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Ensure that rc5 doesn't try to use a key longer than 2040 bits

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The maximum key length for rc5 is 2040 bits so we should not attempt to
use keys longer than this.

Issue found by OSS-Fuzz and Guido Vranken.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8834)
This commit is contained in:
Matt Caswell 2019-04-26 12:11:13 +01:00
parent 08607613d5
commit 792cb4ee8d
5 changed files with 31 additions and 5 deletions
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2
crypto/err/openssl.txt
View file

@ -889,6 +889,7 @@ EVP_F_PKEY_SET_TYPE:158:pkey_set_type
EVP_F_POLY1305_CTRL:216:poly1305_ctrl
EVP_F_RC2_MAGIC_TO_METH:109:rc2_magic_to_meth
EVP_F_RC5_CTRL:125:rc5_ctrl
EVP_F_R_32_12_16_INIT_KEY:242:r_32_12_16_init_key
EVP_F_S390X_AES_GCM_CTRL:201:s390x_aes_gcm_ctrl
EVP_F_S390X_AES_GCM_TLS_CIPHER:208:s390x_aes_gcm_tls_cipher
EVP_F_SCRYPT_ALG:228:scrypt_alg
@ -2385,6 +2386,7 @@ ESS_R_ESS_SIGNING_CERT_V2_ADD_ERROR:101:ess signing cert v2 add error
EVP_R_AES_KEY_SETUP_FAILED:143:aes key setup failed
EVP_R_ARIA_KEY_SETUP_FAILED:176:aria key setup failed
EVP_R_BAD_DECRYPT:100:bad decrypt
EVP_R_BAD_KEY_LENGTH:195:bad key length
EVP_R_BUFFER_TOO_SMALL:155:buffer too small
EVP_R_CAMELLIA_KEY_SETUP_FAILED:157:camellia key setup failed
EVP_R_CIPHER_NOT_GCM_MODE:184:cipher not gcm mode

4
crypto/evp/e_rc5.c
View file

@ -66,6 +66,10 @@ static int rc5_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
static int r_32_12_16_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
const unsigned char *iv, int enc)
{
if (EVP_CIPHER_CTX_key_length(ctx) > 255) {
EVPerr(EVP_F_R_32_12_16_INIT_KEY, EVP_R_BAD_KEY_LENGTH);
return 0;
}
RC5_32_set_key(&data(ctx)->ks, EVP_CIPHER_CTX_key_length(ctx),
key, data(ctx)->rounds);
return 1;

3
crypto/evp/evp_err.c
View file

@ -185,6 +185,8 @@ static const ERR_STRING_DATA EVP_str_functs[] = {
{ERR_PACK(ERR_LIB_EVP, EVP_F_POLY1305_CTRL, 0), "poly1305_ctrl"},
{ERR_PACK(ERR_LIB_EVP, EVP_F_RC2_MAGIC_TO_METH, 0), "rc2_magic_to_meth"},
{ERR_PACK(ERR_LIB_EVP, EVP_F_RC5_CTRL, 0), "rc5_ctrl"},
{ERR_PACK(ERR_LIB_EVP, EVP_F_R_32_12_16_INIT_KEY, 0),
"r_32_12_16_init_key"},
{ERR_PACK(ERR_LIB_EVP, EVP_F_S390X_AES_GCM_CTRL, 0), "s390x_aes_gcm_ctrl"},
{ERR_PACK(ERR_LIB_EVP, EVP_F_S390X_AES_GCM_TLS_CIPHER, 0),
"s390x_aes_gcm_tls_cipher"},
@ -199,6 +201,7 @@ static const ERR_STRING_DATA EVP_str_reasons[] = {
{ERR_PACK(ERR_LIB_EVP, 0, EVP_R_ARIA_KEY_SETUP_FAILED),
"aria key setup failed"},
{ERR_PACK(ERR_LIB_EVP, 0, EVP_R_BAD_DECRYPT), "bad decrypt"},
{ERR_PACK(ERR_LIB_EVP, 0, EVP_R_BAD_KEY_LENGTH), "bad key length"},
{ERR_PACK(ERR_LIB_EVP, 0, EVP_R_BUFFER_TOO_SMALL), "buffer too small"},
{ERR_PACK(ERR_LIB_EVP, 0, EVP_R_CAMELLIA_KEY_SETUP_FAILED),
"camellia key setup failed"},

25
doc/man3/EVP_rc5_32_12_16_cbc.pod
View file

@ -33,7 +33,26 @@ EVP_rc5_32_12_16_ofb()
RC5 encryption algorithm in CBC, CFB, ECB and OFB modes respectively. This is a
variable key length cipher with an additional "number of rounds" parameter. By
default the key length is set to 128 bits and 12 rounds.
default the key length is set to 128 bits and 12 rounds. Alternative key lengths
can be set using L<EVP_CIPHER_CTX_set_key_length(3)>. The maximum key length is
2040 bits.
The following rc5 specific I<ctrl>s are supported (see
L<EVP_CIPHER_CTX_ctrl(3)>).
=over 4
=item EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, rounds, NULL)
Sets the number of rounds to B<rounds>. This must be one of RC5_8_ROUNDS,
RC5_12_ROUNDS or RC5_16_ROUNDS.
=item EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC5_ROUNDS, 0, &rounds)
Stores the number of rounds currently configured in B<*rounds> where B<*rounds>
is an int.
=back
=back
@ -43,10 +62,6 @@ These functions return an B<EVP_CIPHER> structure that contains the
implementation of the symmetric cipher. See L<EVP_CIPHER_meth_new(3)> for
details of the B<EVP_CIPHER> structure.
=head1 BUGS
Currently the number of rounds in RC5 can only be set to 8, 12 or 16.
This is a limitation of the current RC5 code rather than the EVP interface.
=head1 SEE ALSO

2
include/openssl/evperr.h
View file

@ -151,6 +151,7 @@ int ERR_load_EVP_strings(void);
# define EVP_F_POLY1305_CTRL 216
# define EVP_F_RC2_MAGIC_TO_METH 109
# define EVP_F_RC5_CTRL 125
# define EVP_F_R_32_12_16_INIT_KEY 242
# define EVP_F_S390X_AES_GCM_CTRL 201
# define EVP_F_S390X_AES_GCM_TLS_CIPHER 208
# define EVP_F_SCRYPT_ALG 228
@ -162,6 +163,7 @@ int ERR_load_EVP_strings(void);
# define EVP_R_AES_KEY_SETUP_FAILED 143
# define EVP_R_ARIA_KEY_SETUP_FAILED 176
# define EVP_R_BAD_DECRYPT 100
# define EVP_R_BAD_KEY_LENGTH 195
# define EVP_R_BUFFER_TOO_SMALL 155
# define EVP_R_CAMELLIA_KEY_SETUP_FAILED 157
# define EVP_R_CIPHER_NOT_GCM_MODE 184