X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=crypt.c;h=f3bfed3be755ccce6ba9ec1d89c40934babedc35;hp=49e9e8ae7863fed3f40881a356957f115bf31769;hb=e7593d7c153bfca2131b18621fb24ae18c1c0cb3;hpb=d4522ff1dcfdfff491ef3c27aca1dd1220af0c6f diff --git a/crypt.c b/crypt.c index 49e9e8ae..f3bfed3b 100644 --- a/crypt.c +++ b/crypt.c @@ -1,10 +1,10 @@ /* - * Copyright (C) 2005-2009 Andre Noll + * Copyright (C) 2005-2011 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file crypt.c openssl-based RSA encryption/decryption routines */ +/** \file crypt.c Openssl-based encryption/decryption routines. */ #include #include @@ -13,12 +13,19 @@ #include #include #include +#include +#include #include "para.h" #include "error.h" #include "string.h" #include "crypt.h" #include "fd.h" + +struct asymmetric_key { + RSA *rsa; +}; + /** * Fill a buffer with random content. * @@ -102,50 +109,58 @@ static EVP_PKEY *load_key(const char *file, int private) } /** - * read an RSA key from a file + * Read an asymmetric key from a file. * - * \param key_file the file containing the key - * \param rsa RSA structure is returned here - * \param private if non-zero, read the private key, otherwise the public key + * \param key_file The file containing the key. + * \param private if non-zero, read the private key, otherwise the public key. + * \param result The key structure is returned here. * - * \return The size of the RSA key on success, negative on errors. + * \return The size of the key on success, negative on errors. * * \sa openssl(1), rsa(1). */ -int get_rsa_key(char *key_file, RSA **rsa, int private) +int get_asymmetric_key(const char *key_file, int private, + struct asymmetric_key **result) { - EVP_PKEY *key = load_key(key_file, private); + struct asymmetric_key *key; + RSA *rsa; + EVP_PKEY *pkey = load_key(key_file, private); - if (!key) + if (!pkey) return (private == LOAD_PRIVATE_KEY)? -E_PRIVATE_KEY : -E_PUBLIC_KEY; - *rsa = EVP_PKEY_get1_RSA(key); - EVP_PKEY_free(key); - if (!*rsa) + rsa = EVP_PKEY_get1_RSA(pkey); + EVP_PKEY_free(pkey); + if (!rsa) return -E_RSA; - return RSA_size(*rsa); + key = para_malloc(sizeof(*key)); + key->rsa = rsa; + *result = key; + return RSA_size(rsa); } /** - * free an RSA structure + * Deallocate an asymmetric key structure. * - * \param rsa pointer to the RSA struct to free + * \param key Pointer to the key structure to free. * - * This must be called for any key obtained by get_rsa_key(). + * This must be called for any key obtained by get_asymmetric_key(). */ -void rsa_free(RSA *rsa) +void free_asymmetric_key(struct asymmetric_key *key) { - if (rsa) - RSA_free(rsa); + if (!key) + return; + RSA_free(key->rsa); + free(key); } /** - * decrypt a buffer using an RSA key + * Decrypt a buffer using a private key. * - * \param key_file full path of the rsa key - * \param outbuf the output buffer - * \param inbuf the encrypted input buffer - * \param rsa_inlen the length of \a inbuf + * \param key_file Full path of the key. + * \param outbuf The output buffer. + * \param inbuf The encrypted input buffer. + * \param inlen The length of \a inbuf in bytes. * * The \a outbuf must be large enough to hold at least \a rsa_inlen bytes. * @@ -153,15 +168,15 @@ void rsa_free(RSA *rsa) * * \sa RSA_private_decrypt(3) **/ -int para_decrypt_buffer(char *key_file, unsigned char *outbuf, unsigned char *inbuf, - unsigned rsa_inlen) +int priv_decrypt(const char *key_file, unsigned char *outbuf, + unsigned char *inbuf, int inlen) { - RSA *rsa; - int ret, inlen = rsa_inlen; + struct asymmetric_key *priv; + int ret; if (inlen < 0) return -E_RSA; - ret = get_rsa_key(key_file, &rsa, LOAD_PRIVATE_KEY); + ret = get_asymmetric_key(key_file, LOAD_PRIVATE_KEY, &priv); if (ret < 0) return ret; /* @@ -169,44 +184,76 @@ int para_decrypt_buffer(char *key_file, unsigned char *outbuf, unsigned char *in * factor to protect against this kind of attack. */ ret = -E_BLINDING; - if (RSA_blinding_on(rsa, NULL) == 0) + if (RSA_blinding_on(priv->rsa, NULL) == 0) goto out; - ret = RSA_private_decrypt(inlen, inbuf, outbuf, rsa, RSA_PKCS1_OAEP_PADDING); - RSA_blinding_off(rsa); + ret = RSA_private_decrypt(inlen, inbuf, outbuf, priv->rsa, + RSA_PKCS1_OAEP_PADDING); + RSA_blinding_off(priv->rsa); if (ret <= 0) ret = -E_DECRYPT; out: - rsa_free(rsa); + free_asymmetric_key(priv); return ret; } /** - * encrypt a buffer using an RSA key + * Encrypt a buffer using an RSA key * - * \param rsa: public rsa key - * \param inbuf the input buffer - * \param len the length of \a inbuf - * \param outbuf the output buffer + * \param pub: The public key. + * \param inbuf The input buffer. + * \param len The length of \a inbuf. + * \param outbuf The output buffer. * - * \return The size of the encrypted data on success, negative on errors + * \return The size of the encrypted data on success, negative on errors. * * \sa RSA_public_encrypt(3) */ -int para_encrypt_buffer(RSA *rsa, unsigned char *inbuf, +int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf, unsigned len, unsigned char *outbuf) { int ret, flen = len; /* RSA_public_encrypt expects a signed int */ if (flen < 0) return -E_ENCRYPT; - ret = RSA_public_encrypt(flen, inbuf, outbuf, rsa, RSA_PKCS1_OAEP_PADDING); + ret = RSA_public_encrypt(flen, inbuf, outbuf, pub->rsa, + RSA_PKCS1_OAEP_PADDING); return ret < 0? -E_ENCRYPT : ret; } +#define RC4_ALIGN 8 +struct stream_cipher { + RC4_KEY key; +}; + +/** + * Allocate and initialize a stream cipher structure. + * + * \param data The key. + * \param len The size of the key. + * + * \return A new stream cipher structure. + */ +struct stream_cipher *sc_new(const unsigned char *data, int len) +{ + struct stream_cipher *sc = para_malloc(sizeof(*sc)); + RC4_set_key(&sc->key, len, data); + return sc; +} + +/** + * Deallocate a stream cipher structure. + * + * \param sc A stream cipher previously obtained by sc_new(). + */ +void sc_free(struct stream_cipher *sc) +{ + free(sc); +} + /** * Encrypt and send a buffer. * - * \param rc4c The rc4 crypt context. + * \param scc The context. * \param buf The buffer to send. * \param len The size of \a buf in bytes. * @@ -214,15 +261,22 @@ int para_encrypt_buffer(RSA *rsa, unsigned char *inbuf, * * \sa \ref write_all(), RC4(3). */ -int rc4_send_bin_buffer(struct rc4_context *rc4c, const char *buf, size_t len) +int sc_send_bin_buffer(struct stream_cipher_context *scc, const char *buf, + size_t len) { int ret; unsigned char *tmp; + static unsigned char remainder[RC4_ALIGN]; + size_t l1 = ROUND_DOWN(len, RC4_ALIGN), l2 = ROUND_UP(len, RC4_ALIGN); assert(len); - tmp = para_malloc(len); - RC4(&rc4c->send_key, len, (const unsigned char *)buf, tmp); - ret = write_all(rc4c->fd, (char *)tmp, &len); + tmp = para_malloc(l2); + RC4(&scc->send->key, l1, (const unsigned char *)buf, tmp); + if (len > l1) { + memcpy(remainder, buf + l1, len - l1); + RC4(&scc->send->key, len - l1, remainder, tmp + l1); + } + ret = write_all(scc->fd, (char *)tmp, &len); free(tmp); return ret; } @@ -230,31 +284,32 @@ int rc4_send_bin_buffer(struct rc4_context *rc4c, const char *buf, size_t len) /** * Encrypt and send a \p NULL-terminated buffer. * - * \param rc4c The rc4 crypt context. + * \param scc The context. * \param buf The buffer to send. * - * \return The return value of the underyling call to rc4_send_bin_buffer(). + * \return The return value of the underyling call to sc_send_bin_buffer(). */ -int rc4_send_buffer(struct rc4_context *rc4c, const char *buf) +int sc_send_buffer(struct stream_cipher_context *scc, const char *buf) { - return rc4_send_bin_buffer(rc4c, buf, strlen(buf)); + return sc_send_bin_buffer(scc, buf, strlen(buf)); } /** * Format, encrypt and send a buffer. * - * \param rc4c The rc4 crypt context. + * \param scc The context. * \param fmt A format string. * - * \return The return value of the underyling call to rc4_send_buffer(). + * \return The return value of the underyling call to sc_send_buffer(). */ -__printf_2_3 int rc4_send_va_buffer(struct rc4_context *rc4c, const char *fmt, ...) +__printf_2_3 int sc_send_va_buffer(struct stream_cipher_context *scc, + const char *fmt, ...) { char *msg; int ret; PARA_VSPRINTF(fmt, msg); - ret = rc4_send_buffer(rc4c, msg); + ret = sc_send_buffer(scc, msg); free(msg); return ret; } @@ -262,7 +317,7 @@ __printf_2_3 int rc4_send_va_buffer(struct rc4_context *rc4c, const char *fmt, . /** * Receive a buffer and decrypt it. * - * \param rc4c The rc4 crypt context. + * \param scc The context. * \param buf The buffer to write the decrypted data to. * \param size The size of \a buf. * @@ -271,13 +326,14 @@ __printf_2_3 int rc4_send_va_buffer(struct rc4_context *rc4c, const char *fmt, . * * \sa recv(2), RC4(3). */ -int rc4_recv_bin_buffer(struct rc4_context *rc4c, char *buf, size_t size) +int sc_recv_bin_buffer(struct stream_cipher_context *scc, char *buf, + size_t size) { unsigned char *tmp = para_malloc(size); - ssize_t ret = recv(rc4c->fd, tmp, size, 0); + ssize_t ret = recv(scc->fd, tmp, size, 0); if (ret > 0) - RC4(&rc4c->recv_key, ret, tmp, (unsigned char *)buf); + RC4(&scc->recv->key, ret, tmp, (unsigned char *)buf); else if (ret < 0) ret = -ERRNO_TO_PARA_ERROR(errno); free(tmp); @@ -287,26 +343,44 @@ int rc4_recv_bin_buffer(struct rc4_context *rc4c, char *buf, size_t size) /** * Receive a buffer, decrypt it and write terminating NULL byte. * - * \param rc4c The rc4 crypt context. + * \param scc The context. * \param buf The buffer to write the decrypted data to. * \param size The size of \a buf. * - * Read at most \a size - 1 bytes from file descriptor given by \a rc4c, - * decrypt the received data and write a NULL byte at the end of the decrypted - * data. + * Read at most \a size - 1 bytes from file descriptor given by \a scc, decrypt + * the received data and write a NULL byte at the end of the decrypted data. * * \return The return value of the underlying call to \ref - * rc4_recv_bin_buffer(). + * sc_recv_bin_buffer(). */ -int rc4_recv_buffer(struct rc4_context *rc4c, char *buf, size_t size) +int sc_recv_buffer(struct stream_cipher_context *scc, char *buf, size_t size) { int n; assert(size); - n = rc4_recv_bin_buffer(rc4c, buf, size - 1); + n = sc_recv_bin_buffer(scc, buf, size - 1); if (n >= 0) buf[n] = '\0'; else *buf = '\0'; return n; } + +/** + * Compute the hash of the given input data. + * + * \param data Pointer to the data to compute the hash value from. + * \param len The length of \a data in bytes. + * \param hash Result pointer. + * + * \a hash must point to an area at least \p HASH_SIZE bytes large. + * + * \sa sha(3), openssl(1). + * */ +void hash_function(const char *data, unsigned long len, unsigned char *hash) +{ + SHA_CTX c; + SHA1_Init(&c); + SHA1_Update(&c, data, len); + SHA1_Final(hash, &c); +}