diff options
Diffstat (limited to 'crypto/rsa.c')
| -rw-r--r-- | crypto/rsa.c | 110 |
1 files changed, 95 insertions, 15 deletions
diff --git a/crypto/rsa.c b/crypto/rsa.c index c50f2d2a4d06..6c7734083c98 100644 --- a/crypto/rsa.c +++ b/crypto/rsa.c @@ -24,14 +24,38 @@ struct rsa_mpi_key { MPI qinv; }; +static int rsa_check_payload(MPI x, MPI n) +{ + MPI n1; + + if (mpi_cmp_ui(x, 1) <= 0) + return -EINVAL; + + n1 = mpi_alloc(0); + if (!n1) + return -ENOMEM; + + if (mpi_sub_ui(n1, n, 1) || mpi_cmp(x, n1) >= 0) { + mpi_free(n1); + return -EINVAL; + } + + mpi_free(n1); + return 0; +} + /* * RSAEP function [RFC3447 sec 5.1.1] * c = m^e mod n; */ static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m) { - /* (1) Validate 0 <= m < n */ - if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0) + /* + * Even though (1) in RFC3447 only requires 0 <= m <= n - 1, we are + * slightly more conservative and require 1 < m < n - 1. This is in line + * with SP 800-56Br2, Section 7.1.1. + */ + if (rsa_check_payload(m, key->n)) return -EINVAL; /* (2) c = m^e mod n */ @@ -50,8 +74,12 @@ static int _rsa_dec_crt(const struct rsa_mpi_key *key, MPI m_or_m1_or_h, MPI c) MPI m2, m12_or_qh; int ret = -ENOMEM; - /* (1) Validate 0 <= c < n */ - if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0) + /* + * Even though (1) in RFC3447 only requires 0 <= c <= n - 1, we are + * slightly more conservative and require 1 < c < n - 1. This is in line + * with SP 800-56Br2, Section 7.1.2. + */ + if (rsa_check_payload(c, key->n)) return -EINVAL; m2 = mpi_alloc(0); @@ -70,14 +98,13 @@ static int _rsa_dec_crt(const struct rsa_mpi_key *key, MPI m_or_m1_or_h, MPI c) goto err_free_mpi; /* (2iii) h = (m_1 - m_2) * qInv mod p */ - mpi_sub(m12_or_qh, m_or_m1_or_h, m2); - mpi_mulm(m_or_m1_or_h, m12_or_qh, key->qinv, key->p); + ret = mpi_sub(m12_or_qh, m_or_m1_or_h, m2) ?: + mpi_mulm(m_or_m1_or_h, m12_or_qh, key->qinv, key->p); /* (2iv) m = m_2 + q * h */ - mpi_mul(m12_or_qh, key->q, m_or_m1_or_h); - mpi_addm(m_or_m1_or_h, m2, m12_or_qh, key->n); - - ret = 0; + ret = ret ?: + mpi_mul(m12_or_qh, key->q, m_or_m1_or_h) ?: + mpi_addm(m_or_m1_or_h, m2, m12_or_qh, key->n); err_free_mpi: mpi_free(m12_or_qh); @@ -205,6 +232,40 @@ static int rsa_check_key_length(unsigned int len) return -EINVAL; } +static int rsa_check_exponent_fips(MPI e) +{ + MPI e_max = NULL; + int err; + + /* check if odd */ + if (!mpi_test_bit(e, 0)) { + return -EINVAL; + } + + /* check if 2^16 < e < 2^256. */ + if (mpi_cmp_ui(e, 65536) <= 0) { + return -EINVAL; + } + + e_max = mpi_alloc(0); + if (!e_max) + return -ENOMEM; + + err = mpi_set_bit(e_max, 256); + if (err) { + mpi_free(e_max); + return err; + } + + if (mpi_cmp(e, e_max) >= 0) { + mpi_free(e_max); + return -EINVAL; + } + + mpi_free(e_max); + return 0; +} + static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsigned int keylen) { @@ -232,6 +293,11 @@ static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, return -EINVAL; } + if (fips_enabled && rsa_check_exponent_fips(mpi_key->e)) { + rsa_free_mpi_key(mpi_key); + return -EINVAL; + } + return 0; err: @@ -290,6 +356,11 @@ static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key, return -EINVAL; } + if (fips_enabled && rsa_check_exponent_fips(mpi_key->e)) { + rsa_free_mpi_key(mpi_key); + return -EINVAL; + } + return 0; err: @@ -336,21 +407,30 @@ static int __init rsa_init(void) return err; err = crypto_register_template(&rsa_pkcs1pad_tmpl); - if (err) { - crypto_unregister_akcipher(&rsa); - return err; - } + if (err) + goto err_unregister_rsa; + + err = crypto_register_template(&rsassa_pkcs1_tmpl); + if (err) + goto err_unregister_rsa_pkcs1pad; return 0; + +err_unregister_rsa_pkcs1pad: + crypto_unregister_template(&rsa_pkcs1pad_tmpl); +err_unregister_rsa: + crypto_unregister_akcipher(&rsa); + return err; } static void __exit rsa_exit(void) { + crypto_unregister_template(&rsassa_pkcs1_tmpl); crypto_unregister_template(&rsa_pkcs1pad_tmpl); crypto_unregister_akcipher(&rsa); } -subsys_initcall(rsa_init); +module_init(rsa_init); module_exit(rsa_exit); MODULE_ALIAS_CRYPTO("rsa"); MODULE_LICENSE("GPL"); |