From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heinrich Schuchardt Date: Wed, 8 Jan 2020 19:07:01 +0100 Subject: [PATCH v4 4/6] lib: rsa: generate additional parameters for public key In-Reply-To: <20191121001121.21854-5-takahiro.akashi@linaro.org> References: <20191121001121.21854-1-takahiro.akashi@linaro.org> <20191121001121.21854-5-takahiro.akashi@linaro.org> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 11/21/19 1:11 AM, AKASHI Takahiro wrote: > In the current implementation of FIT_SIGNATURE, five parameters for > a RSA public key are required while only two of them are essential. > (See rsa-mod-exp.h and uImage.FIT/signature.txt) > This is a result of considering relatively limited computer power > and resources on embedded systems, while such a assumption may not > be quite practical for other use cases. > > In this patch, added is a function, rsa_gen_key_prop(), which will > generate additional parameters for other uses, in particular > UEFI secure boot, on the fly. > > Note: the current code uses some "big number" rouKtines from BearSSL > for the calculation. > > Signed-off-by: AKASHI Takahiro > --- > include/u-boot/rsa-mod-exp.h | 23 ++ > lib/rsa/Kconfig | 1 + > lib/rsa/Makefile | 1 + > lib/rsa/rsa-keyprop.c | 725 +++++++++++++++++++++++++++++++++++ > 4 files changed, 750 insertions(+) > create mode 100644 lib/rsa/rsa-keyprop.c > > diff --git a/include/u-boot/rsa-mod-exp.h b/include/u-boot/rsa-mod-exp.h > index 8a428c4b6a1a..1da8af1bb83d 100644 > --- a/include/u-boot/rsa-mod-exp.h > +++ b/include/u-boot/rsa-mod-exp.h > @@ -26,6 +26,29 @@ struct key_prop { > uint32_t exp_len; /* Exponent length in number of uint8_t */ > }; > > +/** > + * rsa_gen_key_prop() - Generate key properties of RSA public key > + * @key: Specifies key data in DER format > + * @keylen: Length of @key > + * @prop: Generated key property > + * > + * This function takes a blob of encoded RSA public key data in DER > + * format, parse it and generate all the relevant properties > + * in key_prop structure. > + * Return a pointer to struct key_prop in @prop on success. > + * > + * Return: 0 on success, negative on error > + */ > +int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **proc); > + > +/** > + * rsa_free_key_prop() - Free key properties > + * @prop: Pointer to struct key_prop > + * > + * This function frees all the memories allocated by rsa_gen_key_prop(). > + */ > +void rsa_free_key_prop(struct key_prop *prop); > + > /** > * rsa_mod_exp_sw() - Perform RSA Modular Exponentiation in sw > * > diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig > index 71e4c06bf883..d1d6f6cf64a3 100644 > --- a/lib/rsa/Kconfig > +++ b/lib/rsa/Kconfig > @@ -33,6 +33,7 @@ config RSA_VERIFY > config RSA_VERIFY_WITH_PKEY > bool "Execute RSA verification without key parameters from FDT" > depends on RSA > + imply RSA_PUBLIC_KEY_PARSER Do we really need RSA_PUBLIC_KEY_PARSER whenever we use CONFIG_RSA=y? E.g. on a system without the UEFI sub-system? Otherwise simply let RSA_PUBLIC_KEY_PARSER depend on RSA. > help > The standard RSA-signature verification code (FIT_SIGNATURE) uses > pre-calculated key properties, that are stored in fdt blob, in > diff --git a/lib/rsa/Makefile b/lib/rsa/Makefile > index c07305188e0c..14ed3cb4012b 100644 > --- a/lib/rsa/Makefile > +++ b/lib/rsa/Makefile > @@ -6,4 +6,5 @@ > # Wolfgang Denk, DENX Software Engineering, wd at denx.de. > > obj-$(CONFIG_$(SPL_)RSA_VERIFY) += rsa-verify.o rsa-checksum.o > +obj-$(CONFIG_RSA_VERIFY_WITH_PKEY) += rsa-keyprop.o > obj-$(CONFIG_RSA_SOFTWARE_EXP) += rsa-mod-exp.o > diff --git a/lib/rsa/rsa-keyprop.c b/lib/rsa/rsa-keyprop.c > new file mode 100644 > index 000000000000..9464df009343 > --- /dev/null > +++ b/lib/rsa/rsa-keyprop.c > @@ -0,0 +1,725 @@ > +// SPDX-License-Identifier: GPL-2.0+ and MIT > +/* > + * RSA library - generate parameters for a public key > + * > + * Copyright (c) 2019 Linaro Limited > + * Author: AKASHI Takahiro > + * > + * Big number routines in this file come from BearSSL: > + * Copyright (c) 2016 Thomas Pornin > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +/** > + * br_dec16be() - Convert 16-bit big-endian integer to native > + * @src: Pointer to data > + * Return: Native-endian integer > + */ > +static unsigned br_dec16be(const void *src) > +{ > + return be16_to_cpup(src); > +} > + > +/** > + * br_dec32be() - Convert 32-bit big-endian integer to native > + * @src: Pointer to data > + * Return: Native-endian integer > + */ > +static uint32_t br_dec32be(const void *src) > +{ > + return be32_to_cpup(src); > +} > + > +/** > + * br_enc32be() - Convert native 32-bit integer to big-endian > + * @dst: Pointer to buffer to store big-endian integer in > + * @x: Native 32-bit integer > + */ > +static void br_enc32be(void *dst, uint32_t x) > +{ > + __be32 tmp; > + > + tmp = cpu_to_be32(x); > + memcpy(dst, &tmp, sizeof(tmp)); > +} > + > +/* from BearSSL's src/inner.h */ > + > +/* > + * Negate a boolean. > + */ > +static uint32_t NOT(uint32_t ctl) > +{ > + return ctl ^ 1; > +} > + > +/* > + * Multiplexer: returns x if ctl == 1, y if ctl == 0. > + */ > +static uint32_t MUX(uint32_t ctl, uint32_t x, uint32_t y) > +{ > + return y ^ (-ctl & (x ^ y)); > +} > + > +/* > + * Equality check: returns 1 if x == y, 0 otherwise. > + */ > +static uint32_t EQ(uint32_t x, uint32_t y) > +{ > + uint32_t q; > + > + q = x ^ y; > + return NOT((q | -q) >> 31); > +} > + > +/* > + * Inequality check: returns 1 if x != y, 0 otherwise. > + */ > +static uint32_t NEQ(uint32_t x, uint32_t y) > +{ > + uint32_t q; > + > + q = x ^ y; > + return (q | -q) >> 31; We want to minimize the code size of U-Boot. So, please, review this code and remove all of this bogus. Best regards Heinrich > +} > + > +/* > + * Comparison: returns 1 if x > y, 0 otherwise. > + */ > +static uint32_t GT(uint32_t x, uint32_t y) > +{ > + /* > + * If both x < 2^31 and y < 2^31, then y-x will have its high > + * bit set if x > y, cleared otherwise. > + * > + * If either x >= 2^31 or y >= 2^31 (but not both), then the > + * result is the high bit of x. > + * > + * If both x >= 2^31 and y >= 2^31, then we can virtually > + * subtract 2^31 from both, and we are back to the first case. > + * Since (y-2^31)-(x-2^31) = y-x, the subtraction is already > + * fine. > + */ > + uint32_t z; > + > + z = y - x; > + return (z ^ ((x ^ y) & (x ^ z))) >> 31; > +} > + > +/* > + * Compute the bit length of a 32-bit integer. Returned value is between 0 > + * and 32 (inclusive). > + */ > +static uint32_t BIT_LENGTH(uint32_t x) > +{ > + uint32_t k, c; > + > + k = NEQ(x, 0); > + c = GT(x, 0xFFFF); x = MUX(c, x >> 16, x); k += c << 4; > + c = GT(x, 0x00FF); x = MUX(c, x >> 8, x); k += c << 3; > + c = GT(x, 0x000F); x = MUX(c, x >> 4, x); k += c << 2; > + c = GT(x, 0x0003); x = MUX(c, x >> 2, x); k += c << 1; > + k += GT(x, 0x0001); > + return k; > +} > + > +#define GE(x, y) NOT(GT(y, x)) > +#define LT(x, y) GT(y, x) > +#define MUL(x, y) ((uint64_t)(x) * (uint64_t)(y)) > + > +/* > + * Integers 'i32' > + * -------------- > + * > + * The 'i32' functions implement computations on big integers using > + * an internal representation as an array of 32-bit integers. For > + * an array x[]: > + * -- x[0] contains the "announced bit length" of the integer > + * -- x[1], x[2]... contain the value in little-endian order (x[1] > + * contains the least significant 32 bits) > + * > + * Multiplications rely on the elementary 32x32->64 multiplication. > + * > + * The announced bit length specifies the number of bits that are > + * significant in the subsequent 32-bit words. Unused bits in the > + * last (most significant) word are set to 0; subsequent words are > + * uninitialized and need not exist at all. > + * > + * The execution time and memory access patterns of all computations > + * depend on the announced bit length, but not on the actual word > + * values. For modular integers, the announced bit length of any integer > + * modulo n is equal to the actual bit length of n; thus, computations > + * on modular integers are "constant-time" (only the modulus length may > + * leak). > + */ > + > +/* > + * Extract one word from an integer. The offset is counted in bits. > + * The word MUST entirely fit within the word elements corresponding > + * to the announced bit length of a[]. > + */ > +static uint32_t br_i32_word(const uint32_t *a, uint32_t off) > +{ > + size_t u; > + unsigned j; > + > + u = (size_t)(off >> 5) + 1; > + j = (unsigned)off & 31; > + if (j == 0) { > + return a[u]; > + } else { > + return (a[u] >> j) | (a[u + 1] << (32 - j)); > + } > +} > + > +/* from BearSSL's src/int/i32_bitlen.c */ > + > +/* > + * Compute the actual bit length of an integer. The argument x should > + * point to the first (least significant) value word of the integer. > + * The len 'xlen' contains the number of 32-bit words to access. > + * > + * CT: value or length of x does not leak. > + */ > +static uint32_t br_i32_bit_length(uint32_t *x, size_t xlen) > +{ > + uint32_t tw, twk; > + > + tw = 0; > + twk = 0; > + while (xlen -- > 0) { > + uint32_t w, c; > + > + c = EQ(tw, 0); > + w = x[xlen]; > + tw = MUX(c, w, tw); > + twk = MUX(c, (uint32_t)xlen, twk); > + } > + return (twk << 5) + BIT_LENGTH(tw); > +} > + > +/* from BearSSL's src/int/i32_decode.c */ > + > +/* > + * Decode an integer from its big-endian unsigned representation. The > + * "true" bit length of the integer is computed, but all words of x[] > + * corresponding to the full 'len' bytes of the source are set. > + * > + * CT: value or length of x does not leak. > + */ > +static void br_i32_decode(uint32_t *x, const void *src, size_t len) > +{ > + const unsigned char *buf; > + size_t u, v; > + > + buf = src; > + u = len; > + v = 1; > + for (;;) { > + if (u < 4) { > + uint32_t w; > + > + if (u < 2) { > + if (u == 0) { > + break; > + } else { > + w = buf[0]; > + } > + } else { > + if (u == 2) { > + w = br_dec16be(buf); > + } else { > + w = ((uint32_t)buf[0] << 16) > + | br_dec16be(buf + 1); > + } > + } > + x[v ++] = w; > + break; > + } else { > + u -= 4; > + x[v ++] = br_dec32be(buf + u); > + } > + } > + x[0] = br_i32_bit_length(x + 1, v - 1); > +} > + > +/* from BearSSL's src/int/i32_encode.c */ > + > +/* > + * Encode an integer into its big-endian unsigned representation. The > + * output length in bytes is provided (parameter 'len'); if the length > + * is too short then the integer is appropriately truncated; if it is > + * too long then the extra bytes are set to 0. > + */ > +static void br_i32_encode(void *dst, size_t len, const uint32_t *x) > +{ > + unsigned char *buf; > + size_t k; > + > + buf = dst; > + > + /* > + * Compute the announced size of x in bytes; extra bytes are > + * filled with zeros. > + */ > + k = (x[0] + 7) >> 3; > + while (len > k) { > + *buf ++ = 0; > + len --; > + } > + > + /* > + * Now we use k as index within x[]. That index starts at 1; > + * we initialize it to the topmost complete word, and process > + * any remaining incomplete word. > + */ > + k = (len + 3) >> 2; > + switch (len & 3) { > + case 3: > + *buf ++ = x[k] >> 16; > + /* fall through */ > + case 2: > + *buf ++ = x[k] >> 8; > + /* fall through */ > + case 1: > + *buf ++ = x[k]; > + k --; > + } > + > + /* > + * Encode all complete words. > + */ > + while (k > 0) { > + br_enc32be(buf, x[k]); > + k --; > + buf += 4; > + } > +} > + > +/* from BearSSL's src/int/i32_ninv32.c */ > + > +/* > + * Compute -(1/x) mod 2^32. If x is even, then this function returns 0. > + */ > +static uint32_t br_i32_ninv32(uint32_t x) > +{ > + uint32_t y; > + > + y = 2 - x; > + y *= 2 - y * x; > + y *= 2 - y * x; > + y *= 2 - y * x; > + y *= 2 - y * x; > + return MUX(x & 1, -y, 0); > +} > + > +/* from BearSSL's src/int/i32_add.c */ > + > +/* > + * Add b[] to a[] and return the carry (0 or 1). If ctl is 0, then a[] > + * is unmodified, but the carry is still computed and returned. The > + * arrays a[] and b[] MUST have the same announced bit length. > + * > + * a[] and b[] MAY be the same array, but partial overlap is not allowed. > + */ > +static uint32_t br_i32_add(uint32_t *a, const uint32_t *b, uint32_t ctl) > +{ > + uint32_t cc; > + size_t u, m; > + > + cc = 0; > + m = (a[0] + 63) >> 5; > + for (u = 1; u < m; u ++) { > + uint32_t aw, bw, naw; > + > + aw = a[u]; > + bw = b[u]; > + naw = aw + bw + cc; > + > + /* > + * Carry is 1 if naw < aw. Carry is also 1 if naw == aw > + * AND the carry was already 1. > + */ > + cc = (cc & EQ(naw, aw)) | LT(naw, aw); > + a[u] = MUX(ctl, naw, aw); > + } > + return cc; > +} > + > +/* from BearSSL's src/int/i32_sub.c */ > + > +/* > + * Subtract b[] from a[] and return the carry (0 or 1). If ctl is 0, > + * then a[] is unmodified, but the carry is still computed and returned. > + * The arrays a[] and b[] MUST have the same announced bit length. > + * > + * a[] and b[] MAY be the same array, but partial overlap is not allowed. > + */ > +static uint32_t br_i32_sub(uint32_t *a, const uint32_t *b, uint32_t ctl) > +{ > + uint32_t cc; > + size_t u, m; > + > + cc = 0; > + m = (a[0] + 63) >> 5; > + for (u = 1; u < m; u ++) { > + uint32_t aw, bw, naw; > + > + aw = a[u]; > + bw = b[u]; > + naw = aw - bw - cc; > + > + /* > + * Carry is 1 if naw > aw. Carry is 1 also if naw == aw > + * AND the carry was already 1. > + */ > + cc = (cc & EQ(naw, aw)) | GT(naw, aw); > + a[u] = MUX(ctl, naw, aw); > + } > + return cc; > +} > + > +/* from BearSSL's src/int/i32_div32.c */ > + > +/* > + * Constant-time division. The dividend hi:lo is divided by the > + * divisor d; the quotient is returned and the remainder is written > + * in *r. If hi == d, then the quotient does not fit on 32 bits; > + * returned value is thus truncated. If hi > d, returned values are > + * indeterminate. > + */ > +static uint32_t br_divrem(uint32_t hi, uint32_t lo, uint32_t d, uint32_t *r) > +{ > + /* TODO: optimize this */ > + uint32_t q; > + uint32_t ch, cf; > + int k; > + > + q = 0; > + ch = EQ(hi, d); > + hi = MUX(ch, 0, hi); > + for (k = 31; k > 0; k --) { > + int j; > + uint32_t w, ctl, hi2, lo2; > + > + j = 32 - k; > + w = (hi << j) | (lo >> k); > + ctl = GE(w, d) | (hi >> k); > + hi2 = (w - d) >> j; > + lo2 = lo - (d << k); > + hi = MUX(ctl, hi2, hi); > + lo = MUX(ctl, lo2, lo); > + q |= ctl << k; > + } > + cf = GE(lo, d) | hi; > + q |= cf; > + *r = MUX(cf, lo - d, lo); > + return q; > +} > + > +/* > + * Wrapper for br_divrem(); the remainder is returned, and the quotient > + * is discarded. > + */ > +static uint32_t br_rem(uint32_t hi, uint32_t lo, uint32_t d) > +{ > + uint32_t r; > + > + br_divrem(hi, lo, d, &r); > + return r; > +} > + > +/* > + * Wrapper for br_divrem(); the quotient is returned, and the remainder > + * is discarded. > + */ > +static uint32_t br_div(uint32_t hi, uint32_t lo, uint32_t d) > +{ > + uint32_t r; > + > + return br_divrem(hi, lo, d, &r); > +} > + > +/* from BearSSL's src/int/i32_muladd.c */ > + > +/* > + * Multiply x[] by 2^32 and then add integer z, modulo m[]. This > + * function assumes that x[] and m[] have the same announced bit > + * length, and the announced bit length of m[] matches its true > + * bit length. > + * > + * x[] and m[] MUST be distinct arrays. > + * > + * CT: only the common announced bit length of x and m leaks, not > + * the values of x, z or m. > + */ > +static void br_i32_muladd_small(uint32_t *x, uint32_t z, const uint32_t *m) > +{ > + uint32_t m_bitlen; > + size_t u, mlen; > + uint32_t a0, a1, b0, hi, g, q, tb; > + uint32_t chf, clow, under, over; > + uint64_t cc; > + > + /* > + * We can test on the modulus bit length since we accept to > + * leak that length. > + */ > + m_bitlen = m[0]; > + if (m_bitlen == 0) { > + return; > + } > + if (m_bitlen <= 32) { > + x[1] = br_rem(x[1], z, m[1]); > + return; > + } > + mlen = (m_bitlen + 31) >> 5; > + > + /* > + * Principle: we estimate the quotient (x*2^32+z)/m by > + * doing a 64/32 division with the high words. > + * > + * Let: > + * w = 2^32 > + * a = (w*a0 + a1) * w^N + a2 > + * b = b0 * w^N + b2 > + * such that: > + * 0 <= a0 < w > + * 0 <= a1 < w > + * 0 <= a2 < w^N > + * w/2 <= b0 < w > + * 0 <= b2 < w^N > + * a < w*b > + * I.e. the two top words of a are a0:a1, the top word of b is > + * b0, we ensured that b0 is "full" (high bit set), and a is > + * such that the quotient q = a/b fits on one word (0 <= q < w). > + * > + * If a = b*q + r (with 0 <= r < q), we can estimate q by > + * doing an Euclidean division on the top words: > + * a0*w+a1 = b0*u + v (with 0 <= v < w) > + * Then the following holds: > + * 0 <= u <= w > + * u-2 <= q <= u > + */ > + a0 = br_i32_word(x, m_bitlen - 32); > + hi = x[mlen]; > + memmove(x + 2, x + 1, (mlen - 1) * sizeof *x); > + x[1] = z; > + a1 = br_i32_word(x, m_bitlen - 32); > + b0 = br_i32_word(m, m_bitlen - 32); > + > + /* > + * We estimate a divisor q. If the quotient returned by br_div() > + * is g: > + * -- If a0 == b0 then g == 0; we want q = 0xFFFFFFFF. > + * -- Otherwise: > + * -- if g == 0 then we set q = 0; > + * -- otherwise, we set q = g - 1. > + * The properties described above then ensure that the true > + * quotient is q-1, q or q+1. > + */ > + g = br_div(a0, a1, b0); > + q = MUX(EQ(a0, b0), 0xFFFFFFFF, MUX(EQ(g, 0), 0, g - 1)); > + > + /* > + * We subtract q*m from x (with the extra high word of value 'hi'). > + * Since q may be off by 1 (in either direction), we may have to > + * add or subtract m afterwards. > + * > + * The 'tb' flag will be true (1) at the end of the loop if the > + * result is greater than or equal to the modulus (not counting > + * 'hi' or the carry). > + */ > + cc = 0; > + tb = 1; > + for (u = 1; u <= mlen; u ++) { > + uint32_t mw, zw, xw, nxw; > + uint64_t zl; > + > + mw = m[u]; > + zl = MUL(mw, q) + cc; > + cc = (uint32_t)(zl >> 32); > + zw = (uint32_t)zl; > + xw = x[u]; > + nxw = xw - zw; > + cc += (uint64_t)GT(nxw, xw); > + x[u] = nxw; > + tb = MUX(EQ(nxw, mw), tb, GT(nxw, mw)); > + } > + > + /* > + * If we underestimated q, then either cc < hi (one extra bit > + * beyond the top array word), or cc == hi and tb is true (no > + * extra bit, but the result is not lower than the modulus). In > + * these cases we must subtract m once. > + * > + * Otherwise, we may have overestimated, which will show as > + * cc > hi (thus a negative result). Correction is adding m once. > + */ > + chf = (uint32_t)(cc >> 32); > + clow = (uint32_t)cc; > + over = chf | GT(clow, hi); > + under = ~over & (tb | (~chf & LT(clow, hi))); > + br_i32_add(x, m, over); > + br_i32_sub(x, m, under); > +} > + > +/* from BearSSL's src/int/i32_reduce.c */ > + > +/* > + * Reduce an integer (a[]) modulo another (m[]). The result is written > + * in x[] and its announced bit length is set to be equal to that of m[]. > + * > + * x[] MUST be distinct from a[] and m[]. > + * > + * CT: only announced bit lengths leak, not values of x, a or m. > + */ > +static void br_i32_reduce(uint32_t *x, const uint32_t *a, const uint32_t *m) > +{ > + uint32_t m_bitlen, a_bitlen; > + size_t mlen, alen, u; > + > + m_bitlen = m[0]; > + mlen = (m_bitlen + 31) >> 5; > + > + x[0] = m_bitlen; > + if (m_bitlen == 0) { > + return; > + } > + > + /* > + * If the source is shorter, then simply copy all words from a[] > + * and zero out the upper words. > + */ > + a_bitlen = a[0]; > + alen = (a_bitlen + 31) >> 5; > + if (a_bitlen < m_bitlen) { > + memcpy(x + 1, a + 1, alen * sizeof *a); > + for (u = alen; u < mlen; u ++) { > + x[u + 1] = 0; > + } > + return; > + } > + > + /* > + * The source length is at least equal to that of the modulus. > + * We must thus copy N-1 words, and input the remaining words > + * one by one. > + */ > + memcpy(x + 1, a + 2 + (alen - mlen), (mlen - 1) * sizeof *a); > + x[mlen] = 0; > + for (u = 1 + alen - mlen; u > 0; u --) { > + br_i32_muladd_small(x, a[u], m); > + } > +} > + > +/** > + * rsa_free_key_prop() - Free key properties > + * @prop: Pointer to struct key_prop > + * > + * This function frees all the memories allocated by rsa_gen_key_prop(). > + */ > +void rsa_free_key_prop(struct key_prop *prop) > +{ > + if (!prop) > + return; > + > + free((void *)prop->modulus); > + free((void *)prop->public_exponent); > + free((void *)prop->rr); > + > + free(prop); > +} > + > +/** > + * rsa_gen_key_prop() - Generate key properties of RSA public key > + * @key: Specifies key data in DER format > + * @keylen: Length of @key > + * @prop: Generated key property > + * > + * This function takes a blob of encoded RSA public key data in DER > + * format, parse it and generate all the relevant properties > + * in key_prop structure. > + * Return a pointer to struct key_prop in @prop on success. > + * > + * Return: 0 on success, negative on error > + */ > +int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop) > +{ > + struct rsa_key rsa_key; > + uint32_t *n = NULL, *rr = NULL, *rrtmp = NULL; > + const int max_rsa_size = 4096; > + int rlen, i, ret; > + > + *prop = calloc(sizeof(**prop), 1); > + n = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5)); > + rr = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5)); > + rrtmp = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5)); > + if (!(*prop) || !n || !rr || !rrtmp) { > + ret = -ENOMEM; > + goto err; > + } > + > + ret = rsa_parse_pub_key(&rsa_key, key, keylen); > + if (ret) > + goto err; > + > + /* modulus */ > + /* removing leading 0's */ > + for (i = 0; i < rsa_key.n_sz && !rsa_key.n[i]; i++) > + ; > + (*prop)->num_bits = (rsa_key.n_sz - i) * 8; > + (*prop)->modulus = malloc(rsa_key.n_sz - i); > + if (!(*prop)->modulus) { > + ret = -ENOMEM; > + goto err; > + } > + memcpy((void *)(*prop)->modulus, &rsa_key.n[i], rsa_key.n_sz - i); > + > + /* exponent */ > + (*prop)->public_exponent = calloc(1, sizeof(uint64_t)); > + if (!(*prop)->public_exponent) { > + ret = -ENOMEM; > + goto err; > + } > + memcpy((void *)(*prop)->public_exponent + sizeof(uint64_t) > + - rsa_key.e_sz, > + rsa_key.e, rsa_key.e_sz); > + (*prop)->exp_len = rsa_key.e_sz; > + > + /* n0 inverse */ > + br_i32_decode(n, &rsa_key.n[i], rsa_key.n_sz - i); > + (*prop)->n0inv = br_i32_ninv32(n[1]); > + > + /* R^2 mod n; R = 2^(num_bits) */ > + rlen = (*prop)->num_bits * 2; /* #bits of R^2 = (2^num_bits)^2 */ > + rr[0] = 0; > + *(uint8_t *)&rr[0] = (1 << (rlen % 8)); > + for (i = 1; i < (((rlen + 31) >> 5) + 1); i++) > + rr[i] = 0; > + br_i32_decode(rrtmp, rr, ((rlen + 7) >> 3) + 1); > + br_i32_reduce(rr, rrtmp, n); > + > + rlen = ((*prop)->num_bits + 7) >> 3; /* #bytes of R^2 mod n */ > + (*prop)->rr = malloc(rlen); > + if (!(*prop)->rr) { > + ret = -ENOMEM; > + goto err; > + } > + br_i32_encode((void *)(*prop)->rr, rlen, rr); > + > + return 0; > + > +err: > + free(n); > + free(rr); > + free(rrtmp); > + rsa_free_key_prop(*prop); > + return ret; > +} >