1 files changed, 458 insertions, 0 deletions
diff --git a/src/charon/lib/crypto/rsa/rsa_public_key.c b/src/charon/lib/crypto/rsa/rsa_public_key.c
new file mode 100644
index 000000000..6601b6cda
--- /dev/null
+++ b/src/charon/lib/crypto/rsa/rsa_public_key.c
@@ -0,0 +1,458 @@
+/**
+ * @file rsa_public_key.c
+ * 
+ * @brief Implementation of rsa_public_key_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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 <gmp.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "rsa_public_key.h"
+
+#include <daemon.h>
+#include <crypto/hashers/hasher.h>
+#include <asn1/asn1.h>
+
+/* 
+ * For simplicity,
+ * we use these predefined values for
+ * hash algorithm OIDs. These also contain
+ * the length of the following hash.
+ * These values are also used in rsa_private_key.c.
+ * TODO: We may move them in asn1 sometime...
+ */
+
+u_int8_t md2_oid[] = {
+	0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,
+	0x48,0x86,0xf7,0x0d,0x02,0x02,0x05,0x00,
+	0x04,0x10
+};
+
+u_int8_t md5_oid[] = {
+	0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,
+	0x48,0x86,0xf7,0x0d,0x02,0x05,0x05,0x00,
+	0x04,0x10
+};
+
+u_int8_t sha1_oid[] = {
+	0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x0e,
+	0x03,0x02,0x1a,0x05,0x00,0x04,0x14
+};
+
+u_int8_t sha256_oid[] = {
+	0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,
+	0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,
+	0x00,0x04,0x20
+};
+
+u_int8_t sha384_oid[] = {
+	0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,
+	0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,
+	0x00,0x04,0x30
+};
+
+u_int8_t sha512_oid[] = {
+	0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,
+	0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,
+	0x00,0x04,0x40
+};
+
+/* ASN.1 definition public key */
+static const asn1Object_t pubkey_objects[] = {
+	{ 0, "RSAPublicKey",		ASN1_SEQUENCE,     ASN1_OBJ  }, /*  0 */
+	{ 1,   "modulus",			ASN1_INTEGER,      ASN1_BODY }, /*  1 */
+	{ 1,   "publicExponent",	ASN1_INTEGER,      ASN1_BODY }, /*  2 */
+};
+
+#define PUB_KEY_RSA_PUBLIC_KEY		0
+#define PUB_KEY_MODULUS				1
+#define PUB_KEY_EXPONENT			2
+#define PUB_KEY_ROOF				3
+
+typedef struct private_rsa_public_key_t private_rsa_public_key_t;
+
+/**
+ * Private data structure with signing context.
+ */
+struct private_rsa_public_key_t {
+	/**
+	 * Public interface for this signer.
+	 */
+	rsa_public_key_t public;
+	
+	/**
+	 * Public modulus.
+	 */
+	mpz_t n;
+	
+	/**
+	 * Public exponent.
+	 */
+	mpz_t e;
+	
+	/**
+	 * Keysize in bytes.
+	 */
+	size_t k;
+	
+	/**
+	 * @brief Implements the RSAEP algorithm specified in PKCS#1.
+	 * 
+	 * @param this		calling object
+	 * @param data		data to process
+	 * @return			processed data
+	 */
+	chunk_t (*rsaep) (private_rsa_public_key_t *this, chunk_t data);
+		
+	/**
+	 * @brief Implements the RSASVP1 algorithm specified in PKCS#1.
+	 * 
+	 * @param this		calling object
+	 * @param data		data to process
+	 * @return			processed data
+	 */
+	chunk_t (*rsavp1) (private_rsa_public_key_t *this, chunk_t data);
+};
+
+
+typedef struct rsa_public_key_info_t rsa_public_key_info_t;
+
+/**
+ * KeyInfo, as it appears in a public key file
+ */
+struct rsa_public_key_info_t {
+	/**
+	 * Algorithm for this key
+	 */
+	chunk_t algorithm_oid;
+	
+	/**
+	 * Public key, parseable with rsa_public_key_rules
+	 */
+	chunk_t public_key;
+};
+
+private_rsa_public_key_t *rsa_public_key_create_empty();
+
+/**
+ * Implementation of private_rsa_public_key_t.rsaep and private_rsa_public_key_t.rsavp1
+ */
+static chunk_t rsaep(private_rsa_public_key_t *this, chunk_t data)
+{
+	mpz_t m, c;
+	chunk_t encrypted;
+	
+	mpz_init(c);
+	mpz_init(m);
+	
+	mpz_import(m, data.len, 1, 1, 1, 0, data.ptr);
+	
+	mpz_powm(c, m, this->e, this->n);
+
+    encrypted.len = this->k;
+    encrypted.ptr = mpz_export(NULL, NULL, 1, encrypted.len, 1, 0, c);
+	
+	mpz_clear(c);
+	mpz_clear(m);	
+	
+	return encrypted;
+}
+
+/**
+ * Implementation of rsa_public_key.verify_emsa_pkcs1_signature.
+ */
+static status_t verify_emsa_pkcs1_signature(private_rsa_public_key_t *this, chunk_t data, chunk_t signature)
+{
+	hasher_t *hasher = NULL;
+	chunk_t hash;
+	chunk_t em;
+	u_int8_t *pos;
+	
+	if (signature.len > this->k)
+	{
+		return INVALID_ARG;	
+	}
+	
+	/* unpack signature */
+	em = this->rsavp1(this, signature);
+	
+	/* result should look like this:
+	 * EM = 0x00 || 0x01 || PS || 0x00 || T. 
+	 * PS = 0xFF padding, with length to fill em
+	 * T = oid || hash
+	 */	
+	
+	/* check magic bytes */
+	if ((*(em.ptr) != 0x00) ||
+		(*(em.ptr+1) != 0x01))
+	{
+		free(em.ptr);
+		return FAILED;
+	}
+	
+	/* find magic 0x00 */
+	pos = em.ptr + 2;
+	while (pos <= em.ptr + em.len)
+	{
+		if (*pos == 0x00)
+		{
+			/* found magic byte, stop */
+			pos++;
+			break;
+		}
+		else if (*pos != 0xFF)
+		{
+			/* bad padding, decryption failed ?!*/
+			free(em.ptr);
+			return FAILED;	
+		}
+		pos++;
+	}
+
+	if (pos + 20 > em.ptr + em.len)
+	{
+		/* not enought room for oid compare */
+		free(em.ptr);
+		return FAILED;	
+	}
+	
+	if (memcmp(md2_oid, pos, sizeof(md2_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_MD2);
+		pos += sizeof(md2_oid);
+	}
+	else if (memcmp(md5_oid, pos, sizeof(md5_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_MD5);
+		pos += sizeof(md5_oid);
+	}
+	else if (memcmp(sha1_oid, pos, sizeof(sha1_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA1);
+		pos += sizeof(sha1_oid);
+	}
+	else if (memcmp(sha256_oid, pos, sizeof(sha256_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA256);
+		pos += sizeof(sha256_oid);
+	}
+	else if (memcmp(sha384_oid, pos, sizeof(sha384_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA384);
+		pos += sizeof(sha384_oid);
+	}
+	else if (memcmp(sha512_oid, pos, sizeof(sha512_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA512);
+		pos += sizeof(sha512_oid);
+	}
+	
+	if (hasher == NULL)
+	{
+		/* not supported hash algorithm */
+		free(em.ptr);
+		return NOT_SUPPORTED;	
+	}
+	
+	if (pos + hasher->get_hash_size(hasher) != em.ptr + em.len)
+	{
+		/* bad length */
+		free(em.ptr);
+		hasher->destroy(hasher);
+		return FAILED;	
+	}
+	
+	/* build own hash for a compare */
+	hasher->allocate_hash(hasher, data, &hash);
+	hasher->destroy(hasher);
+	
+	if (memcmp(hash.ptr, pos, hash.len) != 0)
+	{
+		/* hash does not equal */
+		free(hash.ptr);
+		free(em.ptr);
+		return FAILED;	
+			
+	}
+	
+	/* seems good */
+	free(hash.ptr);
+	free(em.ptr);
+	return SUCCESS;	
+}
+	
+/**
+ * Implementation of rsa_public_key.get_key.
+ */
+static status_t get_key(private_rsa_public_key_t *this, chunk_t *key)
+{	
+	chunk_t n, e;
+
+	n.len = this->k;
+	n.ptr = mpz_export(NULL, NULL, 1, n.len, 1, 0, this->n);
+	e.len = this->k;
+	e.ptr = mpz_export(NULL, NULL, 1, e.len, 1, 0, this->e);
+	
+	key->len = this->k * 2;
+	key->ptr = malloc(key->len);
+	memcpy(key->ptr, n.ptr, n.len);
+	memcpy(key->ptr + n.len, e.ptr, e.len);
+	free(n.ptr);
+	free(e.ptr);
+	
+	return SUCCESS;
+}
+
+/**
+ * Implementation of rsa_public_key.save_key.
+ */
+static status_t save_key(private_rsa_public_key_t *this, char *file)
+{
+	return NOT_SUPPORTED;
+}
+
+/**
+ * Implementation of rsa_public_key.get_modulus.
+ */
+static mpz_t *get_modulus(private_rsa_public_key_t *this)
+{
+	return &this->n;
+}
+
+/**
+ * Implementation of rsa_public_key.clone.
+ */
+static rsa_public_key_t* _clone(private_rsa_public_key_t *this)
+{
+	private_rsa_public_key_t *clone = rsa_public_key_create_empty();
+	
+	mpz_init_set(clone->n, this->n);
+	mpz_init_set(clone->e, this->e);
+	clone->k = this->k;
+	
+	return &clone->public;
+}
+
+/**
+ * Implementation of rsa_public_key.destroy.
+ */
+static void destroy(private_rsa_public_key_t *this)
+{
+	mpz_clear(this->n);
+	mpz_clear(this->e);
+	free(this);
+}
+
+/**
+ * Generic private constructor
+ */
+private_rsa_public_key_t *rsa_public_key_create_empty()
+{
+	private_rsa_public_key_t *this = malloc_thing(private_rsa_public_key_t);
+	
+	/* public functions */
+	this->public.verify_emsa_pkcs1_signature = (status_t (*) (rsa_public_key_t*,chunk_t,chunk_t))verify_emsa_pkcs1_signature;
+	this->public.get_key = (status_t (*) (rsa_public_key_t*,chunk_t*))get_key;
+	this->public.save_key = (status_t (*) (rsa_public_key_t*,char*))save_key;
+	this->public.get_modulus = (mpz_t *(*) (rsa_public_key_t*))get_modulus;
+	this->public.clone = (rsa_public_key_t* (*) (rsa_public_key_t*))_clone;
+	this->public.destroy = (void (*) (rsa_public_key_t*))destroy;
+	
+	/* private functions */
+	this->rsaep = rsaep;
+	this->rsavp1 = rsaep; /* same algorithm */
+	
+	return this;
+}
+	
+/*
+ * See header
+ */
+rsa_public_key_t *rsa_public_key_create_from_chunk(chunk_t blob)
+{
+	asn1_ctx_t ctx;
+	chunk_t object;
+	u_int level;
+	int objectID = 0;
+	private_rsa_public_key_t *this;
+	
+	this = rsa_public_key_create_empty();
+	mpz_init(this->n);
+	mpz_init(this->e);
+	
+	asn1_init(&ctx, blob, 0, FALSE);
+	
+	while (objectID < PUB_KEY_ROOF) 
+	{
+		if (!extract_object(pubkey_objects, &objectID, &object, &level, &ctx))
+		{
+			destroy(this);
+			return FALSE;
+		}
+		switch (objectID)
+		{
+			case PUB_KEY_MODULUS:
+				mpz_import(this->n, object.len, 1, 1, 1, 0, object.ptr);
+				break;
+			case PUB_KEY_EXPONENT:
+				mpz_import(this->e, object.len, 1, 1, 1, 0, object.ptr);
+				break;
+		}
+		objectID++;
+	}
+	
+	this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8;
+	return &this->public;
+}
+
+/*
+ * See header
+ */
+rsa_public_key_t *rsa_public_key_create_from_file(char *filename)
+{
+	struct stat stb;
+	FILE *file;
+	char *buffer;
+	chunk_t chunk;
+	
+	if (stat(filename, &stb) == -1)
+	{
+		return NULL;
+	}
+	
+	buffer = alloca(stb.st_size);
+	
+	file = fopen(filename, "r");
+	if (file == NULL)
+	{
+		return NULL;
+	}
+	
+	if (fread(buffer, stb.st_size, 1, file) != 1)
+	{
+		return NULL;
+	}
+	
+	chunk.ptr = buffer;
+	chunk.len = stb.st_size;
+	
+	return rsa_public_key_create_from_chunk(chunk);
+}