X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/blobdiff_plain/c6940f12e2ad6ba778324f50b9a779db36238518..ebbc254d829ca8d52add37b57a7149126a4c5fed:/import.c

diff --git a/import.c b/import.c
index a3c24050..05cfdc14 100644
--- a/import.c
+++ b/import.c
@@ -308,9 +308,10 @@ static int ssh2_read_mpint(void *data, int len, struct mpint_pos *ret)
  */
 
 enum { OSSH_DSA, OSSH_RSA };
+enum { OSSH_ENC_3DES, OSSH_ENC_AES };
 struct openssh_key {
     int type;
-    int encrypted;
+    int encrypted, encryption;
     char iv[32];
     unsigned char *keyblob;
     int keyblob_len, keyblob_size;
@@ -333,7 +334,7 @@ static struct openssh_key *load_openssh_key(const Filename *filename,
     ret->encrypted = 0;
     memset(ret->iv, 0, sizeof(ret->iv));
 
-    fp = f_open(*filename, "r", FALSE);
+    fp = f_open(filename, "r", FALSE);
     if (!fp) {
 	errmsg = "unable to open key file";
 	goto error;
@@ -357,7 +358,7 @@ static struct openssh_key *load_openssh_key(const Filename *filename,
 	errmsg = "unrecognised key type";
 	goto error;
     }
-    memset(line, 0, strlen(line));
+    smemclr(line, strlen(line));
     sfree(line);
     line = NULL;
 
@@ -387,21 +388,29 @@ static struct openssh_key *load_openssh_key(const Filename *filename,
 		if (!strcmp(p, "ENCRYPTED"))
 		    ret->encrypted = 1;
 	    } else if (!strcmp(line, "DEK-Info")) {
-		int i, j;
-
-		if (strncmp(p, "DES-EDE3-CBC,", 13)) {
-		    errmsg = "ciphers other than DES-EDE3-CBC not supported";
+		int i, j, ivlen;
+
+		if (!strncmp(p, "DES-EDE3-CBC,", 13)) {
+		    ret->encryption = OSSH_ENC_3DES;
+		    ivlen = 8;
+		} else if (!strncmp(p, "AES-128-CBC,", 12)) {
+		    ret->encryption = OSSH_ENC_AES;
+		    ivlen = 16;
+		} else {
+		    errmsg = "unsupported cipher";
 		    goto error;
 		}
-		p += 13;
-		for (i = 0; i < 8; i++) {
-		    if (1 != sscanf(p, "%2x", &j))
-			break;
+		p = strchr(p, ',') + 1;/* always non-NULL, by above checks */
+		for (i = 0; i < ivlen; i++) {
+		    if (1 != sscanf(p, "%2x", &j)) {
+			errmsg = "expected more iv data in DEK-Info";
+			goto error;
+		    }
 		    ret->iv[i] = j;
 		    p += 2;
 		}
-		if (i < 8) {
-		    errmsg = "expected 16-digit iv in DEK-Info";
+		if (*p) {
+		    errmsg = "more iv data than expected in DEK-Info";
 		    goto error;
 		}
 	    }
@@ -433,13 +442,13 @@ static struct openssh_key *load_openssh_key(const Filename *filename,
                     memcpy(ret->keyblob + ret->keyblob_len, out, len);
                     ret->keyblob_len += len;
 
-                    memset(out, 0, sizeof(out));
+                    smemclr(out, sizeof(out));
                 }
 
 		p++;
 	    }
 	}
-	memset(line, 0, strlen(line));
+	smemclr(line, strlen(line));
 	sfree(line);
 	line = NULL;
     }
@@ -454,23 +463,23 @@ static struct openssh_key *load_openssh_key(const Filename *filename,
 	goto error;
     }
 
-    memset(base64_bit, 0, sizeof(base64_bit));
+    smemclr(base64_bit, sizeof(base64_bit));
     if (errmsg_p) *errmsg_p = NULL;
     return ret;
 
     error:
     if (line) {
-	memset(line, 0, strlen(line));
+	smemclr(line, strlen(line));
 	sfree(line);
 	line = NULL;
     }
-    memset(base64_bit, 0, sizeof(base64_bit));
+    smemclr(base64_bit, sizeof(base64_bit));
     if (ret) {
 	if (ret->keyblob) {
-            memset(ret->keyblob, 0, ret->keyblob_size);
+            smemclr(ret->keyblob, ret->keyblob_size);
             sfree(ret->keyblob);
         }
-        memset(ret, 0, sizeof(*ret));
+        smemclr(ret, sizeof(*ret));
 	sfree(ret);
     }
     if (errmsg_p) *errmsg_p = errmsg;
@@ -485,9 +494,9 @@ int openssh_encrypted(const Filename *filename)
     if (!key)
 	return 0;
     ret = key->encrypted;
-    memset(key->keyblob, 0, key->keyblob_size);
+    smemclr(key->keyblob, key->keyblob_size);
     sfree(key->keyblob);
-    memset(key, 0, sizeof(*key));
+    smemclr(key, sizeof(*key));
     sfree(key);
     return ret;
 }
@@ -520,6 +529,10 @@ struct ssh2_userkey *openssh_read(const Filename *filename, char *passphrase,
 	 *  - let block B equal MD5(A || passphrase || iv)
 	 *  - block C would be MD5(B || passphrase || iv) and so on
 	 *  - encryption key is the first N bytes of A || B
+	 *
+	 * (Note that only 8 bytes of the iv are used for key
+	 * derivation, even when the key is encrypted with AES and
+	 * hence there are 16 bytes available.)
 	 */
 	struct MD5Context md5c;
 	unsigned char keybuf[32];
@@ -538,11 +551,21 @@ struct ssh2_userkey *openssh_read(const Filename *filename, char *passphrase,
 	/*
 	 * Now decrypt the key blob.
 	 */
-	des3_decrypt_pubkey_ossh(keybuf, (unsigned char *)key->iv,
-				 key->keyblob, key->keyblob_len);
+	if (key->encryption == OSSH_ENC_3DES)
+	    des3_decrypt_pubkey_ossh(keybuf, (unsigned char *)key->iv,
+				     key->keyblob, key->keyblob_len);
+	else {
+	    void *ctx;
+	    assert(key->encryption == OSSH_ENC_AES);
+	    ctx = aes_make_context();
+	    aes128_key(ctx, keybuf);
+	    aes_iv(ctx, (unsigned char *)key->iv);
+	    aes_ssh2_decrypt_blk(ctx, key->keyblob, key->keyblob_len);
+	    aes_free_context(ctx);
+	}
 
-        memset(&md5c, 0, sizeof(md5c));
-        memset(keybuf, 0, sizeof(keybuf));
+        smemclr(&md5c, sizeof(md5c));
+        smemclr(keybuf, sizeof(keybuf));
     }
 
     /*
@@ -675,12 +698,12 @@ struct ssh2_userkey *openssh_read(const Filename *filename, char *passphrase,
 
     error:
     if (blob) {
-        memset(blob, 0, blobsize);
+        smemclr(blob, blobsize);
         sfree(blob);
     }
-    memset(key->keyblob, 0, key->keyblob_size);
+    smemclr(key->keyblob, key->keyblob_size);
     sfree(key->keyblob);
-    memset(key, 0, sizeof(*key));
+    smemclr(key, sizeof(*key));
     sfree(key);
     if (errmsg_p) *errmsg_p = errmsg;
     return retval;
@@ -853,6 +876,9 @@ int openssh_write(const Filename *filename, struct ssh2_userkey *key,
 
     /*
      * Encrypt the key.
+     *
+     * For the moment, we still encrypt our OpenSSH keys using
+     * old-style 3DES.
      */
     if (passphrase) {
 	/*
@@ -885,15 +911,15 @@ int openssh_write(const Filename *filename, struct ssh2_userkey *key,
 	 */
 	des3_encrypt_pubkey_ossh(keybuf, iv, outblob, outlen);
 
-        memset(&md5c, 0, sizeof(md5c));
-        memset(keybuf, 0, sizeof(keybuf));
+        smemclr(&md5c, sizeof(md5c));
+        smemclr(keybuf, sizeof(keybuf));
     }
 
     /*
      * And save it. We'll use Unix line endings just in case it's
      * subsequently transferred in binary mode.
      */
-    fp = f_open(*filename, "wb", TRUE);      /* ensure Unix line endings */
+    fp = f_open(filename, "wb", TRUE);      /* ensure Unix line endings */
     if (!fp)
 	goto error;
     fputs(header, fp);
@@ -910,19 +936,19 @@ int openssh_write(const Filename *filename, struct ssh2_userkey *key,
 
     error:
     if (outblob) {
-        memset(outblob, 0, outlen);
+        smemclr(outblob, outlen);
         sfree(outblob);
     }
     if (spareblob) {
-        memset(spareblob, 0, sparelen);
+        smemclr(spareblob, sparelen);
         sfree(spareblob);
     }
     if (privblob) {
-        memset(privblob, 0, privlen);
+        smemclr(privblob, privlen);
         sfree(privblob);
     }
     if (pubblob) {
-        memset(pubblob, 0, publen);
+        smemclr(pubblob, publen);
         sfree(pubblob);
     }
     return ret;
@@ -1027,7 +1053,7 @@ static struct sshcom_key *load_sshcom_key(const Filename *filename,
     ret->keyblob = NULL;
     ret->keyblob_len = ret->keyblob_size = 0;
 
-    fp = f_open(*filename, "r", FALSE);
+    fp = f_open(filename, "r", FALSE);
     if (!fp) {
 	errmsg = "unable to open key file";
 	goto error;
@@ -1041,7 +1067,7 @@ static struct sshcom_key *load_sshcom_key(const Filename *filename,
 	errmsg = "file does not begin with ssh.com key header";
 	goto error;
     }
-    memset(line, 0, strlen(line));
+    smemclr(line, strlen(line));
     sfree(line);
     line = NULL;
 
@@ -1086,7 +1112,7 @@ static struct sshcom_key *load_sshcom_key(const Filename *filename,
 		len += line2len - 1;
 		assert(!line[len]);
 
-		memset(line2, 0, strlen(line2));
+		smemclr(line2, strlen(line2));
 		sfree(line2);
 		line2 = NULL;
             }
@@ -1132,7 +1158,7 @@ static struct sshcom_key *load_sshcom_key(const Filename *filename,
 		p++;
 	    }
 	}
-	memset(line, 0, strlen(line));
+	smemclr(line, strlen(line));
 	sfree(line);
 	line = NULL;
     }
@@ -1147,16 +1173,16 @@ static struct sshcom_key *load_sshcom_key(const Filename *filename,
 
     error:
     if (line) {
-	memset(line, 0, strlen(line));
+	smemclr(line, strlen(line));
 	sfree(line);
 	line = NULL;
     }
     if (ret) {
 	if (ret->keyblob) {
-            memset(ret->keyblob, 0, ret->keyblob_size);
+            smemclr(ret->keyblob, ret->keyblob_size);
             sfree(ret->keyblob);
         }
-        memset(ret, 0, sizeof(*ret));
+        smemclr(ret, sizeof(*ret));
 	sfree(ret);
     }
     if (errmsg_p) *errmsg_p = errmsg;
@@ -1196,9 +1222,9 @@ int sshcom_encrypted(const Filename *filename, char **comment)
 
     done:
     *comment = dupstr(key->comment);
-    memset(key->keyblob, 0, key->keyblob_size);
+    smemclr(key->keyblob, key->keyblob_size);
     sfree(key->keyblob);
-    memset(key, 0, sizeof(*key));
+    smemclr(key, sizeof(*key));
     sfree(key);
     return answer;
 }
@@ -1364,8 +1390,8 @@ struct ssh2_userkey *sshcom_read(const Filename *filename, char *passphrase,
 	des3_decrypt_pubkey_ossh(keybuf, iv, (unsigned char *)ciphertext,
 				 cipherlen);
 
-        memset(&md5c, 0, sizeof(md5c));
-        memset(keybuf, 0, sizeof(keybuf));
+        smemclr(&md5c, sizeof(md5c));
+        smemclr(keybuf, sizeof(keybuf));
 
         /*
          * Hereafter we return WRONG_PASSPHRASE for any parsing
@@ -1468,12 +1494,12 @@ struct ssh2_userkey *sshcom_read(const Filename *filename, char *passphrase,
 
     error:
     if (blob) {
-        memset(blob, 0, blobsize);
+        smemclr(blob, blobsize);
         sfree(blob);
     }
-    memset(key->keyblob, 0, key->keyblob_size);
+    smemclr(key->keyblob, key->keyblob_size);
     sfree(key->keyblob);
-    memset(key, 0, sizeof(*key));
+    smemclr(key, sizeof(*key));
     sfree(key);
     if (errmsg_p) *errmsg_p = errmsg;
     return ret;
@@ -1638,15 +1664,15 @@ int sshcom_write(const Filename *filename, struct ssh2_userkey *key,
 	des3_encrypt_pubkey_ossh(keybuf, iv, (unsigned char *)ciphertext,
 				 cipherlen);
 
-        memset(&md5c, 0, sizeof(md5c));
-        memset(keybuf, 0, sizeof(keybuf));
+        smemclr(&md5c, sizeof(md5c));
+        smemclr(keybuf, sizeof(keybuf));
     }
 
     /*
      * And save it. We'll use Unix line endings just in case it's
      * subsequently transferred in binary mode.
      */
-    fp = f_open(*filename, "wb", TRUE);      /* ensure Unix line endings */
+    fp = f_open(filename, "wb", TRUE);      /* ensure Unix line endings */
     if (!fp)
 	goto error;
     fputs("---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----\n", fp);
@@ -1674,15 +1700,15 @@ int sshcom_write(const Filename *filename, struct ssh2_userkey *key,
 
     error:
     if (outblob) {
-        memset(outblob, 0, outlen);
+        smemclr(outblob, outlen);
         sfree(outblob);
     }
     if (privblob) {
-        memset(privblob, 0, privlen);
+        smemclr(privblob, privlen);
         sfree(privblob);
     }
     if (pubblob) {
-        memset(pubblob, 0, publen);
+        smemclr(pubblob, publen);
         sfree(pubblob);
     }
     return ret;