fdt_add_bignum() is useful for algorithms other than just RSA. To allow its use for ECDSA, move it to a common file under lib/.
The new file is suffixed with '-libcrypto' because it has a direct dependency on openssl. This is due to the use of the "BIGNUM *" type.
Signed-off-by: Alexandru Gagniuc mr.nuke.me@gmail.com --- include/u-boot/fdt-libcrypto.h | 15 +++++++ lib/fdt-libcrypto.c | 72 ++++++++++++++++++++++++++++++++++ lib/rsa/rsa-sign.c | 65 +----------------------------- tools/Makefile | 1 + 4 files changed, 89 insertions(+), 64 deletions(-) create mode 100644 include/u-boot/fdt-libcrypto.h create mode 100644 lib/fdt-libcrypto.c
diff --git a/include/u-boot/fdt-libcrypto.h b/include/u-boot/fdt-libcrypto.h new file mode 100644 index 0000000000..a6873487ed --- /dev/null +++ b/include/u-boot/fdt-libcrypto.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c) 2020, Alexandru Gagniuc mr.nuke.me@gmail.com + * Copyright (c) 2013, Google Inc. + */ + +#ifndef _FDT_LIBCRYPTO_H +#define _FDT_LIBCRYPTO_H + +#include <openssl/bn.h> + +int fdt_add_bignum(void *blob, int noffset, const char *prop_name, + BIGNUM *num, int num_bits); + +#endif /* _FDT_LIBCRYPTO_H */ diff --git a/lib/fdt-libcrypto.c b/lib/fdt-libcrypto.c new file mode 100644 index 0000000000..ecb0344c8f --- /dev/null +++ b/lib/fdt-libcrypto.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2020, Alexandru Gagniuc mr.nuke.me@gmail.com + * Copyright (c) 2013, Google Inc. + */ + +#include <libfdt.h> +#include <u-boot/fdt-libcrypto.h> + +int fdt_add_bignum(void *blob, int noffset, const char *prop_name, + BIGNUM *num, int num_bits) +{ + int nwords = num_bits / 32; + int size; + uint32_t *buf, *ptr; + BIGNUM *tmp, *big2, *big32, *big2_32; + BN_CTX *ctx; + int ret; + + tmp = BN_new(); + big2 = BN_new(); + big32 = BN_new(); + big2_32 = BN_new(); + + /* + * Note: This code assumes that all of the above succeed, or all fail. + * In practice memory allocations generally do not fail (unless the + * process is killed), so it does not seem worth handling each of these + * as a separate case. Technicaly this could leak memory on failure, + * but a) it won't happen in practice, and b) it doesn't matter as we + * will immediately exit with a failure code. + */ + if (!tmp || !big2 || !big32 || !big2_32) { + fprintf(stderr, "Out of memory (bignum)\n"); + return -ENOMEM; + } + ctx = BN_CTX_new(); + if (!ctx) { + fprintf(stderr, "Out of memory (bignum context)\n"); + return -ENOMEM; + } + BN_set_word(big2, 2L); + BN_set_word(big32, 32L); + BN_exp(big2_32, big2, big32, ctx); /* B = 2^32 */ + + size = nwords * sizeof(uint32_t); + buf = malloc(size); + if (!buf) { + fprintf(stderr, "Out of memory (%d bytes)\n", size); + return -ENOMEM; + } + + /* Write out modulus as big endian array of integers */ + for (ptr = buf + nwords - 1; ptr >= buf; ptr--) { + BN_mod(tmp, num, big2_32, ctx); /* n = N mod B */ + *ptr = cpu_to_fdt32(BN_get_word(tmp)); + BN_rshift(num, num, 32); /* N = N/B */ + } + + /* + * We try signing with successively increasing size values, so this + * might fail several times + */ + ret = fdt_setprop(blob, noffset, prop_name, buf, size); + free(buf); + BN_free(tmp); + BN_free(big2); + BN_free(big32); + BN_free(big2_32); + + return ret ? -FDT_ERR_NOSPACE : 0; +} diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c index 1f0d81bd7a..557c690a6d 100644 --- a/lib/rsa/rsa-sign.c +++ b/lib/rsa/rsa-sign.c @@ -9,6 +9,7 @@ #include <string.h> #include <image.h> #include <time.h> +#include <u-boot/fdt-libcrypto.h> #include <openssl/bn.h> #include <openssl/rsa.h> #include <openssl/pem.h> @@ -680,70 +681,6 @@ int rsa_get_params(RSA *key, uint64_t *exponent, uint32_t *n0_invp, return ret; }
-static int fdt_add_bignum(void *blob, int noffset, const char *prop_name, - BIGNUM *num, int num_bits) -{ - int nwords = num_bits / 32; - int size; - uint32_t *buf, *ptr; - BIGNUM *tmp, *big2, *big32, *big2_32; - BN_CTX *ctx; - int ret; - - tmp = BN_new(); - big2 = BN_new(); - big32 = BN_new(); - big2_32 = BN_new(); - - /* - * Note: This code assumes that all of the above succeed, or all fail. - * In practice memory allocations generally do not fail (unless the - * process is killed), so it does not seem worth handling each of these - * as a separate case. Technicaly this could leak memory on failure, - * but a) it won't happen in practice, and b) it doesn't matter as we - * will immediately exit with a failure code. - */ - if (!tmp || !big2 || !big32 || !big2_32) { - fprintf(stderr, "Out of memory (bignum)\n"); - return -ENOMEM; - } - ctx = BN_CTX_new(); - if (!ctx) { - fprintf(stderr, "Out of memory (bignum context)\n"); - return -ENOMEM; - } - BN_set_word(big2, 2L); - BN_set_word(big32, 32L); - BN_exp(big2_32, big2, big32, ctx); /* B = 2^32 */ - - size = nwords * sizeof(uint32_t); - buf = malloc(size); - if (!buf) { - fprintf(stderr, "Out of memory (%d bytes)\n", size); - return -ENOMEM; - } - - /* Write out modulus as big endian array of integers */ - for (ptr = buf + nwords - 1; ptr >= buf; ptr--) { - BN_mod(tmp, num, big2_32, ctx); /* n = N mod B */ - *ptr = cpu_to_fdt32(BN_get_word(tmp)); - BN_rshift(num, num, 32); /* N = N/B */ - } - - /* - * We try signing with successively increasing size values, so this - * might fail several times - */ - ret = fdt_setprop(blob, noffset, prop_name, buf, size); - free(buf); - BN_free(tmp); - BN_free(big2); - BN_free(big32); - BN_free(big2_32); - - return ret ? -FDT_ERR_NOSPACE : 0; -} - int rsa_add_verify_data(struct image_sign_info *info, void *keydest) { BIGNUM *modulus, *r_squared; diff --git a/tools/Makefile b/tools/Makefile index b1595ad814..af7698fd01 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -106,6 +106,7 @@ dumpimage-mkimage-objs := aisimage.o \ socfpgaimage.o \ lib/crc16.o \ lib/hash-checksum.o \ + lib/fdt-libcrypto.o \ lib/sha1.o \ lib/sha256.o \ lib/sha512.o \