From 5a7de97309f5af4458b1a25a2a529a1a893c5269 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Tue, 14 Jun 2016 16:14:58 +0300 Subject: crypto: rsa - return raw integers for the ASN.1 parser Return the raw key with no other processing so that the caller can copy it or MPI parse it, etc. The scope is to have only one ANS.1 parser for all RSA implementations. Update the RSA software implementation so that it does the MPI conversion on top. Signed-off-by: Tudor Ambarus Signed-off-by: Herbert Xu --- crypto/rsa.c | 105 +++++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 80 insertions(+), 25 deletions(-) (limited to 'crypto/rsa.c') diff --git a/crypto/rsa.c b/crypto/rsa.c index 77d737f52147..dc692d43b666 100644 --- a/crypto/rsa.c +++ b/crypto/rsa.c @@ -10,16 +10,23 @@ */ #include +#include #include #include #include #include +struct rsa_mpi_key { + MPI n; + MPI e; + MPI d; +}; + /* * RSAEP function [RFC3447 sec 5.1.1] * c = m^e mod n; */ -static int _rsa_enc(const struct rsa_key *key, MPI c, MPI m) +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) @@ -33,7 +40,7 @@ static int _rsa_enc(const struct rsa_key *key, MPI c, MPI m) * RSADP function [RFC3447 sec 5.1.2] * m = c^d mod n; */ -static int _rsa_dec(const struct rsa_key *key, MPI m, MPI c) +static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c) { /* (1) Validate 0 <= c < n */ if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0) @@ -47,7 +54,7 @@ static int _rsa_dec(const struct rsa_key *key, MPI m, MPI c) * RSASP1 function [RFC3447 sec 5.2.1] * s = m^d mod n */ -static int _rsa_sign(const struct rsa_key *key, MPI s, MPI m) +static int _rsa_sign(const struct rsa_mpi_key *key, MPI s, MPI m) { /* (1) Validate 0 <= m < n */ if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0) @@ -61,7 +68,7 @@ static int _rsa_sign(const struct rsa_key *key, MPI s, MPI m) * RSAVP1 function [RFC3447 sec 5.2.2] * m = s^e mod n; */ -static int _rsa_verify(const struct rsa_key *key, MPI m, MPI s) +static int _rsa_verify(const struct rsa_mpi_key *key, MPI m, MPI s) { /* (1) Validate 0 <= s < n */ if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0) @@ -71,7 +78,7 @@ static int _rsa_verify(const struct rsa_key *key, MPI m, MPI s) return mpi_powm(m, s, key->e, key->n); } -static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm) +static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm) { return akcipher_tfm_ctx(tfm); } @@ -79,7 +86,7 @@ static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm) static int rsa_enc(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); - const struct rsa_key *pkey = rsa_get_key(tfm); + const struct rsa_mpi_key *pkey = rsa_get_key(tfm); MPI m, c = mpi_alloc(0); int ret = 0; int sign; @@ -118,7 +125,7 @@ err_free_c: static int rsa_dec(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); - const struct rsa_key *pkey = rsa_get_key(tfm); + const struct rsa_mpi_key *pkey = rsa_get_key(tfm); MPI c, m = mpi_alloc(0); int ret = 0; int sign; @@ -156,7 +163,7 @@ err_free_m: static int rsa_sign(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); - const struct rsa_key *pkey = rsa_get_key(tfm); + const struct rsa_mpi_key *pkey = rsa_get_key(tfm); MPI m, s = mpi_alloc(0); int ret = 0; int sign; @@ -195,7 +202,7 @@ err_free_s: static int rsa_verify(struct akcipher_request *req) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); - const struct rsa_key *pkey = rsa_get_key(tfm); + const struct rsa_mpi_key *pkey = rsa_get_key(tfm); MPI s, m = mpi_alloc(0); int ret = 0; int sign; @@ -233,6 +240,16 @@ err_free_m: return ret; } +static void rsa_free_mpi_key(struct rsa_mpi_key *key) +{ + mpi_free(key->d); + mpi_free(key->e); + mpi_free(key->n); + key->d = NULL; + key->e = NULL; + key->n = NULL; +} + static int rsa_check_key_length(unsigned int len) { switch (len) { @@ -251,49 +268,87 @@ static int rsa_check_key_length(unsigned int len) static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsigned int keylen) { - struct rsa_key *pkey = akcipher_tfm_ctx(tfm); + struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm); + struct rsa_key raw_key = {0}; int ret; - ret = rsa_parse_pub_key(pkey, key, keylen); + /* Free the old MPI key if any */ + rsa_free_mpi_key(mpi_key); + + ret = rsa_parse_pub_key(&raw_key, key, keylen); if (ret) return ret; - if (rsa_check_key_length(mpi_get_size(pkey->n) << 3)) { - rsa_free_key(pkey); - ret = -EINVAL; + mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz); + if (!mpi_key->e) + goto err; + + mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz); + if (!mpi_key->n) + goto err; + + if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) { + rsa_free_mpi_key(mpi_key); + return -EINVAL; } - return ret; + + return 0; + +err: + rsa_free_mpi_key(mpi_key); + return -ENOMEM; } static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key, unsigned int keylen) { - struct rsa_key *pkey = akcipher_tfm_ctx(tfm); + struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm); + struct rsa_key raw_key = {0}; int ret; - ret = rsa_parse_priv_key(pkey, key, keylen); + /* Free the old MPI key if any */ + rsa_free_mpi_key(mpi_key); + + ret = rsa_parse_priv_key(&raw_key, key, keylen); if (ret) return ret; - if (rsa_check_key_length(mpi_get_size(pkey->n) << 3)) { - rsa_free_key(pkey); - ret = -EINVAL; + mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz); + if (!mpi_key->d) + goto err; + + mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz); + if (!mpi_key->e) + goto err; + + mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz); + if (!mpi_key->n) + goto err; + + if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) { + rsa_free_mpi_key(mpi_key); + return -EINVAL; } - return ret; + + return 0; + +err: + rsa_free_mpi_key(mpi_key); + return -ENOMEM; } static int rsa_max_size(struct crypto_akcipher *tfm) { - struct rsa_key *pkey = akcipher_tfm_ctx(tfm); + struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm); return pkey->n ? mpi_get_size(pkey->n) : -EINVAL; } static void rsa_exit_tfm(struct crypto_akcipher *tfm) { - struct rsa_key *pkey = akcipher_tfm_ctx(tfm); + struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm); - rsa_free_key(pkey); + rsa_free_mpi_key(pkey); } static struct akcipher_alg rsa = { @@ -310,7 +365,7 @@ static struct akcipher_alg rsa = { .cra_driver_name = "rsa-generic", .cra_priority = 100, .cra_module = THIS_MODULE, - .cra_ctxsize = sizeof(struct rsa_key), + .cra_ctxsize = sizeof(struct rsa_mpi_key), }, }; -- cgit From 9b45b7bba3d22de52e09df63c50f390a193a3f53 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 29 Jun 2016 19:32:21 +0800 Subject: crypto: rsa - Generate fixed-length output Every implementation of RSA that we have naturally generates output with leading zeroes. The one and only user of RSA, pkcs1pad wants to have those leading zeroes in place, in fact because they are currently absent it has to write those zeroes itself. So we shouldn't be stripping leading zeroes in the first place. In fact this patch makes rsa-generic produce output with fixed length so that pkcs1pad does not need to do any extra work. This patch also changes DH to use the new interface. Signed-off-by: Herbert Xu --- crypto/dh.c | 2 +- crypto/rsa.c | 8 ++++---- include/linux/mpi.h | 2 +- lib/mpi/mpicoder.c | 55 +++++++++++++++++++++++++---------------------------- 4 files changed, 32 insertions(+), 35 deletions(-) (limited to 'crypto/rsa.c') diff --git a/crypto/dh.c b/crypto/dh.c index 5e960fe28681..9d19360e7189 100644 --- a/crypto/dh.c +++ b/crypto/dh.c @@ -129,7 +129,7 @@ static int dh_compute_value(struct kpp_request *req) if (ret) goto err_free_base; - ret = mpi_write_to_sgl(val, req->dst, &req->dst_len, &sign); + ret = mpi_write_to_sgl(val, req->dst, req->dst_len, &sign); if (ret) goto err_free_base; diff --git a/crypto/rsa.c b/crypto/rsa.c index dc692d43b666..4c280b6a3ea9 100644 --- a/crypto/rsa.c +++ b/crypto/rsa.c @@ -108,7 +108,7 @@ static int rsa_enc(struct akcipher_request *req) if (ret) goto err_free_m; - ret = mpi_write_to_sgl(c, req->dst, &req->dst_len, &sign); + ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign); if (ret) goto err_free_m; @@ -147,7 +147,7 @@ static int rsa_dec(struct akcipher_request *req) if (ret) goto err_free_c; - ret = mpi_write_to_sgl(m, req->dst, &req->dst_len, &sign); + ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign); if (ret) goto err_free_c; @@ -185,7 +185,7 @@ static int rsa_sign(struct akcipher_request *req) if (ret) goto err_free_m; - ret = mpi_write_to_sgl(s, req->dst, &req->dst_len, &sign); + ret = mpi_write_to_sgl(s, req->dst, req->dst_len, &sign); if (ret) goto err_free_m; @@ -226,7 +226,7 @@ static int rsa_verify(struct akcipher_request *req) if (ret) goto err_free_s; - ret = mpi_write_to_sgl(m, req->dst, &req->dst_len, &sign); + ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign); if (ret) goto err_free_s; diff --git a/include/linux/mpi.h b/include/linux/mpi.h index f219559e5e80..1cc5ffb769af 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -80,7 +80,7 @@ void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign); int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, int *sign); void *mpi_get_secure_buffer(MPI a, unsigned *nbytes, int *sign); -int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned *nbytes, +int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes, int *sign); #define log_mpidump g10_log_mpidump diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 823cf5f5196b..7150e5c23604 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -237,16 +237,13 @@ EXPORT_SYMBOL_GPL(mpi_get_buffer); * @a: a multi precision integer * @sgl: scatterlist to write to. Needs to be at least * mpi_get_size(a) long. - * @nbytes: in/out param - it has the be set to the maximum number of - * bytes that can be written to sgl. This has to be at least - * the size of the integer a. On return it receives the actual - * length of the data written on success or the data that would - * be written if buffer was too small. + * @nbytes: the number of bytes to write. Leading bytes will be + * filled with zero. * @sign: if not NULL, it will be set to the sign of a. * * Return: 0 on success or error code in case of error */ -int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, +int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes, int *sign) { u8 *p, *p2; @@ -258,43 +255,44 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, #error please implement for this limb size. #endif unsigned int n = mpi_get_size(a); - int i, x, y = 0, lzeros, buf_len; - - if (!nbytes) - return -EINVAL; + int i, x, buf_len; if (sign) *sign = a->sign; - lzeros = count_lzeros(a); - - if (*nbytes < n - lzeros) { - *nbytes = n - lzeros; + if (nbytes < n) return -EOVERFLOW; - } - *nbytes = n - lzeros; buf_len = sgl->length; p2 = sg_virt(sgl); - for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB, - lzeros %= BYTES_PER_MPI_LIMB; - i >= 0; i--) { + while (nbytes > n) { + if (!buf_len) { + sgl = sg_next(sgl); + if (!sgl) + return -EINVAL; + buf_len = sgl->length; + p2 = sg_virt(sgl); + } + + i = min_t(unsigned, nbytes - n, buf_len); + memset(p2, 0, i); + p2 += i; + buf_len -= i; + nbytes -= i; + } + + for (i = a->nlimbs - 1; i >= 0; i--) { #if BYTES_PER_MPI_LIMB == 4 - alimb = cpu_to_be32(a->d[i]); + alimb = a->d[i] ? cpu_to_be32(a->d[i]) : 0; #elif BYTES_PER_MPI_LIMB == 8 - alimb = cpu_to_be64(a->d[i]); + alimb = a->d[i] ? cpu_to_be64(a->d[i]) : 0; #else #error please implement for this limb size. #endif - if (lzeros) { - y = lzeros; - lzeros = 0; - } - - p = (u8 *)&alimb + y; + p = (u8 *)&alimb; - for (x = 0; x < sizeof(alimb) - y; x++) { + for (x = 0; x < sizeof(alimb); x++) { if (!buf_len) { sgl = sg_next(sgl); if (!sgl) @@ -305,7 +303,6 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, *p2++ = *p++; buf_len--; } - y = 0; } return 0; } -- cgit