X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=gcrypt.c;h=694c0adb8454b73dc0e5b67876fc7a03617b61d0;hp=5202c9b713eba8eba300d9ef336ffeae801ba03b;hb=ba83a291cd486e8ab53ac64d81b17d8f5705d715;hpb=1bec000ff43c20d8c2f904678d1845ee65b4ba18 diff --git a/gcrypt.c b/gcrypt.c index 5202c9b7..694c0adb 100644 --- a/gcrypt.c +++ b/gcrypt.c @@ -1,8 +1,4 @@ -/* - * Copyright (C) 2011 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ +/* Copyright (C) 2011 Andre Noll , see file COPYING. */ /** \file gcrypt.c Libgrcypt-based encryption/decryption routines. */ @@ -56,21 +52,41 @@ void get_random_bytes_or_die(unsigned char *buf, int num) } /* - * This is called at the beginning of every program that uses libgcrypt. We - * don't have to initialize any random seed here, but we must initialize the - * gcrypt library. This task is performed by gcry_check_version() which can - * also check that the gcrypt library version is at least the minimal required - * version. + * This is called at the beginning of every program that uses libgcrypt. The + * call to gcry_check_version() initializes the gcrypt library and checks that + * we have at least the minimal required version. */ -void init_random_seed_or_die(void) +void crypt_init(void) { const char *req_ver = "1.5.0"; + int seed; - if (gcry_check_version(req_ver)) - return; - PARA_EMERG_LOG("fatal: need at least libgcrypt-%s, have: %s\n", - req_ver, gcry_check_version(NULL)); - exit(EXIT_FAILURE); + if (!gcry_check_version(req_ver)) { + PARA_EMERG_LOG("fatal: need at least libgcrypt-%s, have: %s\n", + req_ver, gcry_check_version(NULL)); + exit(EXIT_FAILURE); + } + + /* + * Allocate a pool of secure memory. This also drops privileges where + * needed. + */ + gcry_control(GCRYCTL_INIT_SECMEM, 65536, 0); + + /* Tell Libgcrypt that initialization has completed. */ + gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0); + + get_random_bytes_or_die((unsigned char *)&seed, sizeof(seed)); + srandom(seed); +} + +void crypt_shutdown(void) +{ + /* + * WK does not see a way to apply a patch for the sake of Valgrind, so + * as of 2018 libgrypt has no deinitialization routine to free the + * resources on exit. + */ } /** S-expression for the public part of an RSA key. */ @@ -189,64 +205,6 @@ static inline int get_long_form_num_length_bytes(unsigned char c) return c & 0x7f; } -static int find_pubkey_bignum_offset(const unsigned char *data, int len) -{ - const unsigned char *p = data, *end = data + len; - - /* the whole thing starts with one sequence */ - if (*p != ASN1_TYPE_SEQUENCE) - return -E_ASN1_PARSE; - p++; - if (p >= end) - return -E_ASN1_PARSE; - if (is_short_form(*p)) - p++; - else - p += 1 + get_long_form_num_length_bytes(*p); - if (p >= end) - return -E_ASN1_PARSE; - /* another sequence containing the object id, skip it */ - if (*p != ASN1_TYPE_SEQUENCE) - return -E_ASN1_PARSE; - p++; - if (p >= end) - return -E_ASN1_PARSE; - if (!is_short_form(*p)) - return -E_ASN1_PARSE; - p += 1 + get_short_form_length(*p); - if (p >= end) - return -E_ASN1_PARSE; - /* all numbers are wrapped in a bit string object that follows */ - if (*p != ASN1_TYPE_BIT_STRING) - return -E_ASN1_PARSE; - p++; - if (p >= end) - return -E_ASN1_PARSE; - if (is_short_form(*p)) - p++; - else - p += 1 + get_long_form_num_length_bytes(*p); - p++; /* skip number of unused bits in the bit string */ - if (p >= end) - return -E_ASN1_PARSE; - - /* next, we have a sequence of two integers (n and e) */ - if (*p != ASN1_TYPE_SEQUENCE) - return -E_ASN1_PARSE; - p++; - if (p >= end) - return -E_ASN1_PARSE; - if (is_short_form(*p)) - p++; - else - p += 1 + get_long_form_num_length_bytes(*p); - if (p >= end) - return -E_ASN1_PARSE; - if (*p != ASN1_TYPE_INTEGER) - return -E_ASN1_PARSE; - return p - data; -} - /* * Returns: Number of bytes scanned. This may differ from the value returned via * bn_bytes because the latter does not include the ASN.1 prefix and a leading @@ -279,7 +237,7 @@ static int read_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn, PARA_DEBUG_LOG("bn_size %d (0x%x)\n", bn_size, (unsigned)bn_size); gret = gcry_mpi_scan(bn, GCRYMPI_FMT_STD, cp, bn_size, NULL); if (gret) { - PARA_ERROR_LOG("%s while scanning n\n", + PARA_ERROR_LOG("gcry_mpi_scan: %s\n", gcry_strerror(gcry_err_code(gret))); return-E_MPI_SCAN; } @@ -348,6 +306,7 @@ static int get_private_key(const char *key_file, struct asymmetric_key **result) gcry_sexp_t sexp; struct asymmetric_key *key; + *result = NULL; ret = decode_key(key_file, PRIVATE_KEY_HEADER, PRIVATE_KEY_FOOTER, &blob); if (ret < 0) @@ -426,86 +385,21 @@ free_blob: return ret; } -/** Public keys start with this header. */ -#define PUBLIC_KEY_HEADER "-----BEGIN PUBLIC KEY-----" -/** Public keys end with this footer. */ -#define PUBLIC_KEY_FOOTER "-----END PUBLIC KEY-----" - -static int get_asn_public_key(const char *key_file, struct asymmetric_key **result) +int apc_get_pubkey(const char *key_file, struct asymmetric_key **result) { - gcry_mpi_t n = NULL, e = NULL; - unsigned char *blob, *cp, *end; - int blob_size, ret, n_size; + unsigned char *blob, *p, *end; + int ret; gcry_error_t gret; - size_t erroff; + size_t nr_scanned, erroff, decoded_size; + gcry_mpi_t e, n; gcry_sexp_t sexp; struct asymmetric_key *key; - ret = decode_key(key_file, PUBLIC_KEY_HEADER, PUBLIC_KEY_FOOTER, - &blob); + ret = decode_ssh_key(key_file, &blob, &decoded_size); if (ret < 0) return ret; - blob_size = ret; - end = blob + blob_size; - ret = find_pubkey_bignum_offset(blob, blob_size); - if (ret < 0) - goto free_blob; - PARA_DEBUG_LOG("decoding public RSA params at offset %d\n", ret); - cp = blob + ret; - - ret = read_bignum(cp, end, &n, &n_size); - if (ret < 0) - goto free_blob; - cp += ret; - - ret = read_bignum(cp, end, &e, NULL); - if (ret < 0) - goto release_n; - - gret = gcry_sexp_build(&sexp, &erroff, RSA_PUBKEY_SEXP, n, e); - if (gret) { - PARA_ERROR_LOG("offset %zu: %s\n", erroff, - gcry_strerror(gcry_err_code(gret))); - ret = -E_SEXP_BUILD; - goto release_e; - } - key = para_malloc(sizeof(*key)); - key->sexp = sexp; - key->num_bytes = n_size; - *result = key; - ret = n_size; - PARA_INFO_LOG("successfully read %d bit asn public key\n", n_size * 8); - -release_e: - gcry_mpi_release(e); -release_n: - gcry_mpi_release(n); -free_blob: - free(blob); - return ret; -} - -static int get_ssh_public_key(unsigned char *data, int size, gcry_sexp_t *result) -{ - int ret; - gcry_error_t gret; - unsigned char *blob = NULL, *p, *end; - size_t nr_scanned, erroff, decoded_size; - gcry_mpi_t e = NULL, n = NULL; - - PARA_DEBUG_LOG("decoding %d byte public rsa-ssh key\n", size); - ret = uudecode((char *)data, size, (char **)&blob, &decoded_size); - if (ret < 0) - goto free_blob; - end = blob + decoded_size; - dump_buffer("decoded key", blob, decoded_size); - ret = check_ssh_key_header(blob, decoded_size); - if (ret < 0) - goto free_blob; p = blob + ret; - ret = -E_SSH_PARSE; - if (p >= end) - goto free_blob; + end = blob + decoded_size; PARA_DEBUG_LOG("scanning modulus and public exponent\n"); gret = gcry_mpi_scan(&e, GCRYMPI_FMT_SSH, p, end - p, &nr_scanned); if (gret) { @@ -514,8 +408,6 @@ static int get_ssh_public_key(unsigned char *data, int size, gcry_sexp_t *result goto free_blob; } PARA_DEBUG_LOG("scanned e (%zu bytes)\n", nr_scanned); -// gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_e); -// PARA_CRIT_LOG("e: %s\n", buf); p += nr_scanned; if (p >= end) goto release_e; @@ -526,17 +418,19 @@ static int get_ssh_public_key(unsigned char *data, int size, gcry_sexp_t *result goto release_e; } PARA_DEBUG_LOG("scanned n (%zu bytes)\n", nr_scanned); -// gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_n); -// PARA_CRIT_LOG("n: %s\n", buf); - gret = gcry_sexp_build(result, &erroff, RSA_PUBKEY_SEXP, n, e); + gret = gcry_sexp_build(&sexp, &erroff, RSA_PUBKEY_SEXP, n, e); if (gret) { PARA_ERROR_LOG("offset %zu: %s\n", erroff, gcry_strerror(gcry_err_code(gret))); ret = -E_SEXP_BUILD; goto release_n; } - ret = nr_scanned / 32 * 32; + ret = ROUND_DOWN(nr_scanned, 32); PARA_INFO_LOG("successfully read %d bit ssh public key\n", ret * 8); + key = para_malloc(sizeof(*key)); + key->num_bytes = ret; + key->sexp = sexp; + *result = key; release_n: gcry_mpi_release(n); release_e: @@ -546,48 +440,7 @@ free_blob: return ret; } -int get_asymmetric_key(const char *key_file, int private, - struct asymmetric_key **result) -{ - int ret, ret2; - void *map; - size_t map_size; - unsigned char *start, *end; - gcry_sexp_t sexp; - struct asymmetric_key *key; - - if (private) - return get_private_key(key_file, result); - ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL); - if (ret < 0) - return ret; - ret = is_ssh_rsa_key(map, map_size); - if (!ret) { - ret = para_munmap(map, map_size); - if (ret < 0) - return ret; - return get_asn_public_key(key_file, result); - } - start = map + ret; - end = map + map_size; - ret = -E_SSH_PARSE; - if (start >= end) - goto unmap; - ret = get_ssh_public_key(start, end - start, &sexp); - if (ret < 0) - goto unmap; - key = para_malloc(sizeof(*key)); - key->num_bytes = ret; - key->sexp = sexp; - *result = key; -unmap: - ret2 = para_munmap(map, map_size); - if (ret >= 0 && ret2 < 0) - ret = ret2; - return ret; -} - -void free_asymmetric_key(struct asymmetric_key *key) +void apc_free_pubkey(struct asymmetric_key *key) { if (!key) return; @@ -605,7 +458,7 @@ static int decode_rsa(gcry_sexp_t sexp, unsigned char *outbuf, size_t *nbytes) return 1; } -int priv_decrypt(const char *key_file, unsigned char *outbuf, +int apc_priv_decrypt(const char *key_file, unsigned char *outbuf, unsigned char *inbuf, int inlen) { gcry_error_t gret; @@ -615,7 +468,7 @@ int priv_decrypt(const char *key_file, unsigned char *outbuf, gcry_sexp_t in, out, priv_key; size_t nbytes; - ret = check_key_file(key_file, true); + ret = check_private_key_file(key_file); if (ret < 0) return ret; PARA_INFO_LOG("decrypting %d byte input\n", inlen); @@ -667,11 +520,12 @@ in_mpi_release: key_release: gcry_sexp_release(priv_key); free_key: - free_asymmetric_key(priv); + gcry_sexp_release(priv->sexp); + free(priv); return ret; } -int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf, +int apc_pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf, unsigned len, unsigned char *outbuf) { gcry_error_t gret; @@ -737,33 +591,20 @@ struct stream_cipher { gcry_cipher_hd_t handle; }; -struct stream_cipher *sc_new(const unsigned char *data, int len, - bool use_aes) +struct stream_cipher *sc_new(const unsigned char *data, int len) { gcry_error_t gret; struct stream_cipher *sc = para_malloc(sizeof(*sc)); - if (use_aes) { - assert(len >= 2 * AES_CRT128_BLOCK_SIZE); - gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_AES128, - GCRY_CIPHER_MODE_CTR, 0); - assert(gret == 0); - gret = gcry_cipher_setkey(sc->handle, data, - AES_CRT128_BLOCK_SIZE); - assert(gret == 0); - gret = gcry_cipher_setctr(sc->handle, - data + AES_CRT128_BLOCK_SIZE, AES_CRT128_BLOCK_SIZE); - assert(gret == 0); - return sc; - } - gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_ARCFOUR, - GCRY_CIPHER_MODE_STREAM, 0); - if (gret) { - PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret)); - free(sc); - return NULL; - } - gret = gcry_cipher_setkey(sc->handle, data, (size_t)len); + assert(len >= 2 * AES_CRT128_BLOCK_SIZE); + gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_AES128, + GCRY_CIPHER_MODE_CTR, 0); + assert(gret == 0); + gret = gcry_cipher_setkey(sc->handle, data, + AES_CRT128_BLOCK_SIZE); + assert(gret == 0); + gret = gcry_cipher_setctr(sc->handle, + data + AES_CRT128_BLOCK_SIZE, AES_CRT128_BLOCK_SIZE); assert(gret == 0); return sc; }