From: Lukas Wunner Date: Mon, 7 Apr 2025 19:32:42 +0000 (+0200) Subject: crypto: ecdsa - Fix NIST P521 key size reported by KEYCTL_PKEY_QUERY X-Git-Tag: v6.16-rc1~206^2~280 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b7f9397c98c72902f9364056413c73fe6dee1d8;p=thirdparty%2Fkernel%2Flinux.git crypto: ecdsa - Fix NIST P521 key size reported by KEYCTL_PKEY_QUERY When user space issues a KEYCTL_PKEY_QUERY system call for a NIST P521 key, the key_size is incorrectly reported as 528 bits instead of 521. That's because the key size obtained through crypto_sig_keysize() is in bytes and software_key_query() multiplies by 8 to yield the size in bits. The underlying assumption is that the key size is always a multiple of 8. With the recent addition of NIST P521, that's no longer the case. Fix by returning the key_size in bits from crypto_sig_keysize() and adjusting the calculations in software_key_query(). The ->key_size() callbacks of sig_alg algorithms now return the size in bits, whereas the ->digest_size() and ->max_size() callbacks return the size in bytes. This matches with the units in struct keyctl_pkey_query. Fixes: a7d45ba77d3d ("crypto: ecdsa - Register NIST P521 and extend test suite") Signed-off-by: Lukas Wunner Reviewed-by: Stefan Berger Reviewed-by: Ignat Korchagin Signed-off-by: Herbert Xu --- diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index dd44a966947fb..89dc887d2c5c7 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -205,6 +205,7 @@ static int software_key_query(const struct kernel_pkey_params *params, goto error_free_tfm; len = crypto_sig_keysize(sig); + info->key_size = len; info->max_sig_size = crypto_sig_maxsize(sig); info->max_data_size = crypto_sig_digestsize(sig); @@ -213,8 +214,8 @@ static int software_key_query(const struct kernel_pkey_params *params, info->supported_ops |= KEYCTL_SUPPORTS_SIGN; if (strcmp(params->encoding, "pkcs1") == 0) { - info->max_enc_size = len; - info->max_dec_size = len; + info->max_enc_size = len / BITS_PER_BYTE; + info->max_dec_size = len / BITS_PER_BYTE; info->supported_ops |= KEYCTL_SUPPORTS_ENCRYPT; if (pkey->key_is_private) @@ -235,6 +236,7 @@ static int software_key_query(const struct kernel_pkey_params *params, goto error_free_tfm; len = crypto_akcipher_maxsize(tfm); + info->key_size = len * BITS_PER_BYTE; info->max_sig_size = len; info->max_data_size = len; info->max_enc_size = len; @@ -245,8 +247,6 @@ static int software_key_query(const struct kernel_pkey_params *params, info->supported_ops |= KEYCTL_SUPPORTS_DECRYPT; } - info->key_size = len * 8; - ret = 0; error_free_tfm: diff --git a/crypto/ecdsa-p1363.c b/crypto/ecdsa-p1363.c index 4454f1f8f33f5..e0c55c64711c8 100644 --- a/crypto/ecdsa-p1363.c +++ b/crypto/ecdsa-p1363.c @@ -21,7 +21,8 @@ static int ecdsa_p1363_verify(struct crypto_sig *tfm, const void *digest, unsigned int dlen) { struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); - unsigned int keylen = crypto_sig_keysize(ctx->child); + unsigned int keylen = DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child), + BITS_PER_BYTE); unsigned int ndigits = DIV_ROUND_UP_POW2(keylen, sizeof(u64)); struct ecdsa_raw_sig sig; @@ -45,7 +46,8 @@ static unsigned int ecdsa_p1363_max_size(struct crypto_sig *tfm) { struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); - return 2 * crypto_sig_keysize(ctx->child); + return 2 * DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child), + BITS_PER_BYTE); } static unsigned int ecdsa_p1363_digest_size(struct crypto_sig *tfm) diff --git a/crypto/ecdsa-x962.c b/crypto/ecdsa-x962.c index 90a04f4b9a2f5..ee71594d10a06 100644 --- a/crypto/ecdsa-x962.c +++ b/crypto/ecdsa-x962.c @@ -82,7 +82,7 @@ static int ecdsa_x962_verify(struct crypto_sig *tfm, int err; sig_ctx.ndigits = DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child), - sizeof(u64)); + sizeof(u64) * BITS_PER_BYTE); err = asn1_ber_decoder(&ecdsasignature_decoder, &sig_ctx, src, slen); if (err < 0) @@ -103,7 +103,8 @@ static unsigned int ecdsa_x962_max_size(struct crypto_sig *tfm) { struct ecdsa_x962_ctx *ctx = crypto_sig_ctx(tfm); struct sig_alg *alg = crypto_sig_alg(ctx->child); - int slen = crypto_sig_keysize(ctx->child); + int slen = DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child), + BITS_PER_BYTE); /* * Verify takes ECDSA-Sig-Value (described in RFC 5480) as input, diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c index 117526d15ddeb..a70b60a90a3c7 100644 --- a/crypto/ecdsa.c +++ b/crypto/ecdsa.c @@ -167,7 +167,7 @@ static unsigned int ecdsa_key_size(struct crypto_sig *tfm) { struct ecc_ctx *ctx = crypto_sig_ctx(tfm); - return DIV_ROUND_UP(ctx->curve->nbits, 8); + return ctx->curve->nbits; } static unsigned int ecdsa_digest_size(struct crypto_sig *tfm) diff --git a/crypto/ecrdsa.c b/crypto/ecrdsa.c index b3dd8a3ddeb79..2c0602f0cd406 100644 --- a/crypto/ecrdsa.c +++ b/crypto/ecrdsa.c @@ -249,7 +249,7 @@ static unsigned int ecrdsa_key_size(struct crypto_sig *tfm) * Verify doesn't need any output, so it's just informational * for keyctl to determine the key bit size. */ - return ctx->pub_key.ndigits * sizeof(u64); + return ctx->pub_key.ndigits * sizeof(u64) * BITS_PER_BYTE; } static unsigned int ecrdsa_max_size(struct crypto_sig *tfm) diff --git a/crypto/rsassa-pkcs1.c b/crypto/rsassa-pkcs1.c index d01ac75635e00..94fa5e9600e79 100644 --- a/crypto/rsassa-pkcs1.c +++ b/crypto/rsassa-pkcs1.c @@ -301,7 +301,7 @@ static unsigned int rsassa_pkcs1_key_size(struct crypto_sig *tfm) { struct rsassa_pkcs1_ctx *ctx = crypto_sig_ctx(tfm); - return ctx->key_size; + return ctx->key_size * BITS_PER_BYTE; } static int rsassa_pkcs1_set_pub_key(struct crypto_sig *tfm, diff --git a/crypto/sig.c b/crypto/sig.c index dfc7cae908028..53a3dd6fbe3fe 100644 --- a/crypto/sig.c +++ b/crypto/sig.c @@ -102,6 +102,11 @@ static int sig_default_set_key(struct crypto_sig *tfm, return -ENOSYS; } +static unsigned int sig_default_size(struct crypto_sig *tfm) +{ + return DIV_ROUND_UP_POW2(crypto_sig_keysize(tfm), BITS_PER_BYTE); +} + static int sig_prepare_alg(struct sig_alg *alg) { struct crypto_alg *base = &alg->base; @@ -117,9 +122,9 @@ static int sig_prepare_alg(struct sig_alg *alg) if (!alg->key_size) return -EINVAL; if (!alg->max_size) - alg->max_size = alg->key_size; + alg->max_size = sig_default_size; if (!alg->digest_size) - alg->digest_size = alg->key_size; + alg->digest_size = sig_default_size; base->cra_type = &crypto_sig_type; base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; diff --git a/include/crypto/sig.h b/include/crypto/sig.h index 11024708c0692..fa6dafafab3f0 100644 --- a/include/crypto/sig.h +++ b/include/crypto/sig.h @@ -128,7 +128,7 @@ static inline void crypto_free_sig(struct crypto_sig *tfm) /** * crypto_sig_keysize() - Get key size * - * Function returns the key size in bytes. + * Function returns the key size in bits. * Function assumes that the key is already set in the transformation. If this * function is called without a setkey or with a failed setkey, you may end up * in a NULL dereference.