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| author | Stefan Berger <stefanb@linux.ibm.com> | 2024-04-04 10:18:45 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-01-09 13:31:40 +0100 |
| commit | e7fcd5d696c4d020b4218f5015631596ab382475 (patch) | |
| tree | f15df8a34091533f29a30bc5f8b05b75133dcba4 /crypto | |
| parent | 93011887013dbaa0e3a0285176ca89be153df651 (diff) | |
| download | linux-e7fcd5d696c4d020b4218f5015631596ab382475.tar.gz linux-e7fcd5d696c4d020b4218f5015631596ab382475.tar.bz2 linux-e7fcd5d696c4d020b4218f5015631596ab382475.zip | |
crypto: ecdsa - Convert byte arrays with key coordinates to digits
[ Upstream commit d67c96fb97b5811e15c881d5cb72e293faa5f8e1 ]
For NIST P192/256/384 the public key's x and y parameters could be copied
directly from a given array since both parameters filled 'ndigits' of
digits (a 'digit' is a u64). For support of NIST P521 the key parameters
need to have leading zeros prepended to the most significant digit since
only 2 bytes of the most significant digit are provided.
Therefore, implement ecc_digits_from_bytes to convert a byte array into an
array of digits and use this function in ecdsa_set_pub_key where an input
byte array needs to be converted into digits.
Suggested-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: 3b0565c70350 ("crypto: ecdsa - Avoid signed integer overflow on signature decoding")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/ecdsa.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c index 3f9ec273a121..e819d0983bd3 100644 --- a/crypto/ecdsa.c +++ b/crypto/ecdsa.c @@ -222,9 +222,8 @@ static int ecdsa_ecc_ctx_reset(struct ecc_ctx *ctx) static int ecdsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsigned int keylen) { struct ecc_ctx *ctx = akcipher_tfm_ctx(tfm); + unsigned int digitlen, ndigits; const unsigned char *d = key; - const u64 *digits = (const u64 *)&d[1]; - unsigned int ndigits; int ret; ret = ecdsa_ecc_ctx_reset(ctx); @@ -238,12 +237,17 @@ static int ecdsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsig return -EINVAL; keylen--; - ndigits = (keylen >> 1) / sizeof(u64); + digitlen = keylen >> 1; + + ndigits = DIV_ROUND_UP(digitlen, sizeof(u64)); if (ndigits != ctx->curve->g.ndigits) return -EINVAL; - ecc_swap_digits(digits, ctx->pub_key.x, ndigits); - ecc_swap_digits(&digits[ndigits], ctx->pub_key.y, ndigits); + d++; + + ecc_digits_from_bytes(d, digitlen, ctx->pub_key.x, ndigits); + ecc_digits_from_bytes(&d[digitlen], digitlen, ctx->pub_key.y, ndigits); + ret = ecc_is_pubkey_valid_full(ctx->curve, &ctx->pub_key); ctx->pub_key_set = ret == 0; |