diff options
author | Dr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com> | 2019-10-03 14:20:52 +0200 |
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committer | Dr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com> | 2019-10-03 14:38:57 +0200 |
commit | 1a9a56865cb66d9fca067ba00d0e030f4b6974aa (patch) | |
tree | b7bd543f0d367b3ba25196bbefa02032ae105ff0 /crypto/rsa/rsa_pk1.c | |
parent | 6f3ccda84fb0995166252cc0db2ff3df17539b2b (diff) |
rsa: replace magic number '11' by RSA_PKCS1_PADDING_SIZE
Suggested by Matt Hart
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10084)
(cherry picked from commit f1d1903dd3dd1d68a5eae190b8c2a88bfe0a68ac)
Diffstat (limited to 'crypto/rsa/rsa_pk1.c')
-rw-r--r-- | crypto/rsa/rsa_pk1.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/crypto/rsa/rsa_pk1.c b/crypto/rsa/rsa_pk1.c index 5deab15173..a3d0b7cef8 100644 --- a/crypto/rsa/rsa_pk1.c +++ b/crypto/rsa/rsa_pk1.c @@ -57,7 +57,7 @@ int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen, * D - data. */ - if (num < 11) + if (num < RSA_PKCS1_PADDING_SIZE) return -1; /* Accept inputs with and without the leading 0-byte. */ @@ -120,7 +120,7 @@ int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen, int i, j; unsigned char *p; - if (flen > (tlen - 11)) { + if (flen > (tlen - RSA_PKCS1_PADDING_SIZE)) { RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2, RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); return 0; @@ -169,7 +169,7 @@ int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, * section 7.2.2. */ - if (flen > num || num < 11) { + if (flen > num || num < RSA_PKCS1_PADDING_SIZE) { RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, RSA_R_PKCS_DECODING_ERROR); return -1; @@ -226,8 +226,8 @@ int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, good &= constant_time_ge(tlen, mlen); /* - * Move the result in-place by |num|-11-|mlen| bytes to the left. - * Then if |good| move |mlen| bytes from |em|+11 to |to|. + * Move the result in-place by |num|-RSA_PKCS1_PADDING_SIZE-|mlen| bytes to the left. + * Then if |good| move |mlen| bytes from |em|+RSA_PKCS1_PADDING_SIZE to |to|. * Otherwise leave |to| unchanged. * Copy the memory back in a way that does not reveal the size of * the data being copied via a timing side channel. This requires copying @@ -235,16 +235,16 @@ int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, * length. Clear bits do a non-copy with identical access pattern. * The loop below has overall complexity of O(N*log(N)). */ - tlen = constant_time_select_int(constant_time_lt(num - 11, tlen), - num - 11, tlen); - for (msg_index = 1; msg_index < num - 11; msg_index <<= 1) { - mask = ~constant_time_eq(msg_index & (num - 11 - mlen), 0); - for (i = 11; i < num - msg_index; i++) + tlen = constant_time_select_int(constant_time_lt(num - RSA_PKCS1_PADDING_SIZE, tlen), + num - RSA_PKCS1_PADDING_SIZE, tlen); + for (msg_index = 1; msg_index < num - RSA_PKCS1_PADDING_SIZE; msg_index <<= 1) { + mask = ~constant_time_eq(msg_index & (num - RSA_PKCS1_PADDING_SIZE - mlen), 0); + for (i = RSA_PKCS1_PADDING_SIZE; i < num - msg_index; i++) em[i] = constant_time_select_8(mask, em[i + msg_index], em[i]); } for (i = 0; i < tlen; i++) { mask = good & constant_time_lt(i, mlen); - to[i] = constant_time_select_8(mask, em[i + 11], to[i]); + to[i] = constant_time_select_8(mask, em[i + RSA_PKCS1_PADDING_SIZE], to[i]); } OPENSSL_clear_free(em, num); |