\n"
-int loadrsakey(char *filename, struct RSAKey *key, char *passphrase) {
- FILE *fp;
+#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,
+ char **commentptr, char *passphrase) {
unsigned char buf[16384];
unsigned char keybuf[16];
int len;
int i, j, ciphertype;
int ret = 0;
struct MD5Context md5c;
+ char *comment;
- fp = fopen(filename, "rb");
- if (!fp)
- goto end;
-
- /* Slurp the whole file into a buffer. */
+ /* 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 < sizeof(rsa_signature) ||
- memcmp(buf, rsa_signature, sizeof(rsa_signature)) != 0)
- goto end; /* failure to have sig at front */
+ i = 0;
- i = sizeof(rsa_signature);
+ /*
+ * A zero byte. (The signature includes a terminating NUL.)
+ */
+ if (len-i < 1 || buf[i] != 0)
+ goto end;
+ i++;
- /* Next, one byte giving encryption type, and one reserved uint32. */
+ /* One byte giving encryption type, and one reserved uint32. */
if (len-i < 1)
goto end;
ciphertype = buf[i];
/* Next, the comment field. */
j = GET_32BIT(buf+i);
- if (len-i < 4+j) goto end; i += 4+j;
- /*
- * FIXME: might need to use this string.
- */
+ i += 4;
+ if (len-i < j) goto end;
+ comment = malloc(j+1);
+ if (comment) {
+ memcpy(comment, buf+i, j);
+ comment[j] = '\0';
+ }
+ i += j;
+ if (commentptr)
+ *commentptr = comment;
+ if (key)
+ key->comment = comment;
+ if (!key) {
+ return ciphertype != 0;
+ }
/*
* Decrypt remainder of buffer.
MD5Update(&md5c, passphrase, strlen(passphrase));
MD5Final(keybuf, &md5c);
des3_decrypt_pubkey(keybuf, buf+i, (len-i+7)&~7);
- memset(keybuf, 0, sizeof(buf)); /* burn the evidence */
+ memset(keybuf, 0, sizeof(keybuf)); /* burn the evidence */
}
/*
return ret;
}
-/*
- * See whether an RSA key is encrypted.
- */
-int rsakey_encrypted(char *filename) {
+int loadrsakey(char *filename, struct RSAKey *key, char *passphrase) {
FILE *fp;
- unsigned char buf[1+sizeof(rsa_signature)];
- int len;
+ unsigned char buf[64];
fp = fopen(filename, "rb");
if (!fp)
return 0; /* doesn't even exist */
- /* Slurp the whole file into a buffer. */
- len = fread(buf, 1, sizeof(buf), fp);
+ /*
+ * 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, NULL, passphrase);
+ }
+
+ /*
+ * Otherwise, we have nothing. Return empty-handed.
+ */
fclose(fp);
- if (len < sizeof(buf))
- return 0; /* not even valid */
- if (buf[sizeof(buf)-1])
- return 1; /* encrypted */
return 0;
}
+
+/*
+ * See whether an RSA key is encrypted. Return its comment field as
+ * well.
+ */
+int rsakey_encrypted(char *filename, char **comment) {
+ FILE *fp;
+ unsigned char buf[64];
+
+ fp = fopen(filename, "rb");
+ 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)) {
+ return loadrsakey_main(fp, NULL, comment, NULL);
+ }
+ return 0; /* wasn't the right kind of file */
+}