X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=gcrypt.c;h=58fa507b6e1f96303998e0f6ba0ae47f90beb493;hb=3699a583f3a7e9514c0f47b8b07f56b050430b67;hp=8d6db3490db95057b32168c3302fd0e2a0ee4e48;hpb=ab98d5b8b03e0e2fdcf010fc8f6a6b0ab8f87564;p=paraslash.git

diff --git a/gcrypt.c b/gcrypt.c
index 8d6db349..58fa507b 100644
--- a/gcrypt.c
+++ b/gcrypt.c
@@ -56,7 +56,7 @@ void get_random_bytes_or_die(unsigned char *buf, int num)
  * 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;
@@ -66,10 +66,29 @@ void init_random_seed_or_die(void)
 			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. */
 #define RSA_PUBKEY_SEXP "(public-key (rsa (n %m) (e %m)))"
 /** S-expression for a private RSA key. */
@@ -87,12 +106,17 @@ static const char *gcrypt_strerror(gcry_error_t gret)
 	return gcry_strerror(gcry_err_code(gret));
 }
 
-static int decode_key(const char *key_file, const char *header_str,
-		const char *footer_str, unsigned char **result)
+/** Private keys start with this header. */
+#define PRIVATE_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
+/** Private keys end with this footer. */
+#define PRIVATE_KEY_FOOTER "-----END RSA PRIVATE KEY-----"
+
+static int decode_key(const char *key_file, unsigned char **result,
+		size_t *blob_size)
 {
 	int ret, ret2, i, j;
 	void *map;
-	size_t map_size, key_size, blob_size;
+	size_t map_size, key_size;
 	unsigned char *blob = NULL;
 	char *begin, *footer, *key;
 
@@ -100,13 +124,13 @@ static int decode_key(const char *key_file, const char *header_str,
 	if (ret < 0)
 		goto out;
 	ret = -E_KEY_MARKER;
-	if (strncmp(map, header_str, strlen(header_str)))
+	if (strncmp(map, PRIVATE_KEY_HEADER, strlen(PRIVATE_KEY_HEADER)))
 		goto unmap;
-	footer = strstr(map, footer_str);
+	footer = strstr(map, PRIVATE_KEY_FOOTER);
 	ret = -E_KEY_MARKER;
 	if (!footer)
 		goto unmap;
-	begin = map + strlen(header_str);
+	begin = map + strlen(PRIVATE_KEY_HEADER);
 	/* skip whitespace at the beginning */
 	for (; begin < footer; begin++) {
 		if (para_isspace(*begin))
@@ -125,15 +149,8 @@ static int decode_key(const char *key_file, const char *header_str,
 		key[j++] = begin[i];
 	}
 	key[j] = '\0';
-	ret = base64_decode(key, j, (char **)&blob, &blob_size);
+	ret = base64_decode(key, j, (char **)&blob, blob_size);
 	free(key);
-	if (ret < 0)
-		goto free_unmap;
-	ret = blob_size;
-	goto unmap;
-free_unmap:
-	free(blob);
-	blob = NULL;
 unmap:
 	ret2 = para_munmap(map, map_size);
 	if (ret >= 0 && ret2 < 0)
@@ -188,11 +205,11 @@ static inline int get_long_form_num_length_bytes(unsigned char c)
 
 /*
  * 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
- * zero is not considered as an additional byte for bn_bytes.
+ * bitsp because the latter does not include the ASN.1 prefix and a leading
+ * zero is not considered as an additional byte for the number of bits.
  */
 static int read_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn,
-		int *bn_bytes)
+		unsigned *bitsp)
 {
 	int i, bn_size;
 	gcry_error_t gret;
@@ -218,7 +235,7 @@ 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;
 	}
@@ -230,8 +247,8 @@ static int read_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn,
 		cp++;
 		bn_size--;
 	}
-	if (bn_bytes)
-		*bn_bytes = bn_size;
+	if (bitsp)
+		*bitsp = bn_size * 8;
 	cp += bn_size;
 //	unsigned char *buf;
 //	gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, *bn);
@@ -239,6 +256,54 @@ static int read_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn,
 	return cp - start;
 }
 
+struct rsa_params {
+	gcry_mpi_t n, e, d, p, q, u;
+};
+
+static int read_pem_rsa_params(unsigned char *start, unsigned char *end,
+		struct rsa_params *p)
+{
+	unsigned char *cp = start;
+	unsigned bits;
+	int ret;
+
+	ret = read_bignum(cp, end, &p->n, &bits);
+	if (ret < 0)
+		return ret;
+	cp += ret;
+	ret = read_bignum(cp, end, &p->e, NULL);
+	if (ret < 0)
+		goto release_n;
+	cp += ret;
+	ret = read_bignum(cp, end, &p->d, NULL);
+	if (ret < 0)
+		goto release_e;
+	cp += ret;
+	ret = read_bignum(cp, end, &p->p, NULL);
+	if (ret < 0)
+		goto release_d;
+	cp += ret;
+	ret = read_bignum(cp, end, &p->q, NULL);
+	if (ret < 0)
+		goto release_p;
+	cp += ret;
+	ret = read_bignum(cp, end, &p->u, NULL);
+	if (ret < 0)
+		goto release_q;
+	return bits;
+release_q:
+	gcry_mpi_release(p->q);
+release_p:
+	gcry_mpi_release(p->p);
+release_d:
+	gcry_mpi_release(p->d);
+release_e:
+	gcry_mpi_release(p->e);
+release_n:
+	gcry_mpi_release(p->n);
+	return ret;
+}
+
 static int find_privkey_bignum_offset(const unsigned char *data, int len)
 {
 	const unsigned char *p = data, *end = data + len;
@@ -271,96 +336,60 @@ static int find_privkey_bignum_offset(const unsigned char *data, int len)
 	return p - data;
 }
 
-/** Private keys start with this header. */
-#define PRIVATE_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
-/** Private keys end with this footer. */
-#define PRIVATE_KEY_FOOTER "-----END RSA PRIVATE KEY-----"
-
 static int get_private_key(const char *key_file, struct asymmetric_key **result)
 {
-	gcry_mpi_t n = NULL, e = NULL, d = NULL, p = NULL, q = NULL,
-		u = NULL;
-	unsigned char *blob, *cp, *end;
-	int blob_size, ret, n_size;
+	struct rsa_params params;
+	unsigned char *blob, *end;
+	int ret;
+	unsigned bits;
 	gcry_error_t gret;
-	size_t erroff;
+	size_t erroff, blob_size;
 	gcry_sexp_t sexp;
 	struct asymmetric_key *key;
 
 	*result = NULL;
-	ret = decode_key(key_file, PRIVATE_KEY_HEADER, PRIVATE_KEY_FOOTER,
-		&blob);
+	ret = decode_key(key_file, &blob, &blob_size);
 	if (ret < 0)
 		return ret;
-	blob_size = ret;
 	end = blob + blob_size;
 	ret = find_privkey_bignum_offset(blob, blob_size);
 	if (ret < 0)
 		goto free_blob;
 	PARA_INFO_LOG("reading RSA params at offset %d\n", ret);
-	cp = blob + ret;
-
-	ret = read_bignum(cp, end, &n, &n_size);
+	ret = read_pem_rsa_params(blob + ret, end, &params);
 	if (ret < 0)
 		goto free_blob;
-	cp += ret;
-
-	ret = read_bignum(cp, end, &e, NULL);
-	if (ret < 0)
-		goto release_n;
-	cp += ret;
-
-	ret = read_bignum(cp, end, &d, NULL);
-	if (ret < 0)
-		goto release_e;
-	cp += ret;
-
-	ret = read_bignum(cp, end, &p, NULL);
-	if (ret < 0)
-		goto release_d;
-	cp += ret;
-
-	ret = read_bignum(cp, end, &q, NULL);
-	if (ret < 0)
-		goto release_p;
-	cp += ret;
-	ret = read_bignum(cp, end, &u, NULL);
-	if (ret < 0)
-		goto release_q;
+	bits = ret;
 	/*
 	 * OpenSSL uses slightly different parameters than gcrypt. To use these
 	 * parameters we need to swap the values of p and q and recompute u.
 	 */
-	if (gcry_mpi_cmp(p, q) > 0) {
-		gcry_mpi_swap(p, q);
-		gcry_mpi_invm(u, p, q);
+	if (gcry_mpi_cmp(params.p, params.q) > 0) {
+		gcry_mpi_swap(params.p, params.q);
+		gcry_mpi_invm(params.u, params.p, params.q);
 	}
-	gret = gcry_sexp_build(&sexp, &erroff, RSA_PRIVKEY_SEXP,
-		n, e, d, p, q, u);
+	gret = gcry_sexp_build(&sexp, &erroff, RSA_PRIVKEY_SEXP, params.n,
+		params.e, params.d, params.p, params.q, params.u);
 
 	if (gret) {
 		PARA_ERROR_LOG("offset %zu: %s\n", erroff,
 			gcry_strerror(gcry_err_code(gret)));
 		ret = -E_SEXP_BUILD;
-		goto release_u;
+		goto free_params;
 	}
 	key = para_malloc(sizeof(*key));
 	key->sexp = sexp;
 	*result = key;
-	ret = n_size * 8;
+	ret = bits;
 	PARA_INFO_LOG("succesfully read %d bit private key\n", ret);
-release_u:
-	gcry_mpi_release(u);
-release_q:
-	gcry_mpi_release(q);
-release_p:
-	gcry_mpi_release(p);
-release_d:
-	gcry_mpi_release(d);
-release_e:
-	gcry_mpi_release(e);
-release_n:
-	gcry_mpi_release(n);
+free_params:
+	gcry_mpi_release(params.n);
+	gcry_mpi_release(params.e);
+	gcry_mpi_release(params.d);
+	gcry_mpi_release(params.u);
+	gcry_mpi_release(params.p);
+	gcry_mpi_release(params.q);
+
 free_blob:
 	free(blob);
 	return ret;