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From 754862899058cfb5f2341c81f9e04dd2f7b37056 Mon Sep 17 00:00:00 2001 |
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From: Clemens Lang <cllang@redhat.com> |
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Date: Thu, 17 Nov 2022 18:37:17 +0100 |
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Subject: [PATCH] pbkdf2: Set minimum password length of 8 bytes |
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MIME-Version: 1.0 |
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Content-Type: text/plain; charset=UTF-8 |
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Content-Transfer-Encoding: 8bit |
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The Implementation Guidance for FIPS 140-3 says in section D.N |
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"Password-Based Key Derivation for Storage Applications" that "the |
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vendor shall document in the module’s Security Policy the length of |
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a password/passphrase used in key derivation and establish an upper |
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bound for the probability of having this parameter guessed at random. |
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This probability shall take into account not only the length of the |
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password/passphrase, but also the difficulty of guessing it. The |
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decision on the minimum length of a password used for key derivation is |
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the vendor’s, but the vendor shall at a minimum informally justify the |
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decision." |
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We are choosing a minimum password length of 8 bytes, because NIST's |
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ACVP testing uses passwords as short as 8 bytes, and requiring longer |
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passwords combined with an implicit indicator (i.e., returning an error) |
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would cause the module to fail ACVP testing. |
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Signed-off-by: Clemens Lang <cllang@redhat.com> |
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--- |
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providers/implementations/kdfs/pbkdf2.c | 27 ++++++++++++++++++++++++- |
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1 file changed, 26 insertions(+), 1 deletion(-) |
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diff --git a/providers/implementations/kdfs/pbkdf2.c b/providers/implementations/kdfs/pbkdf2.c |
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index 2a0ae63acc..aa0adce5e6 100644 |
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--- a/providers/implementations/kdfs/pbkdf2.c |
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+++ b/providers/implementations/kdfs/pbkdf2.c |
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@@ -35,6 +35,21 @@ |
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#define KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO 0xFFFFFFFF |
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#define KDF_PBKDF2_MIN_ITERATIONS 1000 |
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#define KDF_PBKDF2_MIN_SALT_LEN (128 / 8) |
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+/* The Implementation Guidance for FIPS 140-3 says in section D.N |
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+ * "Password-Based Key Derivation for Storage Applications" that "the vendor |
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+ * shall document in the module’s Security Policy the length of |
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+ * a password/passphrase used in key derivation and establish an upper bound |
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+ * for the probability of having this parameter guessed at random. This |
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+ * probability shall take into account not only the length of the |
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+ * password/passphrase, but also the difficulty of guessing it. The decision on |
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+ * the minimum length of a password used for key derivation is the vendor’s, |
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+ * but the vendor shall at a minimum informally justify the decision." |
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+ * |
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+ * We are choosing a minimum password length of 8 bytes, because NIST's ACVP |
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+ * testing uses passwords as short as 8 bytes, and requiring longer passwords |
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+ * combined with an implicit indicator (i.e., returning an error) would cause |
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+ * the module to fail ACVP testing. */ |
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+#define KDF_PBKDF2_MIN_PASSWORD_LEN (8) |
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static OSSL_FUNC_kdf_newctx_fn kdf_pbkdf2_new; |
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static OSSL_FUNC_kdf_freectx_fn kdf_pbkdf2_free; |
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@@ -186,9 +201,15 @@ static int kdf_pbkdf2_set_ctx_params(void *vctx, const OSSL_PARAM params[]) |
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ctx->lower_bound_checks = pkcs5 == 0; |
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} |
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- if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL) |
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+ if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL) { |
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+ if (ctx->lower_bound_checks != 0 |
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+ && p->data_size < KDF_PBKDF2_MIN_PASSWORD_LEN) { |
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+ ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH); |
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+ return 0; |
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+ } |
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if (!pbkdf2_set_membuf(&ctx->pass, &ctx->pass_len, p)) |
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return 0; |
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+ } |
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if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) { |
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if (ctx->lower_bound_checks != 0 |
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@@ -297,6 +318,10 @@ static int pbkdf2_derive(const char *pass, size_t passlen, |
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} |
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if (lower_bound_checks) { |
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+ if (passlen < KDF_PBKDF2_MIN_PASSWORD_LEN) { |
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+ ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH); |
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+ return 0; |
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+ } |
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if ((keylen * 8) < KDF_PBKDF2_MIN_KEY_LEN_BITS) { |
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ERR_raise(ERR_LIB_PROV, PROV_R_KEY_SIZE_TOO_SMALL); |
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return 0; |
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-- |
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2.38.1 |
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