diff options
Diffstat (limited to 'crypto/openssh/ssh-rsa.c')
-rw-r--r-- | crypto/openssh/ssh-rsa.c | 265 |
1 files changed, 137 insertions, 128 deletions
diff --git a/crypto/openssh/ssh-rsa.c b/crypto/openssh/ssh-rsa.c index c6f25b3..cdc18a4 100644 --- a/crypto/openssh/ssh-rsa.c +++ b/crypto/openssh/ssh-rsa.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-rsa.c,v 1.51 2014/02/02 03:44:31 djm Exp $ */ +/* $OpenBSD: ssh-rsa.c,v 1.53 2015/06/15 01:32:50 djm Exp $ */ /* * Copyright (c) 2000, 2003 Markus Friedl <markus@openbsd.org> * @@ -17,6 +17,8 @@ #include "includes.h" +#ifdef WITH_OPENSSL + #include <sys/types.h> #include <openssl/evp.h> @@ -25,163 +27,167 @@ #include <stdarg.h> #include <string.h> -#include "xmalloc.h" -#include "log.h" -#include "buffer.h" -#include "key.h" +#include "sshbuf.h" #include "compat.h" -#include "misc.h" -#include "ssh.h" +#include "ssherr.h" +#define SSHKEY_INTERNAL +#include "sshkey.h" #include "digest.h" -static int openssh_RSA_verify(int, u_char *, u_int, u_char *, u_int, RSA *); +static int openssh_RSA_verify(int, u_char *, size_t, u_char *, size_t, RSA *); /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ int -ssh_rsa_sign(const Key *key, u_char **sigp, u_int *lenp, - const u_char *data, u_int datalen) +ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, + const u_char *data, size_t datalen, u_int compat) { int hash_alg; - u_char digest[SSH_DIGEST_MAX_LENGTH], *sig; - u_int slen, dlen, len; - int ok, nid; - Buffer b; + u_char digest[SSH_DIGEST_MAX_LENGTH], *sig = NULL; + size_t slen; + u_int dlen, len; + int nid, ret = SSH_ERR_INTERNAL_ERROR; + struct sshbuf *b = NULL; - if (key == NULL || key_type_plain(key->type) != KEY_RSA || - key->rsa == NULL) { - error("%s: no RSA key", __func__); - return -1; - } + if (lenp != NULL) + *lenp = 0; + if (sigp != NULL) + *sigp = NULL; + + if (key == NULL || key->rsa == NULL || + sshkey_type_plain(key->type) != KEY_RSA) + return SSH_ERR_INVALID_ARGUMENT; + slen = RSA_size(key->rsa); + if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM) + return SSH_ERR_INVALID_ARGUMENT; /* hash the data */ hash_alg = SSH_DIGEST_SHA1; nid = NID_sha1; - if ((dlen = ssh_digest_bytes(hash_alg)) == 0) { - error("%s: bad hash algorithm %d", __func__, hash_alg); - return -1; - } - if (ssh_digest_memory(hash_alg, data, datalen, - digest, sizeof(digest)) != 0) { - error("%s: ssh_digest_memory failed", __func__); - return -1; - } + if ((dlen = ssh_digest_bytes(hash_alg)) == 0) + return SSH_ERR_INTERNAL_ERROR; + if ((ret = ssh_digest_memory(hash_alg, data, datalen, + digest, sizeof(digest))) != 0) + goto out; - slen = RSA_size(key->rsa); - sig = xmalloc(slen); - - ok = RSA_sign(nid, digest, dlen, sig, &len, key->rsa); - explicit_bzero(digest, sizeof(digest)); - - if (ok != 1) { - int ecode = ERR_get_error(); + if ((sig = malloc(slen)) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } - error("%s: RSA_sign failed: %s", __func__, - ERR_error_string(ecode, NULL)); - free(sig); - return -1; + if (RSA_sign(nid, digest, dlen, sig, &len, key->rsa) != 1) { + ret = SSH_ERR_LIBCRYPTO_ERROR; + goto out; } if (len < slen) { - u_int diff = slen - len; - debug("slen %u > len %u", slen, len); + size_t diff = slen - len; memmove(sig + diff, sig, len); explicit_bzero(sig, diff); } else if (len > slen) { - error("%s: slen %u slen2 %u", __func__, slen, len); - free(sig); - return -1; + ret = SSH_ERR_INTERNAL_ERROR; + goto out; } /* encode signature */ - buffer_init(&b); - buffer_put_cstring(&b, "ssh-rsa"); - buffer_put_string(&b, sig, slen); - len = buffer_len(&b); + if ((b = sshbuf_new()) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } + if ((ret = sshbuf_put_cstring(b, "ssh-rsa")) != 0 || + (ret = sshbuf_put_string(b, sig, slen)) != 0) + goto out; + len = sshbuf_len(b); + if (sigp != NULL) { + if ((*sigp = malloc(len)) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } + memcpy(*sigp, sshbuf_ptr(b), len); + } if (lenp != NULL) *lenp = len; - if (sigp != NULL) { - *sigp = xmalloc(len); - memcpy(*sigp, buffer_ptr(&b), len); + ret = 0; + out: + explicit_bzero(digest, sizeof(digest)); + if (sig != NULL) { + explicit_bzero(sig, slen); + free(sig); } - buffer_free(&b); - explicit_bzero(sig, slen); - free(sig); - - return 0; + if (b != NULL) + sshbuf_free(b); + return ret; } int -ssh_rsa_verify(const Key *key, const u_char *signature, u_int signaturelen, - const u_char *data, u_int datalen) +ssh_rsa_verify(const struct sshkey *key, + const u_char *signature, size_t signaturelen, + const u_char *data, size_t datalen, u_int compat) { - Buffer b; - int hash_alg; - char *ktype; - u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob; - u_int len, dlen, modlen; - int rlen, ret; + char *ktype = NULL; + int hash_alg, ret = SSH_ERR_INTERNAL_ERROR; + size_t len, diff, modlen, dlen; + struct sshbuf *b = NULL; + u_char digest[SSH_DIGEST_MAX_LENGTH], *osigblob, *sigblob = NULL; - if (key == NULL || key_type_plain(key->type) != KEY_RSA || - key->rsa == NULL) { - error("%s: no RSA key", __func__); - return -1; - } + if (key == NULL || key->rsa == NULL || + sshkey_type_plain(key->type) != KEY_RSA || + BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) + return SSH_ERR_INVALID_ARGUMENT; - if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) { - error("%s: RSA modulus too small: %d < minimum %d bits", - __func__, BN_num_bits(key->rsa->n), - SSH_RSA_MINIMUM_MODULUS_SIZE); - return -1; + if ((b = sshbuf_from(signature, signaturelen)) == NULL) + return SSH_ERR_ALLOC_FAIL; + if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { + ret = SSH_ERR_INVALID_FORMAT; + goto out; } - buffer_init(&b); - buffer_append(&b, signature, signaturelen); - ktype = buffer_get_cstring(&b, NULL); if (strcmp("ssh-rsa", ktype) != 0) { - error("%s: cannot handle type %s", __func__, ktype); - buffer_free(&b); - free(ktype); - return -1; + ret = SSH_ERR_KEY_TYPE_MISMATCH; + goto out; } - free(ktype); - sigblob = buffer_get_string(&b, &len); - rlen = buffer_len(&b); - buffer_free(&b); - if (rlen != 0) { - error("%s: remaining bytes in signature %d", __func__, rlen); - free(sigblob); - return -1; + if (sshbuf_get_string(b, &sigblob, &len) != 0) { + ret = SSH_ERR_INVALID_FORMAT; + goto out; + } + if (sshbuf_len(b) != 0) { + ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; + goto out; } /* RSA_verify expects a signature of RSA_size */ modlen = RSA_size(key->rsa); if (len > modlen) { - error("%s: len %u > modlen %u", __func__, len, modlen); - free(sigblob); - return -1; + ret = SSH_ERR_KEY_BITS_MISMATCH; + goto out; } else if (len < modlen) { - u_int diff = modlen - len; - debug("%s: add padding: modlen %u > len %u", __func__, - modlen, len); - sigblob = xrealloc(sigblob, 1, modlen); + diff = modlen - len; + osigblob = sigblob; + if ((sigblob = realloc(sigblob, modlen)) == NULL) { + sigblob = osigblob; /* put it back for clear/free */ + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } memmove(sigblob + diff, sigblob, len); explicit_bzero(sigblob, diff); len = modlen; } - /* hash the data */ hash_alg = SSH_DIGEST_SHA1; if ((dlen = ssh_digest_bytes(hash_alg)) == 0) { - error("%s: bad hash algorithm %d", __func__, hash_alg); - return -1; - } - if (ssh_digest_memory(hash_alg, data, datalen, - digest, sizeof(digest)) != 0) { - error("%s: ssh_digest_memory failed", __func__); - return -1; + ret = SSH_ERR_INTERNAL_ERROR; + goto out; } + if ((ret = ssh_digest_memory(hash_alg, data, datalen, + digest, sizeof(digest))) != 0) + goto out; ret = openssh_RSA_verify(hash_alg, digest, dlen, sigblob, len, key->rsa); + out: + if (sigblob != NULL) { + explicit_bzero(sigblob, len); + free(sigblob); + } + if (ktype != NULL) + free(ktype); + if (b != NULL) + sshbuf_free(b); explicit_bzero(digest, sizeof(digest)); - explicit_bzero(sigblob, len); - free(sigblob); - debug("%s: signature %scorrect", __func__, (ret == 0) ? "in" : ""); return ret; } @@ -204,15 +210,15 @@ static const u_char id_sha1[] = { }; static int -openssh_RSA_verify(int hash_alg, u_char *hash, u_int hashlen, - u_char *sigbuf, u_int siglen, RSA *rsa) +openssh_RSA_verify(int hash_alg, u_char *hash, size_t hashlen, + u_char *sigbuf, size_t siglen, RSA *rsa) { - u_int ret, rsasize, oidlen = 0, hlen = 0; + size_t ret, rsasize = 0, oidlen = 0, hlen = 0; int len, oidmatch, hashmatch; const u_char *oid = NULL; u_char *decrypted = NULL; - ret = 0; + ret = SSH_ERR_INTERNAL_ERROR; switch (hash_alg) { case SSH_DIGEST_SHA1: oid = id_sha1; @@ -223,37 +229,40 @@ openssh_RSA_verify(int hash_alg, u_char *hash, u_int hashlen, goto done; } if (hashlen != hlen) { - error("bad hashlen"); + ret = SSH_ERR_INVALID_ARGUMENT; goto done; } rsasize = RSA_size(rsa); - if (siglen == 0 || siglen > rsasize) { - error("bad siglen"); + if (rsasize <= 0 || rsasize > SSHBUF_MAX_BIGNUM || + siglen == 0 || siglen > rsasize) { + ret = SSH_ERR_INVALID_ARGUMENT; + goto done; + } + if ((decrypted = malloc(rsasize)) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; goto done; } - decrypted = xmalloc(rsasize); if ((len = RSA_public_decrypt(siglen, sigbuf, decrypted, rsa, RSA_PKCS1_PADDING)) < 0) { - error("RSA_public_decrypt failed: %s", - ERR_error_string(ERR_get_error(), NULL)); + ret = SSH_ERR_LIBCRYPTO_ERROR; goto done; } - if (len < 0 || (u_int)len != hlen + oidlen) { - error("bad decrypted len: %d != %d + %d", len, hlen, oidlen); + if (len < 0 || (size_t)len != hlen + oidlen) { + ret = SSH_ERR_INVALID_FORMAT; goto done; } oidmatch = timingsafe_bcmp(decrypted, oid, oidlen) == 0; hashmatch = timingsafe_bcmp(decrypted + oidlen, hash, hlen) == 0; - if (!oidmatch) { - error("oid mismatch"); - goto done; - } - if (!hashmatch) { - error("hash mismatch"); + if (!oidmatch || !hashmatch) { + ret = SSH_ERR_SIGNATURE_INVALID; goto done; } - ret = 1; + ret = 0; done: - free(decrypted); + if (decrypted) { + explicit_bzero(decrypted, rsasize); + free(decrypted); + } return ret; } +#endif /* WITH_OPENSSL */ |