Major new upstream release, just ran svn-upgrade for now (and wrote some

debian/changelong entries).

1 files changed, 366 insertions, 0 deletions

diff --git a/src/libstrongswan/asn1/pem.c b/src/libstrongswan/asn1/pem.c
new file mode 100755
index 000000000..e88db249d
--- /dev/null
+++ b/src/libstrongswan/asn1/pem.c
@@ -0,0 +1,366 @@
+/*
+ * Copyright (C) 2001-2004 Andreas Steffen, Zuercher Hochschule Winterthur
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stddef.h>
+#include <sys/types.h>
+
+#include "pem.h"
+
+#include <library.h>
+#include <debug.h>
+#include <asn1/asn1.h>
+#include <asn1/ttodata.h>
+
+#include <utils/lexparser.h>
+#include <crypto/hashers/hasher.h>
+#include <crypto/crypters/crypter.h>
+
+#define PKCS5_SALT_LEN	8	/* bytes */
+
+/**
+ * check the presence of a pattern in a character string
+ */
+static bool present(const char* pattern, chunk_t* ch)
+{
+	u_int pattern_len = strlen(pattern);
+
+	if (ch->len >= pattern_len && strncmp(ch->ptr, pattern, pattern_len) == 0)
+	{
+		ch->ptr += pattern_len;
+		ch->len -= pattern_len;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * find a boundary of the form -----tag name-----
+ */
+static bool find_boundary(const char* tag, chunk_t *line)
+{
+	chunk_t name = chunk_empty;
+
+	if (!present("-----", line))
+		return FALSE;
+	if (!present(tag, line))
+		return FALSE;
+	if (*line->ptr != ' ')
+		return FALSE;
+	line->ptr++;  line->len--;
+	
+	/* extract name */
+	name.ptr = line->ptr;
+	while (line->len > 0)
+	{
+		if (present("-----", line))
+		{
+			DBG2("  -----%s %.*s-----", tag, (int)name.len, name.ptr);
+			return TRUE;
+		}
+		line->ptr++;  line->len--;  name.len++;
+	}
+	return FALSE;
+}
+
+/*
+ * decrypts a passphrase protected encrypted data block
+ */
+static err_t pem_decrypt(chunk_t *blob, encryption_algorithm_t alg, size_t key_size,
+						 chunk_t *iv, chunk_t *passphrase)
+{
+	hasher_t *hasher;
+	crypter_t *crypter;
+	chunk_t salt = { iv->ptr, PKCS5_SALT_LEN };
+	chunk_t hash;
+	chunk_t decrypted;
+	chunk_t key = {alloca(key_size), key_size};
+	u_int8_t padding, *last_padding_pos, *first_padding_pos;
+	
+	if (passphrase == NULL || passphrase->len == 0)
+		return "missing passphrase";
+
+	/* build key from passphrase and IV */
+	hasher = hasher_create(HASH_MD5);
+	hash.len = hasher->get_hash_size(hasher);
+	hash.ptr = alloca(hash.len);
+	hasher->get_hash(hasher, *passphrase, NULL);
+	hasher->get_hash(hasher, salt, hash.ptr);
+	memcpy(key.ptr, hash.ptr, hash.len);
+
+	if (key.len > hash.len)
+	{
+		hasher->get_hash(hasher, hash, NULL);
+		hasher->get_hash(hasher, *passphrase, NULL);
+		hasher->get_hash(hasher, salt, hash.ptr);	
+		memcpy(key.ptr + hash.len, hash.ptr, key.len - hash.len);
+	}	
+	hasher->destroy(hasher);
+	
+	/* decrypt blob */
+	crypter = crypter_create(alg, key_size);
+	crypter->set_key(crypter, key);
+	if (crypter->decrypt(crypter, *blob, *iv, &decrypted) != SUCCESS)
+	{
+		return "data size is not multiple of block size";
+	}
+	memcpy(blob->ptr, decrypted.ptr, blob->len);
+	chunk_free(&decrypted);
+	
+	/* determine amount of padding */
+	last_padding_pos = blob->ptr + blob->len - 1;
+	padding = *last_padding_pos;
+	first_padding_pos = (padding > blob->len) ? blob->ptr : last_padding_pos - padding;
+
+	/* check the padding pattern */
+	while (--last_padding_pos > first_padding_pos)
+	{
+		if (*last_padding_pos != padding)
+			return "invalid passphrase";
+	}
+	/* remove padding */
+	blob->len -= padding;
+	return NULL;
+}
+
+/*  Converts a PEM encoded file into its binary form
+ *
+ *  RFC 1421 Privacy Enhancement for Electronic Mail, February 1993
+ *  RFC 934 Message Encapsulation, January 1985
+ */
+err_t pem_to_bin(chunk_t *blob, chunk_t *passphrase, bool *pgp)
+{
+	typedef enum {
+		PEM_PRE    = 0,
+		PEM_MSG    = 1,
+		PEM_HEADER = 2,
+		PEM_BODY   = 3,
+		PEM_POST   = 4,
+		PEM_ABORT  = 5
+	} state_t;
+
+	encryption_algorithm_t alg = ENCR_UNDEFINED;
+	size_t key_size = 0;
+
+	bool encrypted = FALSE;
+
+	state_t state  = PEM_PRE;
+
+	chunk_t src    = *blob;
+	chunk_t dst    = *blob;
+	chunk_t line   = chunk_empty;
+	chunk_t iv     = chunk_empty;
+
+	u_char iv_buf[16]; /* MD5 digest size */
+
+	/* zero size of converted blob */
+	dst.len = 0;
+
+	/* zero size of IV */
+	iv.ptr = iv_buf;
+	iv.len = 0;
+
+	while (fetchline(&src, &line))
+	{
+		if (state == PEM_PRE)
+		{
+			if (find_boundary("BEGIN", &line))
+			{
+				state = PEM_MSG;
+			}
+			continue;
+		}
+		else
+		{
+			if (find_boundary("END", &line))
+			{
+				state = PEM_POST;
+				break;
+			}
+			if (state == PEM_MSG)
+			{
+				state = (memchr(line.ptr, ':', line.len) == NULL) ? PEM_BODY : PEM_HEADER;
+			}
+			if (state == PEM_HEADER)
+			{
+				err_t ugh = NULL;
+				chunk_t name  = chunk_empty;
+				chunk_t value = chunk_empty;
+
+				/* an empty line separates HEADER and BODY */
+				if (line.len == 0)
+				{
+					state = PEM_BODY;
+					continue;
+				}
+
+				/* we are looking for a parameter: value pair */
+				DBG2("  %.*s", (int)line.len, line.ptr);
+				ugh = extract_parameter_value(&name, &value, &line);
+				if (ugh != NULL)
+					continue;
+
+				if (match("Proc-Type", &name) && *value.ptr == '4')
+					encrypted = TRUE;
+				else if (match("DEK-Info", &name))
+				{
+					size_t len = 0;
+					chunk_t dek;
+
+					if (!extract_token(&dek, ',', &value))
+						dek = value;
+
+					if (match("DES-EDE3-CBC", &dek))
+					{
+						alg = ENCR_3DES;
+						key_size = 24;
+					}
+					else if (match("AES-128-CBC", &dek))
+					{
+						alg = ENCR_AES_CBC;
+						key_size = 16;
+					}
+					else if (match("AES-192-CBC", &dek))
+					{
+						alg = ENCR_AES_CBC;
+						key_size = 24;
+					}
+					else if (match("AES-256-CBC", &dek))
+					{
+						alg = ENCR_AES_CBC;
+						key_size = 32;
+					}
+					else
+					{
+						return "encryption algorithm not supported";
+					}
+
+					eat_whitespace(&value);
+					ugh = ttodata(value.ptr, value.len, 16, iv.ptr, 16, &len);
+					if (ugh)
+						return "error in IV";
+
+					iv.len = len;
+				}
+			}
+			else /* state is PEM_BODY */
+			{
+				const char *ugh = NULL;
+				size_t len = 0;
+				chunk_t data;
+				
+				/* remove any trailing whitespace */
+				if (!extract_token(&data ,' ', &line))
+				{
+					data = line;
+				}
+				
+				/* check for PGP armor checksum */
+				if (*data.ptr == '=')
+				{
+					*pgp = TRUE;
+					data.ptr++;
+					data.len--;
+					DBG2("  Armor checksum: %.*s", (int)data.len, data.ptr);
+		    		continue;
+				}
+
+				ugh = ttodata(data.ptr, data.len, 64, dst.ptr, blob->len - dst.len, &len);
+				if (ugh)
+				{
+					state = PEM_ABORT;
+					break;
+				}
+				else
+				{
+					dst.ptr += len;
+					dst.len += len;
+				}
+			}
+		}
+	}
+	/* set length to size of binary blob */
+	blob->len = dst.len;
+
+	if (state != PEM_POST)
+		return "file coded in unknown format, discarded";
+
+	return (encrypted)? pem_decrypt(blob, alg, key_size, &iv, passphrase) : NULL;
+}
+
+/* load a coded key or certificate file with autodetection
+ * of binary DER or base64 PEM ASN.1 formats and armored PGP format
+ */
+bool pem_asn1_load_file(const char *filename, chunk_t *passphrase,
+						const char *type, chunk_t *blob, bool *pgp)
+{
+	err_t ugh = NULL;
+
+	FILE *fd = fopen(filename, "r");
+
+	if (fd)
+	{
+		int bytes;
+		fseek(fd, 0, SEEK_END );
+		blob->len = ftell(fd);
+		rewind(fd);
+		blob->ptr = malloc(blob->len);
+		bytes = fread(blob->ptr, 1, blob->len, fd);
+		fclose(fd);
+		DBG1("  loading %s file '%s' (%d bytes)", type, filename, bytes);
+
+		*pgp = FALSE;
+
+		/* try DER format */
+		if (is_asn1(*blob))
+		{
+			DBG2("  file coded in DER format");
+			return TRUE;
+		}
+
+		if (passphrase != NULL)
+			DBG4("  passphrase:", passphrase->ptr, passphrase->len);
+
+		/* try PEM format */
+		ugh = pem_to_bin(blob, passphrase, pgp);
+
+		if (ugh == NULL)
+		{
+			if (*pgp)
+			{
+				DBG2("  file coded in armored PGP format");
+				return TRUE;
+			}
+			if (is_asn1(*blob))
+			{
+				DBG2("  file coded in PEM format");
+				return TRUE;
+			}
+			ugh = "file coded in unknown format, discarded";
+		}
+
+		/* a conversion error has occured */
+		DBG1("  %s", ugh);
+		chunk_free(blob);
+	}
+	else
+	{
+		DBG1("  could not open %s file '%s'", type, filename);
+	}
+	return FALSE;
+}